Phytochemicals from anti-diabetic medicinal plants: A comprehensive review of glycemic control mechanisms

 Corresponding author: Sadia Islam Copyright © 2025 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. Phytochemicals from anti-diabetic medicinal plants: A comprehensive review of glycemic control mechanisms Md. Abu Sayem 1, Hafizul Islam 2, Ripon Chandra Shil 3, Md. Khaja Mohi Uddin 4, Amzad Hossen 5, Rashedur Rahman 6, Md. Mahmudul Hasan 7, Tanzila Akter 8, Afrin Sultana 9 and Sadia Islam 10, * 1 Department of Haematology, Chittagong Medical College Hospital, Chittagong, Bangladesh. 2 Department of Transfusion Services, The Ohio State UniversityWexner Medical Center, USA. 3 Department of Microbiology, National Institute of Neurosciences & Hospital, Dhaka, Bangladesh. 4 Department of Laboratory Medicine, Dhaka Medical College Hospital, Dhaka, Bangladesh. 5 Department of Hematology & Clinical Pathology, National Institute of Burn and Plastic Surgery, Dhaka, Bangladesh. 6 Department of Laboratory Medicine, Central Police Hospital, Dhaka, Bangladesh. 7 Department of Pathology & Biochemistry, Mugda Medical College Hospital, Dhaka, Bangladesh. 8 Department of Virology, National Institute of Laboratory Medicine & Referral Center, Dhaka, Bangladesh. 9 Department of Laboratory Medicine, National Institute of Laboratory Medicine and Referral Center, Dhaka, Bangladesh. 10 Department of Laboratory Medicine, Bangladesh Specialized Hospital PLC, Dhaka, Bangladesh. World Journal of Advanced Research and Reviews, 2025, 26(01), 3576-3590 Publication history: Received on 15 March 2025; revised on 23 April 2025; accepted on 25 April 2025 Article DOI: https://doi.org/10.30574/wjarr.2025.26.1.1444 Abstract Diabetes mellitus, a growing global health concern, is typically managed through pharmaceutical interventions; however, plant-based therapies have emerged as a promising adjunct to conventional treatments. This paper examines the therapeutic potential of anti-diabetic plants, focusing on their mechanisms of action, including regulation of blood glucose, enhancement of insulin sensitivity, and the mitigation of diabetes-related complications such as oxidative stress and inflammation. Prominent plants, such as Momordica charantia (bitter melon), Trigonella foenum-graecum (fenugreek), and Berberis aristata (berberine), contain bioactive compounds that contribute to their anti-diabetic effects through diverse pathways, including insulin mimetic actions, AMPK activation, and β-cell regeneration. Additionally, many of these plants offer antioxidant and anti-inflammatory properties, providing a holistic approach to managing the disease and preventing long-term complications. Despite the promising findings from in vitro, in vivo, and clinical studies, the integration of plant-based therapies into mainstream diabetes care faces several challenges, including the lack of large-scale clinical trials, variability in standardization, concerns regarding bioavailability, and the potential for herb-drug interactions. This review underscores the need for more rigorous clinical trials to establish the efficacy, safety, and optimal dosing of these therapies. When standardized and integrated with conventional medical practices, plant-based therapies have the potential to be affordable, accessible, and effective adjuncts in diabetes management, particularly in low-resource settings where access to conventional medications may be limited. Furthermore, the synergistic combination of modern pharmacological treatments and plant-based therapies could offer a more personalized, comprehensive, and sustainable approach to diabetes care, improving patient outcomes worldwide. Future research should also focus on innovative drug delivery systems, such as nanotechnology, to enhance the bioavailability and efficacy of these plant-derived compounds, ensuring their safe and effective use in diabetes management. Keywords: Anti-diabetic medicinal plants; Insulin sensitivity; Phytotherapy; Herb-drug interactions; Glycemic control World Journal of Advanced Research and Reviews, 2025, 26(01), 3576-3590 3577 1. Introduction Diabetes mellitus (DM) is a chronic, progressive, and complex metabolic disorder characterized by sustained hyperglycemia due to either impaired insulin secretion, reduced insulin sensitivity, or a combination of both. The condition is primarily classified into two major types: Type 1 diabetes (T1D) and Type 2 diabetes (T2D). T1D is an autoimmune disorder where the body’s immune system destroys the insulin-producing β-cells in the pancreas, leading to an absolute insulin deficiency. This type typically manifests during childhood or adolescence but can occur at any age. In contrast, T2D is a multifactorial metabolic condition marked by insulin resistance and a progressive decline in insulin production. It is responsible for over 90% of diabetes cases globally and is closely associated with modifiable risk factors such as obesity, poor dietary patterns, physical inactivity, and smoking, as well as non-modifiable factors including age, genetic predisposition, and ethnicity1,2. The global burden of diabetes has increased dramatically in recent decades, making it a critical public health concern. According to the International Diabetes Federation (IDF), approximately 537 million adults (aged 20–79 years) were diagnosed with diabetes in 2021. This figure is projected to reach 643 million by 2030 and 783 million by 2045, with the steepest rises occurring in lowand middle-income countries (LMICs)3. These regions are undergoing rapid urbanization and lifestyle transitions, yet often lack adequate healthcare infrastructure to effectively manage chronic diseases. Beyond its rising prevalence, diabetes is a major contributor to a range of life-threatening complications, including cardiovascular disease, kidney failure, retinopathy, neuropathy, and lower-limb amputations, all of which contribute significantly to increased mortality, disability, and healthcare costs4. To mitigate the risks and complications associated with diabetes, current management strategies primarily aim to maintain optimal blood glucose levels, prevent long-term complications, and enhance overall quality of life. These strategies encompass a combination of lifestyle modifications and pharmacological interventions. Lifestyle changes, such as dietary adjustments, regular exercise, and weight management, form the cornerstone of diabetes management. These modifications help to improve insulin sensitivity, reduce excess body weight, and ultimately lower the risk of associated complications. However, lifestyle changes alone may not be sufficient for effective long-term control, which is why pharmacological treatments are also a crucial part of diabetes management5. Common pharmacological interventions include metformin (a biguanide), which is widely used due to its ability to improve insulin sensitivity and decrease hepatic glucose production, thereby lowering blood sugar levels. Sulfonylureas stimulate the pancreas to release more insulin, but they come with risks such as hypoglycemia and weight gain. Newer classes of medications, such as DPP-4 inhibitors, SGLT2 inhibitors, and GLP-1 receptor agonists, offer additional benefits like cardiovascular protection, weight loss, and better postprandial glucose regulation6. However, despite their widespread use and efficacy, these conventional treatments are not without limitations. Many of the synthetic medications used in diabetes management have associated side effects, which can include gastrointestinal discomfort, hypoglycemia, and weight gain, complicating long-term management. Additionally, the efficacy of these treatments can decline over time due to the progressive nature of β-cell dysfunction, particularly in patients with T2D7. As the disease advances, patients may require higher doses or combination therapies, yet the effectiveness of these drugs may diminish as pancreatic function continues to deteriorate. Another significant issue is the financial burden that these medications impose, especially for lowand middle-income populations, where the high cost of lifelong medication use can limit accessibility to necessary treatment. Furthermore, most conventional drugs focus primarily on glycemic control, without addressing the oxidative stress, chronic inflammation, and metabolic imbalances that play a critical role in the pathophysiology of diabetes8. Given these challenges, there has been growing interest in plant-based therapies as potential adjuncts or even alternatives to synthetic medications. This interest is based on the longstanding use of medicinal plants in traditional healthcare systems, such as Ayurveda, Traditional Chinese Medicine (TCM), Unani, and African ethnomedicine. For centuries, these traditional systems have relied on herbal remedies to manage hyperglycemia, improve digestion, and support overall metabolic health. Modern scientific research has increasingly validated many of these plant-based therapies, with numerous studies identifying bioactive phytochemicals that possess significant anti-diabetic properties. These plants are gaining scientific recognition for their ability to regulate blood sugar and offer complementary therapeutic effects for diabetes management9. Research has shown that plants with anti-diabetic activity often contain a variety of bioactive compounds such as flavonoids, alkaloids, terpenoids, saponins, and phenolic acids. These compounds exhibit multiple pharmacological actions that work synergistically to address various aspects of diabetes. Some phytochemicals stimulate insulin secretion from the pancreatic β-cells, while others enhance insulin sensitivity in tissues such as the liver, muscles, and adipose tissue, all of which help in better glucose utilization10. Certain phytochemicals also act by inhibiting World Journal of Advanced Research and Reviews, 2025, 26(01), 3576-3590 3578 carbohydrate-digesting enzymes like α-amylase and α-glucosidase, which can slow the absorption of glucose, thereby lowering postprandial blood sugar levels. Moreover, some bioactive compounds promote glucose uptake in peripheral tissues and facilitate glycogen storage, both of which help in managing blood glucose levels11. Additionally, many of these compounds possess antioxidant and anti-inflammatory properties, reducing the oxidative stress and inflammation that contribute to the development and progression of diabetes12. What sets plant-based therapies apart is their ability to offer multi-targeted actions. Unlike conventional drugs that may target a single pathway or mechanism, many phytochemicals from medicinal plants can address multiple facets of diabetes at once—such as improving insulin function, reducing oxidative stress, and mitigating inflammation13. This makes them potentially more effective in providing a holistic approach to diabetes management. Additionally, plantbased treatments are generally associated with fewer side effects and lower toxicity compared to synthetic drugs. This not only makes them safer but also more accessible and affordable, especially in areas where modern pharmaceuticals may be cost-prohibitive. These qualities make plant-based therapies an appealing option, particularly in low-resource settings where they can be more easily sourced and implemented in the management of diabetes14. This paper aims to review the phytochemicals from anti-diabetic medicinal plants and their mechanisms in glycemic control, highlighting their therapeutic potential as complementary or alternative treatments for diabetes. It compares plant-based remedies to conventional therapies and explores future directions for their integration into diabetes management. 2. Mechanisms of anti-diabetic action in medicinal plants Medicinal plants have long been utilized in traditional medicine for the management of diabetes, and recent scientific studies have substantiated their anti-diabetic properties. These plants exert their therapeutic effects through various pharmacological mechanisms that influence glucose metabolism, insulin secretion and sensitivity, oxidative stress, inflammation, and gut microbiota. The following mechanisms highlight the diverse roles medicinal plants play in controlling blood glucose levels and improving overall metabolic health. 2.1. Stimulating Insulin Secretion One of the well-known mechanisms of action in anti-diabetic medicinal plants is the stimulation of insulin secretion from pancreatic β-cells. Gymnema sylvestre, commonly referred to as the "sugar destroyer," has been extensively studied for its ability to enhance insulin secretion. Active compounds in Gymnema sylvestre, particularly gymnemic acids, promote insulin release from β-cells in the pancreas and assist in the regeneration of damaged β-cells15. This is particularly beneficial in Type 2 diabetes, where insulin secretion is often reduced as a result of β-cell dysfunction. In addition to stimulating insulin secretion, Gymnema sylvestre helps lower blood glucose levels by inhibiting the absorption of glucose from the intestines, thus contributing to better overall glycemic control16. Another plant that has shown similar effects is Allium sativum (garlic), which has been demonstrated to promote insulin secretion and enhance the sensitivity of insulin receptors. This dual effect makes it a promising candidate for diabetes management, particularly in cases of insulin resistance and β-cell dysfunction17. 2.2. Enhancing Insulin Sensitivity Cinnamomum verum (cinnamon) is a popular spice that has been shown to improve insulin sensitivity. Cinnamon contains bioactive compounds such as cinnamaldehyde, proanthocyanidins, and flavonoids, which have been demonstrated to activate insulin receptors and enhance insulin receptor signaling in peripheral tissues. This improves glucose uptake by muscle and fat cells, which helps reduce insulin resistance—a major pathophysiological feature of Type 2 diabetes. Research has suggested that cinnamon’s action involves the phosphorylation of key proteins in the insulin signaling pathway, which aids in enhancing the action of insulin at the cellular level. Furthermore, cinnamon helps to regulate the hepatic glucose production, thus reducing blood glucose levels in the postprandial state18. Additionally, Berberine, an alkaloid found in several medicinal plants like Berberis vulgaris, has gained attention for its ability to improve insulin sensitivity. Berberine activates AMP-activated protein kinase (AMPK), a key regulator of cellular energy balance, which plays a critical role in increasing glucose uptake in skeletal muscle and enhancing insulin sensitivity19. World Journal of Advanced Research and Reviews, 2025, 26(01), 3576-3590 3579 2.3. Inhibiting α-Glucosidase and α-Amylase Several medicinal plants exert anti-diabetic effects by inhibiting the digestive enzymes α-glucosidase and α-amylase, which are responsible for breaking down carbohydrates into simple sugars in the gastrointestinal tract. For example, Salacia reticulata, a traditional herb used in Ayurvedic medicine, has been found to inhibit both α-amylase and αglucosidase enzymes, thereby delaying carbohydrate digestion and reducing postprandial blood sugar spikes20. This mechanism is beneficial for Type 2 diabetes patients, as it helps regulate the absorption of glucose from the gut, leading to more stable blood glucose levels after meals. Other plants, such as Phaseolus vulgaris (white kidney bean), have shown similar effects. White kidney beans contain an inhibitor called phaseolamin, which acts to block α-amylase activity, reducing carbohydrate digestion and the resultant glucose spike21. 2.4. Modulating Glucose Uptake Momordica charantia (bitter melon) is widely recognized for its role in enhancing glucose uptake by peripheral tissues. The active compounds in bitter melon, such as charantin, polypeptides, and insulin-like proteins, mimic the effects of insulin by facilitating the uptake of glucose into cells, particularly muscle and adipose tissue. This is particularly useful for controlling elevated blood glucose levels in diabetic individuals, as it promotes the conversion of glucose to glycogen and enhances glucose metabolism22. Bitter melon also improves glucose tolerance by regulating enzymes involved in glucose metabolism, such as glucokinase and pyruvate kinase, which helps improve glycogen storage in the liver and reduces blood glucose concentrations. In addition to bitter melon, other plants like Trigonella foenum-graecum (fenugreek) have been shown to enhance glucose uptake and improve insulin sensitivity, further supporting their role in diabetes management23. 2.5. Antioxidant and Anti-Inflammatory Effects Chronic oxidative stress and inflammation play pivotal roles in the pathogenesis of diabetes and its complications, including insulin resistance and β-cell dysfunction. Several medicinal plants are rich in antioxidant and antiinflammatory compounds, which contribute to their anti-diabetic effects24. Ocimum sanctum (holy basil)25 and Curcuma longa (turmeric)26 are well-documented for their potent antioxidant and anti-inflammatory activities. Holy basil contains eugenol, which exerts antioxidant effects and reduces inflammation by modulating key signaling pathways, including nuclear factor-kappa B (NF-kB). Similarly, curcumin, the active compound in turmeric, is a powerful antioxidant that reduces oxidative stress and modulates inflammatory cytokines. Curcumin’s ability to influence the NF-kB pathway, which regulates immune responses, plays a critical role in reducing systemic inflammation associated with diabetes and its complications. Both plants help mitigate oxidative damage, protect β-cells from apoptosis (cell death), and improve insulin sensitivity, thus contributing to better glycemic control. Additionally, they help prevent complications such as diabetic neuropathy and cardiovascular disease, which are exacerbated by chronic inflammation and oxidative stress. 2.6. Modulation of Gut Microbiota (Emerging Topic) The human gut microbiota is increasingly recognized as a crucial factor in the regulation of glucose metabolism and insulin sensitivity. The gut microbiome influences metabolic processes through the production of short-chain fatty acids (SCFAs), regulation of inflammation, and interaction with various endocrine pathways27. Emerging research suggests that medicinal plants can modulate the gut microbiota, influencing the balance of beneficial and harmful bacteria in the intestines. For example, Ginseng and Berberine have been shown to alter the gut microbiome in ways that enhance insulin sensitivity and glucose metabolism. Berberine, in particular, promotes the growth of beneficial bacteria and suppresses the growth of pathogenic microorganisms. This results in a reduction in gut-derived endotoxins that contribute to systemic inflammation and insulin resistance. Changes in gut microbiota can lead to increased SCFA production, which has been linked to improved insulin sensitivity and glucose tolerance. SCFAs, particularly butyrate, play an important role in maintaining the integrity of the gut barrier, reducing inflammation, and enhancing metabolic functions. These findings highlight the potential of targeting the gut microbiome as an innovative approach to diabetes management, and plant-based therapies may offer a promising solution in this area27. World Journal of Advanced Research and Reviews, 2025, 26(01), 3576-3590 3580 Table 1 Mechanisms of Anti-Diabetic Action in Medicinal Plants Mechanism Medicinal Plants Involved Key Actions and Effects Stimulating Insulin Secretion Gymnema sylvestre, Allium sativum (Garlic) - Promotes insulin release from β-cells in the pancreas. - Regenerates damaged β-cells. - Enhances insulin secretion. Enhancing Insulin Sensitivity Cinnamomum verum (Cinnamon), Berberine (Berberis vulgaris) - Activates insulin receptors and enhances receptor signaling. - Reduces insulin resistance and improves glucose uptake. Inhibiting αGlucosidase & αAmylase Salacia reticulata, Phaseolus vulgaris (White Kidney Bean) - Inhibits α-glucosidase and α-amylase enzymes. - Slows carbohydrate digestion and absorption. - Prevents postprandial hyperglycemia. Modulating Glucose Uptake Momordica charantia (Bitter Melon), Trigonella foenumgraecum (Fenugreek) - Mimics insulin by facilitating glucose uptake into muscle and adipose tissue. - Enhances glucose conversion to glycogen. Antioxidant & AntiInflammatory Effects Ocimum sanctum (Holy Basil), Curcuma longa (Turmeric) - Reduces oxidative stress and inflammation. - Protects β-cells from damage. - Improves insulin sensitivity. Modulation of Gut Microbiota Ginseng, Berberine - Alters gut microbiome to enhance insulin sensitivity. - Increases production of beneficial SCFAs. - Reduces inflammation and insulin resistance. 3. Anti-Diabetic Medicinal Plants and Their Phytochemicals This section provides a comprehensive review of several key medicinal plants known for their anti-diabetic properties, emphasizing their active phytochemicals, mechanisms of action, and supporting scientific evidence. These plants are widely recognized for their therapeutic potential in managing diabetes mellitus, particularly in improving glycemic control and promoting overall metabolic health. While some of these plants are well-established in traditional medicine, others offer promising new avenues for diabetes management based on emerging research. 3.1. Momordica charantia (Bitter Melon) Bitter melon, or Momordica charantia, has long been used in traditional medicine across Asia, Africa, and the Caribbean. The plant contains bioactive compounds such as charantin, polypeptide-p, vicine, and alkaloids, which are responsible for its anti-diabetic properties. The key mechanism by which bitter melon exerts its effect is by mimicking insulin, which helps in promoting glucose uptake in peripheral tissues, thereby lowering blood sugar. Additionally, bitter melon facilitates the conversion of glucose into glycogen, contributing to improved blood glucose regulation. Studies show that bitter melon exhibits insulin-like activity through its polypeptides and charantin, making it a useful adjunct in managing diabetes. Research conducted in vitro has demonstrated the insulin-mimetic properties of bitter melon, while in vivo animal studies have shown that it effectively reduces blood glucose levels. Clinical trials have also supported its use, showing improved insulin sensitivity and reduced blood sugar in diabetic patients27. 3.2. Trigonella foenum-graecum (Fenugreek) Fenugreek (Trigonella foenum-graecum) is a widely used herb in traditional medicine, particularly in India and the Middle East. The plant is rich in compounds like 4-hydroxyisoleucine, saponins, and flavonoids, which contribute to its anti-diabetic effects. Fenugreek works primarily by stimulating insulin secretion and enhancing insulin sensitivity, which are critical processes in the management of diabetes. It also aids in glucose metabolism and enhances glycogen synthesis. The saponins found in fenugreek play a significant role in improving glucose absorption and activating insulin receptors, making it easier for cells to take up glucose. In vitro studies have shown that fenugreek enhances insulin secretion and glucose uptake, while in vivo research demonstrates its ability to reduce blood glucose and improve glycemic control in animal models. Clinical studies suggest that fenugreek supplementation can enhance insulin sensitivity and reduce blood sugar levels in diabetic individuals28. World Journal of Advanced Research and Reviews, 2025, 26(01), 3576-3590 3581 3.3. Gymnema sylvestre Gymnema sylvestre, native to India and Africa, is a revered herb in Ayurvedic medicine. The active compounds in Gymnema, such as gymnemic acids, saponins, and flavonoids, are believed to have potent anti-diabetic effects. One of its primary mechanisms is stimulating insulin secretion and promoting the regeneration of β-cells, which are crucial for insulin production. Gymnema also reduces sugar absorption from the gastrointestinal tract, further contributing to its glucose-lowering effects. Moreover, it enhances glucose utilization by the body, which helps lower blood sugar levels. In vitro studies have shown that Gymnema promotes insulin secretion and β-cell regeneration. Animal studies further support these findings, showing improved glucose uptake and insulin sensitivity. Clinical trials have also reported significant reductions in blood sugar levels after Gymnema supplementation in diabetic patients29. 3.4. Ocimum sanctum (Holy Basil) Holy basil, or Ocimum sanctum, is another widely used medicinal herb in India and Southeast Asia, particularly in Ayurvedic medicine. This herb contains eugenol, ursolic acid, and various flavonoids, which contribute to its medicinal properties. Holy basil exerts its anti-diabetic effects through its powerful antioxidant and anti-inflammatory properties. It helps protect pancreatic β-cells from oxidative stress, which is critical for maintaining insulin production. Additionally, holy basil enhances insulin sensitivity and regulates glucose metabolism, offering a multifaceted approach to managing diabetes. In vitro studies have confirmed the herb’s antioxidant and anti-inflammatory properties, while in vivo studies have demonstrated its ability to lower blood glucose levels and improve insulin sensitivity. Clinical trials have shown that holy basil supplementation can improve glycemic control and reduce oxidative stress in diabetic patients30. 3.5. Berberis aristata Berberis aristata, also known as Indian barberry, is native to the Himalayan region and widely used in traditional medicine in India. The plant contains berberine, a potent bioactive compound that plays a crucial role in its anti-diabetic effects. Berberine works by activating AMP-activated protein kinase (AMPK), a key regulator of energy metabolism. By activating AMPK, berberine increases insulin sensitivity, reduces hepatic glucose production, and improves lipid metabolism. In addition to its insulin-sensitizing properties, berberine also has anti-inflammatory effects, which help reduce the complications associated with diabetes. In vitro studies have shown that berberine activates AMPK and improves glucose uptake, while animal studies support its ability to lower blood glucose and lipid levels. Clinical trials in humans have also demonstrated that berberine supplementation can help manage blood glucose levels and improve insulin sensitivity31. 3.6. Cinnamomum verum (Cinnamon) Cinnamon, or Cinnamomum verum, is a well-known spice native to Sri Lanka, widely used both in culinary practices and traditional medicine. The active compounds in cinnamon, such as cinnamaldehyde, proanthocyanidins, and flavonoids, contribute to its anti-diabetic effects. Cinnamon enhances insulin receptor sensitivity, improving insulin signaling in the body. It also helps regulate hepatic glucose production, preventing excess glucose release from the liver. Additionally, cinnamon inhibits carbohydrate-digesting enzymes, slowing the absorption of glucose from the digestive tract. In vitro studies have shown that cinnamon increases insulin receptor sensitivity, while animal models confirm its ability to reduce blood glucose levels and improve insulin sensitivity. Clinical trials have demonstrated that cinnamon supplementation can significantly reduce fasting blood glucose levels and improve overall insulin sensitivity in individuals with type 2 diabetes26. 3.7. Curcuma longa (Turmeric) Turmeric, or Curcuma longa, is commonly used in India and Southeast Asia both as a spice and in traditional medicine. The active compound in turmeric, curcumin, along with other curcuminoids, is responsible for its potent medicinal properties. Curcumin exerts powerful antioxidant and anti-inflammatory effects, which are essential for managing diabetes-related oxidative stress and inflammation. Furthermore, curcumin improves insulin sensitivity and helps protect pancreatic β-cells, which are essential for insulin production. In vitro studies have shown that curcumin significantly reduces oxidative stress, while in vivo research has demonstrated its ability to improve glucose tolerance and insulin sensitivity in diabetic animal models. Clinical studies also suggest that curcumin supplementation can lead to improved glycemic control and reduced inflammation in individuals with diabetes28. 3.8. Pterocarpus marsupium Pterocarpus marsupium, known as the Indian Kino tree, is widely used in traditional Indian medicine to manage diabetes. The plant contains compounds like pterostilbene and flavonoids, which have been found to have anti-diabetic World Journal of Advanced Research and Reviews, 2025, 26(01), 3576-3590 3582 effects. Pterocarpus marsupium enhances insulin secretion and promotes the regeneration of β-cells, thereby improving insulin production. Additionally, it increases peripheral glucose uptake and reduces blood glucose levels by inhibiting gluconeogenesis in the liver. In vitro studies have shown that Pterocarpus marsupium enhances insulin secretion and glucose uptake, while animal models have demonstrated reduced blood glucose levels. Though clinical evidence is limited, early studies suggest that it may hold promise for managing diabetes in humans29. 3.9. Salacia reticulata Salacia reticulata, a plant native to India and Sri Lanka, has been used in Ayurvedic medicine for centuries to treat diabetes. The active compounds in Salacia reticulata, including salacinol and kotalanol, have potent inhibitory effects on carbohydrate-digesting enzymes such as α-glucosidase and α-amylase. By inhibiting these enzymes, Salacia reticulata delays the digestion and absorption of carbohydrates, thus reducing postprandial blood glucose spikes. In vitro studies have demonstrated that Salacia reticulata effectively inhibits α-glucosidase and α-amylase, while in vivo studies have shown that it can lower postprandial blood glucose levels. Some clinical trials also support its efficacy, suggesting that Salacia reticulata can help regulate blood glucose levels in diabetic individuals22. 3.10. Syzygium cumini (Jamun) Syzygium cumini, commonly known as Jamun, is native to the Indian subcontinent and Southeast Asia. The active compounds in Jamun, including eugenol, anthocyanins, and flavonoids, contribute to its anti-diabetic properties. Jamun enhances insulin secretion and improves glucose metabolism. It also exhibits potent antioxidant and anti-inflammatory effects, which help combat oxidative stress and inflammation commonly associated with diabetes. In vitro studies have shown that Jamun possesses insulin-mimetic and antioxidant properties, while animal studies have demonstrated its ability to reduce blood glucose and improve glycemic control. Clinical studies suggest that Jamun can help regulate blood sugar levels in diabetic patients23. 3.11. Allium sativum (Garlic) Garlic, or Allium sativum, is a widely used medicinal plant with a long history of use in Asia, Europe, and Africa. The active compounds in garlic, such as allicin and diallyl disulfide, play a crucial role in its anti-diabetic effects. Garlic stimulates insulin secretion, improves insulin sensitivity, and reduces oxidative stress, all of which contribute to better glycemic control. It also helps improve lipid profiles and reduce blood glucose levels. In vitro studies have demonstrated that garlic enhances insulin secretion and exhibits antioxidant activity. Animal models have shown that garlic supplementation can improve blood glucose and lipid levels, while clinical trials have indicated that it can reduce blood glucose levels and improve insulin sensitivity in diabetic patients30. 3.12. Stereospermum personatum Stereospermum personatum is native to India and is used in traditional medicine to treat various ailments, including diabetes. The plant contains triterpenoids, flavonoids, and alkaloids, which contribute to its hypoglycemic effects. It works by improving insulin sensitivity and increasing glucose uptake by peripheral tissues, which helps reduce blood glucose levels. In vitro studies have shown that Stereospermum personatum has the potential to enhance glucose uptake, while in vivo studies have demonstrated its ability to lower blood glucose levels in diabetic animal models. Although clinical evidence is limited, the plant shows promise as a potential anti-diabetic agent32. 3.13. Senna obtusifolia (Senna) Senna, or Senna obtusifolia, is widely used in Africa and Asia for its medicinal properties, particularly as a laxative. The active compounds in Senna, including sennosides, flavonoids, and anthraquinones, exhibit mild hypoglycemic effects. Senna may reduce blood sugar levels by improving gastrointestinal transit and gut health, which can indirectly influence glucose absorption and blood sugar regulation. In vitro studies have shown mild hypoglycemic effects, while in vivo research has demonstrated some reduction in blood glucose levels. Although clinical evidence is limited, Senna’s role in gut health and digestion suggests potential benefits for managing diabetes32. 3.14. Amomum subulatum (Black Cardamom) Amomum subulatum, commonly known as Black Cardamom, is native to the Himalayan region and used in Ayurvedic medicine for treating various health conditions, including diabetes. The active compounds in Black Cardamom, such as essential oils, flavonoids, and terpenoids, help improve insulin secretion and sensitivity. It also reduces blood glucose by enhancing pancreatic β-cell function. Additionally, its antioxidant and anti-inflammatory properties support overall metabolic health. In vitro studies have shown that Black Cardamom can regulate insulin secretion, while animal studies World Journal of Advanced Research and Reviews, 2025, 26(01), 3576-3590 3583 have demonstrated improved glucose tolerance and insulin sensitivity. Early clinical studies suggest that Black Cardamom can help regulate blood glucose levels in diabetic patients32. 3.15. Moringa oleifera (Moringa) Moringa (Moringa oleifera), commonly known as the "drumstick tree," is native to South Asia and is widely used for its nutritional and medicinal benefits. The plant contains bioactive compounds like glucosinolates, flavonoids, polyphenols, and vitamins, all of which contribute to its anti-diabetic properties. Moringa is known to help lower blood sugar levels by enhancing insulin secretion and increasing insulin sensitivity. Additionally, it has antioxidant properties that help reduce oxidative stress, a common issue in diabetes. Moringa also inhibits glucose absorption in the intestines, preventing spikes in blood sugar levels after meals. In vitro studies have shown that Moringa extracts exhibit significant anti-diabetic effects, and in vivo animal studies have demonstrated its potential to lower blood glucose and improve insulin sensitivity. Clinical trials suggest that Moringa supplementation can lead to improved glycemic control and reduced blood sugar levels in diabetic individuals33. 3.16. Zingiber officinale (Ginger) Ginger (Zingiber officinale) is a widely known spice and medicinal plant that has been used for centuries to treat various health conditions, including diabetes. The active compounds in ginger, such as gingerol, shogaol, and paradol, have demonstrated significant anti-diabetic effects. Ginger primarily works by improving insulin sensitivity and reducing insulin resistance, a key factor in the development of type 2 diabetes. It also reduces oxidative stress and inflammation, both of which are often elevated in diabetic patients. Additionally, ginger helps regulate blood sugar by enhancing glucose uptake in tissues and inhibiting the activity of certain enzymes that break down carbohydrates. In vitro studies have shown that ginger reduces blood glucose levels, and animal studies have confirmed its ability to improve insulin sensitivity. Clinical trials have indicated that ginger supplementation can help reduce fasting blood glucose levels and improve overall glycemic control in people with type 2 diabetes27. 3.17. Ficus benghalensis (Banyan Tree) Ficus benghalensis, commonly known as the Banyan tree, is native to tropical regions of Asia. The plant is traditionally used in Ayurvedic medicine for treating various ailments, including diabetes. The active compounds in Ficus benghalensis, including flavonoids, tannins, and alkaloids, have shown potential in managing blood sugar levels. Ficus benghalensis exerts its anti-diabetic effects by stimulating insulin secretion from pancreatic β-cells and increasing the uptake of glucose by peripheral tissues. Additionally, it has anti-inflammatory and antioxidant properties that help mitigate the complications of diabetes. In vitro studies have demonstrated that extracts from the Banyan tree can help regulate glucose metabolism. Animal studies have also shown that Ficus benghalensis can lower blood glucose levels and improve insulin sensitivity. Though clinical evidence is limited, the plant’s long-standing use in traditional medicine suggests it has potential for managing diabetes33. 3.18. Andrographis paniculata (Andrographis) Andrographis paniculata, commonly known as the "King of Bitters," is a herb native to South Asia and is widely used in traditional medicine for treating a variety of diseases, including diabetes. The active compounds in Andrographis, particularly andrographolides, have been shown to have strong anti-diabetic effects. Andrographis improves insulin sensitivity and reduces blood glucose levels by promoting the action of insulin in the body. It also has anti-inflammatory and antioxidant properties, which help reduce the oxidative stress and inflammation associated with diabetes. In vitro studies have shown that Andrographis paniculata improves glucose metabolism and insulin action. Animal studies further support these effects, demonstrating a reduction in blood glucose levels. Although clinical studies are limited, preliminary research suggests that Andrographis supplementation could be a beneficial adjunct in the management of diabetes25. World Journal of Advanced Research and Reviews, 2025, 26(01), 3576-3590 3584 Table 2 Summary of Anti-Diabetic Medicinal Plants and Their Active Compounds Plant Name Active Compounds Mechanism of Action Supporting Evidence Momordica charantia (Bitter Melon) Charantin, polypeptide-p, vicine, alkaloids Mimics insulin, promotes glucose uptake, and facilitates glucose to glycogen conversion In vitro, in vivo, and clinical studies demonstrate improved blood glucose regulation and insulin sensitivity. Trigonella foenumgraecum (Fenugreek) 4-Hydroxyisoleucine, saponins, flavonoids Stimulates insulin secretion, enhances insulin sensitivity, improves glucose metabolism In vitro, in vivo, and clinical trials show improved insulin sensitivity and blood glucose control. Gymnema sylvestre Gymnemic acids, saponins, flavonoids Stimulates insulin secretion, regenerates β-cells, reduces sugar absorption, improves glucose utilization In vitro, animal studies, and clinical trials support its ability to reduce blood sugar and improve insulin sensitivity. Ocimum sanctum (Holy Basil) Eugenol, ursolic acid, flavonoids Antioxidant, anti-inflammatory, protects β-cells, improves insulin sensitivity, regulates glucose metabolism In vitro, in vivo, and clinical studies demonstrate lowered blood glucose levels and improved insulin sensitivity. Berberis aristata Berberine Activates AMPK, increases insulin sensitivity, reduces hepatic glucose production, improves lipid metabolism In vitro, animal studies, and clinical trials show improved glucose uptake and insulin sensitivity. Cinnamomum verum (Cinnamon) Cinnamaldehyde, proanthocyanidins, flavonoids Enhances insulin receptor sensitivity, regulates hepatic glucose production, inhibits carbohydrate digestion In vitro, animal studies, and clinical trials demonstrate improved insulin sensitivity and reduced blood glucose levels. Curcuma longa (Turmeric) Curcumin, curcuminoids Antioxidant, anti-inflammatory, improves insulin sensitivity, protects β-cells In vitro, in vivo, and clinical studies suggest improved glycemic control and reduced inflammation. Pterocarpus marsupium Pterostilbene, flavonoids Enhances insulin secretion, promotes β-cell regeneration, reduces gluconeogenesis In vitro, animal studies show improved blood glucose regulation and insulin secretion. Salacia reticulata Salacinol, kotalanol Inhibits carbohydrate-digesting enzymes (α-glucosidase, αamylase), delays carbohydrate absorption In vitro, in vivo, and some clinical trials show reduced postprandial blood glucose levels. Syzygium cumini (Jamun) Eugenol, anthocyanins, flavonoids Enhances insulin secretion, improves glucose metabolism, antioxidant and antiinflammatory effects In vitro, animal studies, and clinical trials show reduced blood glucose and improved glycemic control. Allium sativum (Garlic) Allicin, diallyl disulfide Stimulates insulin secretion, improves insulin sensitivity, reduces oxidative stress In vitro, animal studies, and clinical trials demonstrate reduced blood glucose levels and improved insulin sensitivity. Stereospermum personatum Triterpenoids, flavonoids, alkaloids Improves insulin sensitivity, increases glucose uptake In vitro and animal studies show potential for lowering blood glucose levels. Senna obtusifolia (Senna) Sennosides, flavonoids, anthraquinones Improves gastrointestinal transit, indirectly regulates glucose absorption In vitro and animal studies show mild hypoglycemic effects.