Effect of Jamun (Syzygium cumini) seed powder on glycaemic index and insulin sensitivity in type 2 diabetes

Introduction

Black plum or Syzygium cumini is a good source of bioactive compounds like flavonoids, polyphenols, antioxidants, iron and vitamin C. The Jamun tree is a tropical evergreen flowering tree and is one of the significant medicinal plants of the family Myrtaceae that has been utilized for long in Indian and other regular medications around the globe. The main countries that grow jamun are Asian nations like Pakistan, India, Sri Lanka and Bangladesh (Bhakshu et al., 2022; Syama, 2017; Rizvi et al., 2022) [7,39,31]. Jamun fruit is oval to elliptic, 1.5 to 3.5 cm long, dark purple or almost black, juicy, fleshy and edible, having a sweet, astringent flavour with a single large seed (Kumar and Singh, 2021) [16] . Its fruits are delicious and have great importance in folk medicine. The jamun fruit is of less interest than the jamun itself, which is used medicinally. The medicinal and therapeutic uses of different parts like bark, fruit and seed (Arooj et al., 2025) [2] . The priority of food fortification is to target micronutrients to staple foods, so that as many people as possible, including vulnerable groups, can access them. Jamun seed powder is also added to many food products to enhance their nutritional value (Nagar et al., 2025) [24] . The jamun fruit contains 83.7-85.8g moisture, 0.7-0.129g protein, 0.15-0.3g fat, 0.3-0.9g crude fiber, 14g carbohydrate, 0.32-0.4g ash, 8.3-15mg calcium, 35mg magnesium, 15-16.2 phosphorus, 1.2-1.62mg iron, 26.2mg sodium, 55mg potassium, 0.23mg copper, 13mg sulfur, 8mg chlorine, 80 I.U. vitamin A, 0.008-0.03mg thiamine, 0.009-0.01mg riboflavin, 0.2-0.29mg niacin, 5.7-18mg ascorbic acid, 7 mg choline and 3 mcg folic acid per 100 g of edible portion (Safdar and Khan, 2006) [32] . Tandel, 2025) [20] .

The premise of "Food as Medicine" has been in place since time immemorial. Modern medicine has also acknowledged the healing properties of numerous foods derived from plants. There is an increasing awareness among the scientists that both nutrient and non-nutrient components of the diet may play a significant role in management of several chronic and metabolic diseases such as diabetes, cardio vascular diseases, cancer, cataract, gastro-protective, antioxidant, CNS depressant, anti-allergic, antibacterial, cardio-protective properties. (Banu and Jyothi, 2016; Kumar, and Singh, 2021; Hemavathi et al., 2024) [6,16,9] . [35,17] . It is referred to as the "third killer" of humanity, and it is affecting some 10% of the world's indigenous population today. It is a medical condition featuring high blood pressure, abnormal cholesterol levels, insulin resistance and visceral obesity, according to World Health Organization (WHO). (Rizvi et al., 2022) [31] Globally, the incidence of diabetics is expected to hit over 300 million by 2025. India is home to the world's largest diabetic populace. Bangladesh, Pakistan, India, Indonesia and China are expected to have five of the top 10 countries with the highest percentage of diabetics by 2030. T2DM is a global issue affecting about 230 million people in the world or about 6% of adult's population (Imran et al., 2022) [10] . Worldwide, 1 in 10 adults (20 to 79 years old) suffer from diabetes. Based on the IDF Diabetes Atlas, the total number of adult patients in the country is 537 million, of which the majority (>90%) have type 2 diabetes (T2DM). Metabolic diseases like diabetes mellitus and hyperlipidaemia are now an epidemic, and they will be a major public health problem in the world (Ni et al 2022; Gaurav et al., 2025) [26,8] . Thus, the aim of the present review is the assessment of antidiabetic activity of seed powder of Syzygium cumini (Jamun) in the treatment of Type 2 Diabetes Mellitus (T2DM). It provides a summary of the existing scientific evidence relating to its effects on glycaemic control, insulin sensitivity and metabolic regulation. The review also emphasizes its phytochemical constituents, mechanism of action and identifies the gaps for further research and clinical validation.

Methodology

The effects of Syzygium cumini (Jamun) seed powder on glycaemic control and insulin sensitivity in Type 2 Diabetes Mellitus (T2DM) were evaluated using a systematic literature review. Electronic search was made on the scientific databases PubMed, Google Scholar, ScienceDirect and Scopus from 2006 to 2025. The following key words were used in the search process: Jamun seed powder, Syzygium cumini, antidiabetic activity, glycaemic control, and insulin sensitivity. The articles which included the Jamun seeds and diabetes were peer-reviewed, animal studies, clinical trials, phytochemical studies, and review papers. Articles that were not related to diabetic outcome, duplicate articles and articles not published in English were excluded. We found 140 records, and after screening and eligibility assessment, 40 studies were included in the final review. Information on phytochemical composition, dose, study design, fasting plasma glucose (FPG) level, postprandial glucose (PPG) level, HbA1c, insulin resistance, and antioxidant activity were gathered and evaluated descriptively. [38,19] . The seeds of Jamun are also rich in fatty acids, fatty oils (30g/kg), palmitic, stearic, oleic, linoleic, lauric, malvalic, sterculic and vernolic acids. Of these the ones with a higher percentage are oleic acid (32.2%) and myristic acid (31.7%).

Seeds also contain low level phytosterols including β- [38,19] are mainly attributed to these phytochemical constituents.

Bioactive Components of Jamun

The nutrients and medicinal properties of Jamun are quite remarkable in the presence of a variety of bioactive compounds and phytochemicals. The therapeutic potential of its phytochemicals includes alkaloids, anthocyanins, tannins, cardiac glycosides, flavonoids, phenols, terpenoids, glycosides, steroids, saponins, reducing sugars, proanthocyanidins, amino acids and phytosterols (Mulkalwar et al., 2021; Jagetia, 2024) [23,12] . These bioactive compounds contribute to various physiological effects of jamun, such as hypoglycemic, anti-inflammatory, anti-bacterial, anti-viral and neuroprotective properties (Singh et al., 2019) [37] . Jamun seeds have a special medicinal importance when compared with other parts of the fruit. Traditionally, they are used for treating diabetes, allergies, viral infections, inflammation and gastric ulcers. Besides these, jamun seeds have diuretic, anti-nociceptive, hypothermic, chemoprotective and cardio-protective properties. Jamun seeds are regarded as one of the natural sources with several bioactive compounds, which make them potential sources for the management of cardiometabolic disorders (Kumar et al., 2022) [15] .

The processing technique is also found to contribute significantly towards the maintenance of nutritional and functional quality of jamun products. The antioxidant activity of the freeze-dried jamun powder has been reported as higher than that of hot-air-dried jamun powder, since the freeze-dried powder retains the essential bioactive compounds like ascorbic acid, anthocyanins and total phenols. The freeze-drying process requires little heating and no presence of liquid water, which makes it an effective method of preserving heat-sensitive nutrients and antioxidant compounds (Kumar et al., 2023; Kapoor et al., 2015) [17,13] . Therefore, freeze drying is regarded as better processing method to preserve the nutritional and therapeutic value of jamun. [18] Jamun seeds against Diabetes Mellitus Syzygium cumini (Jamun) has a rich history of medicinal and antidiabetic applications, with numerous bioactive compounds such as flavonoids, terpenes, anthocyanins, glycosides, jambolin, and ellagic acid playing a crucial role in these therapeutic properties. Application of jamun for diabetes dates back to ages long before the discovery of insulin, through Ayurvedic and Indian folk medicine (Asanaliar and Nadig, 2020) [3] . These phytochemical components play a vital role in imparting the pharmacological properties of jamun, which can be used as a natural remedy for diabetes. Diabetes is a growing health problem worldwide and in developing countries, it is especially difficult to manage due to the increase in prevalence in both rural and urban areas, low levels of awareness, poor health service provision, and cost of treatment. Chemical drugs are the normal method of treatment for diabetes, but they tend to have bad side effects. Hence, the medicinal plants have attracted interest as alternate, safe and economical method for reducing the incidence and control of diabetes (Yedjou et al., 2023; Saini et al., 2025) [40,33] . Thus, early intervention via dietary improvement, physical activity, regular screening, and awareness are also seen as crucial in controlling diabetes and preventing its complications (Ramachandran, 2014; Kaur et al., 2025) [27,14] . The seeds and pulp of Jamun is found to be very helpful in the anti-diabetic activity. The glycosides found in jamun seeds are thought to have a significant role in reducing blood glucose levels and preventing diseases like neuropathy and cataract which are associated with diabetes (Baliga et al., 2013; Amin, 2020) [5,1] . Furthermore, these compounds like jambolin and ellagic acid help to prevent the conversion of starch to sugar when there is excess production of glucose, which helps in stabilizing blood sugar (Singh et al., 2019; Mitra, 2007; Amin, 2020) [37,1] . The polyphenolic compounds found in the jamun seed powder (JSP) also aid in the metabolism of starch into energy, helping to manage blood sugar levels and alleviate symptoms such as excessive urination and thirst, common in diabetes (Ayenampudi et al., 2023) [4] . These good attributes make jamun an alternative treatment for type 2 diabetes. Jamun seed extracts have also been found to have antidiabetic activity in a few experimental studies. Isolated compounds including mycaminose, ethyl acetate and methanol extracts of Syzygium cumini seed kernels significantly lowered blood glucose levels in diabetic rats induced by streptozotocin as reported by Rather et al. (2019) [28] and Neha et al. (2015) [25] . The antidiabetic activity of mycaminose was observed at 50 mg/kg and jamun seed kernel extracts at 200 mg/kg and 400 mg/kg respectively, which further supports the therapeutic potential of the constituents of jamun seed. Jamun has also been proven to be effective in the treatment of diabetes in clinical studies. The fasting plasma glucose (FPG) level reduced by 9 per cent, 18 per cent and 30 per cent after 30 days, 60 days and 90 days respectively in the treatment group, whereas the postprandial plasma glucose (PP glucose) reduced by 8 per cent, 15 per cent and 22 per cent after 30 days, 60 days and 90 days respectively in the treatment group as given by Sidana et al. (2017) [35] . What's more, the HbA1c level in the treatment group dropped significantly from 8.99 ± 1.39 per cent to 8.31 ± 1.40 per cent after 90 days, while the control group experienced a slight rise. These results suggest that the use of Jamun has beneficial effects on glycaemic control in diabetic patients.

Jamun as antihyperlipidemic agent

Hyperlipidaemia is common with diabetes, and raises the risk of heart disease. The effect on lowering lipid levels is extensively studied in Jamun. The extracts of jamun seed and fruit have been shown to possess hypocholesterolaemia activity with a decrease in total cholesterol, LDL, VLDL and triglycerides and an increase in HDL in several experimental studies (Rekha et al., 2010; Raza et al., 2017) [30, 39] . Such effects have been noted in animal models on alloxan and streptozotocin induced diabetes in which jamun also lowered the activity of HMG-CoA reductase which is crucial to the formation of cholesterol (Siddiqui et al., 2014) [36] . Apart from this, minor but significant antihyperlipidemic property of jamun has been observed in high cholesterol diet fed animals for both water and ethanol extracts (Sharma et al., 2011) [34] . These observations are corroborated by some human studies which indicated that the jamun seed powder supplementation for 60 days caused decrease in blood cholesterol level. The outcomes from this suggest that jamun can be used as a natural antihyperlipidemic agent (Jagetia, 2018) [11] .

Recommendation

From the present review it can be inferred that Syzygium cumini (Jamun) seed powder has a promising scope of use as a natural adjunct in the management of Type 2 Diabetes Mellitus as it contains several antihyperglycemic, antioxidant and insulin sensitizing effects (Mulkalwar et al., 2021; Sidana et al., 2017) [23,35] . Based on current evidence, Jamun seed powder can be used as a functional food ingredient or dietary supplement to enhance glycaemic control, lower fasting and postprandial blood glucose levels, and promote overall metabolic health (Amin, 2020; Kumar et al., 2022; Rizvi et al., 2022) [1,15,31] . Therefore, it could be observed that its application may be opted for as a complementary dietary intervention to the conventional antidiabetic treatment, especially during the early stage of diabetes and pre-diabetic condition (Yedjou et al., 2023; Saini et al., 2025) [40,33] . Nevertheless, although these are encouraging results, additional well-designed clinical trials are needed to determine the optimal dose, safety, and effectiveness of this product in humans, before promoting its therapeutic use broadly (Bhakshu et al., 2022; Ni et al., 2022) [7,26] .

Conclusion

According to this review, Syzygium cumini (Jamun) seed powder could be a promising therapeutic agent for the control of type 2 diabetes mellitus. Existing literature reports that the seeds of jamun contain bioactive compounds like flavonoids, polyphenols, tannins, glycosides, and anthocyanins which synergistically support the antihyperglycemic, antioxidant, and insulin-sensitizing effects of jamun. Experimental studies and clinical trials indicate that Jamun seed powder has the potential to lower FBG, PPBG, HbA1c, improve insulin sensitivity and promote pancreatic beta cell function. Besides, its lipid regulating and antioxidant effect might also play a part in the prevention of diabetes-associated complications. Moreover, Syzygium cumini seed powder may be recommended as a potential, low-cost and natural cotherapy for glycaemic management in T2DM. Although promising results, differences in study design, dose and preparation require additional large-scale, long-term and well-standardized clinical trials to ensure its safety, efficacy, and clinical applicability in daily clinical practice.

References

1. Amin MM. Phyto-medicinal effects of Syzygium cumini on diabetes: A review. International Journal of Research in AYUSH and Pharmaceutical Sciences. 2020:392-402.
2. Arooj M, Naveed S, Khalid N. Formulation and assessment of modified biryani using Indian rennet, fenugreek seed, and jamun seed powder for modulating glucose indices. Journal of Agriculture and Food Research. 2025;21:101835.
3. Asanaliar M, Nadig P. Syzygium cumini (jamun) therapeutic potential: a comprehensive review on phytochemical constituents and emphasis on its pharmacological actions related to diabetic intervention. International Journal of Basic and Clinical Pharmacology. 2020;9(2):363-370.
4. Ayenampudi SB, Verma R, Adeyeye SAO. The potential health benefits and food applications of jamun (Syzygium cumini L.), an indigenous fruit of India. Nutrition & Food Science. 2023;53(5):793-809.
5. Baliga MS, Fernandes S, Thilakchand KR, D'Souza P, Rao S. Scientific validation of the antidiabetic effects of Syzygium jambolanum DC (black plum), a traditional medicinal plant of India. The Journal of Alternative and Complementary Medicine. 2013;19(3):191-197.
6. Banu H, Jyothi A. Hypoglycemic and hypocholesterolemic effect of Eugenia jambolana (Kala Jamun) spicy mix on type II diabetic subjects. 2016;30:40.
7. Bhakshu LM, Ratnam KV, Pandita D, Pandita A, Yadav PR, Raju RV. Perspectives of Syzygium cumini (L.) Skeels as a potential rational herbal medicine for diabetes. In: Antidiabetic Plants for Drug Discovery. Apple Academic Press; 2022. p. 55-82.
8. Gaurav A, Jha AR, Ingole N, Ambad R. Evaluation of hypoglycemic and hypolipidemic effects of jamun (Syzygium cumini) and paneer flower (Withania coagulans) and comparison with that of metformin in rabbit (Oryctolagus cuniculus): an experimental study. Journal of Pharmacy and Bioallied Sciences. 2025;17(Suppl 1):S413-S416.
9. Hemavathi KN, Middha SK, Dwivedi N, Hemalatha P, Nisa A, Kavyashree B, et al. Selected medicinal plants for combating diabetes: A green anti-hyperglycemic approach. In: Metabolites of Medicinal Plants: Insightful Approaches. Bentham Science Publishers; 2024. p. 142-181.
10. Imran S, Ain HBU, Tufail T, Nasir M, Maqsood M, Kanwal J, et al. Comprehensive review on therapeutic effect of jamun and fenugreek seeds against non-insulin dependent type 2 diabetes mellitus. Pakistan BioMedical Journal. 2022:24-28.
11. Jagetia GC. A review on the role of jamun, Syzygium cumini Skeels in the treatment of diabetes. International Journal of Complementary & Alternative Medicine. 2018;11(2):91-95.
12. Jagetia GC. Bioactive phytoconstituents and medicinal properties of jamun (Syzygium cumini). Journal of Exploratory Research in Pharmacology. 2024;9(3):180212.
13. Kapoor S, Ranote PS, Sharma S. Bioactive components and quality assessment of jamun (Syzygium cumini L.) powder supplemented chapatti. Indian Journal of Science and Technology. 2015;8(3):287-295.
14. Kaur S, Chaudhary R. A comprehensive review of the effects of Psidium guajava and Syzygium cumini leaves on diabetes mellitus. Preventive Nutrition and Food Science. 2025;30(3):209.
15. Kumar M, Zhang B, Nishad J, Verma A, Sheri V, Dhumal S, et al. Jamun (Syzygium cumini (L.) Skeels) seed: A review on nutritional profile, functional food properties, health-promoting applications, and safety aspects. Processes. 2022;10(11):2169.
16. Kumar S, Singh B. Syzygium cumini (jamun): its medicinal uses. International Journal of Pharmacognosy. 2021;8:361-372.
17. Kumar S, Seluriyal P, Sharma S, Kumar V, Bisht B, Joshi S, et al. Functional and nutritional prospectives of low-fat cookies fortified with jamun pulp, jamun seed, mango kernel powder. Applied Food Research. 2023;3(2):100340.
18. Kumar V, Khatri N, Kumar D, Shekhawat M, Garg V, Kumar A, Kakkar S. Modern perspectives on the traditional uses, phytochemical profiles, and therapeutic benefits of Syzygium cumini. Integrative Medicine Discovery. 2025;9:e25007.
19. Marufa MA, Das PC, Iqbal A. Utilization of jamun seed powder in composite cake formulation. Journal of the Bangladesh Agricultural University. 2019;17(4):599605.
20. Maurya RBR, Tandel BJ. Formulation of jamun seed tablets as a natural anti-diabetic agent. World Journal of Pharmaceutical Research. 2025;14(14):302-315.
21. Meharban A. Evaluation of hydro-ethanolic extract of Syzygium cumini seeds in high fat diet and streptozotocin induced type 2 diabetes mellitus in Wistar albino rats [dissertation]. Rajiv Gandhi University of Health Sciences, India; 2021.
22. Mitra A. Effects of a composite of tulsi leaves, amla, bitter gourd, gurmur leaves, jamun fruit and seed in type 2 diabetic patients. Journal of Clinical and Diagnostic Research. 2007;6:511-520.
23. Mulkalwar S, Kulkarni V, Deshpande T, Bhide H, Patel A, Tilak AV. Antihyperglycemic activity of Syzygium cumini (jamun) in diabetic rats. Journal of Pharmaceutical Research International. 2021;33(35A):12-19.
24. Nagar C, Saini AK, Dhaked G, Kishore B. A KAP study on fortified foods in adolescence and adulthood at Ranapratapnagar, Udaipur. International Journal of Advanced Biochemistry Research. 2025;9(5):570-573.
25. Neha Ayya NA, Vijaya Nalwade VN, Khan TN. Effect of jamun (Syzygium cumini L.) seed powder supplementation on blood glucose level of type II diabetic subjects. 2015.
26. Ni X, Zhang L, Feng X, Tang L. New hypoglycemic drugs: combination drugs and targets discovery. Frontiers in Pharmacology. 2022;13:877797.
27. Ramachandran A. Know the signs and symptoms of diabetes. Indian Journal of Medical Research. 2014;140(5):579-581.
28. Rather GJ, Hamidudin M, Ikram M, Zaman R. Antidiabetic potential and related activity of jamun (Syzygium cumini Linn.) and its utilization in Unani medicine: An overview. International Journal of Herbal Medicine. 2019;7(5):07-11.
29. Raza A, Butt MS, Suleria HAR. Jamun (Syzygium cumini) seed and fruit extract attenuate hyperglycemia in diabetic rats. Asian Pacific Journal of Tropical Biomedicine. 2017;7(8):750-754.
30. Rekha N, Balaji R, Deecaraman M. Antihyperglycemic and antihyperlipidemic effects of extracts of the pulp of Syzygium cumini and bark of Cinnamomum zeylanicum in streptozotocin-induced diabetic rats. Journal of Applied Biosciences. 2010;28(1):1718-1730.
31. Rizvi MK, Rabail R, Munir S, Inam-Ur-Raheem M, Qayyum MMN, Kieliszek M, et al. Astounding health benefits of jamun (Syzygium cumini) toward metabolic syndrome. Molecules. 2022;27(21):7184.
32. Safdar M, Khan A. Effect of jamun fruit extract on serum glucose and lipid profile in type 2 diabetic individuals. Pakistan Journal of Nutrition. 2006;5(6):573-576.
33. Saini T, Sharma S, Dash KK, Sandhu R, Dadwal V, Shams R, et al. Role of bioactive phytochemicals in plant seeds and leaves for diabetes control and prevention: a comprehensive review. Phytochemistry Reviews. 2025:1-26.
34. Sharma SB, Tanwar RS, Nasir A, Prabhu KM. Antihyperlipidemic effect of active principle isolated from seed of Eugenia jambolana on alloxan-induced diabetic rabbits. Journal of Medicinal Food. 2011;14(4):353-359.
35. Sidana S, Singh VB, Meena BL, Beniwal S, Singh K, Kumar D, Singla R. Effect of Syzygium cumini (jamun) seed powder on glycemic control: A double-blind randomized controlled trial. Journal of Medical Society. 2017;31(3):185-189.
36. Siddiqui S, Sharma B, Ram G. Anti-hyperglycemic and anti-hyperlipemia effects of Syzygium cumini seed in alloxan-induced diabetes mellitus in Swiss albino mice (Mus musculus). Medicinal & Aromatic Plants. 2014;3(4):166.
37. Singh Y, Bhatnagar P, Kumar S. A review on bio-active compounds and medicinal strength of jamun (Syzygium cumini Skeels). International Journal of Chemical Studies. 2019;7(4):3112-3117.
38. Sood M, Bandral JD, Kaur M. Development and quality evaluation of jamun seed powder supplemented noodles. Journal of Pharmacognosy and Phytochemistry. 2018;7(3):1411-1416.
39. Syama HP. Phytochemical investigation of Syzygium cumini seeds in ameliorating lifestyle associated diseases [dissertation]. Agro Processing and Natural Products Division, National Institute for Interdisciplinary Science and Technology (CSIR), Thiruvananthapuram; 2017.
40. Yedjou CG, Grigsby J, Mbemi A, Nelson D, Mildort B, Latinwo L, Tchounwou PB. The management of diabetes mellitus using medicinal plants and vitamins. International Journal of Molecular Sciences. 2023;24(10):9085.