Diabetes mellitus (DM) is a chronic metabolic disorder characterized by persistent hyperglycemia resulting from defects in insulin secretion, insulin action, or both [1,2]. The global prevalence of diabetes is rapidly increasing, posing significant health, social, and economic challenges [3-5]. Traditional antidiabetic drugs such as sulfonylureas and biguanides, though effective, are often associated with adverse effects and high costs, making herbal therapies an appealing alternative, especially in developing nations [6,7].

Syzygium cumini, commonly known as Jamun or Indian Blackberry, belongs to the family Myrtaceae. The seeds, bark, and leaves of this plant are traditionally used in Ayurveda and Unani medicine for the treatment of diabetes, diarrhea, and inflammation [8-10]. The bioactive compounds in Syzygium cumini, including flavonoids, phenolic acids, and terpenoids, are known to exert antioxidant and hypoglycemic effects [11-13]. This study aims to scientifically validate the anti-diabetic potential of Syzygium cumini extracts and identify the phytochemical constituents responsible for their activity [14,15].        

Plant Material

Fresh Syzygium cumini plant material was collected, authenticated, and shade-dried. The dried parts were coarsely powdered for extraction [8,9].

Preparation of Extracts

The powdered plant material was subjected to aqueous and alcoholic extraction using a Soxhlet apparatus [11]. The extracts were concentrated under reduced pressure and stored at 4°C until further use [12,13].

Experimental Animals

Healthy adult Wistar albino rats (150–200 g) were used for the study. The animals were maintained under standard laboratory conditions with free access to food and water [16].

Induction of Diabetes:

Diabetes was induced by intraperitoneal administration of alloxan monohydrate (120 mg/kg body weight)  after  a 

72-hour fast. Rats with fasting blood glucose levels above 200 mg/dL were considered diabetic [17,18].

Treatment Protocol

The animals were divided into five groups:

• Normal control (saline)

• Diabetic control (alloxan only)

• Standard control (glibenclamide, 10 mg/kg)

• Aqueous extract (20 mg/kg)

• Alcoholic extract (30 mg/kg)

Treatments were administered orally for 21 days. Fasting blood glucose levels were measured on days 7, 14, and 21, while oral glucose tolerance tests were conducted on days 8, 15, and 22 [19,20].

Phytochemical Screening

Standard qualitative tests were performed to detect alkaloids, flavonoids, tannins, saponins, sterols, and triterpenes [21,22].

The aqueous and alcoholic extracts of Syzygium cumini produced a significant reduction in fasting blood glucose levels in diabetic rats. The hypoglycemic effect was comparable to that of the standard drug, glibenclamide [17,23]. Additionally, the extracts improved glucose tolerance as observed in OGTT results [20,24].

Phytochemical screening revealed the presence of several bioactive compounds known to influence glucose metabolism and pancreatic function [21.22.25]. Flavonoids and saponins, in particular, have been reported to enhance insulin secretion and protect beta cells from oxidative stress [26-28]. The regeneration of pancreatic beta cells observed in the treated groups suggests a restorative mechanism of action [29,30].

The results corroborate previous studies demonstrating the anti-diabetic efficacy of Syzygium cumini seed and bark extracts [8,9,11]. The combined presence of antioxidants and hypoglycemic agents makes Syzygium cumini a promising candidate for natural diabetes management [24,25,27].

The present study confirms the anti-diabetic potential of Syzygium cumini in alloxan-induced diabetic rats. Both aqueous and alcoholic extracts exhibited significant hypoglycemic activity comparable to the standard drug glibenclamide [17.23]. The effect may be attributed to the synergistic action of bioactive phytochemicals that promote pancreatic beta-cell regeneration and enhance insulin secretion [26,30]. Further studies involving isolation and characterization of active compounds, as well as clinical evaluation, are warranted to develop Syzygium cumini-based antidiabetic formulations [27,28].

Acknowledgment

The author expresses sincere gratitude to guide Mr. Arif Mohammad Shaik, M. Pharma, Assistant Professor, Department of Pharmacology, and Dr. D. Venkata Ramana, M. Pharm, PhD, Principal, Holy Mary Institute of Science & Technology, for the valuable guidance, support, and encouragement throughout the research work.

1. World Health Organization. Definition, Diagnosis and Classification of Diabetes Mellitus and Its Complications. Vol. 1, Part 1, World Health Organization, 1999.

2. Alberti, Kurt George Matthew Mayer, and P. Z. Zimmet. “Definition, Diagnosis and Classification of Diabetes Mellitus and Its Complications. Part 1: Diagnosis and Classification of Diabetes Mellitus.” Diabetic Medicine, vol. 15, no. 7, 1998, pp. 539–553.

3. 3] Gress, Todd W., et al. “Hypertension and Antihypertensive Therapy as Risk Factors for Type 2 Diabetes Mellitus.” New England Journal of Medicine, vol. 342, no. 13, 2000, pp. 905–912.

4. Ahmed, Awad M. “History of Diabetes Mellitus.” Saudi Medical Journal, vol. 23, no. 4, 2002, pp. 373–378.

5. Zimmet, Paul Z., Daniel J. McCarty, and Maximilian P. de Courten. “The Global Epidemiology of Non-Insulin-Dependent Diabetes Mellitus and the Metabolic Syndrome.” Journal of Diabetes and Its Complications, vol. 11, no. 2, 1997, pp. 60–68.

6. Turner, R. C., et al. “Intensive Blood-Glucose Control with Sulphonylureas or Insulin Compared with Conventional Treatment and Risk of Complications in Patients with Type 2 Diabetes (UKPDS 33).” The Lancet, vol. 352, no. 9131, 1998, pp. 837–853.

7. Day, Caroline. “Traditional Plant Treatments for Diabetes Mellitus: Pharmaceutical Foods.” British Journal of Nutrition, vol. 80, no. 1, 1998, pp. 5–6.

8. Omonije, Oluyemisi Omotayo, et al. “Anti-Diabetic Activities of Chromolaena odorata Methanol Root Extract and Its Attenuation Effect on Diabetic-Induced Hepatorenal Impairments in Rats.” Clinical Phytoscience, vol. 5, 2019, p. 23.

9. Ardiana, Lia, et al. “Antidiabetic Activity Studies of White Tea (Camellia sinensis (L.) O. Kuntze) Ethanolic Extracts in Streptozotocin-Nicotinamide Induced Diabetic Rats.” Pharmacognosy Journal, vol. 10, no. 1, 2018, pp. 186–189.

10. Patel, Ameebahen B., et al. “Antidiabetic Activity of Moringa oleifera Lam.” Algerian Journal of Natural Products, vol. 5, no. 2, 2017, pp. 446–453.

11. Mrabti, Hanae Naceiri, et al. “Separation, Identification, and Antidiabetic Activity of Catechin Isolated from Arbutus unedo L. Plant Roots.” Journal of Ethnopharmacology, vol. 226, 2018, pp. 23–30.

12. Haque, Md. Uzzal, and Samiron Sana. “Antidiabetic Activity of Plants, Fruits and Vegetables: A Review.” International Journal of Biological and Medical Research, vol. 7, no. 1, 2016, pp. 5452–5458.

13. Radhika, D., and R. Priya. “Assessment of Anti-Diabetic Activity of Some Selected Seaweeds.” European Journal of Biomedical and Pharmaceutical Sciences, vol. 2, no. 6, 2015, pp. 151–154.

14. Ghazanfar, Khalid, et al. “Antidiabetic Activity of Artemisia amygdalina Decne in Streptozotocin-Induced Diabetic Rats.” Journal of Pharmacy and Bioallied Sciences, vol. 3, no. 2, 2014, pp. 242–248.

15. Kamboj, Anil, et al. “Evaluation of Antidiabetic Activity of Hydroalcoholic Extract of Cestrum nocturnum Leaves in Streptozotocin-Induced Diabetic Rats.” Pharmacognosy Journal, vol. 9, no. 5, 2013, pp. 446–453.

16. Browning, Jeffrey D., and Jay D. Horton. “Molecular Mediators of Hepatic Steatosis and Liver Injury.” Journal of Clinical Investigation, vol. 114, no. 2, 2004, pp. 147–152.

17. Pari, L., and G. Saravanan. “Antidiabetic Effect of Cogent db, a Herbal Drug in Alloxan-Induced Diabetes Mellitus.” Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, vol. 131, no. 1, 2002, pp. 19–25.

18. Li, Fenglin, et al. “The Optimal Extraction Parameters and Anti-Diabetic Activity of Flavonoids from Ipomoea batatas Leaf.” African Journal of Traditional, Complementary and Alternative Medicines, vol. 6, no. 2, 2009, pp. 195–202.

19. Wulan, Dyah Ratna, et al. “Antidiabetic Activity of Ruellia tuberosa L., Role of α-Amylase Inhibitor: In Silico, In Vitro, and In Vivo Approaches.” Asian Pacific Journal of Tropical Biomedicine, Sept. 2015.

20. Sikarwar, Mukesh S., and M. B. Patil. “Antidiabetic Activity of Crateva nurvala Stem Bark Extracts in Alloxan-Induced Diabetic Rats.” Journal of Pharmacy and Bioallied Sciences, vol. 2, no. 1, 2010, pp. 18–21.

21. Okokon, Jude E., et al. “Antidiabetic Activities of Ethanolic Extract and Fraction of Anthocleista djalonensis.” Asian Pacific Journal of Tropical Biomedicine, vol. 2, no. 6, 2012, pp. 461–464.

22. Misra, Himanshu, et al. “Antidiabetic Activity of Medium-Polar Extract from the Leaves of Stevia rebaudiana (Bertoni) on Alloxan-Induced Diabetic Rats.” Journal of Pharmacy and Bioallied Sciences, vol. 3, no. 2, 2011, pp. 242–248.

23. Sunmonu, Taofik O., and Anthony J. Afolayan. “Evaluation of Antidiabetic Activity and Associated Toxicity of Artemisia afra Aqueous Extract in Wistar Rats.” African Journal of Traditional, Complementary and Alternative Medicines, vol. 6, no. 2, 2013, pp. 195–202.

24. Vahab, Abdul A., and Jyoti Harindran. “Anti-Diabetic Activity of Terminalia catappa Bark Extracts in Alloxan-Induced Diabetic Rats.” Journal of Pharmacy and Bioallied Sciences, vol. 2, no. 1, 2014, pp. 18–21.

25. Scheen, André J. “Pathophysiology of Type 2 Diabetes.” Acta Clinica Belgica, vol. 58, no. 6, 2003, pp. 335–341.

26. Saltiel, Alan R., and C. R. Kahn. “Insulin Signalling and the Regulation of Glucose and Lipid Metabolism.” Nature, vol. 414, no. 6865, 2001, pp. 799–806.

27. Brownlee, Michael, and Anthony Cerami. “The Biochemistry of the Complications of Diabetes Mellitus.” Annual Review of Biochemistry, vol. 50, 1981, pp. 385–432.

28. Aronoff, Stephen L., et al. “Glucose Metabolism and Regulation: Beyond Insulin and Glucagon.” Diabetes Spectrum, vol. 17, no. 3, 2004, pp. 183–190.

29. Faber, O. K., and C. Binder. “C-Peptide Response to Glucagon: A Test for the Residual β-Cell Function in Diabetes Mellitus.” Diabetes, vol. 26, no. 7, 1977, pp. 605–610.

30. Sherwin, Robert, and Philip Felig. “Pathophysiology of Diabetes Mellitus.” The Medical Clinics of North America, vol. 62, no. 4, 1978, pp. 695–711.

31. Inzucchi, Silvio E. “Diagnosis of Diabetes.” New England Journal of Medicine, vol. 367, no. 6, 2012, pp. 542–550.

32. Smith, George Davey, et al. “Genetic Epidemiology and Public Health: Hope, Hype, and Future Prospects.” The Lancet, vol. 366, no. 9495, 2005, pp. 1484–1498.

33. Vambergue, A., et al. “[Pathophysiology of Gestational Diabetes].” Journal de Gynécologie, Obstétrique et Biologie de la Reproduction, vol. 31, no. 6 Suppl., 2002, pp. 4S3–4S10.

34. Levin, Marvin E., et al. “Effects of Diabetes Mellitus on Bone Mass in Juvenile and Adult-Onset Diabetes.” New England Journal of Medicine, vol. 294, no. 5, 1976, pp. 241–245.

35. Ioannidis, Ioannis. “Pathophysiology of Type 1 Diabetes.” Diabetes in Clinical Practice: Questions and Answers from Case Studies, 2007, p. 23.

36. Ross, E. J., and D. C. Linch. “Cushing’s Syndrome—Killing Disease: Discriminatory Value of Signs and Symptoms Aiding Early Diagnosis.” The Lancet, vol. 320, no. 8299, 1982, pp. 646–649.

37. Browning, Jeffrey D., and Jay D. Horton. “Molecular Mediators of Hepatic Steatosis and Liver Injury.” Journal of Clinical Investigation, vol. 114, no. 2, 2004, pp. 147–152.

38. Turner, R. C., et al. “Intensive Blood-Glucose Control with Sulphonylureas or Insulin Compared with Conventional Treatment and Risk of Complications in Patients with Type 2 Diabetes (UKPDS 33).” The Lancet, vol. 352, no. 9131, 1998, pp. 837–853.

39. Pari, L., and G. Saravanan. “Antidiabetic Effect of Cogent db, a Herbal Drug in Alloxan-Induced Diabetes Mellitus.” Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, vol. 131, no. 1, 2002, pp. 19–25.