COMPARATIVE PHYTOCHEMICAL PROFILING AND SYNERGISTIC ANTI-DIABETIC POTENTIAL OF BANABA, MORINGA, JAMUN, AND FENUGREEK EXTRACTS AGAINST TYPE 2 DIABETES MELLITUS

Abstract

Type 2 diabetes mellitus (T2DM) is a global metabolic pandemic affecting over 537 million adults, with conventional pharmacotherapy often limited by adverse effects and secondary treatment failure. This study performs a comprehensive comparative phytochemical profiling and evaluates the synergistic anti-diabetic potential of four traditional medicinal plants Banaba (Lagerstroemia speciosa), Moringa (Moringa oleifera), Jamun (Syzygium cumini), and Fenugreek (Trigonella foenum-graecum) through a multi-tier experimental framework. Sequential Soxhlet and maceration extractions were conducted, followed by quantitative estimation of total phenolic (TPC), flavonoid (TFC), tannin (TTC), and alkaloid content. HPLC and GC-MS profiling confirmed distinct marker compounds: corosolic acid (24.65 mg/g) in Banaba; quercetin (12.42 mg/g) and kaempferol (7.84 mg/g) in Moringa; gallic acid (14.62 mg/g) and ellagic acid (11.05 mg/g) in Jamun; and trigonelline (18.42 mg/g) in Fenugreek. In vitro antioxidant (DPPH, FRAP) and enzyme inhibition assays (α-amylase, α-glucosidase) confirmed dose-dependent activity, with Jamun exhibiting the highest radical scavenging capacity and Banaba the strongest α-glucosidase inhibition. Synergistic interactions were quantified using the Chou–Talalay Combination Index (CI), with the quaternary combination producing the strongest synergy (CI = 0.46 for α-amylase; CI = 0.42 for α-glucosidase). Response Surface Methodology (RSM) identified the optimum mixture ratio as 38% Banaba, 18% Moringa, 30% Jamun, and 14% Fenugreek (R² = 0.973). In vivo validation in streptozotocin-induced diabetic rats confirmed that the optimised combination reduced fasting blood glucose to 102.4 ± 6.1 mg/dL by day 21, comparable to metformin (108.7 ± 6.3 mg/dL), while simultaneously restoring lipid profiles and hepatic antioxidant enzyme activities. These findings establish a robust preclinical foundation for a novel, evidence-based polyherbal formulation for T2DM management.