Comparative Phytochemical Profiling and In-Vitro α-Amylase Inhibitory Activity of Two Botanical Sources of Gojivha: Onosma Bracteatum Wall. and Elephantopus Scaber Linn.

Background: Gojivha is a botanically controversial Ayurvedic drug traditionally indicated in Prameha. Onosma bracteatum Wall. is the source recognised by the Ayurvedic Pharmacopoeia of India (API), whereas Elephantopus scaber Linn. is used as a regional substitute in Maharashtra and South India. Our aim is to test their comparative antidiabetic potential. Objective: To compare the pharmacognostic, phytochemical and in-vitro α-amylase inhibitory profiles of the two sources. Methods: Powdered whole plants were evaluated for organoleptic, microscopic and physicochemical parameters (API methods), preliminary and quantitative phytochemistry (total phenols, tannins, flavonoids), TLC and HPLC (gallic acid, quercetin). Ethanolic extracts (200-1000 μg/mL) were tested for α-amylase inhibition by the DNS method against acarbose, in triplicate. Data were analysed by two-way ANOVA with Tukey's HSD test. Results: O. bracteatum had higher total phenols (21.99% vs 16.92%), tannins (13.54% vs 7.03%), gallic acid (0.74% vs 0.15%) and quercetin (0.33% vs not detected); E. scaber had higher total flavonoids (0.63% vs 0.42%). Inhibition was concentration-dependent for all samples. At 1000 μg/mL, inhibition was 95.04% for acarbose, 74.78% for O. bracteatum and 71.37% for E. scaber. Sample, concentration and their interaction were significant (P < 0.001). Averaged over all concentrations, E. scaber (58.60%) was slightly more active than O. bracteatum (56.31%; mean difference 2.29%, 95% CI 0.45-4.14, P = 0.012), but the ranking reversed at 600 and 1000 μg/mL. Conclusion: Both sources inhibit α-amylase in a dose-dependent manner, with modest and concentration-dependent differences between them, and neither matched acarbose. The findings give preliminary support to E. scaber as a regional alternative source of Gojivha; fractionation, kinetic and in-vivo studies are needed.