Chemical composition by PTP 1B inhibitory activity guided analysis of plant-based antidiabetic polyherbal drug used in ethnomedical systems

Abstract Background Due to growing resistance and continued depletion of drugs that can be used as replacements, people turn to herbal medicines. A polyherbal drug was studied to investigate its chemical composition and possible mode of action. Methods Phytochemicals were isolated using Column and Thin Layer Chromatography, and antidiabetic activity was ascertained using an enzyme inhibition model. Active compounds identity was established using 1HNMR, 13CNMR, HSQC-NMR, UV, FT-IR and MS spectroscopy. Results Results showed that the polyherbal drug consisted of alkaloids and anthocyanins as the major active components. The alkaloids PTP 1B inhibition was not significantly different from that of metformin with percentage inhibition of Alkaloid 1, 78.6 ± 3.2% and Alkaloid 2, 79.6 ± 2.3. The anthocyanins inhibited PTP 1B enzyme significantly better than metformin with percentage inhibition of Flavonoid 1, 88.2 ± 3.2, Flavonoid 2, 90.3 ± 2.3 and Flavonoid 3 93.6 ± 2.9. One new alkaloid compound, Alkaloid 1, 1, 2-dimethoxy-12-methyl-7-(3-methylbut-2-en-1-yl)-12, 13-dihydro1,3benzodioxolo5,6-cphenanthridin-13-ol, one previously reported alkaloid, Alkaloid 2 berberine, IUPAC name, 9,10-dimethoxy-5,6-dihydro1,3dioxolo4',5':6,7isoquinolino2,1-b2benzazin-7-ium and three anthocyanins, Flavonoid 1, malvidin 3-o-glucoside, Flavonoid 2, pelargonidin-3-O-gucoside and Flavonoid 3 malvidin 3, 5-O-diglucoside were identified as the active compounds in the polyherbal drug extract. Conclusion Presence of alkaloids and anthocyanins that have PTP 1B inhibitory activity showed that the polyherbal drug is a potential medicine for managing diabetes.