Abstract:
Background Due to growing resistance and continued depletion of drugs that can be used as replacements, people
turn to herbal antidiabetic medicines. A polyherbal drug consisting of a mixture of two herbal plants, Zanthoxylum
chalybeum and Xeroderris stuhlmannii root powder mixed in equal amounts using a tea cup, 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 two alkaloids and three anthocyanins as the major
active components. PTP 1B inhibition of alkaloids was not significantly different from that of metformin with percentage
inhibition of 78.6 ± 3.2 and 79.6 ± 2.3%. The anthocyanins inhibited PTP 1B enzyme significantly better
than metformin with percentage inhibition of 88.2 ± 3.2, 90.3 ± 2.3 and 93.6 ± 2.9%. One new compound, an alkaloid, 1,
2-dimethoxy-12-methyl-7-(3-methylbut-2-en-1-yl)-12, 13-dihydro [1,3] benzodioxolo [5,6-c] phenanthridin-13-ol, one
previously reported alkaloid berberine, IUPAC name, 9,10-dimethoxy-5,6-dihydro[1,3] dioxolo [4’,5’:6,7] isoquinolino
[2,1-b][2] benzazin-7-ium and three anthocyanins,, malvidin 3-o-glucoside, pelargonidin-3-O-gucoside and 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.
