Effects of Plant Part Substitution in a Thai Traditional Recipe on α-Glucosidase Inhibition

Abstract

A Thai polyherbal antipyretic remedy, TPDM6315, consists of herbal constituents that possess anti-diabetic properties. It contains 15 plants, of which the roots of 3 crude drugs, Solanum indicum (R-Si), Solanum trilobatum (R-St), and Gymnopetalum integrifolium (R-Gi), are insufficiently supplied in the herbal market, while their stems or aerial parts (S-Si, S-St, and S-Gi, respectively), are available. This study aimed to determine the anti-diabetic properties of the recipe extract and evaluate the possible substitution of those crude drugs. The chemical properties and the in vitro α-glucosidase inhibition were investigated in the single herbal ingredient and the recipe extracts. The results indicated that TPDM6315 extracts inhibited α-glucosidase as a mixed-type inhibitor. The high-performance liquid chromatography (HPLC) profiles between the root and stem of those herbs were different but highly similar to the recipe extracts. The substituted recipe (S-Et, containing S-Si, S-St, and S-Gi) exhibited higher potency on α-glucosidase inhibition than the original recipe (R-Et, containing R-Si, R-St, and R-Gi) (P<0.01). This study revealed substitution in TPDM6315 was possible for α-glucosidase inhibitory properties since it only partially affected the overall chemical profile while raising the α-glucosidase inhibitory activity of the recipe extracts.