The Pharmacognostic Standards, Antioxidant and Antidiabetic Activities, and Hepatic Safety Profile of An Indonesian Antidiabetic Polyherbal Formulation

This study evaluated the physicochemical characters, antioxidant activities, total phenolic content, glucose uptake stimulatory activities, and the hepatic safety of a polyherbal formulation containing seven plant components used by Klinik Wisata Kesehatan Jamu Kalibakung, Tegal, Indonesia, to treat diabetic patients. The selected physicochemical parameters of the formulation were characterized according to the WHO quality control methods for herbal materials. Furthermore, the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH RSA), ferric reducing antioxidant power (FRAP), and total phenolic content (TPC) were evaluated in accordance with the standard method. Also, the cytotoxic effects of formulation on the skeletal muscle L6 and hepatic HepG2 cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The glucose uptake stimulatory activity of the formulation in L6 was evaluated using the indirect glucose oxidase method. Meanwhile, the physicochemical properties were specified as follows: foreign matters (1.32 +/- 0.05%), loss on drying (11.50 +/- 0.07%), total ash (5.68 +/- 0.07%), acid-insoluble ash (0.94 +/- 0.04%), water-soluble extractable (18.22 +/- 0.60%), and ethanol-soluble extractable (16.90 +/- 0.77%). The results showed ethanol extract had superior DPPH RSA (960.70 +/- 2.58 mM Trolox equivalent (TE)/g dry weight (DW)), FRAP (1112.69 +/- 8.39 mM TE/g DW), and TPC (1768.40 +/- 32.40 mg gallic acid equivalent (GAE)/g DW) over its water counterpart. The respective IC50 values of water extract on L6 and HepG2 were 209.10 +/- 5.45 and 225.17 +/- 11.00 mu g/mL, while those of ethanol extract were 94.80 +/- 1.56 and 40.24 +/- 3.53 mu g/mL. Compared to the control, the water and ethanol extracts increased glucose uptake by 23.88 +/- 5.21 and 55.58 +/- 1.24% respectively. This study characterized the physicochemical parameters for an antidiabetic polyherbal formulation with excellent antioxidant and glucose uptake stimulatory activities. Also, its current use as a decoction was safe for the skeletal muscle and hepatic cells.