Crude Drug Standardization and Antioxidant Properties of an Indonesian Antidiabetic Polyherbal Formulation and Plant Constituents

Jamu pahitan, traditionally used for diabetes treatment in Indonesia, is prepared as a mixture of Andrographis paniculata (Burm.f.) Wall. ex Nees, Carica papaya L., Curcuma aeruginosa Roxb., Orthosiphon aristatus (Blume) Miq., and Tinospora crispa (L.) Hook.f. & Thomson. This study evaluated the quality profile and antioxidant activity of Jamu pahitan’s crude drug components and assessed antioxidant properties and content of andrographolide and sinensetin of ethanolic extracts of the polyherbal formulation. The quality of the crude drugs was analyzed and standardized according to the official monographs. The antioxidant activity was evaluated by standard total phenolic content (TPC), diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, and ferric-reducing antioxidant power (FRAP) assays. The andrographolide and sinensetin contents of Jamu pahitan were determined using the thin layer chromatography (TLC) densitometry method. The crude drugs met quality parameters set in their respective official monograph. Orthosiphon aristatus showed the strongest antioxidant activity and contained the highest TPC among other tested crude drugs. Jamu pahitan’s antioxidant activity and TPC were in the median range of those of plant components, with additive or antagonistic interaction effects toward antioxidant activity. Jamu pahitan 2 consisted of standardized crude drug components showing DPPH scavenging activity and FRAP of 14.97±0,47 and 2.94±0,05 mmol Trolox equivalent (TE)/g dry weight (DW), with andrographolide (0.96±0.02%), sinensetin (0.97±0.09%), and phenolic compounds (8.16±0.21 mg Gallic acid equivalent (GAE)/g DW) as the antioxidant compounds. It can be concluded that all crude drugs were of good quality, with andrographolide, sinensetin, and phenolic compounds are responsible for the antioxidant activity.