Present invention provides a method for obtaining maximum antilithiatic potential of Tribulus tetrestris by statistically optimized extraction conditions for preparation of aqueous extract from Tribulus terrestris. Response surface methodology is employed to observe the influence of three variables i.e. temperature (°C), time-(h) and solid: liquid ratio {S: L) on the extraction yield (%) and protein content (mg/g) of T. terrestris aqueous extract. RSM results reveal thatihe high S: L ratio, low temperature and reduced incubation time are optimal conditions for aqueous extraction. Under such extraction conditions the protein content reaches to the value 6 6+1 99 mg/g pn th nbtqjnprf oytrnntinp yjpMig- 27.32±1.62%. The physico-chemical evaluation of standardized aqueous extracts (AE1-AE4) with desired protein content and extraction yield reveals maximum saponin (18.2±0.20mg/g).and alkaloid (575.6±0.35mg/g) contents in AE4, while AE3 contains maximum flavonoid content i.e. 197.8±0.37mg/g.
