A method of obtaining one or more fractions from one or more plants is disclosed. The method includes subjecting one or more parts of the one or more plants to hydro-alcoholic extraction in presence of a water-insoluble solvent to obtain one or more extracts. The method further includes subjecting the one or more extracts to one or more of de-pigmentation, de-fatting and detoxification process to obtain the one or more fractions. The one or more fractions thus obtained contain a desired pharmacologically active ingredient in concentration greater than concentrations of other pharmacologically active ingredients present in the at least one fraction. Further, the one or more fractions are less toxic as compared with corresponding one or more fractions obtained by conventional methods. In addition, the one or more fractions are therapeutically more effective in various diseases as compared to one or more fractions obtained by conventional methods.