Pharmacognostical and phytochemical standardization of Houttuynia cordata Thunb.: A potent medicinal herb of North–Eastern India and China

Aim: Houttuynia cordata Thunb. (Saururaceae) is one of the perennial herb indigenous to North-East India and China. Despite the popular utilization of this herb as medicine, still no study has been reported so far regarding the pharmacognostical standardization. Thus, the aim of the present study was to scientifically establish a standard monograph on the basis of pharmacognostical and phytochemical aspects. Methods: The quality control standardization of H. cordata was done as per the methods described in the World Health Organization guidelines (2002). Results: The diagnostic characters of the H. Cordata leaf and rhizome portion were evaluated based on the macroscopical and microscopical characters. Determination of various physicochemical parameters such as water soluble ash (1.12% w/w), acid insoluble ash (4.02% w/w), sulphated ash (3.15% w/w), alcohol soluble extractive (12.8% w/w), water soluble extractive (14.9% w/w), loss on drying (3.42% w/w) and crude fibres content (13.10% w/w) was ascertained. Heavy metal, microbial load, fluorescence drug analysis, and preliminary phytochemical screening of different fractions were also carried out. Total phenols (45.74 mg/g tannic acid equivalent, TAE), tannins (33.29mg/g TAE), flavonoids (104.55 mg/g rutin equivalent, RE), and flavonols (17.16mg/g RE) were quantified from the ethanolic extract of the whole plant. Quantification of quercetin in the ethanolic extract was assessed by HPTLC analysis and was found to contain 4.39%, w/w. Conclusion: The obtained qualitative and quantitative standards will provide referential information for correct identification and standardization of this medicinal plant.