ISOLATION OF CHEMICAL CONSTITUENTS AND EVALUATION OF ANTIDANDRUFF ACTIVITY OF THE LEAVES OF URTICA DIOICA L.

Chhavi Singla, Mohammed Ali*, Shahnaz Sultana and Showkat Rassol Mir

ABSTRACT

Urtica dioica L. (Urticaceae) is a perennial herb and its leaves are used to treat anemia, asthma, allergy, arthritis, baldness, bronchitis, chicken pox, colds, dandruff, diabetes, diarrhoea, eczema, flu, gingivitis, excess menstrual flow, nettle rash, piles, rheumatism, sinusitis, sprains, tendonitis, ulcers and wounds. This study was intended to isolate and identify the chemical constituents from the leaves of Urtica dioica and to evaluate their antidandruff activity. The leaf powder of U. dioica was extracted exhaustively with methanol in a Soxhlet apparatus. The concentrated methanolic extract was dissolved in ethanol (95%) and fractionated by partitioning the solution with petroleum ether, chloroform, ethyl acetate and n-butanol. The chloroform fraction exhibited marked antidandruff activity against the growth of Malassezia furfur. It was adsorbed on silica gel (60-120 mesh) for the preparation of a slurry. The dried slurry was chromatographed over a silica gel column. The column was eluted with petroleum ether, chloroform and methanol, successively, in order of increasing polarity to isolate 2,6,7-trihydroxynaphthalene (6,7– dihydroxy-β-naphthol, 1), ellagic acid (2) and rutin (quercetin- 3- O- rutinoside) (3). Their structures were established on the basis of spectral data analysis and chemical reactions. Dandruff is a skin disorder caused by a fungus Malassezia furfur. The petroleum ether, chloroform, ethyl acetate, n-butanol and aqueous fractions of the methanolic extract of the leaves of U. dioica against Malassezia furfur at concentration of 10 mg/ml each showed zone of inhibition between 6.81 – 22.13 mm. Among all the testing portions the chloroform fraction exhibited marked antidandruff activity. The zone of inhibition in mm was in order of 22.13> 16.47> 12.0> 7.53> 6.81 for chloroform, aqueous, n-butanol, ethyl acetate and petroleum ether extracts, respectively.

Keywords: Urtica dioica L., leaves, phytoconstituents, isolation, characterization, antidandruff activity.