Quality Assessment of Rhinacanthus nasutus

Abstract

Dried whole plants of Rhinacanthus nasutus (L.) Kurz (Acanthaceae) were collected from 15 Thai traditional drugstores located around four regions of Thailand. The pharmacognostic specifications were performed according to the World Health Organization (WHO) guidelines for herbal standardization. Microscopic investigation revealed multicellular and glandular trichomes as well as lithocyst cells occured on both leaf surfaces. Calcium carbonate and raphide crystal were found on the epidermal and parenchyma cell of the stem. The powdered crude drug displayed microscopic identification of both leaves and stems. The mean contents of foreign matter, acid insoluble ash, total ash, moisture content, ethanolsoluble extractive, water-soluble extractive and loss on drying were 0.2, 6.5, 10.7, 8.7, 1.8, 16.9 and 9.5 % of dry weight respectively. TLC fingerprint of the methanolic extracts were demonstrated.