Pharmacognostic evaluation and development of HPLC fingerprint for standardisation of Waltheria indica l. (Malvaceae)

Abstract

Studies have supported ethnobotanical claims on Waltheria indica L. Malvaceae. However, its standardisation parameters are yet to be defined. This study conducted pharmacognostic evaluation and High-Performance Liquid Chromatography (HPLC) to develop standards for Waltheria indica. The plant was collected, identified, and authenticated. The morphological and anatomical characters were studied by organoleptic evaluation and microscopy, respectively. Physicochemical constants and phytochemical contents were determined. Chromatographic fingerprints of the leaf, stem, and root powders were obtained, and peaks were identified and quantified based on phenolic standards. Physical characters of Waltheria indica were described. Photomicrographs showed abundant stellate trichomes in leaves and stem of the plant. The vascular bundles were arranged in amphicribral form with endarch xylems. The adaxial surface of the leaf has straight epidermal cells with anisocytic and diacytic stomata, while the abaxial surface has wavy epidermal cells with only anisocytic stomata. The alcohol and water extractives values of leaf, stem, and root are (22.2%, 11.8%, and 14.44%) and (15.47%, 7.6% and 7.33%) respectively. Moisture content (6.62%, 2.78%, and 3.63%) and ash values (7.77%, 2.73%, and 2.33%) were within pharmacopoeia limits. Steroids, terpenoids, saponins, tannins, phenols, flavonoids, cardiac glycosides,  anthraquinone, and alkaloids were present in all plant parts. Chromatographic fingerprints of plant parts showed unique peaks for phenolic standards. All plant parts had 4-hydroxybenzoic acid, epigallocatechin gallate, and epicatechin, with epicatechin most abundant in the leaf (1,371,061 ng/g). The standardisation parameters developed would be helpful in monograph preparation for Waltheria indica.