Pharmacognostic Standardization of an Ethnomedicinal Aquatic Herb, Monochoria hastata (L.) Solms for its Antibacterial Potentiality

Objectives: To evaluate antibacterial potentiality, pharmacognostic characteristics and quality control parameters including heavy metals, like lead (Pb) and arsenic (As) accumulation in the aerial parts of an aquatic herb, Monochoria hastata (L.) Solms. Methods: Antibacterial assay was done by agar well diffusion method. Pharmacognostic studies like morpho-anatomical and physicochemical analyses were carried out for organoleptic, microscopic and macroscopic evaluations of living aerial parts, and powder microscopy, fluorescence, proximate and elemental analysis of the dried powder sample. Elements and heavy metals contents were determined by carbon, hydrogen, nitrogen, sulphur / oxygen (CHNS/O) analyzer and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Results: M. hastata (L.) Solms aerial parts showed antibacterial activity against gastrointestinal and topical pathogens. It exhibited an amphistomatic and hydromorphic anatomical characters. The distinguishing features were the presence of stomata in upper and lower epidermis, broad air chambers, cuticle, collateral vascular bundles, sclereidal fibres, pitted tracheids, pitted vessels, calcium oxalate crystals and annular vessels in leaf. The powder sample contained very less amount of acid insoluble ash than water soluble ash and complete absence of foreign organic matter. Carbon, hydrogen, nitrogen and sulfur (CHNS) ratio was 33:6:5:1 and lead content was lesser than the recommended upper limit though the arsenic content was higher than the permissible upper limit. Conclusions: Though the plant has traditionally been used as a potent Ethnomedicinal herb to cure boils, gastritis, hepatopathy and as laxative, but no such evaluation of pharmacognostic identity and quality parameters have been done so far. This is the first report on its pharmacognostic characters and quality control issues like heavy metal accumulation and physicochemical parameters for future use as powder drug.