Phytochemical Screening, Cytotoxicity and Anti-inflammatory Activities of the Leaf Extracts from Lawsonia inermis of Indian Origin to Explore their Potential for Medicinal Uses.

Abstract

Lawsonia inermis Linn popularly known as Henna, plays an important role in ayurvedic or natural herbal medicines. The presence of phytoconstituents in henna, that may affect the animal or human health adversely, needs to be elucidated for L. inermis Linn species grown in India. The aim of this research was to perform phytochemical screening, and study cytotoxicity and anti-inflammatory activities to understand the potential of leaves of Lawsonia inermis of Indian origin to provide a way forward for therapeutic use in medicine. We assessed the phytochemical profile for the presence of phytoconstituents (alkaloids, carbohydrates, glycosides, steroids, flavonoids, saponins, tannins, proteins/amino acids and gums/mucilage) in various extracts of the plant leaves. The extracts were further purified by column chromatography for the isolation of plant constituents and monitored by TLC, analyzed by Fourier transform infrared FT-IR spectroscopy, H1NMR, and GC-MS analysis. Fractions were assessed for cytotoxicity and anti-inflammatory properties at various concentrations. We assessed the anti-inflammatory activity by nitric oxide production in various leaf extracts determined by Griess assay. All the spectral results suggest that the compounds from the extract contain an aromatic nucleus and OH group along with the methoxy group, allyl as well as vinyl group. Fractions of chloroform/methanolic (7:3) leaf extract of Lawsonia inermis confirmed the presence of the two constituents i.e. fraxetin and 1(3H)-isobenzofuranone. We observed a significant difference in cytotoxicity at higher concentrations in methanol and chloroform: methanol (8:2) leaf extracts (p>0.05), we could not find any significant differences amongst other leaf extracts at different concentrations. Some leaf extracts have potential cytotoxic activity on Vero cells. Reducing the chloroform concentration during extraction decreases the cytotoxic effect on cells. Nitric oxide levels decreased from 1000 μg/ml concentration to lower concentrations with varying degrees. Overall the highest nitric oxide production by CHCl3 (70%)/ MeOH (30%) was observed amongst various fractions at different concentrations. Phytochemical screening and the study of cytotoxicity and anti-inflammatory activities highlight the potential of leaves of the plant to provide a way further for their use in medicine. Fraxetin 1(3H) and isobenzofuranone structures were confirmed in fractions of CHCl3 (70%)/ MeOH (30%) extract as potent constituents. Some leaf extracts have potential cytotoxic activity on Vero cells. Reducing the chloroform concentration during extraction, it decreases the cytotoxic effect on cells. The cytotoxicity studies indicate the presence of cytotoxic compounds in some of these extracts, warranting research for the fabrication of suitable formulations comprising these constituents to reduce dose/toxicity for beneficial effects of the plant components.