Anti-diabetic, anti-inflammatory and anti-oxidant properties of four underutilized ethnomedicinal plants of West Bengal, India: an in vitro approach

Abstract

The present study was undertaken to evaluate the in vitro anti-oxidant, anti-diabetic and anti-inflammatory properties of four underutilized ethno-medicinal plants viz. Apluda mutica, Mikania micrantha, Kyllinga nemoralis and Cleome rutidosperma, growing in different parts of West Bengal, India. The anti-oxidant properties were evaluated using four different solvent extracts. The 70% aq. ethanol extract of investigated plant samples were found to have adequate quantities of total phenolic (141.94±0.67-230.45±0.12 mg GAE/g dry extract), total flavonoid (23.27±0.04-71.05 ±0.06 mg RE/ g dry extract) and anti-oxidant capacities documented by DPPH, ABTS, FRAP, reducing power, anti-lipid peroxidation and metal chelating activities. The 70% aq. ethanol extracts of the plants showed most promising antioxidant activity and were investigated for phenolics quantification by HPLC, anti-diabetic properties by assessing α-amylase, α-glucosidase inhibitory activities and anti-inflammatory capabilities by protein denaturation inhibition. HPLC studies revealed the presence of several phenolic acids and flavonoids in variable levels. M. micrantha exhibited α- amylase inhibition (IC50=58.44 ± 0.01 µg/mL), which was comparable to that of standard acarbose (IC50 = 53.80 ± 0.01 µg/mL). The maximum inhibition of protein denaturation was observed in M. micrantha (IC50=89.27 ± 0.01 µg/mL) followed by K. nemoralis (IC50 = 98.78 ± 0.01 µg/mL). The principal component analysis (PCA) revealed clear separation among the wild plants under investigation. The outcomes demonstrate that these plants were shown to contain a remarkable amount of different bioactive compounds, hence affirming their contribution in several biological activities and to serve as a potential anti-oxidant, anti-inflammatory and anti-diabetic agent in food and pharmaceutical industries.