Phytochemical Analysis and Evaluation of Antimicrobial, Antioxidant, Anti-inflammatory and Antiangiogenic activities of Methanol extract of Urochloa ramosa

Abstract

Urochloa ramosa is a plant of the wet, seasonally dry and semi-arid tropics. It is also known as Bracharia ramosa or Brown top millet. Qualitative analysis of phytochemicals in methanol extracts were performed by standard methods. Partially purified phenolics from the methanol extract of leaf sample was subjected for different biological activities. In vitro antimicrobial activity was executed on Bacillus subtilis, Staphylococcus epidermidis and Staphylococcus aureus (Gram positive) and Proteus, Salmonella and Escherichia coli (Gram negative) bacteria and Candida albicans (yeast type fungi). Minimum inhibitory concentration was calculated by Resazurin method. In-vitro antioxidant assay was conducted by DPPH radical, NO. radical, superoxide anion radical scavenging assays and OH radical scavenging activity by DNA protection assay using BHT as the reference compound. IC50 value of methanol extract for each of these assays was calculated. Albumin denaturation assay, antiproteinase activity and membrane stabilization were performed to test the anti-inflammatory potential at various concentrations of methanol extract of U.ramosa. In vivo anti-angiogenesis activity was carried out by shell less chick chorioallantoic membrane assay. In the antimicrobial activity we found that Staphylococcus aureus showed considerable susceptiblity with the MIC value of 145μg and Staphylococcus epidermidis is the most resistant with the MIC value of 378μg/ml. IC50 of 10.10µg/ml, IC50 of 17.32µg/ml and IC50 of 25.12µg/ml demonstrated antioxidant activities of methanol extract of U. ramosa by scavenging DPPH, NO. and superoxide anion radicals respectively. At 100µg/ml concentration, methanol extract significantly protected DNA against the effect of hydroxyl radicals. Protein denaturation was protected between concentrations 100-500µg/ml of methanol extract, maximum proteinase inhibitory activity was significantly found at 500µg/ml concentration and even haemolysis (heat and hypotonicity induced) was prevented considerably at 500µg/ml of methanol extract. Inhibition of proliferation of capillaries was observed in chorioallantoic membrane assay proving methanol extract’s antiangiogenic property. The leaves of Urochloa ramosa are basically enriched with natural phenolics with multitudinous biological potencies that can represent a promising class as bioactive molecules.