In vitro assessment on medicinal properties and chemical composition of Michelia nilagirica bark

Objective:To outline the antibacterial,antioxidant,α-glucosidase inhibition and anticancer properties of Michelia nilagirica (M.nilagirica) bark extract.Methods:The antibacterial activity of bark extracts against human pathogens was assessed by disc diffusion assay.Phytochemical screening,total phenols,flavonoids content,antioxidant and α-glucosidase inhibition properties of bark extracts were investigated by standard methods.In vitro anticancer activity of ethyl acetate extract at various concentrations was observed against HepG2 cells using MTT [3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyl tetrazolium bromide] assay.The presence of diverse bioactive constituents in the ethyl acetate extract was identified using FT-IR and GC-MS analysis.Results:Ethyl acetate extract was found to be the promising agent against human pathogens tested.The ethyl acetate extracts showed the presence of various phytochemicals and comprised the substantial content of phenolics and flavonoids.The ethyl acetate extract showed better antioxidant activities and also revealed remarkable reducing power ability and α-glucosidase inhibition property.The dose dependent assay of extract showed remarkable cancer cell death with IC50 value of (303.26 ± 2.30) μg/mL.FTIRand GC-MS results indicated the presence of major bioactive constituents in the ethyl acetate extract of M.nilagirica bark.Conclusions:Revealing the first report on in vitro biological properties and chemical composition analysis ofM.nilagirica bark extract,our study implied that this plant could be of great importance in food and pharmaceutical industries.

Statistical optimization of thermo-alkali stable xylanase production from Bacillus tequilensis strain ARMATI

Background: Xylanase from bacteria finds use in prebleaching process and bioconversion of lignocelluloses into feedstocks. The xylanolytic enzyme brings about the hydrolysis of complex biomolecules into simple monomer units. This study aims to optimize the cellulase-free xylanase production and cell biomass of Bacillus tequilensis strain ARMATI using response surface methodology (RSM). Results: Statistical screening of medium constituents and the physical factors affecting xylanase and biomass yield of the isolate were optimized by RSM using central composite design at N = 30, namely 30 experimental runs with 4 independent variables. The central composite design showed 3.7 fold and 1.5 fold increased xylanase production and biomass yield of the isolate respectively compared to 'one factor at a time approach',inthe presence of the basal medium containing birchwood xylan (1.5% w/v) and yeast extract (1% w/v), incubated at 40°C for 24 h. Analysis of variance (ANOVA) revealed high coefficient of determination (R2)of0.9978 and 0.9906 for the respective responses at significant level (p < 0.05). The crude xylanase obtained from the isolate showed stability at high temperature (60°C) and alkaline condition (pH 9) up to 4 h of incubation. Conclusions: The cellulase-free xylanase showed an alkali-tolerant and thermo-stable property with potentially applicable nature at industrial scale. This statistical approach established a major contribution in enzyme production from the isolate by optimizing independent factors and represents a first reference on the enhanced production of thermo-alkali stable cellulase-free xylanase from B. tequilensis.