In vitro Screening of Some Indian Medicinal Plants for Their Activity against Extended Spectrum Beta Lactamases.

Context: Extended Spectrum Beta Lactamases (ESBLs) play an important role in pathogenesis of various infections by enabling the bacterial species to be resistant to β-lactam antibiotics including extended-spectrum cephalosporins. Plants were selected on the basis of their traditional applications. Objective: Our investigation screens and evaluates15 Indian medicinal plants for antimicrobial efficacy and synergistic potential against ESBLs producing bacteria. Materials and Methods: 6 bacterial strains were screened for their ability to release ESBLs. Plant extracts in methanol and aqueous solvents were screened for their effect on ESBLs producing bacteria. Antimicrobial-linked ESBLs inhibition activity and minimum inhibitory concentration (MIC) of extracts were evaluated by agar well diffusion and microdilution method. Synergistic interactions between plant extracts exhibiting good antimicrobial activity and extended spectrum cephalosporins were explored by Checkerboard method. Results: Three strains were detected as ESBL positive. The results of susceptibility assay clearly showed strong ESBLs inhibitory effect of Crinum latifolium, Oroxylem indicum, Punica granatum, Sapindus emarginatus and Terminalia chebula and their MIC values ranged from 1.87-30 mg/ml. In vitro interactions between plant extracts and antibiotics cefotaxime and ceftaizidime evaluated in terms of fractional inhibitory concentration (FIC) indices indicated synergism. Discussion and Conclusion: Higher resistance of ESBLs positive strains to β-lactam antibiotics encourages us to search the novel ESBLs inhibitors. Maximum 10-fold decline in the MIC of antibiotics cefotaxime and ceftaizidime was achieved in combination with plant extracts. Owing to enormous clinical significance of ESBL-producing organisms coupled with limited therapeutic options, the results revealed by present study are of paramount importance.

In vitro and in silico Approach to Evaluate the Urease and Collagenase Inhibitory Activity of Embilica officinalis Gaertn Fruit.

Aim: The key virulent factors of bacteria are enzymes. Urease and collagenase enzyme play a vital role in pathogenesis of wide array of bacterial strains and cause numerous diseases. So the aim of present study was to find out the potent drug candidate from Emblica officinalis Gaertn. fruit for these pathogenically important enzymes. Study Design: A study was done to screen out the bacteria producing urease and collagenase from a stack of 19 bacterial strains and the positive strains were checked for their susceptibility to methanol and ethyl acetate extracts of Emblica officinalis Gaertn. fruit. Further extracts were investigated for their potential to antagonize these enzymes. Place and duration of study: Department of Biotechnology KUK, Jwahar Lal University, Delhi between February 2012 and December 2013. Methodology: Screening of bacteria and their susceptibility to methanol and ethyl acetate extracts of E. officinalis was done by using agar diffusion assay. Further investigation of extracts to antagonize urease and collagenase enzymes was checked by using phenol hypochlorite and gelatin diffusion assay respectively. GC-MS analysis, docking and ADME studies were conducted to screen for plant-based urease and collagenase inhibitors. Results: Methanol extract inhibited Jack bean urease enzyme (IC50:0.74 mg/ml) more potently than collagenase Type 1 (IC50:1.13 mg/ml), while ethyl acetate extract inhibited collagenase completely (IC50:4.19 mg/ml) and was observed to be more effective than methanol extract (IC50:5.51 mg/ml). GC-MS analysis revealed an array of 28 and 30 compounds in methanol and ethyl acetate extract respectively. In silico study identified xylenol and erucylamide as active compounds of E. officinalis having good binding score with better ADME properties compared to standard compounds. Conclusion: So our observations find application for the consideration of E. officinalis compounds for further validation towards development of effective drugs against these significant bacterial enzymes.

Antibacterial, Synergistic and β-lactamase Inhibitory Activity of Oroxylem indicum: An In vitro and Molecular Interaction Study.

Aims: The study was aimed to evaluate the antibacterial, synergistic and β-lactamase inhibitory potential of O. indicum against ampicillin resistant and Extended Spectrum β- lactamase (ESBL) producing bacterial strains. Methods: Bacterial strains were screened for ampicillin resistance and ESBL production by disk diffusion method and modified double disc synergy test respectively. Antibacterial and synergistic activities of O. indicum methanol extract and ethyl acetate sub fraction of methanol extract were explored by agar well diffusion method and Checkerboard method respectively. Extracts were subjected to Gas chromatography and Mass spectroscopy (GC-MS) analysis to identify the bioactive compounds. Molecular docking studies were carried out to verify the β-lactamase inhibitory potential of the bioactive compounds. Results: All bacterial strains were found to be resistant to ampicillin and only one strain was detected as ESBL positive. Ethyl acetate sub fraction exhibited strong antibacterial and synergistic activity than the methanol extract. Zone of inhibition and Minimum inhibitory concentration for ethyl acetate sub fraction was 16 mm and 15mg/ml respectively. In vitro interactions between plant extracts and ampicillin evaluated in terms of fractional inhibitory concentration (FIC) indices revealed synergistic effects of plant extracts. The molecular docking studies of major bioactive compounds depicted by GCMS analysis revealed that Wogonin, a flavonoid (GLIDE Score-5.77) possessed the best inhibitory profile against β–lactamase. Conclusion: Synergistic activity of O. indicum may be attributed to the β–lactamase inhibitory potential of the bioactive compounds present in the extract. The findings provide substantial basis for the future use of O. indicum crude extracts as potential antibacterial and antibiotic modulating agent.