Abstracto

Antioxidant and antimicrobial effects of polyoxometalates.

Farzana Rashid, Iqra Pervaiz, Hunaiza Tahir

Drug resistance among pathogenic bacteria leads to the worldwide prevalence of nosocomial and community infections. Polyoxometalates (POMs) are one of the novel therapeutic agents that are tested against microbes. The aim of present study is to investigate the antimicrobial and antioxidant activity of synthetic Polyoxometalates i.e. (irono-substituted phosphotungstate, Cesium phosphotungstate, Silicovanadate) and their synergistic effect with β-lactam antibiotics against some Methicillin resistant Staphylococcus aureus (MRSA). The collected strains were cultured on different enriched and selective media and identified by their physical and morphological characteristics. The antimicrobial activity of POMs was determined by using their different concentrations including 5 mg/ml, 10 mg/ml, 15 mg/ml and 20 mg/ml, with β-lactam antibiotics (Ciprofloxacin and Imipenem). The Minimum inhibitory concentration (MIC) was calculated through standard agar dilution method. The antioxidant activity of POMs was measured by αα-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging activity. The results revealed that antibacterial activity of irono-substitued phosphotungstate (19mm) was more than that of other POMs used. Highest zones were obtained at 20mg/ml concentration of POMs used and MIC was calculated to be 5 mg/ml. Silicovanadate was observed to be more antioxidant as compared to other POMs. POMs possess strong antibacterial and antioxidant activity and can be used in conjugation with other β-lactam antibiotics as they possess synergistic effect with them.