Antibacterial efficacy of Pimenta dioica (Linn.) Merill and Anacardium occidentale L. against drug resistant urinary tract pathogens.

The aim of the present study was to determine antibacterial effect of leaf and bark extracts of Pimenta dioica (Linn.) Merill (Myrtaceae) and Anacardium occidentale L. (Anacardiaceae) against drug resistant clinical isolates of urinary tract infection viz., Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Enterococcus faecalis. Agar well diffusion method was employed to assess inhibitory activity of leaf and bark extracts. Among extracts, bark extract of P. dioica and leaf extract of A. occidentale exhibited high inhibitory activity. The bark extract of P. dioica showed high inhibition of clinical isolates than other extracts. Among bacteria, E. faecalis and K. pneumoniae were inhibited to high and least extent respectively. The inhibitory potential of extracts could be attributed to the presence of bioactive secondary metabolites. Isolation of inhibitory principles from crude extracts and their inhibitory activity against UTI pathogens are to be carried out.

Antimicrobial and Antioxidant activity of leaf and flower extract of Caesalpinia pulcherrima, Delonix regia and Peltaphorum ferrugineum.

The present study was undertaken to determine antimicrobial and antioxidant activities of leaf and flower extracts of Caesalpinia pulcherrima, Delonix regia and Peltaphorum ferrugineum. Antimicrobial activity was tested against Staphylococcus aureus, Salmonella typhi, Candida albicans and Cryptococcus neoformans by Agar well diffusion assay. Antioxidant activity was determined by DPPH free radical scavenging assay, ABTS free radical scavenging assay, Ferric reducing assay and Total antioxidant capacity determination. Total phenolic content of extracts was estimated by Folin-Ciocalteau Reagent method. S. typhi and C. neoformans were susceptible to extracts to greater extent than S. aureus and C. albicans among bacteria and fungi respectively. Except C. pulcherrima extract, the leaf extracts were more effective in inhibiting bacteria than flower extracts. Leaf extracts have shown high antifungal activity than flower extracts. The extracts have shown dose dependent scavenging of DPPH and ABTS radicals. Scavenging of ABTS radicals was more efficient than that of DPPH radicals as revealed by low IC50 values. All leaf extracts except C. pulcherrima displayed stronger scavenging activities than flower extracts. Similar results were observed in ferric reducing assay and total antioxidant capacity determination. Total phenolic content was found to be higher in leaf extracts (except C. pulcherrima) than flower extracts. A correlation has been observed between phenolic content of leaf and flower extracts and the antioxidant activity. A marked antimicrobial and antioxidant activity of leaf and flower extracts was observed which may be attributed to the presence of phenolic compounds and other phytochemicals. The plants can be used to control infectious diseases and oxidative damage.