In vitro haemolytic, antioxidant and antibacterial (ESBLs and MRSA) activity of Datura metel L. flower and leaf extracts

Prevalence of antibiotic resistant bacteria is an issue of concern as it affects the efficiency of antibiotics significantly. It makes the drug manufacturers continuously search for newer molecules that are safe and effective. To meet this challenge, researchers look towards natural resources, particularly plants, for possible new molecules that can be potentially tapped for medicinal purposes. In this context, here, we investigated Datura metel, commonly called the Angel's trumphet as it is known for medicinal properties. We studied the hot water and methanol extracts of its flowers and leaves for antibacterial, antioxidant and antihemolytic activities. We used disc diffusion, phosphomolybdate and spectrophotometric methods. The bacteria tested were Methicillin resistant Staphylococcus aureus (MRSA) and beta lactamase (ESBL) producing E. coli. The zone of inhibition (ZoI), as a measure of bacterial growth inhibition, was checked and found to range from 1.2-17.5 mm at the tested concentrations; ESBL producing E. coli was more subtle than MRSA. Total antioxidant capacity measured at 695 nm showed an average score of 17.4 ng/mL, displaying better activity of methanol extract. Antihemolytic property was tested on 0.5% RBC and percentage hemolysis was measured at optical density of 540 nm. Both the extracts showed considerably similar activity, though hot water lowered the hemolytic activity. Over all, the results suggest that D. metel could be exploited for its potential to inhibit drug resistant bacteria; free radical scavenging activity; and anti-hemolytic properties.