ANTIBACTERIAL EFFICACY AND HPLC ANALYSIS OF THE STEM EXTRACT OF MARTYNIA ANNUA AGAINST MULTI DRUG RESISTANT BACTERIA OF CLINICAL ORIGIN
Abstract
The increasing prevalence of multidrug-resistant (MDR) pathogens poses a significant challenge to global public health. This study evaluates the antibacterial efficacy and phytochemical composition of the stem extract of Martynia annua against clinically isolated MDR bacteria, including Acinetobacter baumannii and Klebsiella pneumoniae. Initial antibiotic susceptibility testing revealed that A. baumannii was resistant to all tested antibiotics, while K. pneumoniae displayed susceptibility to ofloxacin and levofloxacin, with inhibition zones ranging from 26-29 mm. Antibacterial testing of M. annua stem extracts demonstrated variable efficacy. The methanolic extract exhibited the most substantial antibacterial activity, with inhibition zones for K. pneumoniae ranging from 15-20 mm at 4 and 8 µg/ml, while A. baumannii showed inhibition zones ranging from 10-20 mm. The ethyl acetate extract displayed inhibition zones of 14-22 mm for A. baumannii at all tested concentrations, though K. pneumoniae did not show clear zones. The n-hexane extract demonstrated activity against A. baumannii at higher concentrations (32 and 64 µg/ml), with zones of 16-17 mm, but was ineffective at lower concentrations. Minimum inhibitory concentration (MIC) tests revealed that both bacteria showed no growth at 32 and 64 µg/ml for the ethanolic and n-hexane extracts. Minimum bactericidal concentration (MBC) results indicated bactericidal effects at 64 µg/ml for A. baumannii in ethanol and n-hexane, while K. pneumoniae displayed growth under similar conditions. Qualitative phytochemical analysis of the extracts revealed the presence of tannins, flavonoids, alkaloids, phlobatannins, terpenoids, steroids, and coumarins. High-performance liquid chromatography (HPLC) analysis confirmed the presence of bioactive compounds such as catechin, quercetin, rutin, and luteolin. The antioxidant activity, assessed using DPPH assay, demonstrated notable free radical scavenging capacity, with ethanolic extract showing values ranging from 87.0813 to 90.4306% at varying concentrations (100-500 ng/ml), and ascorbic acid (reference standard) ranging from 86.4692 to 94.3155%. These findings highlight the potential of M. annua stem extract as a source of bioactive compounds with antibacterial and antioxidant properties.
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