A multidirectional phytochemical profiling, antimicrobial, antioxidant and toxicity studies of Neurada procumbens L. A desert medicinal plant

Objectives: Neurada procumbens L. (Neuradaceae) is a Cholistani desert plant traditionally employed in fever, inflammations, diabetes and hepatitis. The purpose of this study was to determine the chemical composition, anti-bacterial, antibiofilm and antioxidant activities of various extracts of this important medicinal plant; separately for its aerial and floral parts. Methods: The phytochemical screening (by HPLC analysis), antioxidant (by DPPH assay), antibacterial (by disc diffusion test and MIC) and anti-biofilm potential against seven bacterial strains (E. coli, K. pneumoniae, S. aureus, S. aureus MDR, P. aeruginosa, P. aeruginosa MDR and P. vulgaris) were determined by aqueous, methanol, n-butanol, ethyl acetate, n-hexane and dichloromethane extracts of floral and aerial parts of N. procumbens. Results: The floral MetOH and DCM extracts were found to contain higher polyphenolic contents including 2,3-di methoxy benzoic acid (38.21 µg/mg), chlorogenic acid (26.59 µg/mg) and catechin (14.24 µg/mg) and exhibited a comparatively higher antioxidant (IC₅₀ < 100 μg/ml) potential in DPPH assay. Moreover, these floral MetOH and DCM extracts were found to be most active (>13.5 mm zone of inhibition and MICs 62.5–125 µg/ml) against P. aeruginosa MDR and S. aureus in anti-bacterial activity. In an anti-biofilm assay, MetOH and DCM floral extracts showed a promising potential (>85 % biofilm inhibition) with IC₅₀ < 150 μg/ml against P. aeruginosa MDR and S. aureus MDR better than moxifloxacin and was further confirmed by light and scanning electron microscopy. Moreover, the floral-MetOH extract of N. procumbens has been found to be safe up to 2 g/kg BW with its lethal dose (LD₅₀) as 3872.98 mg/kg BW in rats. Conclusion: Hence, due to presence of essential medicinal compounds with low toxicity effects, the plant is recommended to be safely employed in various pharmaceutical preparations.