Basic nutritional investigationIn vitro bactericidal activity of promising nutraceuticals for targeting multidrug resistant Pseudomonas aeruginosa

- Out of 380 predominant phyto-ligands of 38 plants (∼10 each), 44 showed significantly (P < 0.05) higher inhibition against physiological target exoenzyme S, an effector protein facilitates entry of multidrug resistant Pseudomonas aeruginosa in the host cells.
- Glycyrrhiza glabra (ACRC-14) and Zingiber officinale (ACRC-22) showed significant bactericidal activity attributed to its phyto-constituent's ability to inhibit exoenzyme S (Evalue - 547.17 Kcal/mol), highest among 380 tested compounds.
- The five tested aquoalchoholic herbal extracts were standardized with respect to flavonoid/polyphenol ratio valued between 0.52 and 2.69, as bioactivity functional descriptor to control batch-to-batch variation.
- ACRC-14 showed maximum activity attributed to its highest polyphenolic content (i.e. 97.16± 0.005%) as compared to other tested herbal extracts.

ObjectiveWe evaluated the bactericidal activity of nutraceuticals against multidrug resistant Pseudomonas aeruginosa. The nutritionally valued herbs were screened on the basis of a matrix modeling approach and molecular docking based validation analysis.MethodsThe database of 38 herbs developed earlier using fuzzy logic based scoring analysis was subjected to molecular docking based validation. The molecular docking (Hex 6.12) analyses of predominant phytoligands (∼10 per herb) against exoenzyme S of P. aeruginosa filtered potent herbs were selected. The preauthenticated bacterial inoculum (108 CFU/mL) was added to the sterile nutrient broth impregnated with standardized aqueous-alcoholic herbal extracts (1-1600 μg/mL). After overnight incubation at 37°C, antibacterial activity was evaluated in terms of minimum inhibitory and minimum bactericidal concentrations.ResultsFive herbs were selected on the basis of fuzzy set scoring, an herbal informatics model, and validation analysis based on energy of docking (i.e., Evalue of 380) phytoligands with maximum scoring obtained by Glycyrrhiza glabra. Among the 5 nutraceuticals, G. glabra showed maximum bactericidal activity significantly (P < 0.05) higher than Amikacin, a standard antibiotic, which was in consonance with in silico bioprospection. Zingiber officinale, despite a low Evalue, showed considerably higher inhibition attributed to its higher flavonoid content as compared to other herbs.ConclusionG. glabra (licorice), a flavoring agent; Z. officinale (ginger), a condiment; and Mentha piperita (mint), a fragrance component, showed significant therapeutic potential against multidrug resistant strains of P. aeruginosa.

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