ANTIMICROBIAL ACTIVITY OF PIPER NIGRUM AND SOLANUM NIGRUM AND THEIR SYNERGISTIC EFFECT AGAINST PSEUDOMONAS AERUGINOSA AND PROTEUS VULGARIS

Dr. Nasiruddin Ahmad Farooqui, Usha Kumari* and Dr. Praveen Kumar

ABSTRACT

The escalating prevalence of antimicrobial resistance (AMR) among pathogenic bacteria such as Pseudomonas aeruginosa and Proteus vulgaris has prompted a renewed focus on plant-derived antimicrobials as potential therapeutic alternatives. This review critically evaluates the antimicrobial activity of two widely used medicinal plants, Piper nigrum which is also known as black pepper and Solanum nigrum that goes by the common name of black nightshade, with a specific emphasis on their individual and synergistic effects against P. aeruginosa and P. vulgaris. Both plants are rich in bioactive phytochemicals such as piperine, alkaloids, flavonoids, and glycoalkaloids, which have demonstrated antimicrobial efficacy through diverse mechanisms including disruption of bacterial membranes, inhibition of protein and DNA synthesis, and induction of oxidative stress. The literature surveyed includes in vitro studies employing various extracts—aqueous, ethanolic, methanolic, and essential oils—evaluated for minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), and zones of inhibition. Furthermore, evidence supporting synergistic interactions between P. nigrum and S. nigrum is discussed, highlighting enhanced antibacterial activity when used in combination, as indicated by fractional inhibitory concentration (FIC) indices and checkerboard assays. Despite promising results, the translation of these findings into clinical practice is limited by a lack of in vivo and toxicological studies. This review underscores the potential of these plants as complementary agents in antimicrobial therapy, particularly against multidrug-resistant pathogens, and advocates for further pharmacological and clinical investigations to validate their efficacy and safety. The synergistic approach involving phytocompounds offers a promising avenue for novel antimicrobial drug development.

Keywords: Piper nigrum, Solanum nigrum, Antimicrobial activity, Pseudomonas aeruginosa, Proteus vulgaris, synergistic effect, phytochemicals.