*4.2. Antibacterial Activity*

The unsystematic use of antibiotics promotes the development of multiple drug-resistant pathogenic strains of bacteria, which are very harmful, and there is a lack of proper treatment procedures for these ailments. Therefore, the need to search for new antimicrobials remains. Currently, in addition to antibiotics and chemically-synthesized drugs, curiosity for alternative medicines, such as natural or herbal medicines, is increasing. They may have fewer side effects or toxicity owing to their natural sources [102].

Combating microbial infections without side effects is always a tedious process. In this regard, in addition to classical antibiotics and synthetic drugs, there is an ongoing hunt for potent molecules from natural herbal medicines [102]. *M. koenigii* extracts have demonstrated antibacterial effects on a wide variety of microorganisms. Methanol and ethanol extracts of *M. koenigii* leaves were found to be effective against the bacterial strains *Escherichia coli* (*E. coli)*, *Staphylococcus*, *Streptococcus,* and *Proteus*. Hence, *M. koenigii* leaves could be efficiently used as a natural remedy in everyday meals for the prevention of several bacterial infections [103]. Pyranocarbazoles isolated from *M. koenigii* exhibited antibacterial activity on bacterial strains of *Staphylococcus aureus* and *Klebsiella pneumonia* [40]. Green synthesized silver nanoparticles (AGNPs) from *M. koenigii* exhibited therapeutic efficacy against multidrug resistant MDR bacteria [103]. *M. koenigii* essential oil showed antibiofilm activity against *Pseudomonas aeruginosa* and it was reported that *M. koenigii* essential oil treatment revealed an 80% reduction in biofilm formation by *P. aeruginosa*. Microscopic analyses confirmed the drop in biofilm formation in *Pseudomonas aeruginosa* when treated with *M. koenigii* essential oil. The presence of antibiofilm substances like spathulenol (5.85%), cinnamaldehyde (0.37%), and linalool (0.04%) was reported in gas chromatography-mass spectrometry (GCMS) studies [104]. *M. koenigii* counteraction on uropathogenic bacteria isolated from clinical samples was reported in a different study [105]. *M. koenigii* was tested for its antibiotic action against *Mycobacterium* species, which was appreciable, like first-line anti-tuberculosis drugs. *M. koenigii* half maximal inhibitory concentration ((IC50) 400 μg/mL) was found to be more effective against *Mycobacterium smegmatis* compared to water extracts and petroleum ether. An *M. koenigii* ethanol extract exhibited significant synergistic antibacterial activity against *Mycobacterium smegmatis* and *Mycobacterium bovis* bacillus calmette-guerin (BCG) in combination with the anti-tuberculosis drug rifampicin [106].






**Table 3.** *Cont.*


**Table3.***Cont.*
