Antimicrobial Activity of Leaf and Root Parts of Cenchrus biflorus Roxb

Medicines and herbal formulations are derived from different parts of medicinal plants, which are the best-known sources for treating various diseases. This research focuses on assessing the antimicrobial potential of crude extracts from the leaves and roots of Cenchrus biflorus Roxb.

Methanol, hydroethanol (50:50), and aqueous extracts were obtained using the Soxhlet extraction method. The disc diffusion method was used to study the antimicrobial activity of the extracts against a variety of test microorganisms, including bacteria (Escherichia coli and Bacillus subtilis) and fungus (Aspergillus niger). The disc diffusion method was used to assess bacterial susceptibility, revealing the potent inhibitory effect of the methanol extract on E. coli. All extracts demonstrated significant antimicrobial activity against various microorganisms.

Remarkably, methanol extract of leaf demonstrated the highest antibacterial activity, with a 16.3 ± 1.78 mm zone of inhibition (ZOI) with Activity Index (AI) of 0.875, and a Relative Percentage Inhibition (RPI) of 80 against E. coli, followed by Bacillus subtilis (ZOI = 15.5 ± 1.31 mm, AI = 0.869, RPI = 78.57). The methanol extract of the root showed strong antifungal activity against Aspergillus niger (with a 12.9 ±1 mm ZOI, AI = 0.636, and RPI = 42.85), while the water extract of the root displayed 7.8 mm inhibition zones.

Methanol and hydroethanol extracts of the leaf and root exhibited strong inhibitory effects against selected microbial strains. Each plant solvent extract suppressed microbial development in a distinct manner, and methanol and hydroethanol extracts inhibited microbial development more efficiently than aqueous extracts. Interestingly, water extracts had the least effective inhibitory effects across all strains. Notably, water extracts showed the weakest inhibitory effects against all strains.

The current study demonstrated the efficacy of crude extracts of Cenchrus biflorus Roxb. against the tested strains of bacteria and fungi and also discussed their potential application as antibacterial agents for combating infectious diseases.