Evaluation of In vitro Anti-Inflammatory and Antibacterial Properties of Tuberous Roots of Mirabilis jalapa L. Found in Sri Lanka

Aims: This study aims to evaluate the in vitro anti-inflammatory and antibacterial potential of aqueous and various organic solvent (methanol, dichloromethane, and hexane) extracts of Mirabilis jalapa L. tuberous roots.

Methods: Heat-induced egg albumin denaturation inhibition assay and hypotonicity-induced human red blood cell (HRBC) membrane stabilization methods were used to evaluate the anti-inflammatory activity in vitro. Both disc diffusion and well diffusion methods were utilized to evaluate the antibacterial potential in vitro, using three common wound pathogens. Namely, Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), and Staphylococcus aureus (ATCC 25923).

Results: In the heat-induced egg albumin denaturation inhibition assay, the methanolic extract of M. jalapa exhibited the highest potency (IC50 = 137.9 µg/ml) of anti-inflammatory activity while in the HRBC membrane stabilization method, the aqueous extract of M. jalapa exhibited the highest potency (IC50 = 197.4 µg/ml) of anti-inflammatory activity. There was no significant antibacterial activity shown by all four extracts. However, some inhibitory zones were observed in the well diffusion method against S. aureus. The highest inhibitory zone of 15.33 ± 0.33 mm was expressed by the dichloromethane extract, with a concentration of 400 mg/mL against S. aureus, followed by the hexane extract with an inhibitory zone of 14.00 ± 2.08 mm at the same concentration. The dichloromethane extract showed an inhibitory zone of 11.00 ± 0.58 mm at a 200 mg/mL concentration.

Conclusion: This study demonstrates that the tuberous roots of M. jalapa have significant anti-inflammatory properties but no significant antibacterial properties against the selected pathogens.