Evaluation of Anti-inflammatory Potential of L eu cas zeylanica'. an In vitro S

Abstract

Inflammation is the result of host response to tissue injuries or pathogenic challenges and it ultimately leads to the restoration of a normal tissue structure and function. Although it functions primarily as a protective response, inflammation that is chronic and uncontrolled becomes detrimental to tissues. Due to the adverse side effects of currently used non-steroidal anti-inflammatory drugs over the past years, there’s a tremendous acceleration in research on medicinal plants/plant derived formulations as anti-inflammatory agents. As a large number of plant species are widely employed in Sri Lankan indigenous medicinal systems to alleviate the pathological conditions caused by inflammation, it would be reasonable to assume that these plants would harbor extremely potent anti-inflammatory activities. However, the scientific evidence is insufficient to explain their therapeutic potential. Hence, the present study was undertaken to address this issue. Leucas zeylanica (L.) R. Br., (gata-thumba) is selected for this study due to its extensive use in traditional medicine for the treatment of inflammatory conditions. More over, the bioactivities and the phytochemistry of this plant is not established yet and remains to be explored. The well established in-vitro heat treated bovine serum albumin denaturation assay was employed to determine the anti inflammatory potential of hexane, dichloromethane and water extracts of Leucas zeylanica (whole plant) at different concentrations(1000, 500, 250, 125, 100, 50, 25 and 12.5 fig/mL) and the experiment was performed in triplicate. The hexane and dichloromethane extracts exhibited marked anti-denaturation activity (48.6± 0.62 to 69.2 ± 0.57 % and 56.8 ± 0.28 to 75.5 ± 0.32 % inhibition respectively). This effect was found to be more pronunced at lower concentrations of the plant extract and the dichloromethane extract appeared to be more potent than the reference drug diclofenac sodium. The standard qualitative methods were utilized for phytochemical analysis and it revealed the presence of saponins and phenolic compounds including flavonoids which could be responsible for the observed bioactivity. The study will be continued to characterize the bioactive metabolites by mass spectrometric approaches. Future experiments with purified compoundsin other experimental models would be useful to further support the anti-inflammatory potential of this plant and thereby to validate and rationalize its ethnopharmacological importance in Sri Lankan indigenous medicine.