ANTI INFLAMMATORY

Cymbopogon citratus (lemon grass) is a medicinal grass widely valued in ethnomedicine for its antimicrobial, antioxidant, and anti-inflammatory activities, with its bioactivity linked to essential oils, phenolics, and flavonoids. Although extensively used, there is limited comparative evidence on how solvent polarity influences the anti-inflammatory potential of its extracts. This study therefore evaluated the in vitro anti-inflammatory activities of ethanol (polar) and diethyl ether (non-polar) extracts of C. citratus in order to assess differences in solvent efficiency and bioactivity. Fresh leaves collected from the University of Benin were authenticated and extracted using standardized procedures, information was sourced from laboratory analyses combined with current literatures from PubMed, ResearchGate, ScienceDirect and Google Scholar. Extracts were tested in vitro for inhibition of protein denaturation, heat-induced haemolysis, antiproteinase activity, and lipoxygenase inhibition, with aspirin serving as the standard drug. Extraction yield was slightly higher for diethyl ether (1.72%) than for ethanol (1.56%). Both extracts exhibited concentration-dependent anti-inflammatory activity across all assays. In the protein-denaturation assay, ethanol extract inhibited 65.9% at 500 µg/ml while diethyl ether showed 69.4%, compared with 82.3% for aspirin. In the haemolysis test, ethanol recorded 61.7% and diethyl ether 58.4% inhibition, while aspirin reached 75.6%. Antiproteinase activity was 59.2% for ethanol and 56.8% for diethyl ether, against 70.4% for aspirin. Lipoxygenase inhibition was stronger in the diethyl ether extract (64.5%) than ethanol (60.1%), though both were lower than aspirin (78.2%). The findings confirm that C. citratus possesses measurable in vitro anti-inflammatory activity, supporting its traditional use in managing inflammation-related disorders. Solvent polarity was shown to influence the degree and spectrum of bioactivity, highlighting the importance of solvent selection in herbal preparation. However, the study was limited to in vitro models, two extraction solvents, and a single collection site. Future research should explore in vivo and clinical trials, and adopt advanced extraction techniques.