Antiradical, Antioxidant Activities and Anti-Inflammatory Potential of the Essential Oils of the Varieties of Citrus Limon and Citrus Aurantifolia Growing in Cameroon

Essential oils of the leaves of Eureka, Lisbon and Meyer varieties of Citrus limon, as well as the Mexican, “Sans épines” and Bearss varieties of Citrus aurantifolia of Cameroon were extracted by hydrodistillation, with respective yields 0.64%, 0.90% and 0.46% 0.57%, 0.25% and 0.29%.Chemical composition analysis was carried out by gas chromatography and gas chromatography coupled with mass spectrometry. As a whole, the six samples are very rich in monoterpenes, and limonene; thus proved to be the main compounds.Antiradical and antioxidant properties of our samples were evaluated by the Diphenyl Picryl Hydrazyl (DPPH) method and the β-carotene decolouration method respectively. Citrus aurantifolia var. “Sans épines” proved to be the better antiradical oil with an SC50 value of 3.4g/l against 7.02 mg/l for the BHT used as reference. As antioxidant, the same extract was more effective with an IC50 of 0.26 mg/l against 0.10 mg/l for the BHT.In addition, anti-inflammatory activity of the extracts of Citrus limon var. Meyer and Citrus aurantifolia var. “Sans épines” were measured by an enzymatic method based on the inhibiting action of the substance to be tested on the oxidation of linoleic acid by 5-lipoxygenase of soya beans. This measurement gave IC50 value of 46.5 ppm and 49.35 ppm respectively for Meyer and “San épines” against 0.7 ppm for NDGA.