Anti-inflammatory Activity of Lannea velutina and Sorindeia juglandifolia Leaves Extracts

The dried leaves of Lannea velutina A.Rich. and Sorindeia juglandifolia (A.Rich.) Planch. ex Oliv. are commonly used in traditional medicine across West Africa to treat inflammatory conditions. The present study aimed to evaluate the anti-inflammatory activity of these plants' standardized hydroethanolic (70%) extracts and investigate the potential mechanisms of action based on their antioxidant activity. The induced paw edema model in rats was used to evaluate anti-inflammatory activity, while the DPPH, molybdic acid and ferric-reducing antioxidant power methods were used to assess antioxidant activity. Quantification of the major secondary metabolites classes was done by colorimetry, and the corresponding chemical fingerprint was established by LC-UV/DAD-ESI/MS for extract standardization. The results showed that the Lannea velutina extract had the highest inhibition of paw volume increase at doses of 100 and 200 mg/kg (46.67% and 48.35%), while the Sorindeia juglandifolia extract showed the highest inhibition at doses of 200 and 400 mg/kg (39.15% and 40.93%). Both extracts also showed antioxidant activity. Phenolic derivatives were considered as the main classes of secondary metabolites present in the extracts, with L. velutina having 350.1±20.6 mg GAE/g DE and S. juglandifolia having 463.4±29.4 mg GAE/g DE. Ten phenolic marker compounds were identified in L. velutina and six in S. juglandifolia extracts. The major constituents of L. velutina were identified as myricetin-3-O-glucuronide, quercetin-3-O-glucuronide, catechin, and gallic acid, while those of S. juglandifolia were gallic acid, isoquercitrin, and ethylgallate. The study confirms the anti-inflammatory activity of L. velutina and S. juglandifolia leaves, making them potential targets for producing anti-inflammatory herbal medicines standardized concerning their chemical composition and biological activity.