Anti-inflammatory Effects and Acute Toxicity of Methanol Stem Bark Extract of Morus mesozygia Stapf.

Aim: Morus mesozygia is a specie of the Morus family in Africa that is traditionally used for the treatment of rheumatism. Until this moment, there is no available literature on the scientific evidence of the in vivo anti-inflammatory effects. The aim is to determine the safety of this extract after acute exposure and evaluate the anti-inflammatory effects in vitro and in vivo.

Methodology: The phytochemical screening of the powdered stem bark was determined following standard procedures. Extraction in methanol yielded a brownish extract, which was subjected to total phenolic and flavonoid contents estimation. Antioxidant activity was determined by DPPH free radical scavenging assay. Acute oral toxicity effects was evaluated in female mice and signs of toxicity was observed for 14 days. Anti-inflammatory activity was evaluated using the carrageenan-induced paw oedema and in vitro membrane stabilizing activity assay in rat erythrocytes.

Results: Preliminary phytochemical analysis revealed the presence of flavonoids, saponins, tannins, alkaloids, anthraquonones, and cardiac glycosides. Ratio of total phenolic to total flavonoid content was determined to be 0.53. MEMm showed strong antioxidant activity comparable to ascorbic acid in DPPH free radical scavenging activity assay. No signs of acute toxicity was observed indicating the LD50 is greater than 5000 mg/kg. MEMm (200 and 400 mg/kg) significantly (p < 0.05) reduced oedema formation in rat paw, and showed concentration dependent membrane stabilizing activities in rat erythrocytes.

Conclusion: The present study shows that stem bark methanol extract of Morus mesozygia is safe and contains bioactive constituents with antioxidant, anti-inflammatory and membrane stabilizing properties.