Evaluation of the analgesic, anti-inflammatory, anti-oxidant, phytochemical and toxicological properties of the methanolic leaf extract of commercially processed Moringa oleifera in some laboratory animals.

BACKGROUND Moringa oleifera Lam (Moringaceae) is a highly valued plant, distributed in many countries of the tropics and subtropics. It has an impressive range of medicinal uses with high nutritional value. METHODS The commercially processed M. oleifera was extracted using methanol as its solvent. Phytochemical analysis as well as the anti-oxidant properties of this supplement were also investigated. Acute toxicity was carried out in fasted mice. Carrageenan and histamine tests were used to assess anti-inflammatory effects in rats, while analgesic activities were assessed using the acetic acid-induced writhing test and formalin-induced paw lick test in mice. In the anti-oxidant tests, 1,1-diphenyl-2-picrylhydrazyl, ferrous reducing activity power, 2,21-azinobis-(3-ethylbenthialozine)-6-sulphonic acid and total polyphenolic (TPP) assays were deployed at concentrations of 10 mg/mL and 20 mg/mL. RESULTS The phytochemical analysis showed that the extract contained flavonoids, terpenoids, glycosides, tannins and saponins. In the acetic acid-induced writhing test, the extract significantly reduced the number of writhes at 100 and 200 mg/kg but not so much at 50 mg/kg. In the formalin-induced paw lick test, the effect was similar to that of the acetic writhing test. The analgesic effects were comparable to that of indomethacin used at 10 mg/kg. In the anti-inflammatory test, the extract reduced the formation of oedema especially at a dose of 200 mg/kg. In the anti-oxidant test, the extract was found to possess a free radical-scavenging property and is concentration related. CONCLUSIONS The use of this extract for medicinal and nutritional purposes may have thus been justified; however, caution must be exercised in its use to prevent the toxic effect.