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

Abstract

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.