Antinociceptive effects of the aqueous and methanol extracts of the leaves of Pittosporum mannii Hook. F. (Pittosporaceae) in mice. (1st July 2016)

• Record Type: Journal Article
• Authors: Wandji, Bibiane Aimée; Tatsinkou Bomba, Francis Desire; Awouafack, Maurice Ducret; Nkeng-Efouet, Pepin Alango; Kamanyi, Albert; Nguelefack, Télesphore Benoît
• Is Part Of: Journal of ethnopharmacology. Volume 187(2016)
• Page Start: 224
• Page End: 231
• Publication Date: 2016-07-01
• Subjects: Pittosporum mannii -- Aqueous and methanol extracts -- LCMS -- Antinociception -- Cytotoxicity; Ethnopharmacology -- Periodicals; Pharmacognosy -- Periodicals; Herbs -- Periodicals; Herbs -- Periodicals; Pharmacognosy -- Periodicals; Pharmacognosie -- Périodiques; Herbes -- Périodiques; 615.1
• DOI: 10.1016/j.jep.2016.04.041
• Languages: English
• ISSNs: 0378-8741

Abstract

Abstract: Ethnopharmacological relevance: Pittosporum mannii (Pittosporaceae) is used in Africa traditional medicine to treat various ailments including pain and inflammation. Aim of the study: The present work was undertaken to evaluate the antinociceptive effects of the aqueous (AEPM) and methanol (MEPM) extracts from the leaves of Pittosporum mannii . Methods: High performance liquid chromatography coupled with mass spectrometry (LCMS) was used for the phytochemical analysis of AEPM prepared as decoction and MEPM prepared as cold maceration. The in vitro cytotoxicity of AEPM and MEPM were evaluated on Artemia salina larvae. AEPM and MEPM antinociceptive effects were evaluated at the doses of 35, 75, 150 and 300 mg/kg given orally, against pain induced by acetic acid, formalin, hot plate, capsaicin and glutamate. The rota rod test was also performed at the same doses. To determine the mechanism of action of these extracts, their antinociceptive effects were tested in animals pretreated with yohimbine (α2 -adrenergic antagonist), atropine (muscarinic antagonist) or naloxone (an opioids antagonist). Result: The LCMS analysis showed that both extracts contain pittovidoside and 1- O -rhamnopyranosyl-23-acetoxyimberbic acid 29-methyl ester, the aqueous extract being more concentrated. Oral administration of both extracts significantly reduced pain symptoms induced by acetic acid, formalin, capsaicin, glutamate and hot plate. The antinociceptive effect of AEPM was significantly inhibited by yohimbine, atropine and naloxone while these inhibitors tend to potentiate the activity of MEPM. Both extracts have no effect on Rota rod test. AEPM and MEPM showed respective LC50 of 2.44 and 0.70 mg/ml on Artemia larvae and were therefore, considered non-toxic. Conclusion: These results indicate that AEPM and MEPM possesses analgesic effects with different mechanism of action. Although effects of both extracts may involve TRPV1 receptors and glutamatergic pathway, AEPM may in addition, interact with alpha-adrenergic, muscarinic and opioidergic pathways that are not involve in the effects of MEPM. Graphical abstract: