Anti-inflammatory activity of the fruit extracts of Carpolobia lutea G. DON (Polygalaceae)
Oghenekevwe M. Rhuada , Ogacheko D. Okoko , Gloria A. Ayoola , Ismaila O. Ishola
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Lagos, PMB 12003, Lagos State,
Nigeria. Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of
Medicine, University of Lagos, PMB 12003, Lagos State, Nigeria.
Corresponding author: Gloria A. Ayoola
Email: gayoola@unilag.edu.ng; Phone: +2348063075179
ABSTRACT
Background: Carpolobia luteaG. Don (Polygalaceae) fruits are used traditionally in treating fever, infections and inflammatory conditions.
Objectives: The study sought to evaluate the phytochemical constituents and anti-inflammatory potentials of the fruit extracts of C. lutea.
Methods: Successive extraction was done with methanol (CLFME), n-hexane (CLFn-HE), chloroform (CLFCHE), and ethylacetate (CLFETE). Anti-inflammatory activity was evaluated in vivo using carrageenan-induced paw oedema and xylene-induced ear oedema models. The phytochemical constituents were identified using gaschromatography (GC) and liquid chromatography – mass spectrometry (LC-MS).
Results: CLFME (200 mg/kg) significantly (P< 0.05) inhibited carrageenan-induced paw oedema (83.66%) and xylene induced ear oedema (89.85%). CLFn-HE, CLFCHE, and CLFETE (200 mg/kg) significantly reduced carrageenan-induced paw oedema with percentage inhibitions of 60.00, 70.00 and 65.00%, respectively.
Moreover, CLFn-HE, CLFCHE, and CLFETE (200 mg/kg), reduced xylene-induced ear oedema by 69.14, 71.60, and 69.14%, respectively. Gas chromatography coupled to mass spectroscopic (GC–MS) analysis of CLFn-HE afforded oleic acid, squalene, cis-vaccenic acid, n-hexadecanoic acid, 9-octadecenoic acid (Z) methyl ester, cis13-octadecenoic acid and nonacosane. CLFCHE was subjected to column chromatography, fraction-31 showed
a single spot using Thin layer chromatography (TLC) (n-hexane:ethylacetate, 5:5) with an R value of 0.70. Liquid chromatography coupled to mass spectroscopic (LC-MS) analysis of fraction-31 afforded four peaks with retention times of 0.058, 1.161, 1.572 and 3.080 min, with similar abundant ions (Base peak) of 81.1 and + molecular ion (M ) of 208.2 indicating the presence of isomeric compounds.
Conclusion: The fruit extract of C. lutea possess anti-inflammatory effects which may be mediated through inhibition or release of inflammatory mediators. Thus, C. lutea fruit extract could be a potential phytotherapeutic agent in the management of inflammatory disorders.
Keywords: carrageenan; xylene; paw oedema; flavonoids; mass spectroscopy; chromatography