ISSN 2169-303X
International Journal of Medicinal Plants Research ISSN 2169-303X Vol. 8 (12), pp. 001-009, December, 2019. © International Scholars Journals
Full Length Research Paper
Anti-arthritic and antioxidant properties of the ethanolic stem bark extract of Newbouldia laevis (P. Beauv.) Seaman ex Bureau (Bignoniaceae)
Eric Woode1, George K. Ainooson1, Eric Boakye-Gyasi1, Charles Ansah1, David D. Obiri1, George A Koffour1, Abraham Mensah2 and Mahama Duwiejua3
1Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi.
2Department of Pharmacognosy, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi
3Department of Clinical and Social Pharmacy, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi.
Accepted 21 August, 2019
Abstract
Newbouldia laevis (fam. Bignoniaceae) is used in traditional medicine for the treatment of various conditions. The stem bark is used for pain, ulcer, arthritis, rheumatism and other inflammatory conditions. The purpose of this study is to pharmacologically validate the use of N. laevis stem bark extracts in African traditional medicine for the management of inflammatory conditions such as arthritis. Ethanolic stem-bark extract of N. laevis (10 - 100 mg kg-1) exhibited anti-arthritic activity by inhibiting the polyarthritic phase edema by 25.30 ± 2.53 - 28.11 ± 2.02 % with no significant inhibition of the acute phase response of the rat adjuvant-induced arthritis. Phenols were detected in the total ethanolic extract. Though both the extract and a-tocopherol produced a concentration-dependent increase in reducing power properties, the extract (EC50 2.8 ± 1.59) was six-fold more potent than a-tocopherol (EC50 18.18 ± 4.29). In contrast the ability of the extract to de-colorize DPPH free radical solution (EC50 39.86 ± 3.33 X 10-2) and inhibit lipid peroxidation in rat brain homogenate (IC50 1499.00 ± 408. 22 X 10-3) was less than a-tocopherol and n-propyl gallate. Overall, our results indicate that N. leavis has anti-arthritic and antioxidant properties.
Key words: Newbouldia laevis, anti-inflammatory, lipid peroxidation, total phenol, DPPH scavenging, reducing power.