Antinociceptive and Antioxidant Activities of Methanol Extract and Fractions of the Root Bark of Callichilia stenopetala Stapf. (Family Apocynaceae) In Mice

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Date
2017
Authors
Orabueze, C.I.
Adesegun, S.A.
Coker, H.A
Journal Title
Journal ISSN
Volume Title
Publisher
Natural Product Research Group, University of Benin.
Abstract
The root of Callichilia stenopetala is used as chewing stick in the treatment of toothache and for oral hygiene in South-East Nigeria. The study assessed the antinociceptive and antioxidant activities of methanol root bark extract and fractions of C. stenopetala. Analgesic activity of methanol root bark extract of C. stenopetala and its fractions were evaluated using chemical (acetic acid and formalin) and thermal (hot plate and tail immersion) tests in mice. Morphine sulphate, acetyl salicylic acid and diclofenac sodium at 4, 100 and 10 mg kg-1, respectively were used as standards. Antioxidant potential was evaluated using DPPH (1, 1-diphenyl-2-picrylhyrazyl) free radical scavenging activity and total phenolic content (TPC) assays. Oral acute toxicity was also evaluated. The extract (250 and 500 mg kg-1), ethyl acetate and aqueous fractions (200 mg kg-1) reduced acetic acid-induced writhing with percentage reduction of 65.14, 84.06, 93.27 and 50.63 %, respectively. The ethyl acetate fraction and methanol extract at 500 mg kg-1 significantly increased reaction times in tail immersion and hot plate tests. The formalin test results for the ethyl acetate fraction suggested involvement of central mechanism of pain inhibition. In DPPH scavenging assay and TPC, the extract showed good antioxidant potential, with most of the activity prominent in the polar fractions. At 8000 mg kg-1 no death of animal occurred. These findings suggested that C. stenopetala has pain alleviating effect which may be due to its antioxidant activity and this further substantiated the claimed traditional use of the plant in the management of acute toothache.
Description
Keywords
Callichilia stenopetala , Analgesic , Pain reaction time , Acetic acid , Hot plate
Citation
Orabueze, C. I., Adesegun, S. A., & Coker, H. A. (2017). Tropical Journal of Natural Product Research.