Effects of Aqueous and Methanolic Extracts of Stem Bark of Alstonia boonei De Wild. (Apocynaceae) on Dextran Sodium Sulfate‐Induced Ulcerative Colitis in Wistar Rats

Abstract

Among the most exploited species in Cameroon, Alstonia boonei is widely used in African medicine for the relief of several pathologies including gastrointestinal disorders. This study was conducted in order to assess the effects of aqueous and methanol stem-bark extracts of Alstonia boonei on DSS- (dextran sodium sulfate-) induced intestinal colitis and to determine its antioxidant potential. The classes of secondary metabolites present in these extracts were determined by chemical screening. The production of TNF-α, IL-6, IL-1β, and PGE2 was performed by in vitro ELISA analysis. Anticolitis effects were determined using an in vivo model of ulcerative colitis induced by DSS. The colitis was induced with a double dose of DSS (3% and 1%), and the aqueous and methanol extracts were administered orally from the 6th day after commencement of induction. The phytochemical screening revealed the presence of six classes of secondary metabolites in these crude extracts: tannins, saponins, alkaloids, steroids, flavonoids, and phenols. Methanol and aqueous extracts of Alstonia boonei significantly (P<0.001) inhibited TNF-α, IL-6, IL-1β, and PGE2 production stimulated by LPS. Both extracts at all doses significantly reduced (P<0.01, P<0.001) the signs of DSS-induced colitis in the Wistar rats by decreasing inflammation and chronic colon damage. In addition, the extracts significantly (P<0.001) reduced malondialdehyde and nitric oxide levels in the colon and significantly (P<0.01) increased superoxide dismutase and catalase and reduced glutathione (P<0.05). Both extracts showed greater activity than the reference substance (prednisolone 4 mg/kg) used in this study. This study has demonstrated that aqueous and methanol extracts of Alstonia boonei stem bark have healing properties against colitis experimentally induced by DSS in rats.

Antihypernociceptive and Neuroprotective Effects of the Aqueous and Methanol Stem-Bark Extracts of Nauclea pobeguinii (Rubiaceae) on STZ-Induced Diabetic Neuropathic Pain

“…The animals received a composed feed and drinking water ad libitum . With reference to the work of Adjouzem et al [ 24 ], the experimental procedures have been approved by the local ethics committee and are in accordance with the guidelines for the study of pain in awake animals, published by the NIH Publication No. 85-23 “Principles of Animal Protection,” Laboratory Study of Pain, Ministry of Scientific Research and Technology, which adopted the European Union Guidelines on Animal Care and Experimentation (EWC 86/609).…”

In Vitro Antioxidant, Anti-inflammatory, and In Vivo Anticolitis Effects of Combretin A and Combretin B on Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice

“…The entire colon from the ileocolic junction to the anus was quickly removed, opened longitudinally along the mesenteric fixation line, then washed with saline in a reservoir of ice water and dried with filter paper; then, the total length of the two points was measured [ 29 ].…”

“…The same colon removed, washed, and dried was photographed using a Canon camera (Cyber-shot, 7.2 megapixels, China); then, the samples from this colon were fixed in 10% formalin buffered with PBS. The sections were made in pieces of 5 μ m each; then, staining was done with hematoxylin-eosin (H&E) [ 29 ].…”

Assessment of Larval Toxicity and the Teratogenic Effect of Three Medicinal Plants Used in the Traditional Treatment of Urinary Tract Infections in Benin

“…The works of Awodele et al [12] showed that the aqueous extract of the stem bark of Bridelia ferruginea Benth did not cause mortality in rodents administered orally at various doses of 250 mg/kg to 4000 mg/kg. Regarding Alstonia boonei De Wild, studies carried out with extracts show that this plant species has no toxic effect at the doses tested in the models used [13][14][15]. It clearly appears that the toxicological studies on in vitro and in vivo models are very important before the use of medicinal plants.…”