Gilbert Ateufack

Anti-ulcerogenic properties of the aqueous and methanol extracts from the leaves of Solanum torvum Swartz (Solanaceae) in rats.

ETHNOPHARMACOLOGICAL RELEVANCE Solanum torvum (Solanaceae) is a plant currently used in Cameroon ethnomedicine for the treatment of stomach ailments. AIM OF THE STUDY The present study was undertaken to determine the anti-ulcer potential of the aqueous and methanol extracts from the leaves of Solanum torvum. MATERIALS AND METHODS The aqueous and methanol extracts from the leaves of Solanum torvum were tested orally at the doses of 250, 500 and 750 mg/kg, on gastric ulcerations experimentally induced by HCl/ethanol, indomethacin, pylorus ligation and stress. The fractionation of the methanol extract through silica gel column chromatography produced seven different fractions (A-G) which were tested orally at the dose of 100mg/kg against HCl/ethanol-induced ulceration. RESULTS The methanol extract at the dose of 750 mg/kg produced 98.12, 99.16, 98.70 and 96.03% inhibition when gastric ulcerations were induced by HCl/ethanol, indomethacin, pylorus ligation and stress, respectively. The aqueous extract at the same dose produced 96.55, 96.86, 98.63 and 98.63% inhibition on ulcerations induced respectively by HCl/ethanol, indomethacin, pylorus ligation and stress. All the fractions of the methanol extract significantly inhibited ulcer formation. Fraction F which contains flavonoids and triterpens was the most active and exhibited an inhibitory percentage of 84.74. Both extracts significantly increased mucus production and reduced gastric acid secretion. CONCLUSIONS The aqueous and methanol extracts of the leaves of Solanum turvum possess anti-ulcerogenic properties that may be due to cytoprotective mechanism. These results support the ethnomedical uses of the plant in the treatment of gastric ulcer.

Anti-Nociceptive and Anti-Inflammatory Activities of Extracts from the Stem Bark of Croton macrostachyus (Euphorbiaceae) in Mice and Rats

The present study evaluates the anti-nociceptive and anti-inflammatory properties of the aqueous and methylene chloride/methanol (CH2Cl2 / CH3OH) extracts of the stem bark of Croton macrostachyus. The extracts administered orally at the doses of 150, 300 and 600 mg/kg were examined against pain induced by acetic acid, formalin and pressure and against inflammation induced by carragenan, histamine and formalin. Both extracts induced a significant dose-dependent (P < 0.001) reduction in the number of abdominal constrictions induced by acetic acid. The three doses of the two extracts also significantly reduced (P < 0.001) the two phases of pain induced by formalin. At the dose of 600 mg/kg, the aqueous and the CH2Cl2 / CH3OH extracts exhibited a significant analgesic activity against pressure-induced pain. The two extracts also exhibited anti-inflammatory activity, the CH2Cl2 / CH3OH extract being the most active, inhibited acute inflammation induced by carrageenan, histamine and formalin. Both extracts also significantly reduced the chronic inflammation induced by formalin. These results show that the aqueous and CH2Cl2 / CH3OH extracts of the stem bark of Croton macrostachyus possess analgesic and anti-inflammatory properties. These findings are in accordance with the traditional use of the plant and indicate that Croton macrostachyus is a potent source of analgesic and anti-inflammatory principles.

Gastroprotective and ulcer healing effects of piptadeniastrum Africanum on experimentally induced gastric ulcers in rats

BackgroundGastric peptic ulcer is one of the common disorders of gastrointestinal tract, which occur due to an imbalance between the offensive and defensive factors. It is an illness that affects a considerable number of people worldwide. This study was conducted to evaluate the antiulcerogenic and antiulcer effects and recognize the basic mechanism of action of Piptadeniastrum africanum stem bark extracts.MethodsThe aqueous and methanol extracts of Piptadeniastrum africanum were administered at the doses 125, 250 and 500 mg/kg to evaluate their effects on gastric ulcer induced by the HCl/ethanol mixture, indomethacin and acetic acid in Wistar strain male adult rats, aged between 12 and 16 weeks and weighing between 180 and 220 g. Ranitidine, Maalox and Misoprostol were used as standard drugs. Histopathological examination and nitric oxide level were performed to evaluate the basic mechanism of action of Piptadeniastrum africanum. Phytochemical screening was carried out to identify known phytochemicals present in these extracts.ResultsThe aqueous and methanol extracts of stem bark of Piptadeniastrum africanum significantly inhibited (p < 0.01) gastric ulceration induced by HCl/ethanol to the percentages of inhibition of 81.38; 98.75 and 100 % for the aqueous extract and then 75.83, 89.76 and 96.52 % for the methanol extract, and with the Indomethacin-induced ulcers, aqueous and methanol extracts of bark of Piptadeniastrum africanum reduce significantly (p < 0.01) induced gastric lesions in rats, with percentage of cure 35.75; 52.33 and 98.58 % for the aqueous extract, and 33.7; 51.97; and 65.93 to the methanol extract. The results revealed a significant reduction of ulcerated surface in both extracts and increase of nitric oxide (NO) level with methanol extract. When compared to methanol extract, aqueous extract showed more pronounced effects, corresponding to percentages of healing of 59. 92; 84.12 and 59.65 % for the aqueous extract; and 70.43; 55.49 and 57.59 % for the methanol extract in the ulcer induced by acetic acid, all at the respective doses of 125, 250 and 500 mg/kg. Histopathological observations also demonstrated curative effect. As such, both extracts were found to exhibit preventive and curative effects through the release of NO and growth factors. This could also be due to the presence of phytochemicals such as alkaloids, flavonoids, phenols and saponins which act as antisecretory agents.ConclusionsPiptadeniastrum africanum stem bark extracts thus have gastroprotective and ulcer healing effects, which could result from their activities by stimulating important cellular mechanisms such as migration and proliferation of epithelial cells that may have a cytoprotective effect by stimulating the release of prostaglandins. These results are required to confirm the ethnopharmacological use of Piptadeniastrum africanum stem bark in the treatment of ulcer.

Antiulcer Effects of the Aqueous and Organic Extracts of the Stem Bark of Anthocleista vogelii. in Rats

Abstract The aqueous, hexane, acetone, and methanol extracts of the stem bark of Anthocleista vogelii. Planch. (Loganiaceae) were screened for antiulcerogenic activity using HCl/ethanol gastric necrotizing solution. The methanol extract showed 100% inhibition at a dose of 500 mg/kg compared with the aqueous, hexane, and acetone extracts, which produced 87.91%, 61.39%, and 76.89%, respectively. The methanol and aqueous extracts were further tested against ulceration induced by indomethacin (30 mg/kg) and pylorus ligation at doses of 125, 250, and 500 mg/kg. The aqueous extract at a dose of 500 mg/kg significantly (p ≤ 0.01) reduced indomethacin-induced gastric lesions by 78.62% while the methanol extract at the same dose completely inhibited the action of indomethacin. The aqueous extract of A. vogelii. at doses of 250 and 500 mg/kg induced a decrease of about 15% and 40%, respectively, of the surface area in the pylorus-ligated rats. Similarly, the methanol extract at doses 250 and 500 mg/kg produced a decrease of almost 25% and 70%, respectively. The gastric juice secretion increased significantly (p ≤ 0.05) at a dose of 500 mg/kg in the aqueous extract while the gastric acidity significantly (p ≤ 0.01) decreased at doses of 125 and 500 mg/kg in aqueous and methanol extracts as compared with the control group. These findings show that the aqueous and organic extracts of the stem bark of Anthocleista vogelii. possess potent antiulcer properties thereby lending support to the ethnomedical uses of the plant in the treatment of stomachache.

Antiulcerogenic Activity of 1-Hydroxy-3,7,8-trimethoxyxanthone Isolated from the Methanol Extract of Anthocleista vogelii PLANCH. in Rats

Anthocleista vogelii (Loganiaceae) PLANCH. is used in Cameroonian ethnomedicine for the treatment of stomach ache and for curing fever and is used as purgative. Further investigations have shown that the stem bark of this plant possesses potent antiulcer properties. We have investigated the cytoprotective and antisecretory actions of 1-hydroxy-3,7,8-trimethoxyxanthone (AV), the xanthone obtained from the methanol extract of the stem bark. Oral administration of AV at the doses of 1, 2, and 5 mg/kg prevented in a dose-dependent manner ulcers induced by HCl/ethanol (60.90 to 93.22%), Indometacin (46.86 to 89.68%), and pylorus ligation (0.00 to 70.69%). AV reduced pylorus-ligated gastric acid secretion from 134.17 mEq/l in the controls to 118.55, 121.50, and 96.93 mEq/l, respectively, for the 1, 2, and 5 mg/kg doses and increased mucus secretion significantly in a dose-dependent manner in all experimental models. The cytoprotective and antisecretory properties of AV could thus be due to its ability to strengthen gastric mucosal defences through enhanced gastric mucus production.

Antinociceptive Activities of the Methanolic Extract of the Stem Bark of Boswellia dalzielii Hutch. (Burseraceae) in Rats Are NO/cGMP/ATP-Sensitive-K

Boswellia dalzielii (B. dalzielii) is traditionally used in the treatment of rheumatism, pain, and inflammation. The present investigation evaluates the property and possible mechanism of action of the methanolic extract of B. dalzielii (BDME) on inflammatory and neuropathic pain models. Effects of BDME (250 and 500 mg/kg), orally administered, were verified in mechanical hypernociception induced by LPS or PGE2. Mechanical hyperalgesia, cold allodynia, and heat hyperalgesia were used in vincristine-induced neuropathic pain. NW-nitro-L-arginine methyl ester (inhibitor of nitric oxide synthase), glibenclamide (ATP-sensitive potassium channel blocker), methylene blue (cGMP blocker), or naloxone (opioid antagonist receptor) has been used to evaluate the therapeutic effects of BDME on PGE2-induced hyperalgesia. Chemical profile of BDME was determined by using HPLC-XESI-PDA/MS. BDME showed significant antinociceptive effects in inflammatory pain caused by LPS and PGE2. The extract also significantly inhibited neuropathic pain induced by vincristine. The antinociceptive property of BDME in PGE2 model was significantly blocked by L-NAME, glibenclamide, methylene blue, or naloxone. The present work reveals the antinociceptive activities of BDME both in inflammatory and in neuropathic models of pain. This plant extract may be acting firstly by binding to opioid receptors and secondly by activating the NO/cGMP/ATP-sensitive-K+ channel pathway.

Piptadenin, a Novel 3,4-Secooleanane Triterpene and Piptadenamide, a New Ceramide from the Stem Bark of Piptadeniastrum africanum (Hook.f.) Brenan.

Piptadenin (1), a new triterpene along with piptadenamide (10), a new ceramide, have been isolated from the AcOEt‐soluble fraction of the MeOH extract of the stem bark of Piptadeniastrum africanum along with nine known compounds, 1‐O‐[(3β,22β)‐3,22‐dihydroxy‐28‐oxoolean‐12‐en‐28‐yl]‐β‐d‐glucopyranose (2), 22β‐hydroxyoleanic acid (3), oleanic acid (4), lupeol (5), betulinic acid (6), 5α‐stigmasta‐7,22‐dien‐3β‐ol (7), 5α‐stigmasta‐7,22‐dien‐3‐one (8), (3β)‐stigmast‐5‐en‐3‐yl β‐d‐glucopyranoside (9) and 2,3‐dihydroxypropyl hexacosanoate (11). Except for compound 11, all the isolated compounds are reported for the first time from this plant. The structures of the isolated compounds were elucidated by spectroscopic data including 1D and 2D NMR. The pure compounds 1 – 11 were subjected to the pharmacological screening and compounds 2, 5 – 7 and 9 exhibited potent urease inhibitory activity with IC50 value of 25.8, 28.9, 30.1, 31.8 and 32.7 μm, respectively, whereas compound 1 showed moderate activity (IC50 = 98.7 μm). The potent urease inhibitory activity supplemented the previous literature reports and medicinal uses of this plant.

Anti-inflammatory and anti-arthritic effects of methanol extract of the stem bark of Boswellia dalzielii Hutch (Burseraceae) in rats

Boswellia dalzielii is a tall tree (more than 13 m high) that produces aromatic white flowers. This plant is commonly used in indigenous medicine across Africa against diarrhea, malaria, vomiting, inflammation and arthritis. The present study focuses on the anti-inflammatory and anti-arthritis potential of methanol extract of Boswellia dalzielii (BDME). Anti-inflammatory activity was evaluated in inflammatory models induced by carrageenan, arachidonic acid, histamine, serotonin, prostaglandin and bradykinin. Anti-arthritis activity was measured using complete Freund’s adjuvant model. Intracellular and extracellular ROS production and proliferation of T-cells were evaluated using chemiluminescence and liquid scintillation counter techniques, respectively. TNF-α and IL-1β production were assessed using ELISA and MTT assay performed for cytotoxicity. BDME revealed a significant anti-inflammatory effect by preventing the development of edema caused by carrageenan, arachidonic acid, histamine, serotonin, prostaglandin and bradykinin. For anti-arthritic properties of BDME, the results showed a significant reduction of the joint diameter and a decrease in pain in the treated animals. The extract also showed a noticeable systemic effect, maintaining the values of the evaluated parameters close to normal in treated rats with an inhibition of joint destruction as shown in histopathological analysis. Furthermore, BDME exhibited significant inhibition of extracellular and intracellular ROS production. Still, the extract displayed significant inhibitory activity on T-cell proliferation as well as a reduced production of TNF-α and IL-1β. Boswellia dalzielii could be considered as a promising tract in the prevention and/or management of inflammatory diseases.