Neuroprotective Effects of the Anthocleista Schweinfurthii Gilg. (Loganiaceae) Stem Bark Extract in Postmenopause-Like Model of Ovariectomized Wistar Rats.

Background Estrogen deficiency in postmenopausal period causes severe neuroendocrine changes in brain which influences memory and other nervous functions. Anthocleista schweinfurthii is used traditionally to treat female infertility and menopause related symptoms. This study was performed to investigate the potential neuroprotective effects of aqueous extract of Anthocleista schweinfurthii on brain in a postmenopause-like model of ovariectomized Wistar rats. Methods Thirty animals were sham-operated or ovariectomized (Ovx) 84 days after surgery, six groups of five rats each were daily treated orally during 28 days with: distilled water for groups 1 (sham-operated) and 2 (Ovx), estradiol valerate (group 3) and the three doses of extracts {groups 4, 5 and 6 (Ovx)}. Biochemical and histological evaluations focused on brain. Results Compared to sham-operated control, ovariectomy decreased total protein levels in brain (p<0.01) which was increased by plant extract at the dose of 300 mg/kg (p<0.05), underlying its anabolic properties. Ovariectomy significantly decreased magnesium levels in brain (p<0.001). Anthocleista schweinfurthii increased significantly magnesium levels (p<0.01), showing its capacity to act on synaptic conduction. Ovariectomy induced oxidative stress by increasing malondialdehyde levels (p<0.05) and decreasing reduced glutathione levels (p<0.05) in brain. The plant extract exhibited antioxidative activity by reducing malondialdehyde levels and increasing glutathione levels in brain. Damage in brain structure which was caused by ovariectomy disappeared following the treatment. Conclusions Results suggest that Anthocleista schweinfurthii may have neuroprotective effects in Ovx Wistar rats by increasing total protein, magnesium levels and reducing oxidative stress in brain.

In vivo estrogenic-like activities of Gouania longipetala Hemsl. (Rhamnaceae) bark extracts in a post-menopause-like model of ovariectomized Wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Gouania longipetala is commonly used in Cameroonian traditional medicine to manage women fertility and menopausal complaints. However, despite this use, the estrogenic properties of G. longipetala have not been studied until now. AIM OF STUDY: The present study was aimed to assess estrogenic activities of the stem bark aqueous (GLA) and ethanolic (GLE) extracts of G. longipetala in post-menopause-like model of ovariectomized (Ovx) Wistar rats. MATERIAL AND METHODS: Animals were either sham-operated or Ovx. 84 days after ovariectomy, animals were divided into seven groups of five animals and were daily treated for 28 days with distilled water (10 mL/kg) for group 1, 2% solution of Tween 80 (10 mL/kg) for group 2, estradiol valerate (1 mg/kg) for group 3, GLA (45 or 180 mg/kg) and GLE (40 or 160 mg/kg) for groups 4 to 7 respectively. Sham-operated animals daily received distilled water (10 mL/kg). During the experimental period, the body weight was registered every week. At the day 29, blood pressure was registered by invasive method while uterine and vagina morphometry as well as body, uterine and abdominal fat weights changes were analyzed. Serum levels of total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol were determined. Moreover, oxidative stress markers such as nitrites, reduced glutathione (GSH) and malondialdehyde (MDA) were measured in homogenized liver and aorta. RESULTS: Compared with the sham control, vagina and uterine dystrophy and elevated blood pressure were observed in Ovx rats treated with vehicles. Biochemical parameters showed a significant increase of total cholesterol, triglycerides, LDL-cholesterol and MDA as well as a significant decrease of nitrites and GSH in Ovx animals treated with vehicle as compared to sham group. GLA and GLE displayed estrogen-like effects on vagina and did not affect uterine wet weight and epithelial height compared with vehicle groups. Both extracts displayed anti-atherogenic properties by reducing AI, AIP and LDL-cholesterol level as compared to vehicles groups. GLA and GLE significantly prevented the increase of MDA induced by ovariectomy as compared to rats treated with vehicles. CONCLUSION: This study showed that GLA and GLE exhibited estrogenic effects by providing vaginal lubrication, by modulating blood pressure and improving lipid profile, oxidative status and endothelial function and may not have an undesirable influence on the endometrium in ovariectomized rats.

Effects of the aqueous extract of Pittosporum mannii Hook. f. (Pittosporaceae) stem barks on spontaneous and spasmogen-induced contractile activity of isolated rat duodenum.

ETHNOPHARMACOLOGICAL RELEVANCE: Pittosporum mannii Hook. f. (Pittosporaceae) is a plant widely used in traditional medicine in Cameroon for the treatment of many gastrointestinal disorders including diarrhea. To date, no pharmacological study on the antidiarrheal and the antispasmodic properties of this plant has been reported. The aim of the present study was to evaluate in vitro the relaxant activity of the aqueous extract of stem barks of P. mannii (PMAE) on rat duodenum. MATERIALS AND METHODS: Different concentrations of PMAE were tested separately (10-80 µg/mL) or cumulatively (5-80 µg/mL) on spontaneous and spasmogen (carbachol, histamine and KCl)-induced contractions of isolated rat duodenum strips. RESULTS: At concentrations ranging from 10 to 80 µg/mL, PMAE significantly decreased the tonus and the amplitude of spontaneous contractions. However, at high concentration (80 µg/mL), the extract elicited a transient relaxation was followed by a slight increase of tonus, while the amplitude remained lower compared to the normal spontaneous activity. The relaxant effect of the extract was not significantly affected in the presence of atropine (0.713 µg/mL) and promethazine (0.5 µg/mL). In addition, PMAE (20, 40, and 80 µg/mL) partially but significantly inhibited in a concentration related manner the contractions induced by carbachol (10(-9)-10(-4)M) and histamine (10(-9)-10(-4)M) on rat duodenum. PMAE (10-80 µg/mL) also significantly induced a concentration-dependent relaxation on KCl (20mM, 50mM, 10(-3)-6.10(-3)M)-induced contraction of rat duodenum. CONCLUSIONS: These results show that the aqueous extract of P. mannii stem barks possesses antispasmodic and spasmolytic effects at lower concentrations; therefore, supporting the use of the stem barks of this plant in the folk medicine for the treatment of diarrhea. However, caution should be paid while using higher concentrations that instead might produce spasmogenic effect and might worsen the diarrheal condition. The relaxant effect of PMAE appears to be non-specific of muscarinic or histaminic receptors, but may involve at least in part a mechanism of inhibition of the Ca(2+) influx into the smooth muscle cells through voltage-operated Ca(2+) channels.