Metabolomic profiling and bactericidal effect of Polyalthia longifolia (Sonn.) Twaites. stem bark against methicillin-resistant Staphylococcus aureus.

Objective. The present study was carried out to establish the chemical profile of the methanolic extract of Polyalthia longifolia stem bark and investigate its antibacterial property against some human pathogenic bacteria. Methods. The extract was analysed using liquid and gas chromatography coupled to mass spectrometry. Antibacterial activity of P. longifolia extract against some human pathogenic bacteria was screened using the AlamarBlue method, and MIC and MBC were determined. Results and Conclusion. Liquid chromatography-mass spectrometry (LC-MS) revealed the presence of 21 compounds among which 12 were identified. Gas chromatography-mass spectrometry (GC-MS) allowed identification of 26 compounds, the three major ones being the following: cis vaccenic acid (17.79 %), 3-ethyl-3-hydroxyandrostan-17-one (13.80 %) and copaiferic acid B (12.82 %). P. longifolia extract was active against Gram-positive bacteria with MIC ranging from 1 to 2 mg ml-1 and MBC from 2 to 6 mg ml-1. This study demonstrated the bactericidal effect of the methanolic extract of Polyalthia longifolia stem bark against some human pathogenic bacteria, including methicillin-resistant S. aureus . This effect could be related to the presence in the extract of a broad diversity of well-known compounds with established pharmacological properties. These results support the ethnomedicinal use of P. longifolia stem bark in Cameroon for the management of methicillin-resistant S. aureus (MRSA)-related infections.

Chronic Gastric Ulcer Healing Actions of the Aqueous Extracts of Staple Plant Foods of the North-West, Adamawa, and West Regions of Cameroon.

Aim: This study is aimed at establishing phenolic compound profile and assessing the possible antiulcer activities of aqueous extracts of some staple plant foods from the West and North-West regions of Cameroon against chronic gastric ulcer models in rats. Materials and Methods: Phenolic constituents of extracts were evaluated using HPLC-DAD. Aqueous extracts of Corchorus olitorius, Solanum nigrum, Vigna unguiculata, Triumfetta pentandra, "nkui" spices, and "yellow soup" spices were tested at two doses (200 and 400 mg/kg). After treatments, animals were sacrificed, healing percentage and antioxidant status (catalase, superoxide dismutase, and glutathione peroxidase) were evaluated, and histological examination of gastric mucosa was realized. Results: HPLC-DAD revealed that p-hydroxybenzoic and protocatechuic acids were the phenolic compound present in all extracts. Oral administration of extracts (200 and 400 mg/kg) significantly reduced ulcer surface value and significantly increased mucus production compared to the control groups (p < 0.05). Histological study supported the observed healing activity of different extracts characterized by a reduced inflammatory response. Moreover, administration of aqueous extracts increased the activity of antioxidant enzymes. Conclusion: This study revealed that aqueous extracts of Solanum nigrum, Corchorus olitorius, Vigna unguiculata, Triumfetta pentandra, "yellow soup" spices, and "nkui" spices possess healing antiulcer effects against models of gastric ulcers. The antiulcer mechanisms involved may include increase of gastric mucus production and improvement of the antioxidant activity of gastric tissue. These activities may be due to the phenolic compounds identified in the extracts, especially p-hydroxybenzoic and protocatechuic acids present in all extracts and with known antioxidant, cytoprotective, and healing properties. However, all the diets may promote the healing process of chronic ulcers caused by excessive alcohol consumption/stress.

Antihistaminergic and Anticholinergic Properties of the Root Bark Aqueous Extract of Diospyros mespiliformis (Ebenaceae) on Hypersecretion of Gastric Acid Induced in Wistar Rats.

OBJECTIVE: The objective of this study was to elucidate the antisecretory mechanism of the root bark aqueous extract of Diospyros mespiliformis (RBAEDM) in Wistar rats. Materials and methods. RBAEDM was tested on three experimental animal models of gastric acid hypersecretion including pyloric ligation (PL), PL with histamine, and carbachol pretreatments. The ulcerated surface, mucus mass, pH, gastric acidity, and pepsin activity were determined. Some bioactive compounds revealed by qualitative phytochemistry were quantified. Some markers of oxidative stress in vivo such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and in vitro antioxidant tests (ABTS: 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid, DPPH: 2,2-diphenyl-2-picrylhydrazyl, and FRAP: ferric reducing antioxidant power) were determined. RESULTS: In the three models studied, RBAEDM resulted in increases in the percentages of inhibition ranging from 9.50 to 59.52% of gastric ulcer and mucus mass. This increase was accompanied by the reduction in acidity and pepsin activity. The administration of RBAEDM resulted in a significant decrease (p < 0.05, p < 0.01) in MDA levels correlated with a significant increase (p < 0.05, p < 0.01) in CAT and nitrite levels compared with the negative control. RBAEDM has the ability to scavenge ABTS and DPPH radicals and to reduce FRAP, and the inhibitory concentration of 50% (IC50) of the ABTS radical was 220 µg/mL compared with the butylhydroxytoluene (BHT) control (175 µg/mL). Quantitative phytochemistry revealed abundant polyphenols, flavonoids, tannins, saponins, and anthocyanin. CONCLUSION: RBAEDM protected gastric mucous membrane for gastric acid by mechanisms that would involve both anticholinergic and antihistaminergic pathways.

Eremomastax speciosa (Hochst.) Cufod. counteracts the delaying effect of indomethacin on Helicobacter pylori-associated chronic gastric ulcers healing.

ETHNOPHARMACOLOGICAL RELEVANCE: Information collected from local traditional healers reported that Eremomastax speciosa (Hochst.) Cufod. has for a long time been used to manage gastric ulcers in many regions of Cameroon and beyond. This traditional use is supported by numerous studies. However, efficacy of this plant has never been tested in case of chronic gastric ulcers associating Helicobacter pylori infection. AIM OF THE STUDY: This study was designed to investigate curative effects of the aqueous extract of E. speciosa leaves (AEESL) against chronic gastric ulcers associated to Helicobacter pylori infection. MATERIALS AND METHODS: Two experimental methods of chronic gastric ulcers, involving H. pylori infection, were performed using Wistar rats, namely: acetic acid-induced ulcers and "unhealed ulcers". E. speciosa extract was tested at three doses (100; 200; 400 mg/kg) and at the end of experiments, some in vivo antioxidant parameters were measured, bacterial load in stomach tissue calculated and histopathological examinations performed. RESULTS: E. speciosa reduced ulcer index at all the doses and significantly increased mucus production as well as antioxidant (mainly SOD and GSH) level. Bacterial load in stomach significantly decreased (p < 0.05) in extract-treated groups (200 and 400 mg/kg) as confirmed by histopathological observations. The extract was found to be non toxic to healthy and cancerous cells (IC50 > 1000 µg/mL). CONCLUSIONS: E. speciosa accelerated healing of gastric ulcers even in presence of indomethacin, while decreasing bacterial loads in rats' stomachs. These results provide supplementary support to the use of E. speciosa in ethnomedicine and open new perspectives regarding development of a herbal-based monotherapy able to efficiently replace/supplement standard antiulcer tri/quadritherapy.

Intra- and interobserver reproducibility of grading of helicobacter pylori gastritis according to the updated sydney system

Aims. To study the intra- and interobserver reproducibility of Sydney System amongst pathologists in Cameroon as Sydney System gradation has not gained enough confidence in African pathologists. Methods. We performed a descriptive study including 100 patients who benefited from gastric biopsy by endoscopy. These biopsy specimens were stained with hematein and eosin and modified Giemsa; and read independently using the same microscope by two pathologists with four years experience and no experience with the updated Sydney System. Gastritis was graded according to the updated Sydney System. Levels of intra- and interobserver reproducibility were assessed using the unweighted kappa coefficient. Results. The intraobserver reproducibility of gradation of Helicobacter pylori density; activity; chronic inflammation; atrophy; and intestinal metaplasia showed respective values of kappa: 0.63; 0.34; 0.61; 0.48; and 0.82 for one observer against 0.42; 0.005; 0.41; 0.31; and 0.72 for the other. Interobserver reproducibility kappa values were; respectively; 0.41; 0.18; 0.57; 0.58; and 0.82. Conclusion. Results are encouraging but experience in the updated Sydney System should be improved. The later should be introduced as a means to grade and classify gastritis in Cameroon and African countries

Teratogenic effects, acute and sub chronic toxicity of the leaf aqueous extract of Ocimum suave Wild (Lamiaceae) in rats.

The aqueous extract from the leaves of Ocimum suave was evaluated for acute and sub chronic toxicity and teratogenic effects. Swiss mice were administered single oral doses of 2000, 4000, 6000 and 8000 mg/kg and monitored for death and body weight gained for 7 days (acute toxicity). In sub-acute toxicity, experimental rats, received daily doses of 250, 500 and 1000 mg/kg for 42 consecutive days and the toxic effects were assessed using biochemical and haematological data and histology of vital organs. In a teratogenic study, 1-day pregnant rats were administered orally 500 and 1000 mg/kg of extract daily for 21 consecutive days and 14th day corpora lutea and foetal implants and litter size at birth were noted. Reproductive performance of F(1) generation rats was studied by crossing them at maturity and recording the number, birth weight and physical presentation of the young offspring. Acute intake of extract up to 8000 mg/kg did not produce mortality or significant changes in general behaviour. Sub chronic treatment did not show any change in body and organ weights, feeding habits or behaviour between the control and the treated groups of both sexes. Haematological analysis and blood biochemistry revealed no toxicity effects of the extract. No gross abnormalities or histological changes were observed. Teratogenic and fertility studies did not reveal any toxic manifestations or foetal abnormalities. The leaf aqueous extract of Ocimum suave is non toxic in acute and sub chronic intake.

Gastric cytoprotective anti-ulcer effects of the leaf methanol extract of Ocimum suave (Lamiaceae) in rats.

The anti-ulcerogenic potential of the leaf methanol extract of Ocimum suave (Lamiaceae) was investigated using four methods of gastric lesion induction in experimental Wistar rats (150-200 g): (1) HCl/ethanol-induced gastric lesions, (2) Absolute ethanol-induced gastric lesions, (3) Indomethacin-HCl/ethanol-induced gastric lesions, (4) Pylorus ligation-induced gastric lesions. Administration of the extract of O. suave to the rats by oral route (75-500 mg/kg) dose-dependently prevented the formation of acute gastric lesions induced using the four experimental techniques. The dose-dependent reduction of lesion formation was in all cases accompanied by significant increases in gastric mucus production. At the dose of 250 mg/kg there was complete inhibition of gastric lesions induced using the HCl/ethanol solution. Pre-treatment, by intraperitoneal route, with indomethacin significantly reduced the ability of the extract to inhibit the formation of HCl/ethanol-induced lesions. When the rats were subjected to pylorus ligation, the dose of 500 mg/kg completely inhibited lesion formation but did not have any effect on gastric acid secretion compared with the controls. The mucus secretion promoting effect of the extract was most significant when the gastric environment was highly acidic. These results suggest that a new anti-ulcer therapy regimen may be formulated which does not require the use of antacids and anti-secretory agents.