HYPOGLYCAEMIC EFFECT OF THE METHANOL EXTRACT OF IRVINGIA GABONENSIS SEEDS ON STREPTOZOTOCIN DIABETIC RATS.

The hypoglycaemic effect of the methanol extract of Irvingia gabonensis seeds (Irvingiaceae) was examined in streptozotocin-diabetic rats. A single oral administration of the methanol extract at doses of 150 and 250mg/kg significantly (P < 0.001) lowered the plasma glucose levels in diabetic rats two hours after treatment

Temperature dependent studies on nutritional, total polyphenols, flavonoids content and antioxidant activities of Aframomum citratum (C. Pereira) K.Schum and Tetrapleura tetraptera (Schumach & Thonn.) fruits

Description: Hard shelled fruits, Tetrapleura tetraptera and Aframomum citratum non-timber forest products are used as spices and for many medicinal recipes. Mostly used together, they undergo heat treatment before being milled when cooking "Mbongo Tchobi", a black spicy stew from central and coastal regions in Cameroon. Objectives: Evaluate the impact of roasting these spices on the physicochemical properties (dry matter, ash, raw protein, total sugar, raw fibre, pH, aw, total energy, total fat), phytochemical content (total polyphenol, total flavonoids) and the antioxidant activities (total antioxidant activity, FRAP, DPPH and lipid peroxidation inhibition assays) of their aqueous extracts in a home food consumption context. Methodology: Tetrapleura tetraptera and Aframomum citratum fruits from Ngola locality in YoKadouma (East region in Cameroon) locality were collected, sorted, cleaned and dried (72h, 45°C) in an oven. Cut into small pieces, a part was heated using roasting parameters deduced from preliminary tests (140°C/10min; 180°C/20min and 150°C/12min respectively for T. tetraptera, A. citratum and a formulation 95/5 of the two spices). The heated and unheated spices were ground and an infusion was prepared from boiling water in the proportion of 1/5 (g/ml) for both types of spices. Physicochemical and phytochemical characteristics (dry matter, total ash, fat, sugar, crude fibre and energy contents, pH, aw, total flavonoids and polyphenols) as well as the antioxidant activities of the aqueous extracts of the two spices and a mix of the two spices were evaluated before and after the heat treatment. Results: Heat treatment significantly (p˂0.05) reduces fat and total sugars contents but improves raw fibre contents for all spices. Phenolic content is more important for heated spices and percentage differences before and after heat treatment are between 8 and 23.20% for both spices. Extracts obtained with heated spices possess the best antioxidant potential. Strong significant positive correlations have been established between the phenolic compounds and the reductive antioxidant activities and negative correlations with the antiradical antioxidant activities as they are expressed as IC50 (mg/ml). Conclusion: In most of the features studied, the heated formulation (95/5) possesses the highest characteristics studied and the choice of heating these spices under the roasting parameters identified should be guided by the desire of improving the antioxidant potential because of the nutritional losses observed after heat treatment

In vitro Biological activities of aqueous extracts of Tetrapleura tetraptera (Schumach & Thonn.) taub. and Aframomum citratum (C. Pereira) K.Schum from three Agroecologic zones in Cameroon

Study some phytochemical constituents and biological activities of twelve samples of Tetrapleura tetraptera (Schumach & Thonn.) taub. and nine of Aframomum citratum (C. Pereira) K.Schum fruits collected in three Agroecologic zones in Cameroon: Bimodal forest zone (ZONE V), Unimodal forest zone (ZONE IV) and highlands zone (ZONE III). Methods: Fresh fruits extracts were obtained by aqueous infusion (100°C/15min) and evaluated by spectrophotometric methods for total polyphenol (TPP), total flavonoids (TFLV) contents and antioxidant (DPPH, Total Antioxidant Capacity by the Phosphomolybdenum method or TAC, Iron reducing power or FRAP and inhibition of linoleic acid peroxidation or B.CAROT assays) and anti-inflammatory (Inhibitions of Protein denaturation and 5-LOX activity respectively INH.PROT and INH.5-LOX) properties. Principal Component Analysis providing a transparent view of information was performed. Results: T. tetraptera has the highest levels of TPP, TFLV and biological activities. For both species, fruits from ZONE V have the most important TPP, TFLV levels and biological activities. TPP and TFLV content of A. citratum and T. tetraptera fruits are positively and significantly (p<0.05) correlated. All extracts biological activities (0.25, 2.5, 25, 250 mg/mL) are dose-dependent and they have shown strong antioxidant and anti-inflammatory activities, but less than references (Ascorbic Acid, Diclofenac, Quercetin, and Butylated Hydroxytoluene). There is a positive correlation between TPP, TFLV and TAC, FRAP, B.CAROT assays and inverse correlations are observed with the IC50 (g/mL) of DPPH, INH.5-LOX and INH.PROT assays for both species. Conclusion: The fruits reveal their variabilities and those from ZONE V for both species are economically and healthcare challenging for herbalists, pharmaceutical firms, scientists and consumers. Indeed, most important extraction yield of bioactive compounds correlated with significant biological activities and the use of less material compare to an implementation in others AEZ with the same results are noted

Glycaemic variations after administration of Irvingia gabonensis

The action of Irvingia gabonensis seed fractions in reducing or slowing down the intestinal absorption of glucose was evaluated in normoglycaemic rats. The crude seeds (CS), the defatted seeds (DS) and the protein fraction (PF) were administered at dose of 400mg/ kg body weight to normoglycemic rats submitted to oral glucose test (OGTT) with glucose (2g/kg body weight). The results obtained show a significant reduction of the postprandial glucose level after a glucose load of (2g/kg body weight) as well as fasting blood glucose levels with the three fractions. Keywords: antihyperglycaemic, blood glucose, solubles fibres, Irvingia seeds fractions African Journal of Traditional, Complementary and Alternative Medicines Vol. 3(4) 2006: 94-10

Variabilities of Tetrapleura tetraptera (Schumach & Thonn.) taub. and Aframomum citratum (C. Pereira) K.Schum from three Agro-ecologic zones in Cameroon and effect of extraction methods on the phenolic compounds recovery

The fruits of Tetrapleura tetraptera and Aframomum citratum were identified among the most commonly used and available spices in Cameroonian cities. They are mainly collected in the bimodal forest (Zone V), unimodal forest (Zone IV) and the highlands (Zone III)2 zones. They are part of the traditional pharmacopeia in Central and West African countries. The aim of this study was to characterize fruit samples harvested on the three agroecological zones (AEZ) and to examine few traditional extraction methods for the phenolic compounds recovery in a domestic food consumption situation. Tetrapleura tetraptera fruits were harvested in twelve villages spread over three AEZ (Zones V, IV, III) and Aframomum citratum fruits were selected in nine villages spread over two AEZ (Zones V, IV). Various analysis (dry matter, ash,total fat, crude proteins, total sugars, crude fibre contents; energy, water activity and pH; Fe, Ca, Mg and K contents; total polyphenols and flavonoids contents) using standard analytical, colorimetric, spectroscopy and spectrophotometric procedures were used. For both extraction methods investigated (Maceration, infusion, decoction), an extraction ratio of 1/5 was used. Statistical analysis and Principal Component Analysis (PCA) were performed. The results showed that concerning Tetrapleura tetraptera samples, crude fibre content is significantly (p<0.05) high on samples from Zones IV and III while samples from Zone V possess more sugars, calories, minerals and phenolic compounds. About Aframomum citratum, samples from Zone IV are the most sweet and the ones from Zone V contain more protein, fibre, phenolic and minerals (especially samples from the East region) contents. For both species, decoction was the most efficiency extraction method. The result gives a graphic representation of the studied characteristics which can serve as a decision-making tool (for sampling) to guide the various stakeholders involved in the valuation and exploitation of these fruits

Oxidative Stress and Analysis of Selected SNPs of ACHE (rs 2571598), BCHE (rs 3495), CAT (rs 7943316), SIRT1 (rs 10823108), GSTP1 (rs 1695), and Gene GSTM1, GSTT1 in Chronic Organophosphates Exposed Groups from Cameroon and Pakistan

The detrimental effects of organophosphates (OPs) on human health are thought to be of systemic, i.e., irreversible inhibition of acetylcholinesterase (AChE) at nerve synapses. However, several studies have shown that AChE inhibition alone cannot explain all the toxicological manifestations in prolonged exposure to OPs. The present study aimed to assess the status of antioxidants malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) (reduced), catalase, and ferric reducing antioxidant power (FRAP) in chronic OP-exposed groups from Cameroon and Pakistan. Molecular analysis of genetic polymorphisms (SNPs) of glutathione transferases (GSTM1, GSTP1, GSTT1), catalase gene (CAT, rs7943316), sirtuin 1 gene (SIRT1, rs10823108), acetylcholinesterase gene (ACHE, rs2571598), and butyrylcholinesterase gene (BCHE, rs3495) were screened in the OP-exposed individuals to find the possible causative association with oxidative stress and toxicity. Cholinesterase and antioxidant activities were measured by colorimetric methods using a spectrophotometer. Salting-out method was employed for DNA extraction from blood followed by restriction fragment length polymorphism (RFLP) for molecular analysis. Cholinergic enzymes were significantly decreased in OP-exposed groups. Catalase and SOD were decreased and MDA and FRAP were increased in OP-exposed groups compared to unexposed groups in both groups. GSH was decreased only in Pakistani OPs-exposed group. Molecular analysis of ACHE, BCHE, Catalase, GSTP1, and GSTM1 SNPs revealed a tentative association with their phenotypic expression that is level of antioxidant and cholinergic enzymes. The study concludes that chronic OPs exposure induces oxidative stress which is associated with the related SNP polymorphism. The toxicogenetics of understudied SNPs were examined for the first time to our understanding. The findings may lead to a newer area of investigation on OPs induced health issues and toxicogenetics

Nutrient and Bioactive Composition of Five Gabonese Forest Fruits and Their Potential Contribution to Dietary Reference Intakes of Children Aged 1–3 Years and Women Aged 19–60 Years

Widely consumed forest fruits in Gabon were analysed for nutrient and bioactive compositions and their potential contributions to meeting the nutrient requirements of consumers. Edible pulps of Panda oleosa Pierre, Gambeya lacourtiana (De Wild.) Aubrév. &amp; Pellegr. and Poga oleosa Pierre contained substantial amounts of bioactive compounds; flavonoids (13.5–22.8 mg/100 g), proanthocyanins (2.4–7.6 mg/100 g), polyphenols (49.6–77.3 mg/100 g) and vitamin C (6.7–97.7 mg/100 g). The highest content of β-carotene (76.6 µg/100 g) was registered in fruits of Pseudospondias longifolia Engl. The fruits of P. oleosa had the highest essential minerals Fe, Zn and Se. If a child aged 1 to 3 years consumed about 200 g or if a non-lactating and non-pregnant woman consumed 300 g of Panda oleosa, Afrostyrax lepidophyllus Mildbr., G. lacourtiana, P. longifolia and Poga oleosa, they could obtain substantial DRI ranging between 20–100% for energy, vitamins C and E, iron, magnesium, iron and zinc. Forest fruits can considerably contribute towards the human nutrient requirements. Based on the results of this study, forest foods should be considered in formulating policies governing food and nutrition security in Gabon