Martin FONKOUA

<i>Callistemon Citrinus, Cymbopogon Citratus, and Oxalis Barrelieri </i>Extracts Stimulate Defence of Tomato Against <i>Fusarium</i> Wilt

Dakolé Daboy Charles, Dongmo Lekagne Joseph Blaise, Martin Fonkoua, Julienne Nguefack, Irénée Somda

Plant

In Cameroon, tomato yields remain low due to attacks by pathogens and insects. <i>Fusarium oxysporum</i> f.sp. <i>lycopersici </i>(FOL) is a fungus responsible for <i>Fusarium </i>wilt, a disease responsible for important economic losses. To contribute to the control of this pathogen, the stimulatory effect of the tomato defence system of extracts of plants in the tomato/FOL interaction was evaluated. Tomato plants were treated with the aqueous extracts (AE) of <i>Callistemon citrinus</i> (<i>C. citrinus</i>), <i>Cymbopogon citratus</i> (<i>C. citratus</i>), and <i>Oxalis barrelieri</i> (<i>O. barrelieri</i>) at 10% (W/V). After 4 days of spraying with the extracts, the plants were inoculated with a virulent strain of <i>Fusarium oxysporum</i> f.sp. <i>lycopersici</i> (FOL) in pots experiments. Tomato roots were used to determine the contents of phenols, proteins, carbohydrates, amino acids (AA) and proline. The activities of antioxidant enzymes were evaluated: ascorbate peroxidase (APX), catalase (CAT), guaiacol peroxidase (GPX) and superoxide dismutase (SOD). The results showed that treatment of tomato plants with extracts and their infection with FOL induced an increase in the contents of phenols, proteins, carbohydrates, lipids, amino acids and proline in tomato roots, an increase in APX, GPX, SOD activities and a reduction in CAT activity. Our results suggest that the increase and reduction of enzymatic activities, and the increase in the synthesis of some metabolites could mitigate the oxidative damage that takes place during the expansion of the pathogen. Aqueous extracts of <i>C. citrinus</i>, <i>C. citratus</i> and <i>O. barrelieri</i> could be used as natural products to stimulate the tomato defence system against FOL.

• #plant pathogens and fungal diseases
• #apx
• #cymbopogon citratus
• #fusarium oxysporum

Anti-Arthritic Effect of the Aqueous Extracts of the Roots and Barks of Gossypium herbaceous in Complete Freund’s Adjuvant Induced Arthritis in Female Wistar Rats

Abeng Edoa Catherine, Youovop Fotso Janvier, Martin Fonkoua, Takuissu Guemto Guy, Amamba Akamba Dupon, Nanhah Jules Vidal et 2 autre(s)

Journal of Complementary and Alternative Medical Research

Background: Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation of one or more joints resulting to disability. Age (above 50 years) and life style are the main risk factors. In this study, we evaluated the effects of the aqueous extracts of the roots and barks of Gossypium herbaceum (G. herbaceous) in Complete Freund’s Adjuvant (CFA) induced rheumatoid arthritis in female wistar rats. Materials and Methods: In vitro anti-inflammatory tests were conducted through the inhibition of hemolysis and lipid peroxidation. An acute toxicity test of both extracts was done. 25 female Wistar rats were used. RA was induced in 20 rats (4 groups) by injecting CFA into the sub plantar region of the right hind paw of each rat. On day 25 of the experiment, the rats were sacrificed, and the sera were prepared for the evaluation of some inflammatory and biochemical parameters. The paws were dissected and kept for histological analyzes. Results: The extracts revealed anti-inflammatory activities in vitro, with a higher activity observed from the roots. Both extracts restored body weight and significantly reduced edema compared to the negative control group. The histological analyzes of the RA group revealed the presence of white blood cells in the synovial fluid and cartilage destruction as compared to the groups receiving roots’ aqueous extract and methotrexate. Both extracts significantly restored the levels of some inflammatory and biochemical parameters. Conclusion: Anti-inflammatory and biochemical tests showed that the aqueous extracts of the roots and barks of G. herbaceous are potentially effective in the management of RA.

• #toxin mechanisms and immunotoxins
• #rheumatoid arthritis
• #medicine
• #arthritis

Characterization of Compost Made from Chicken Droppings and Fish Bones, and Its Application to Tomato Cultivation

Dakolé Daboy Charles, Okala Bouillong Noelly Manuela, Molemb Nemeté Aristide, Martin Fonkoua, Dongmo Lekagne Joseph Blaise, Julienne Nguefack

Asian Journal of Advances in Agricultural Research

The effect of compost made from chicken droppings and fish bones on soil quality and tomato production was evaluated. The soil of Bokito (Central Region-Cameroon) was amended with four variants C1, C2, C3 and C4 of compost at 5%, 10%, and 15% compost/soil (w/w). The experimental device was completely randomized en bloc with 5 repetitions for each treatment. The physicochemical, biological and biochemical parameters of compost and amended soils, as well as tomato production were evaluated.&#x0D; The highest concentrations of nitrogen, phosphorus and potassium were obtained with C3 (1.96g/Kg) and C2 (0.42 g/Kg; 0.08 g/Kg) respectively. The different compost variants had a C/N ratio between 21.88 (C1) and 30.27 (C2) and their pH was basic. They were rich in exchangeable ions (Mg2+, Ca2+, K+, Na+) and poor in heavy metals (Pb, Zn, Cu). A significant increase in the C/N ratio was noted in all the amended soils compared to the unamended soil. It varied from 12.50±0.10 (unamended soil) to 30.55±2.04 (C1 10%). Exchangeable ion concentrations (Mg2+, Ca2+, K+, Na+) were higher in amended soils. The bacterial biomass varied from 347 x 105UFC/g (C4) to 609 x105UFC/g (C2) values significantly higher than that of the unamended soil (100 x105UFC/g). The fungal biomass varied from 470 x105UFC/g (C1) to 781 x105UFC/g (C2) values significantly higher than that of the unamended soil (120 x105UFC/g). The 15% C2 component presented the highest cellulase and protease activities with values 3 and 9 times higher than the unamended soil respectively. The compost variants C2 and C1 (15%) were generally more productive with respective values of 85 and 69 fruits, the tomato amended with the chemical fertilizer having given 24 fruits.&#x0D; These results show that compost made from chicken droppings and fish bones could contribute to the development of green manure to enrich the soil, thus improving tomato production.

• #banana cultivation and research
• #phytase and its applications
• #legume nitrogen fixing symbiosis
• #compost

Characterization of Compost Made from hen Manure and Wood Ash and Its Effect on Soil Properties, Production and Nutritional Quality of Tomato (Lycopersicon esculentum Mill.)

Tchinda Fokoua Stella Laure, Dakolé Daboy Charles, Molemb Nemeté Aristide, Okala Bouillong Noelly Manuela, Martin Fonkoua, Julienne Nguefack

Asian Journal of Soil Science and Plant Nutrition

The effect of a compost based on chicken manure and wood ash on the production and nutritional quality of tomatoes was evaluated. The mixtures of the constituents of each compost were made at variable m/m proportions: 25/75 (C1); 50/50 (C2); 75/25 (C3) and 100/0 (C4). Tomato cultivation in pots was done in completely randomized random blocks with 5 repetitions, and 3 compost/soil m/m proportions (5%, 10% and 15%). The physicochemical and biochemical parameters of the compost and the amended soil, as well as the production and nutritional quality of the fruits, were evaluated. The compost showed higher pH values than the unamended soil. The C3 variant exhibited the highest pH (9.97±0.00). The C/N ratio varied from 14.78±0.67 to 15.30±0.35 values higher than that of the unamended soil (11.86±0.27); exchangeable ion concentrations were higher in the compost. The microbial biomass and the enzyme activities of the compost were significantly higher than those of the unamended soil, the greatest values were obtained with the C3 variant. pH, EC, C/N ratio, and exchangeable ion concentrations were higher in all treated soils than in soils amended with chemical fertilizer. Tomato production was higher with the variant (15% C3) with a value of 156.00 ± 1.00 fruits, the soil amended with chemical fertilizer having given 14.00 ± 1.00 fruits. Biological tomatoes obtained with compost were richer in lycopene, vitamin C, phenolic compounds and minerals than those obtained with chemical inputs (Chemical tomatoes). The compost has improved the production and nutritional quality of the tomato, which is an efficient alternative for sustainable agriculture.

• #composting and vermicomposting techniques
• #growth and nutrition in plants
• #banana cultivation and research
• #compost

Comparative Study of the Effect of Two Extraction Solvents on Polyphenols Content and Antioxidant Activity of Alstonia Boonei Bark

Marielle Anastasie Zali, Martin Fonkoua, Charles Dakolé Daboy, William Arnold Tazon, David Goda, Dupon Ambamba Akamba et 2 autre(s)

Asian Journal of Chemical Sciences

Oxidative stress (OS) is the imbalance between the generation of reactive oxygen species (ROS) and the body's antioxidant defenses in favor of ROS. ROS are chemical species that can be neutralized by natural phytochemicals like phenolic compounds present in medicinal plants and whose extraction depends on the solvent system used. Thus, the present study aimed to evaluate the effect of two extraction solvents on the polyphenols content and antioxidant activity of Alstonia boonei barks. For this, the bark of A. boonei were harvested, processed, dried and ground, then the powder was macerated in two solvent systems (water and water-ethanol). Subsequently, the quantitative phytochemical analysis of the different extractions was done by evaluating total polyphenols content (TPC), total flavonoids content (TFC) and alkaloids; followed by an in vitro evaluation of the antioxidants activity through radicals scavenging (DPPH and NO.) and the reducing power of ferric iron to ferrous iron. The relationship between antioxidant potential (DPPH, NO and FRAP) and polyphenols (total polyphenols and total flavonoids) was investigated using simple linear regression. It appears that the aqueous extract allowed better extraction of phenolic compounds from A. boonei bark; and exhibited better antioxidant activity. In addition, a strong correlation (r and R2) was found between polyphenols (TPC and TFC) and antioxidant activity (DPPH, NO and FRAPP). Thus, we preferably recommend the use of water as a solvent for traditional preparations of A. Boonei bark extract for therapeutic purposes.

• #botanical research and applications
• #microbial metabolites in food biotechnology
• #dpph
• #polyphenol

Compost Made from Cow Dung and Sawdust Improves the Physicochemical and Biochemical Properties of the Soil, the Production and the Nutritional Quality of Tomatoes (Lycopersicon esculentum Mill.)

Lekini Bela Jean Gérard, Dakolé Daboy Charles, Molemb Nemeté Aristide, Okala Bouillong Noelly Manuela, Martin Fonkoua, Julienne Nguefack

Asian Journal of Soil Science and Plant Nutrition

The effect of a compost based on cow dung and sawdust on the production and nutritional quality of tomatoes was evaluated. The compost was prepared by mixing the different constituents in variable mass/mass proportions: 25/75, 50/50, 75/25 and 100/0. The experimental device for growing tomatoes in pots was made in completely randomized random blocks with 5 repetitions, and 3 compost/soil mass/mass proportions (5%, 10% and 15%) for each variant. The physicochemical, biological and biochemical parameters of the compost and amended soils, the production and the nutritional quality of the fruits were evaluated. The C3 variant of compost showed the highest pH (9.88 ± 0.01); C4 presented the highest C/N ratio (21.45 ± 0.42); C2 showed the highest contents of nitrogen, phosphorus, magnesium, calcium, potassium, and sodium, the highest values of bacterial and fungal flora and cellulase, protease, β-glucosidase, acid and alkaline phosphatase activities. Analysis of amended soils showed that: C2 (15%) has the highest pH. C1 (10%) presented the highest C/N ratio (42.12 ± 3.98) and C3 (15%) the highest contents of nitrogen, magnesium ions and calcium. C4 (15%) presented the highest potassium and sodium content. The compost significantly improved tomato production. The C2 (15%) compost was the most productive with 154 ± 3.00 fruits, 10 times more than the tomato produced with chemical fertilizer (15.00 ± 1.00 fruits). The Biological tomato showed higher proportions of ash, total sugars, lycopene, vitamin C and polyphenols than the chemical tomato. The results show that the organic treatment improved the physicochemical, biological and biochemical properties of the soil, the production and the nutritional quality of the tomato. The compost constitutes therefore an efficient method for sustainable agriculture.

• #composting and vermicomposting techniques
• #plant growth and agriculture techniques
• #agronomic practices and intercropping systems
• #compost

Differential Changes in Some Antioxidant Enzymes and Biomolecules in Leaves of Tomato Infected by Phytophthora infestans (Mont.) de Bary

Dakolé Daboy Charles, Bekono Mamdjara Larry Axel, Martin Fonkoua, Molemb Nemeté Aristide, Dongmo Lekagne Joseph Blaise, Julienne Nguefack et 1 autre(s)

Asian Journal of Advances in Agricultural Research

In Cameroon, tomato yields remain low due to attack by pathogens and insects. Phytophtora infestans (PI) is a phytopathogenic fungus responsible for the downy mildew of tomatoes, a fungal disease responsible for enormous economic losses. To contribute to the search for means of control, the stimulatory effect of the tomato defence system by extracts of some plants was evaluated. Tomato plants were treated with the aqueous macerates of Callistemon citrinus (C. citrinus) and Cymbopogon citratus (C. citratus) at 10% (W/V). After 4 days of spraying with the macerates, plants were inoculated with a virulent strain of PI. Tomato leaves collected at 2-day intervals for 10 days were used to determine the contents of chlorophyll a, proteins, carbohydrates, lipids, amino acids and proline. The activities of the main antioxidant enzymes were also assessed: Ascorbate Peroxidase (APX), Phenylalanine Ammonia Lyase (PAL), Peroxidase (POX), Superoxide Dismutase (SOD). The results showed that treatment of tomato plants with aqueous macerates of C. citrinus and C. citratus and their inoculation with PI induced an increase in chlorophyll a, protein, carbohydrate, lipid, amino acid and proline contents in tomato leaves; an increase in APX, PAL, POX, and SOD activities. Our results suggested that increased metabolite synthesis on the one hand, and increased enzymatic activities, on the other hand, could mitigate the oxidative damage that occured during pathogen expansion. Aqueous macerates of C. citrinus and C. citratus could be used as natural products to stimulate the defence system in tomato against Phytophtora infestans.

• #agriculture, plant science, crop management
• #apx
• #cymbopogon citratus
• #chemistry

Plant Extracts Induced Resistance to Fusarium oxysporum f.sp. lycopersici in Tomato

Dakolé Daboy Charles, Azah Udom René, Martin Fonkoua, Dongmo Lekagne Joseph Blaise, Julienne Nguefack, Irénée Somda

International Journal of Plant & Soil Science

Tomato (Lycopersicon esculentum Mill.) is the most consumed vegetable in the world after potato. In Cameroon, the plant is cultivated in almost all agroecological areas, however, yields remain low due to attacks by various pathogens and insects. Among the pathogens, Fusarium oxysporum f.sp. lycopersici (FOL) is a phytopathogenic fungus responsible for Fusarium wilt, a disease responsible for enormous economic losses. To contribute to the control of this microbial pathogen, the stimulatory effect of the tomato defence system of extracts of some plants in the tomato/FOL interaction was evaluated. Tomato plants were treated with the aqueous extracts (AE) of Callistemon citrinus (C. citrinus), Cymbopogon citratus (C. citratus), and Oxalis barrelieri (O. barrelieri ). After 4 days of spraying with the extracts, the plants were inoculated with a virulent strain of Fusarium oxysporum f.sp. lycopersici (FOL) under controlled conditions. Tomato roots were used to determine the contents of hydrogen peroxide (H2O2), phenols and malondialdehyde (MDA). The activities of the main antioxidant enzymes were also evaluated in tomato roots: catalase (CAT), phenylalanine ammonia lyase (PAL), peroxidase (POX) and superoxide dismutase (SOD). The results showed that treatment of tomato plants with plant extracts and their infection with FOL induced an increase in the contents of H2O2, phenols and MDA in tomato roots; an increase in PAL, POX, SOD activities and a reduction in CAT activity. Our results suggest that the increase and reduction of enzymatic activities, and the increase in the synthesis of some metabolites could mitigate the oxidative damage that takes place during the expansion of the pathogen. Aqueous extracts of C. citrinus, C. citratus and O. barrelieri at 10% (W/V) could be used as natural products to stimulate the tomato defence system against FOL. These results could contribute to the development of natural products to induce tomato resistance against FOL, thus improving productivity, quantity and quality of production.

• #plant pathogens and fungal diseases
• #essential oils and antimicrobial activity
• #plant-microbe interactions and immunity
• #fusarium oxysporum

Effect of aqueous extract of Scorodophloeus zenkeri bark on chronic hyperglycemia and its complications in a diabetic Wistar rat model induced by streptozotocin

Martin Fonkoua, Marielle Zali Ze, William Arnold Tazon, Janvier Youovop, Guy Takuissu Nguemto, Judith Laure Ngondi

Metabolism Open

Diabetes and its complications represent a real major public health problem in the world because of its high rates of morbidity and mortality. Chronic hyperglycemia, oxidative stress, dyslipidemia and inflammation play a major role in the pathophysiology of diabetes and its vascular complications. The objective of this study was to evaluate the effect of aqueous extract of S. zenkeri on chronic hyperglycemia and its complications in a streptozotocin-induced diabetic Wistar rat model. The barks of S. zenkeri were washed, dried and crushed; the powder was dissolved in distilled water (1:10 weight/volume) then macerated and the filtrate obtained was dried in an oven. Subsequently, after quantification of the bioactive compounds (total polyphenols, flavonoids and alkaloids) present in the extract, an in vivo study was conducted in an animal model of streptozotocin-induced hyperglycemia. For this fact, the rats were divided into four groups of five rats as folow: a normoglycaemia group (NC), an untreated hyperglycaemia group (PC), two hyperglycaemia groups including a test group receiving by esophageal gavage, the aqueous extract of the bark of S zenkerii (AESZ) at a dose of 300 mg/kg body weight and a control group receiving metformin at a dose of 20 mg/kg body weight. During the treatment which lasted 21 days, the weights have been taken every two days and the blood sugar levels every week. At the end of the treatment, the rats were killed under light chloroform anesthesia; the plasma, hemolysate, serum and liver homogenate prepared were used to assay the biochemical parameters of oxidative stress (catalase, MDA), lipid profile (Triglycerides, total cholesterol and HDL-cholesterol) and immunological (CRP and NFS). It emerged that the extract limited weight loss and caused a reduction in blood sugar of -26.59% after 21 days of treatment; the extract caused an increase in the activity of erythrocyte catalase and a reduction in the concentration of hepatic MDA, as well as a very marked reduction in inflammatory cells and CRP. The extract also caused a reduction in dyslipidemiawhich was materialized by a reduction in CRR, AC, AIP and an increase in CPI. These results suggest that this extract contains bioactive compounds capable of reducing chronic hyperglycemia while preventing its complications, thus justifying its traditional use in the management of diabetes.

• #natural antidiabetic agents studies
• #phytochemicals and antioxidant activities
• #advanced glycation end products research
• #streptozotocin

Effectiveness of 3 Polyherbal Formulations (EcXaPu, EcXa, and EcPu) on the Management of Oxidative Stress and Hyperglycemia

Nadine Ndoe Essola, Guy Roussel Takuissu, Martin Fonkoua, Janvier Youovop, Damaris Enyegue Mandob, Judith Laure Ngondi et 1 autre(s)

Nutrition and Metabolic Insights

Oxidative stress and hyperglycemia are major disorders involved in the occurrence and severity not only of chronic non-communicable diseases but also of infectious pathologies. This study aimed to evaluate the in vitro antioxidant and antihyperglycemic properties of EcXaPu, EcXa, and EcPu. The antioxidant properties were evaluated using 3 mechanisms: radical scavenging; reducing property, and metal chelating. Finally, the antihyperglycemic properties were evaluated by 2 mechanisms: glucose adsorption and cellular glucose capture. The different formulations showed their ability to scavenge DPPH, ABTS, and NO radicals with SC 50 ranging from 2.75 to 3.51 mg/ml, from 2.6 to 2.76 mg/ml, and from 2.59 to 3.3 mg/ml, respectively. All the formulations also reduced MoO 4 2+ and Fe 3+ and chelated Cu 2+ and Fe 2+ . The different formulations adsorbed the glucose with glucose adsorption rates ranging from 72.83% to 87.01%. The different formulations also stimulated cellular glucose uptake, with uptake rates ranging from 31.9% to 50.71% in yeast cells and from 21.81% to 39.45% in muscle cells. These formulations could be potential agents to prevent and/or protect against biological disorders associated with oxidative stress and hyperglycemia.

• #phytochemicals and antioxidant activities
• #natural antidiabetic agents studies
• #antioxidant activity and oxidative stress
• #oxidative stress

Flavonoid-enrich extract of Autranella congolensis (Sapotaceae) protects against aluminium chloride-mediated Alzheimer’s disease-like oxidative stress in rat through the antioxidant properties

Dany Joël Ngassa Ngoumen, Damaris Enyegue Mandob, Fils Armand Ella, Bruno Dupon Akamba Ambamba, Jules Vidal Kamga Nanhah, Martin Fonkoua et 1 autre(s)

Metabolic Brain Disease

• #aluminum toxicity and tolerance in plants and animals
• #medicinal plants and neuroprotection
• #natural antidiabetic agents studies
• #sapotaceae

In vitro anticholinesterase potential of some spices consumed in Cameroon and their protective effects on hydrogen peroxide-mediated oxidative stress damage in SK-N-SH cells

Ruth Edwige Kemadjou Dibacto, Dany Joël Ngassa Ngoumen, Fils Armand Ella, Jules Vidal Kamga Nanhah, Bruno Dupon Akamba Ambamba, Pauline Vervaine Hagbe et 4 autre(s)

IBRO Neuroscience Reports

Background Many neurodegenerative such as Alzheimer's disease (AD) are characterized by cholinergic dysfunction and oxidative stress which is a key event in neuronal death process. Thus, anticholinesterase and anti-oxidation compounds are two promising strategies in the development of AD drugs. Beyond their culinary use, spices are today studies for health purpose. In this study, some spices consumed in Cameroon were evaluated for their anticholinesterase and neuroprotective effects. Methods Colorimetric methods were used to determine total flavonoid and alkaloid content of a combinated extract (hydroethanolic + ethanolic extracts) of different selected spices. Aftermaths, anti-cholinesterase activity of spice extract was carried out using Ellman's method. Finally, neuroprotective effects performed on human SK-N-SH cells stressed with H 2 O 2 by assessing neuronal survival ( resazurin assay) and neuronal death (LDH assay). Results Flavonoid content of spices extract were ranged from 22.94 to 32.01 mg EQ/g DM and alkaloid content were ranged from 320 to 896 mg EQu/g DM. Among the spices studied, Xylopia parviflora presented the greatest acetylcholinesterase inhibition with an IC50 = 14 µg/mL. In Cell culture experiments, pre-incubation of SK-N-SH cell with the selected spices at different concentrations were improved neuronal survival and reduced the percentage of neuronal cells dead. Conclusion The present results reveal that selected spices consumed in Cameroon have good anticholinesterase activity as well as neuroprotective effect on SK-N-SH which may provide new natural compounds that could help in the management of Alzheimer's disease.

• #cholinesterase and neurodegenerative diseases
• #medicinal plants and neuroprotection
• #ginkgo biloba and cashew applications
• #neuroprotection

Lipomodulatory and anti-oxidative stress effects of a polyherbal formulation based on garlic and avocado seed extracts on high fat high sucrose diet fed rats

Boris K. G. Azantsa, Ntentie F. Raissa, Mbong Angie Mary-Ann, Mafongang Amelie, Kamtchoum Alexine, Momo Cliffbrown et 5 autre(s)

Metabolism Open

To determine antioxidant potentials of Allium sativum and Persea americana seeds extracts and three formulation-based extracts in vitro, and to evaluate the effects of the best formulation on oxidative stress and dyslipidemia on rats fed with high fat and high sucrose diet (HFHSD). Aqueous extracts of Allium sativum, Persia. americana and three formulations were mixed at various portions (A. s/P. a; w/w): F (1:1), F (3: 1), and F(1:3). They were then tested for their antioxidant potentials in vitro using FRAP, DPPH and NO radicals to identify the best formulation. Four hundred (400) mg/kg b.w. of formulation F(1:1) were administered once daily for 21 days to rats previously fed with HFHSD for 8 weeks. Standard diet, vitamin E, and Atorvastatin were used as controls. After 21 days, body weight, blood glucose, lipid markers, activities of transaminases and markers of the antioxidant systems were assessed. The Formulation F(1:1) showed the best in vitro activity with IC50 values of 6.5 and 2.23 mg/mL respectively for FRAP and DPPH- radical scavenging capacity. HFHSD caused a depletion of antioxidants associated with an increase of pro-oxidants and all the lipid markers except HDL-c Treatment with F(1:1) significantly increased TAC, SOD, and catalase activities, while MDA, protein carbonyls, and NO levels decreased (p < 0.05). Formulation F(1:1) decreased triglycerides (119.88 ± 4.25 mg/dL) and LDL-c (3.78 ± 0.66 mg/dL) levels and significantly increased the HDL-c level: (108.07 ± 6.29 mg/mL). Furthermore, Formulation F(1:1) significantly caused weight loss (2.31%), reduced blood glucose levels (27.38%) and ALT activity. The formulation F(1:1) could be a good candidate for the prevention and treatment of oxidative stress, dyslipidemia and features of metabolic syndrome.

• #phytochemicals and antioxidant activities
• #psidium guajava extracts and applications
• #garlic and onion studies
• #oxidative stress

Relationship between Adiposity, Low-Density Lipoprotein Particles Size and Cardiovascular Risk among Adult Obese Cameroonians

Jacob Tchinda Nkougni, Françoise Raïssa Ntentié, Martin Fonkoua, Boris Gabin Kingue Azantsa, Guy Roussel Takuissu Nguemto, Evelyn Ngwa Lumngwena et 2 autre(s)

Open Journal of Epidemiology

Background: Despite the evidence about the increasing prevalence of dyslipidemia among adult obese Cameroonians, little is known about the Low-Density Lipoprotein (LDL) particles which influence lipid metabolism and affect cardiovascular status. The present study aims to assess the relationship between adiposity, LDL particles size and cardiovascular risk (CVR) among adult obese Cameroonians. Methods: A cross-sectional study was conducted from September 2015 to March 2016 on apparently healthy adults (n = 1006), aged 20 - 70 years and living in the West and North-West regions of Cameroon. Anthropometric measurements, blood pressure (BP), fasting blood glucose (FBG) and lipid profile markers were analyzed and LDL particle phenotypes (LDL phenotype A; LDL phenotype I; LDL phenotype B) were characterized using small, dense LDL-cholesterol (sdLDL-c) levels. Abdominal fat accumulation (AFA) was defined as waist circumference (WC) ≥ 88 cm (men) and ≥90 cm (women) and the CVR was assessed using Framingham score method. Results: In the overall population, 36.6% were overweight, 33.1% were obese and 69.1% were overweight/obese with AFA. The prevalence of LDL phenotype B was 19.8%, 37.5% and 42.8% respectively in normal-weight, overweight and obese. Among the obese, sdLDL and triglycerides levels correlated significantly with WC (r = 0.768; p < 0.05 and r = 0.768; p < 0.05 respectively) and body mass index (BMI) (r = 0.895; p < 0.01 and r = 0.676; p < 0.01 respectively). The risk of having LDL phenotype B in overweight/obese patients with higher CVR was three times greater in overweight/obese patients with AFA (OR: 3.1; CI 95% (0.8 - 9.1); p = 0.007) as compared to those without AFA (OR: 1.6; CI 95% (0.8 - 2.9); p = 0.021). Conclusion: Among obese Cameroonians, anthropometric markers of adiposity (BMI and WC) were strongly correlated to LDL phenotype B which was associated with high CVR dependently of AFA. SdLDL particles could exacerbate the CVR in obese Cameroonians subjects.

• #lipoproteins and cardiovascular health
• #cancer, lipids, and metabolism
• #diabetes, cardiovascular risks, and lipoproteins
• #medicine

Subacute effects of hydroethanolic extracts of the pulp of Gambeya africana on glucose plasmatic levels and oxidative stress markers in diabetic rats

Guy Roussel Takuissu, Martin Fonkoua, Damaris Enyegue Mandob, Dany Joël Ngassa Ngoumen, Bruno Dupon Akamba Ambamba, Jules Vidal Kamga Nanhah et 1 autre(s)

Metabolism Open

The management of hyperglycemia and oxidative stress is a key point in the control of diabetes and its complications. The work evaluated the hypoglycemiant and antioxidant properties of pulp extracts of Gambeya africana fruits. The acute toxicity was conducted for 14 days at the dose of 2000 mg/kg via oral gavage. Diabetes was induced in rats by intravenous administration of streptozotocin (50 mg/kg). The effect of the extract on blood glucose levels of diabetic rats was monitored at 2h after administration; and on the 7th and 14th days of treatment (single dose of 400 mg/kg/day). After 2 weeks of treatment, the rats were sacrificed. The oxidative stress markers (Hydroperoxides, Malonedialdehydes, Superoxide Dismutase, Catalase, and Total Antioxidant Capacity) and hepato/nephrotoxicity markers (Alanine Amino Transferase, urea, and creatinine) were determined. The hydroethanolic extract of G. africana fruits has a lethal dose upper than 2000 mg/kg. It significantly decreased glucose levels by 28.29% and 84.86% respectively after 2h and 14th days of treatment. The extract increased the antioxidant status and decrease oxidative stress, especially in the pancreas. This study suggests that the hydroethanolic pulp extract of G. africana fruits is a good hypoglycemiant and antioxidant agent and could be a potential source of compounds for diabetes management.

• #natural antidiabetic agents studies
• #african botany and ecology studies
• #natural compound pharmacology studies
• #oxidative stress

The neuroprotective effect of Xylopia parviflora against aluminum chloride-induced neurotoxicity in rats

Ruth Edwige Kemadjou Dibacto, Bruno Dupon Akamba Ambamba, Fils Armand Ella, Christine Fernande Biyegue Nyangono, Jules Vidal Kamga Nanhah, Martin Fonkoua et 2 autre(s)

Heliyon

Neurodegenerative disease such as Alzheimer's disease, are progressive disorders which has been linked to oxidative imbalance and associated perturbations characterised by loss of memory, cognition and cholinergic deficit. To date, cholinesterase inhibition and neuroprotection are the two major strategies in drug development. Xylopia parviflora (Annonacea family) is a spice consumed in Cameroon and has been used in traditional medicine to treat various pains. In this study, X. parviflora was evaluated on behavioural studies, ion homeostasis, cholinesterase inhibitory and antioxidant activities. Rats were exposed to aluminium chloride (75 mg/kg) during 60 days, and were treated with the extract of X. parviflora (150 and 300 mg/kg BW) and two drugs references (Donepezil and Curcumin). Behavioural parameters were assessed using the Morris-Maze test and the Open Field, followed by biochemical investigations, namely, cholinesterase enzyme activity (AChE and BChE), oxidative stress (NO, MDA, GSH level, SOD and Catalase activities) and ion homeostasis (Mg 2+ and Ca 2+ levels). AlCl 3 administration shows a decrease in learning and memory improvement during behavioural studies, significant alteration of the central cholinergic system characterised by an increase in AChE and BChE activities to 2.72 ± 0.002 mol/min/g and 5.74 ± 0.12 mol/min/g respectively, disturbance of ion homeostasis with an increase in Ca 2+ level (25.68 ± 3.78 μmol/mg protein) and a decrease in Mg 2+ level (15.97 ± 2.05 μmol/mg protein) and an increase in oxidative stress compared to the positive control group. Treatment with the different doses of X. parviflora increased memory and improved locomotion, improved cholinesterase activities, ion homeostasis and stabilized brain oxidative stress levels. The study suggests that X. parviflora could potentially be used for the management of some biochemical alterations associated with Alzheimer's disease. It could even be a good alternative to chemical drugs for neurotoxicity and memory enhancement.

• #aluminum toxicity and tolerance in plants and animals
• #medicinal plants and neuroprotection
• #alzheimer's disease research and treatments
• #neurotoxicity