Testicular antioxidants and testosterone enhancing effects of the hydro-ethanolic extract of Rauvolfia vomitoria (Apocynacaea) in male Wistar rats

Background: Natural products such as extracts of plants have been seen as a possible alternative to conventional therapies in the treatment and management of male infertility. This study aimed at investigating the testicular antioxidant and testosterone enhancing ability of the hydro-alcoholic extract of Rauvolfia vomitoria in male rats. Methods: Twenty-four male rats were divided into four groups of 6 rats each, treated daily with either vehicle (distilled water; 5 mL/kg) or hydro-ethanolic extract of R. vomitoria (20 mg/kg, 40 mg/kg, and 100mg/kg) for 60 days, and body weights recorded once every three days. At the end of the treatment, each animal was sacrificed, and reproductive organs were dissected out and weighed. Serum from capillary blood was used for testosterone quantification, while testicular homogenates were used for the estimation of antioxidant biomarkers. Results: Treatment with R. vomitoria extract did not alter the animal’s body weight. Instead, the extract at the dose of 40 mg/kg significantly increased (P< 0.05) the weights of all reproductive organs investigated. The plant extract also increased serum testosterone concentrations significantly (P< 0.05), with the highest effect observed in the animals treated with a dose of 40 mg/kg. Testicular antioxidant markers, thiobarbituric acid substances, glutathione, and catalase were equally improved (P< 0.05) by treatment with the plant extract at the dose of 40 mg/kg. Conclusion: Hydro-ethanolic extract of R. vomitoria portrayed beneficial pharmacological properties on reproductive organs, testicular antioxidants, and testosterone concentrations in male rats. These pharmacological activities support the traditional use of the plant in the management of male fertility disorders.

Anthelmintic effect of Portulaca oleracea Linne (Portulacacea) against gastrointestinal parasites Haemonchus contortus Rudolphi and toxicity screenings

Background: The resistance of gastrointestinal worms to synthetic anthelmintics (Levamisole) leads us to highlight the Cameroonian pharmacopoeia. The main objective of the present work is to look for an alternative treatment for haemonchosis, based on active secondary metabolites, from Portulaca oleracea, with less or no side effects and accessible to all. Methods: The Haemonchus contortus cycle test was performed at varying concentrations. Levamisole and PBS were the positive and negative controls respectively. Phytochemical screening was performed by standard staining and precipitation methods. Acute and sub-acute toxicity tests of Portulaca oleracea EA were performed according to OECD 425 and 407 respectively. Results: EM at 48 h of incubation inhibited eggs with an LC50 of 3.44. There was more larvicidal effect of ME with an LC50 value of 3.54 at 48 h incubation. At 24 h of incubation at the final concentration of 1000 µg/mL the anthelmintic effect of EA, ME and levamisole were noted with LC50 values of 0.057, 0.096, and 0.069 respectively. Phytochemical screening revealed the presence of some secondary metabolites in EA and ME of Portulaca oleracea. The result of the assays shows that ME is richer in total polyphenol (50.884 mg EAG/g DM) and flavonoids (5.688 mg RE/g DM) compared to EA which has (12.998 mg EAG/g DM) and (1.847 mg EC/g DM) respectively. However, there are more tannins in EA (5.688 mg RE/g DM) compared to ME (1.847 mg EC/g DM). The acute and subacute toxicity test showed no toxicity in mice and rats respectively. Conclusion: In view of the above, Portulaca oleracea possesses anthelmintic effects on the parasite Haemonchus contortus and is not toxic at the experimental therapeutic dose, which may open a way for the searching of a new anthelmintic drug. Keywords: Haemonchus contortus; Portulaca oleracea; Levamisole; Phytochemical screening; Toxicity.

GC-MS analysis and physiochemical properties of Enterolobium cyclocarpum (elephant ear) seed oil

Background: The present study aimed to extract, evaluate the physicochemical properties, and chemical characterization of the seed Enterolobium cyclocarpum. E. cyclocarpum is a legume of the Leguminosae family. It is used as foliage, for animal feeding and oil is extracted for several application in folk medicine for the treatment of sore throat, colds, diarrhea, headache, intestinal ailments, and stomachache. The leaf infusion is used as a laxative In the West Indies; seeds are chewed for a sore throat. Methods: Three hundred grams (300 g) of each of the pulverized samples were extracted with 100% hexane using Soxhlet extractor to produce a light-brown oil of low viscosity. The physicochemical properties of the oil were analyzed using AOAC standard methods, while the oil components were characterized on an HP-5MS column Gas Chromatography coupled with Mass Spectrometry (GC-MS). Results: The yield of the oil is very low (only 4.11 % by weight), Fatty acid composition showed that undecanoic acid methyl ester (36.68%) was the dominant fatty acid, followed by 3-linoleic acid (25.04%), and 2-linolelaidic acid methyl ester (12.98%). Physicochemical properties of themed oil were moisture content (0.85%); refractive index (25oC), 1.45; Specific gravity, 0.86±0.02; iodine value, 68.55±0.02/100 g of oil; peroxide value, 6.58±0.03 meq. O2/kg of oil; free fatty acids, 2.63±0.01 mg of KOH/g of oil; acid value, 5.26±0.02 mg of KOH/g of oil; saponification value, 189.00±0.03; Unsaponifiable value, 0.66±0.01%. Conclusion: This study has shown that the seed oil of E. cyclocarpum displayed properties and constituents as a substitute oil for industrial, pharmaceutical, and domestic applications.

Phytochemical analysis and antibiotic-modulating activity of Cocos nucifera, Glycine max and Musa sapientum methanol extracts against multidrug resistant Gram-negative bacteria

Background: The rapid emergence of multidrug resistant (MDR) bacteria is occurring worldwide, endangering the efficacy of antibiotics, which have transformed medicine and saved millions of lives. Antibiotic-resistant infections are already widespread in the Sub-Saharan Africa and across the globe. To extend the search for new and more efficient antimicrobial drugs from natural sources, this work has been carried out to study the phytochemical composition and the antibacterial activities of some Cameroonian dietary plants (Cocos nucifera, Glycine max and Musa sapientum) against several MDR Gram-negative strains including Escherichia coli, Enterobacter aerogenes, Providencia stuartii, Klebsiella pneumoniae, Pseudomonas aeruginosa species expressing efflux pumps. Methods: Phytochemical screening of plant extracts was performed using qualitative standard methods and the antimicrobial assays of these extracts alone and in combination with antibiotics were done using serial 96-wells microplate dilution essays. Results: Each plant extract contained at least three mean classes of secondary metabolites. Glycine max, epicarps, leaves and bark of C. nucifera as well as mesocarps of M. sapientum contained each alkaloids, polyphenols, flavonoids, and triterpenes. Moreover, steroids were also found in G. max, steroids and saponins in epicarps and saponins in bark of C. nucifera. Meanwhile epicarps from M. sapientum contained only polyphenols, flavonoids and saponins. Antibacterial assays showed that different parts of C. nucifera were more active than other extracts. Their minimal inhibitory concentrations (MICs) varied from 128 to 2048 µg/mL. The bark part presented the highest antibacterial potential inhibiting the growth of 90% of strains with significant activity (100≤MIC≤512 µg/mL) against 50% of them (three E. coli, four E. aerogenes and three K. pneumoniae). It showed bactericidal effects (MBC/MIC≤4) on 45% of the same bacterial species. It was followed by epicarps and leaves parts which exhibited an inhibitory power against 75% and 60% of bacteria with significant activity on 40% and 20% of them respectively. They also showed bactericidal effects on E. coli ATCC8739 for epicarps extract and E. coli ATCC8739 and P. stuartii NEA16 for leaves extract. Extracts from G. max were less active and those from mesocarps and epicarps of M. sapientum did not showed any activity on all studied bacteria. Bark and epicarps extracts of C. nucifera potentiated the activities of all used antibiotics against at least 70% of bacteria while leaves extract exhibited this effect improving the activities of 67% of antibiotics with improvement activity factors (IAF) ranging from 2 to 256 suggesting that they contain bioactive compounds which could be considered as efflux pumps inhibitors. Extracts from G. max, epicarps and mesocarps of M. sapientum enhanced the inhibitory potential of 56%, 34% and 23% of antibiotics respectively against at least 70% of studied bacteria. These increases of activities also characterize synergistic effects between antibiotics and bioactive compounds of plants. Conclusion: The findings of this work suggest that infections by resistant bacteria can be treated using different parts of C. nucifera as an alternative to commonly used antibiotics.

Antidiabetic activity of aqueous extract of leaves of cnestis ferruginea vahl ex DC. (Connaraceae) on alloxan-diabetic induced mice.

Background: Cnestis ferruginea is a plant species widely used in the traditional african medicine to treat diabetes mellitus. The present study aimed to evaluate the antidiabetic activities of the aqueous extract of the leaves of Cnestis ferruginea (AECF) in diabetic mice. Methods: The mice were grouped into five groups of five animals per group: Group A was not induced with alloxan, Group B animals were induced but not treated, Group C animals were treated with 500 mg / kg of BW of metformin, Group D and E animals were treated with 100, 200 mg/kg BW of AECF respectively. The extracts were administered to the animals orally for 14 days. Fasting blood sugar was measured by a glucometer. Serum concentrations of hematological and biochemical parameters were measured by standard methods. Results: The animals administered with 100 and 200 mg/Kg B.W of extract showed highly significant decrease (P ˂ 0.0001) in blood sugar level compared to the untreated animals. The 100 mg / kg BW dose of AECF produce low significant decrease (P <0.05) of total cholesterol, HDL Cholesterol, AST, ALT, urea, levels of white blood cells, platelets, hematocrit. The 200 mg / kg BW dose of AECF produce in addition significant decrease (P <0.01) of AST and urea. Conclusion: The 200 mg / kg dose of BW of AECF had a greater antidiabetic activity than the dose of 100 mg / kg BW. Keywords: Cnestis ferruginea; antidiabetic activity; alloxan; diabetes mellitus.

Antioxidant and antifungal activities of Myrianthus arboreus P. Beauv. (Moraceae), Allanblackia gabonensis Pellegr. (Clusiaceae) and three other Cameroonian medicinal plants

Background: Biological activities of medicinal plants make them attractive alternative complementary medicines. Therefore, this study aimed to assess the antioxidant and antifungal activities of the methanol extract of Myrianthus arboreus, Allanblackia gabonensis, Gladiolus quartinianus, Peperomia fernandopoiana and Vepris soyauxii. Methods: Total phenolic contents (TPC) and flavonoid contents (FC) were evaluated using standard methods. The antioxidant activity of the extracts was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing power assays. Antifungal activity was evaluated by the broth micro-dilution method. Results: TPC of extracts ranging from 67.89 to 196.01 mgGAE/g TPC were very higher in P. fernandopoiana whole plant (PFW) extract (196.01±10.25 mgGAE/g) and MAL (165.71±10.68 mgGAE/g) whereas the A. gabonensis fruit extract (AGF) and M. arboreus bark extract (MAB) had the highest flavonoid content (66.54 ± 2.12 and 48.13 ± 1.65 mgEC/g of extract, respectively). Apart from M. arboreus leave extract (MAL), all extracts showed important DPPH radical scavenging activity (IC50 < 20 μg/mL). AGFl and PFW exhibited significant ferric reducing power compared to ascorbic acid and other extracts (P<0.05). Each of the tested extracts showed antifungal activity against atleast one of the five pathogenic fungi, with MICs ranging from 128 to 1024 µg/mL. MAL was active on all the tested fungi whereas MAB showed the highest antifungal activity (MIC=128 µg/mL). Conclusion: The findings of this study emphasize the evidence that the methanol extracts of the leave and bark of Myrianthus arboreus could be an alternative to fight against oxidative stresses and infections due to opportunistic yeast pathogens. Keywords: Oxidative stress; fungal infection; medicinal plant; antioxidant activity; antifungal activity.

Anti-oedematous and antinociceptive activities assessment of stem bark aqueous extract of Ficus exasperata Vahl. (Moraceae) in rat and mice.

Background: Ficus exasperata Vahl. (Moraceae) is widely used in African traditional medicine for the treatment of various diseases. The present study is undertaken to assess the anti-oedematous and antinociceptive activities of the stem bark aqueous extract of Ficus exasperata in mice and rats. Methods: The anti-oedematous activity was investigated following carrageenan or histamine-induced rat paw oedema models. Antinociceptive activity was evaluated using acetic acid induced writhing test (1 %, 10 ml/kg), capsaicin-induced neurogenic pain (32 µg/mL, 30 µL) and formalin-induced test (1%, 20 µL). Extract was administrated orally at 37.5, 75 and 150 mg/kg. Results: Pre-treatment of rats with Ficus exasperata stem bark aqueous extract exhibited significant inhibition of paw oedema during all the phases of both carrageenan and histamine induced edema in rat. The maximum inhibition percentages were 94.75 % (3 h) and 30.64 % after one hour at the dose of 37.5 mg/kg, respectively, in carrageenan or histamine models. Antinociceptive activity showed that aqueous extract reduced significantly (p < 0.001) the pain induced by acetic acid with an inhibition percentage of 70.8% (150 mg/kg). In the formalin-induced test, the extract also reduced significantly (p < 0.001) licking time during neurogenic phase and inflammatory phase with inhibition percentages of 44.75% and 52.78% respectively at the dose of 75 and 150 mg/kg. In addition, aqueous extract of F. exasperata reduced significantly (p < 0.001) neurogenic pain induced by capsaïcin by 71.28 % at the highest dose (150 mg/kg). Conclusion: This finding suggests that the stem bark aqueous extract of Ficus exasperata possess potent anti-oedematous and antinociceptive activities.

In vitro antibacterial and antibiotic-potentiation activities of five edible plant extracts and mode of action against several MDR Gram-negative phenotypes

Background: Bacterial infections involving the multidrug resistant (MDR) strains are among the top leading causes of death throughout the world. Healthcare system across the globe has been suffering from an extra-ordinary burden in terms of looking for the new and more potent antimicrobial compounds. The aim of the present study was to determine the antibacterial activity of some Cameroonian edible plants (Garcinia lucida bark, Phoenix dactylifera pericarps, Theobroma cacao pod, Solanum macrocarpon leaves and Termitomyces titanicus whole plant) and their antibiotics-potentiation effects against some MDR Gram-negative bacteria phenotypes expressing efflux pumps (Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa and Providencia stuartii strains). Methods: The antibacterial activities of plant extract alone and in combination with usual antibiotics were carried out using the micro-dilution method. The effects of the most active plant extract (Garcinia lucida bark) on H+-ATPase-mediated proton pumps and on bacterial growth kinetic were performed using experimental protocols, while qualitative reference methods were used to highligh the major groups of secondary metabolites present in the extracts. Results: Qualitative phytochemical screening of plant extracts indicated that all analysed secondary metabolites were present in Theobroma cacao and Termitomyces titanicus while one (saponins) of them was absent in Garcinia lucida and Solanum macrocarpon. Only three of them (polyphenols, flavonoids and saponins) were detected in Phoenix dactylifera. Antibacterial essays showed that G. lucida was the most active plant as it inhibited the growth of all studied bacteria with strong activity (MIC<100 µg/mL) against E. coli ATCC8739, significant activity (100≤MIC≤512 µg/mL) against 80% of bacteria and moderate activity (512<MIC≤2048 µg/mL) against E. coli AG100A and E. aerogenes (EA289 and CM64). It was followed by T. cacao and S. macrocarpon extracts which exhibited an antibacterial potential against 95% and 80% of bacterial strains, respectively. These three extracts exhibited a bactericidal effect on a few bacteria. Extracts from T. titanicus and P. dactylifera were less active as they moderately (512<MIC≤2048 µg/mL) inhibited the growth of 35% and 10% of bacteria. All extracts selectively potentiated the activities of all antibiotics with improvement activity factors (IAF) ranging from 2 to 256. G. lucida, T. cacao and S. macrocarpon potentiated the activities of 100%, 89% and 67% of antibiotics respectively against more than 70%, suggesting that they contain bioactive compounds which could be considered as efflux pumps inhibitors. Whereas T. titanicus and P. dactylifera improved the activities of almost 40% and 20% of antibiotics, respectively. This increase of activities also characterizes synergistic effects between antibiotics and these bioactive compounds. G. lucida extract at all tested concentrations, strongly inhibited the growth of bacterial strain E. coli ATCC8739 and exhibited an inhibitory effect on this bacterial H+-ATPase-mediated proton pumps increasing the pH of the medium. Conclusion: The overall results indicated that food plants among which G. lucida, T. cacao and S. macrocarpon could have a benefit interest in combatting resistant types of bacteria. Keywords: Food plants; infectious diseases; MDR bacteria; efflux pumps; antibiotics; secondary metabolites.

Effects of stifled cooking on the quality and lipid-lowering potential of oils extracted from two species of pumpkin seeds (Citrullus lanatus and Cucumeropsis mannii)

Background: Hyperlipidemia is a major risk factor for cardiovascular diseases. Cucumeropsis mannii and Citrullus lanatus commonly called pumpkin seeds or egussi, the oil-rich seeds, have already demonstrated hypolipidemic activity. In Africa, these seeds are popularly used in the preparation of local foods. During that thermal process, the fatty acid content of pumpkin seeds’ oils may be altered in their functionality. Thus, this work aims at studying the effect of stifled cooking on the quality and the lipid-lowering potential of oils’ extracts from Citrullus lanatus (CL) and Cucumeropsis mannii (CM). Methods: The oils were extracted from the pumpkin seeds (raw and cooked) by a mixture of chloroform and methanol (2/1). The acid, iodine, peroxide and thiobarbituric acid value of the oils were assessed. For 28 days, the oils were subsequently administered by oral intubation to high-fat diet induced hyperlipidemic rats. At the end of the experimentation, the lipid profile, the markers of the hepatic and kidney function were determined. Results: The oils extracted from raw CL and CM significantly reduced (p˂0,05) serum triglyceride, total cholesterol, Low Density Lipoprotein (LDL) cholesterol, uric acid, serum transaminases, creatinine, urea and increases the serum High Density Lipoprotein (HDL)cholesterol level relative to the oils extracted from cooked CM and CL. Moreover, the oil from cooked CL significantly (p<0.05) reduced some lipid profile and toxicity parameters (triglycerides and Alanine animotransferase) while increasing the serum HDL compared to the oil extracted from cooked CM. On the other hand, all the quality parameters of the raw materials followed the limits for vegetable oils, as opposed to cooked samples. Conclusion: Stifled cooking affects the lipid-lowering potential of CM oil compared to that of CL oil. Keywords: Citrullus lanatus; Cucumeropsis mannii; Cucurbitaceae, Hyperlipidemia, Stifled cooking.

Antibiotic-potentiation activities of three animal species extracts, Bitis arietans, Helix aspersa, and Aristaeomorpha foliacea and mode of action against MDR Gram-negative bacteria phenotypes

Background: In recent years, drug resistance to human pathogenic bacteria has been commonly reported from all over the world. As antimicrobial activities of most medicinal plants and antibiotics have been already explored, it is more important to make investigations on animal species mainly invertebrates which could constitute an efficient source of antimicrobial molecules. This work was aimed at contributing to the fight against microbial resistance through the study of antibacterial potential of three animal species (Helix aspersa, Bitis arietans, Aristaeomorpha foliacea) on several multidrug-resistant (MDR) Gram-negative strains overexpressing efflux pumps including Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa. Methods: The microdilution technique was used to evaluate the antibacterial activities of the tested samples by determining their minimal inhibitory concentrations (MICs), as well as the effect of their combination with antibiotics. Studies on the mechanisms of action of the most active sample, dried Bitis arietans extract, was carried out using standard methods for evaluating the effects of this extract on bacterial H+-ATPases-mediated proton pumps and on bacterial growth kinetics. In this latter case, the optical density was read spectrophotometrically. Results: Zoochemical screening indicated the presence of protein constituents and alkaloids and the absence of other metabolites in all tested extracts. Dried B. arietans showed the best antibacterial activity by inhibiting the growth of 90% of studied bacterial strains with MICs ranging from 128 to 2048 μg/ml. Moreover, this extract presented a significant activity (100≤MIC≤512 µg/ml) against 35% of bacteria that are E. coli (ATCC8739, AG100ATet, MC4100), E. aerogenes EA27, K. pneumoniae ATCC11296, P. aeruginosa (PA01, PA124) and a moderate activity (512<MIC≤2048 µg/ml) against 55% of studied bacteria. It was followed by fresh B. arietans which inhibited the growth of 65% of bacteria with significant activity on three bacteria (E. coli ATCC8739, E. aerogenes ATCC13048 and K. pneumoniae ATCC11296. These two extracts showed bactericidal effects on many strains. The other extracts samples selectively exhibited an antibacterial activity against less than 40% of strains. All samples potentiated the activity of at least 56% of used antibiotics against at least 70% of studied bacterial strains. B. arietans extracts at MIC/2 and MIC/4 mostly improved the activities of more than 78% of antibiotics on at least 70% of bacteria with improvement activity factors (IAF) ranging from 2 – 128 suggesting that this animal contains bioactive compounds which could act as efflux pumps inhibitors. Bacterial growth kinetic study showed that when treated with dried B. arietans extract (the most active sample) at different concentrations MIC/2, MIC and 2xMIC, the growth of tested bacteria (E. coli ATCC8739) decreased respectively when the concentrations increased. Furthermore, this extract inhibited the H+-ATPase-mediated proton pumps of this bacterium increasing the pH values. Conclusion: Results obtained in the present work provide interesting data for the use of dried B. arietans extract and invertebrates in general in the traditional therapy for the treatment of bacterial infections involving multidrug-resistant phenotypes. Keywords: Gram-negative bacteria; multidrug resistance; efflux pumps; infectious diseases; animal species; secondary metabolites.