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Donalisio M.,University of Turin | Nana H.M.,University of Turin | Nana H.M.,University of Dschang | Ngono Ngane R.A.,University of Douala | And 9 more authors.
BMC Complementary and Alternative Medicine | Year: 2013

Background: Nauclea latifolia Smith, a shrub belonging to the family Rubiaceae is a very popular medicinal plant in Cameroon and neighboring countries where it is used to treat jaundice, yellow fever, rheumatism, abdominal pains, hepatitis, diarrhea, dysentery, hypertension, as well as diabetes. The ethno-medicinal use against yellow fever, jaundice and diarrhea prompted us to investigate on the antiviral activity of the root bark of N. latifolia. In this study, HSV-2 was chosen as a viral model because of its strong impact on HIV transmission and acquisition. Methods: The crude extract under study was prepared by maceration of air-dried and powdered roots barks of N. latifolia in CH2Cl2/MeOH (50:50) mixture for 48 hours, then it was subjected to filtration and evaporation under vacuum. A phytochemical analysis of the crude extract was performed by High Performance Liquid Chromatography coupled with a photodiode array and mass spectrometry (HPLC-PDA-ESI-qMS). The anti-HSV-2 activity was assayed in vitro by plaque reduction and virus yield assays and the major mechanism of action was investigated by virucidal and time of addition assays. Data values were compared using the Extra sum of squares F test of program GraphPad PRISM 4.Results: The main components detected in the extract belong to the class of indole alkaloids characteristic of Nauclea genus. Strictosamide, vincosamide and pumiloside were tentatively identified together with quinovic acid glycoside. N. latifolia crude extract inhibited both acyclovir sensitive and acyclovir resistant HSV-2 strains, with IC50 values of 5.38 μg/ml for the former and 7.17 μg/ml for the latter. The extract was found to be most active when added post-infection, with IC50 of 3.63 μg/ml. Conclusion: The results of this work partly justify the empirical use of N. latifolia in traditional medicine for the treatment of viral diseases. This extract could be a promising rough material for the development of a new and more effective modern anti-HSV-2 medication also active against acyclovir-resistant HSV-2 strains. © 2013 Donalisio et al.; licensee BioMed Central Ltd.


Nkouawa A.,Asahikawa University | Nkouawa A.,Institute of Medical Research and Medicinal Plants Studies | Sako Y.,Asahikawa University | Moyou-Somo R.,Institute of Medical Research and Medicinal Plants Studies | And 2 more authors.
Southeast Asian Journal of Tropical Medicine and Public Health | Year: 2011

Parasitic helminthiases, such as toxocariasis, cysticercosis and paragonimiasis are a public health threat, since they can affect the brain leading to neurological disorders. Epilepsy and paragonimiasis are common in southwestern Cameroon. We reviewed the literature for studies using antigens to diagnose toxocariasis, cysticercosis, and paragonimiasis. Serology revealed that 61 (36.3%), 26 (15.5%) and 2 (1.2%) of 168 persons examined [78 males (15.2 ± 8.2 years old), 90 females (12.9 ± 5.9 years old), 143 persons < 20 years old] had antibody responses to toxocariasis, paragonimiasis and cysticercosis, respectively. Of the 14 people with epilepsy, 5 were seropositive for Toxocara antigens and 1 was positive for both Toxocara and Paragonimus antigens. Two children were serologically confirmed to have cysticercosis. Serologic screening for cysticercosis may be feasible to detect asymptomatic cysticercosis in children in endemic areas leading to early treatment. The causative Paragonimus species was confirmed to be P. africanus by molecular sequencing. Education, screening and confirmation test for these diseases may be needed for control in Cameroon.


Fondjo F.A.,University of Yaounde I | Kamgang R.,University of Yaounde I | Kamgang R.,Institute of Medical Research and Medicinal Plants Studies | Oyono J.-L.E.,Institute of Medical Research and Medicinal Plants Studies | And 2 more authors.
Tropical Journal of Pharmaceutical Research | Year: 2012

Purpose: The activity of the methanol extract of the whole plant of Kalanchoe crenata (MEKC) was studied for the treatment of diabetes-induced nephropathy in rats. Methods: Five-day old Wistar rats received a single intraperitoneal streptozotocin injection (90 μg/kg body weight) to induce diabetes. Kidney disease onset in the rats was observed six weeks after diabetes induction. The rats were orally administered MEKC (0, 50 and 68 mg/kg) or glibenclamide (5 mg/kg), once daily for 6 weeks. Blood and urine glucose, proteins, lipids, creatinine, malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were then evaluated. Results: After 6 weeks of treatment, 50 and 68 mg/kg MEKC, and glibenclamide significantly (p < 0.01) decreased glycaemia (-35, -44 and -39 %), glycosuria (-38, -47 and -61 %) and proteinuria (-82, -80 and -72 %) in diabetes-nephropathic rats. The extract (68 mg/kg) decreased MDA by up to -44 % (blood), - 35 % (liver) and -34 % (kidney); increased SOD up to 257 % (blood), 116 % (liver) and 118 % (kidney); and CAT by up to 176 % (blood), 78 % (liver) and 96 % (kidney) in the rats, compared with nephropathic control. The extract (50 and 68 mg/kg, respectively) lowered (p < 0.01) total cholesterolemia (-24 and - 27 %), blood triglycerides (-55 and -54 %), blood LDL cholesterol (-48 and -59 %), but increased blood HDL cholesterol (71 and 58 %). Overall, atherogenic index was decreased by 31 %. Conclusion: The results indicate that MEKC holds promise for the development of a standardized phytomedicine for diabetes mellitus and kidney disease treatment. © Pharmacotherapy Group.


Agbor G.A.,Institute of Medical Research and Medicinal Plants Studies | Agbor G.A.,University of Scranton | Vinson J.A.,University of Scranton | Oben J.E.,University of Yaounde I | Ngogang J.Y.,University of Yaounde I
Chinese Journal of Natural Medicines | Year: 2010

Aim: The present study investigates the antioxidant effect of two extracts (hydrolyzed and non-hydrolyzed) of five herbs and eight spices in the prevention of LDL + VLDL oxidation promoted by cupric ion. Methods: The polyphenolic concentrations of these extracts were measured using Folin-Ciocalteu reagent. The antioxidant quality was analyzed by the determination of lag-time, concentration of polyphenol that will inhibit 50% of oxidation of LDL + VLDL (IC 50) and phenol antioxidant index (PAOXI). Results: The hydrolyzed extracts had significant higher polyphenol concentration, longer lag-time, lower IC 50 and higher PAOXI than the non-hydrolyzed extracts (P < 0.001). Thus, hydrolyzed extract contains better quantity and quality polyphenolic antioxidant than the non-hydrolyzed extract. Both hydrolyzed and non-hydrolyzed extracts were better antioxidants than Vitamin E in the inhibition of LDL + VLDL oxidation. Conclusion: The reaction rate and concentration of conjugated diene formed suggested that all the extracts had similar reaction mechanism in the prevention of copper mediated LDL + VLDL oxidation. © 2010 China Pharmaceutical University.


PubMed | University of Yaounde I and Institute of Medical Research and Medicinal Plants Studies
Type: Comparative Study | Journal: Pakistan journal of pharmaceutical sciences | Year: 2016

The present research evaluated the antidiabetic and antioxidant properties of M. lucida stem bark (50 and 500mg/kg) and glibenclamide (25mg/kg, standard drug) in acute (Oral glucose tolerance test) and sub-acute (Streptozotocin 60mg/kg, i.p. diabetic model) administration. A group of healthy rats constituted the normal control. The sub-acute experiment lasted 28 days during which water, food intake and weight gain were measured and biochemical parameters analyzed in both plasma and erythrocytes at the end of the experiment. The chemical substances present in M. lucida bark extract were determined. In the Oral glucose tolerance test, the reduction of blood glucose level was statistically significant for both M. lucida extracts and glibenclamide. However, in the diabetic rats acute administration of 500mg/kg extract had better blood sugar lowering effect than glibenclamide, which was better than 50mg/kg extract. Streptozotocin diabetic animal model was characterized by a decrease in weight gain, erythrocyte SOD and CAT activities and an increase in water and food consumption, lipid peroxidation, cholesterol, triglycerides, plasma glucose, creatinine and urea concentrations, and transaminases activities. M. lucida extract and glibenclamide significantly prevented the alteration of these parameters, thus indicating a corrective effect on diabetes and its complications. This study justifies the traditional claim and provides a rationale for the use of M. lucida to treat diabetes. Its antioxidant properties may serve to curb oxidative stress and hence prevent the diabetic complications related to oxidative stress. Chemical substances, which may be accountable for the antidiabetic and antioxidant properties of M. lucida were detected in the aqueous extract of M. lucida bark.


PubMed | Institute of Medical Research and Medicinal Plants Studies, University of Kinshasa and University of Liège
Type: | Journal: Journal of ethnopharmacology | Year: 2016

Heinsia crinita is used in traditional medicine for the treatment of febrile illness and erectile dysfunction. Its stem bark powder is found in some peripheral markets in the Democratic Republic of the Congo (DRC) as a remedy against malaria. Investigations were conducted on crude extracts of leaves, fruits and stem barks in view to validate their use and to determine which plant part possesses the best antiplasmodial properties.Different plant parts were extracted with methanol, ethanol and dichloromethane. Based on the preliminary assays, the dichloromethane extract of the stem bark was subjected to fractionation using preparative HPLC system and column chromatography. This step led to the isolation of two new iridoids which had their structures elucidated by NMR, UV, MS and FT-IR spectroscopic techniques. Extracts and pure compounds were tested in vitro against the 3D7 strain of Plasmodium falciparum. The inhibition of the parasite growth was evaluated in vitro by colorimetric method (p-LDH assay) and their cytotoxicity evaluated in vitro against the human non-cancer fibroblast cell line (WI38) through WST1 assay. The in vivo antiplasmodial activity was assessed by the inhibition of Plasmodium berghei growth in infected mice treated with the ethanol extract of H. crinita stem bark at the concentrations of 200 and 300mg/Kg/day per os, using a protocol based on the 4-day suppressive test of Peters and compared to a non-treated negative control group of mice (growth = 100%). Finally the antioxidant activity of the same extract was evaluated using ABTS, DPPH and cell-based assays.A moderate in vitro antiplasmodial activity was observed for the dichloromethane extract of the stem bark of H. crinita (ICThe results showed that H. crinita extracts possess antimalarial activity and contain some unusual iridoids with moderate antiplasmodial activity, therefore justifying to some extent its traditional use by the local population in DRC for this purpose. This is the first report of the isolation and antiplasmodial activity of these two new iridoids.


PubMed | University of Dschang and Institute of Medical Research and Medicinal Plants Studies
Type: | Journal: Evidence-based complementary and alternative medicine : eCAM | Year: 2015

Diabetes mellitus is a metabolic disorder of glucose metabolism which correlates with postprandial hyperglycemia and oxidative stress. Control of blood glucose level is imperative in the management of diabetes. The present study tested the hypothesis that Costus afer, an antihyperglycemic medicinal plant, possesses inhibitory activity against carbohydrate hydrolyzing enzymes. Hexane, ethyl acetate, methanol, and water extracts were prepared from the leaf, stem, and rhizome of C. afer and subjected to phytochemical screening, assayed for -amylase and -glucosidase inhibitory activities and antioxidant capacity (determined by total phenolic and total flavonoids contents, ferric reducing antioxidant power (FRAP), and DPPH radical scavenging activity). All extracts inhibited -amylase and -glucosidase activities. Ethyl acetate rhizome and methanol leaf extracts exhibited the best inhibitory activity against -amylase and -glucosidase (IC50: 0.10 and 5.99mg/mL), respectively. Kinetic analysis revealed two modes of enzyme inhibition (competitive and mixed). All extracts showed antioxidant capacity, with hexane extracts exhibiting the best activity. DPPH assay revealed that methanol leaf, rhizome, and ethyl acetate stem extracts (IC50 < 5mg/mL) were the best antioxidants. The presence of bioactive compounds such as flavonoids, alkaloids, phenols, and tannins may account for the antioxidant capacity and carbohydrate hydrolyzing enzyme inhibitory activity of C. afer.


PubMed | Higher Institute of Medical Technoloy, Institute of Medical Research and Medicinal Plants Studies, Jackson State University and Millennium Ecological Museum S C PO. Box. 812 Yaounde
Type: | Journal: Medicinal & aromatic plants | Year: 2015

Medicinal plants have served as valuable starting materials for drug development in both developing and developed countries. Today, more than 80% of the people living in Africa were depended on medicinal plants based medicines to satisfy their healthcare needs. The main goal of the present study was to collect and document information on herbal remedies traditionally used for the treatment of diabetes and/or hypertension in Cameroon. To reach this objective, data were collected from 328 patients who have been diagnosed at least once by a physician as diabetics and/or hypertension patients. One hundred and eighty two (182) among them took for a period of 10 days different varieties of medicinal plants which were prepared in form of decoction, maceration and infusion and administered orally twice or three times daily. As result, 70% of patients who used plants were relieved at the end of the treatment. Thirty-three plants have been recorded and documented for the treatment of diabetes and/or hypertension. The results of this study can stimulate a sustainable development by providing the basis for drugs discovery and by documenting biodiversity for long time exploitation.


Agbor G.A.,University of Scranton | Agbor G.A.,Institute of Medical Research and Medicinal Plants Studies | Akinfiresoye L.,Institute of Medical Research and Medicinal Plants Studies | Sortino J.,Institute of Medical Research and Medicinal Plants Studies | And 2 more authors.
Food Chemistry | Year: 2012

Pre-clinical and clinical studies points to the use of antioxidants as an effective measure to reduce the progression of oxidative stress related disorders. The present study evaluate the effect of three Piper species (Piper guineense, Piper nigrum and Piper umbellatum) for the protection of cardiac, hepatic and renal antioxidant status of atherogenic diet fed hamsters. Hamsters were classified into eight groups: a normal control, atherogenic control and six other experimental groups (fed atherogenic diet supplemented with different doses of P. nigrum, P. guineense and P. umbellatum (1 and 0.25 g/kg) for 12 weeks. At the end of the feeding period the heart, liver and kidney from each group were analyzed for lipid profile and antioxidant enzymes activities. Atherogenic diet induced a significant (P < 0.001) increase in the lipid profile across the board and equally significantly altered the antioxidant enzyme activities. Supplementation with Piper species significantly inhibited the alteration effect of atherogenic diet on the lipid profile and antioxidant enzymes activities. The Piper extracts may possess an antioxidant protective role against atherogenic diet induced oxidative stress in cardiac, hepatic and renal tissues. © 2012 Elsevier Ltd. All rights reserved.


PubMed | Institute of Medical Research and Medicinal Plants Studies and University of Scranton
Type: Journal Article | Journal: Food chemistry | Year: 2014

Pre-clinical and clinical studies points to the use of antioxidants as an effective measure to reduce the progression of oxidative stress related disorders. The present study evaluate the effect of three Piper species (Piper guineense, Piper nigrum and Piper umbellatum) for the protection of cardiac, hepatic and renal antioxidant status of atherogenic diet fed hamsters. Hamsters were classified into eight groups: a normal control, atherogenic control and six other experimental groups (fed atherogenic diet supplemented with different doses of P. nigrum, P. guineense and P. umbellatum (1 and 0.25 g/kg) for 12 weeks. At the end of the feeding period the heart, liver and kidney from each group were analyzed for lipid profile and antioxidant enzymes activities. Atherogenic diet induced a significant (P<0.001) increase in the lipid profile across the board and equally significantly altered the antioxidant enzyme activities. Supplementation with Piper species significantly inhibited the alteration effect of atherogenic diet on the lipid profile and antioxidant enzymes activities. The Piper extracts may possess an antioxidant protective role against atherogenic diet induced oxidative stress in cardiac, hepatic and renal tissues.

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