Publications by authors named "Frederic N Njayou"

Background: Harungana madagascariensis (HM) and Psorospermum aurantiacum (PA), used traditionally for skin care, have been reported to upregulate the expression of intracellular antioxidant genes, thereby preventing melanoma and protecting fibroblast cell lines from Ultraviolet B (UVB)-induced intracellular oxidative stress.

Aims: This investigation aimed to identify major compounds in bioactive fractions using bioassay- guided fractionation.

Methods: The anti-inflammatory effect of fractions was determined by measuring their inhibitory activity on 15-lipoxygenase and nitric oxide (NO) in lipopolysaccharide-stimulated RAW 264.

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People living in developing countries are exposed to hepato-renal injuries induced by heavy metals like lead (Pb), cadmium (Cd), and mercury (Hg) since drinking water supplied is often polluted with a high concentration of those metals. Accordingly, it is necessary to search for antidotes against heavy metals poisoning. Hence, medicinal plants bearing anti-hepatotoxic properties represent a credible option; and such plant is .

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Overproduction of Nitric oxide (NO) and many other pro-inflammatory mediators are responsible for many pathological disorders in humans, including Alzheimer's disease (AD). In this study, active fractions isolated from (Kg) were screened for their inhibitory activities against NO production in lipopolysaccharide (LPS)-activated microglia. Among the 5 fractions tested, Kg25 was the most active and showed potent inhibitory activity towards NO production.

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Ethnopharmacological Relevance: Cameroon is one of the sub-Saharan African countries affected by Chikungunya virus (CHIKV). With the absence of approved treatment, this disease represents globally a major public health concern. Several plants are traditionally used in Cameroon for the treatment of virus induced fever and arthralgia.

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Objective: A fraction from has recently been shown to inhibit hepatitis C virus (HCV) infection and three limonoids (17-epi-methyl-6-hydroxylangolensate, 7-deacetoxy-7-oxogedunin and 7-deacetoxy-7R-hydroxygedunin) were purified from this fraction. The present study aimed at assessing the inhibitory effect of these limonoids on HCV using cell-culture derived HCV (HCVcc) system.

Materials And Methods: Cytotoxic effects of the limonoids on Huh7.

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is used in non-conventional medicine for the management of liver ailments. A fraction, designated EaF10 (methylene chloride/methanol 90:10, v/v) with promising hepatoprotective activity has been isolated. Since the mechanisms underlying EaF10 hepatoprotective action remain unknown, this study was undertaken to investigate the anti-hepatotoxic mechanism of the fraction against carbon tetrachloride (CCl)-induced hepatotoxicity and its antioxidant properties.

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The medicinal plant P. Beauv. (Bignoniaceae) has been traditionally applied for the prevention and treatment of diseases of the kidney and urinary system, the skin, the gastrointestinal tract, and inflammation in general.

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The present work was undertaken to evaluate antidiarrheal activity of ethanolic leaf extract of (Sm) Triana on -induced diarrhea in Wistar rats and its subacute toxicity. Diarrhea was induced by oral administration of 1.2 × 10 cells/mL to rats.

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Drug-induced liver injury (DILI) is a major clinical problem where natural compounds hold promise for its abrogation. (Meliaceae) is used in Cameroonian traditional medicine for the treatment of liver related diseases and has been studied for its hepatoprotective properties. Till date, reports showing the hepatoprotective molecular mechanism of the plant are lacking.

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Background: Khaya grandifoliola (Meliaceae) and Entada africana (Fabaceae) are traditionally used in Bamun (a western tribe of Cameroon) traditional medicine for the treatment of liver related diseases. In this study, the synergistic hepatoprotective effect of respective active fractions of the plants were investigated against paracetamol-induced toxicity in primary cultures of rat hepatocytes.

Methods: Paracetamol conferred hepatocyte toxicity, as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay, alanine aminotransferase (ALT), superoxide dismutase (SOD), catalase (CAT) activities, malondialdehyde (MDA) and glutathione (GSH) content assays.

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In this study, we examined the antiviral properties of Khaya grandifoliola C.DC (Meliaceae) on the hepatitis C virus (HCV) life cycle in vitro and identified some of the chemical constituents contained in the fraction with the most antiviral activity. Dried bark powder was extracted by maceration in a methylene chloride/methanol (MCM) system (50:50; v/v) and separated on silica gel by flash chromatography.

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The in vitro antioxidant properties, cytoprotective activity, and ability to induce nuclear translocation of nuclear factor E2-related factor-2 (Nrf-2) of five solvent fractions of the methylene chloride/methanol (1:1 v/v) extract of Khaya grandifoliola (Meliaceae) and Entada africana (Fabaceae) were evaluated. Five antioxidant endpoints were used in the antioxidant activity investigation. The total phenolic content of the fractions was assessed as to the Folin-Ciocalteu method and the profile of interesting fractions analyzed by high-performance liquid chromatography (HPLC).

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According to some recent studies, Cameroon is one of the sub-Saharan African countries most affected by hepatitis C, with low access to the standard therapy based on the combination of pegylated interferon and ribavirin. A first ethnobotanical survey, conducted in the Western region of Cameroon, reported the use of several medicinal plants in traditional medicine for the healing of liver-related disorders. Crude organic extracts of five plants surveyed were prepared and their effect against hepatitis C virus (HCV) infection investigated.

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Three new limonoids, rubescins A-C (1-3), and three known compounds including, havanensin type limonoid TS3 (4), β-sitosterol, and stigmasterol were isolated from the root bark of Trichilia rubescens. Their structures were elucidated by means of extensive spectroscopic analyses, particularly one dimensional (1D)- and 2D-NMR techniques in conjunction with mass spectrometry. Rubescins A-C (1-3) and limonoid TS3 (4) were evaluated for their protective effects against oxidative stress induced in HC-04 cells by H2O2.

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The antioxidant activities of 53 medicinal plants used in Bamun folk medicine for the management of jaundice and hepatitis were investigated. The studies were done using rat hepatic microsomes for lipid peroxidation and bovine serum albumin (BSA) for carbonyl group formation. Silymarine was used as reference compound.

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