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

Oxidative stress (OS) is well established as a major event in Alzheimer's disease (AD) pathology. One of the mostly-researched classes of antioxidants to manage with overwhelming OS include flavonoids. This study was aimed to investigate the protective effect of A. congolensis extract (HEEAC) on AlCl3-mediated AD-like OS and assess the contribution of its antioxidant flavonoid contents. Female Wistar (250-300 g) rats received orally 50 mg/Kg bw of AlCl3, followed one hour later by doses (150 or 300 mg/kg) of HEEAC or vitamin E at 100 mg/kg daily for eight consecutive weeks. OS related biomarkers were evaluated at the end of treatment. To assess the contribution of flavonoid contents to its activity, HEEAC was fractioned using solvent of varying polarities. Flavonoid-rich extracts obtained were tested for their antioxidant capacity. AlCl3 administration significantly lowered antioxidant enzymes (catalase, glutathione peroxidase) and aconitase levels, reduced total thiol and thiol protein levels and increased lipid peroxidation and protein oxidation levels in brain. When co-administrated with HEEAC at 150 mg/kg, all of these OS related biomarkers were significantly moderated. The efficacity of the extract was significantly higher than vitamin E. Flavonoid-rich fractions extracted mainly n-butanol fraction show strong antioxidant activity, which can be considered as the major antioxidant fraction of this plant. HEEAC protect brain cells against oxidative damage induced by AlCl3, specifically through the strong antioxidant property of its n-butanol flavonoid-rich fraction, which may be a promising agent for preventing oxidative damage in AD.

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

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 (Mg2+ and Ca2+ levels). AlCl3 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 Ca2+ level (25.68 ± 3.78 µmol/mg protein) and a decrease in Mg2+ 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.

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.

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 H2O2 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.

Lipotropic activities of aqueous extract of Vernonia guineensis Benth. in Wistar rats fed high fat diet.

BACKGROUND: Lipotropic molecules are effective therapeutic targets to counteract non-alcoholic fatty liver disease (NAFLD). Lipotropic compounds are capable of removing fat from the liver and/or manage the reduction of the synthesis or deposition of lipids in the liver. The objective of this study was to evaluate the lipotropic effects of the aqueous extract of leaves of Vernonia guineensis (AEVG) on rats fed high fat diet. METHODS: Twenty male rats with an average mass of 235 g were allow acclimatize for seven days, following which they were divided into four groups of five animals each. The test group was treated with high fat diet (HFD) and AEVG at 400 mg/kgBW, while positive control group received HFD and Fenofibrate at 100 mg/kgBW. The normal control group received a normal diet; and the negative control group received HFD. After 14 days of treatment, animals were sacrificed, blood and organs (liver, heart and kidneys), as well as the faeces were collected for the preparation of plasma and homogenates respectively. Some markers of lipid profil (total cholesterol, triglycerides, HDL-c, LDL-c,) and markers of toxicity (AST, ALT, γ-GT, creatinine) were evaluated. RESULTS: The results obtained showed that a HFD at the hepatic level led to the accumulation of lipids (triglycerides (TG) and total cholesterol (TC)) and had adverse effects on hepatic function by promoting cytolysis. At the plasma level, HFD induced hyperlipidemia. Administration of AEVG at 400 mg/kgBW improved the blood lipid profile and reduced the storage of TG and cholesterol in the liver. AEVG also promoted fecal cholesterol excretion and reduced atherogenic indices which include Total Cholesterol/High-Density Lipoprotein cholesterol (TC/HDL-c) and Low-Density Lipoprotein cholesterol/High-Density Lipoprotein cholesterol (LDL-c/HDL-c). The extract exhibited hepato-protective activity (anticholestasis) and improved glomerular filtration. CONCLUSION: These findings suggest that AEVG possesses lipotropic effects confirming its probable use in the management of non-alcoholic fatty liver disease and its cardiometabolic complications. This virtue could be exploited for local pharmaceutical development.

Effect of Beilschmedia obscura on the prevention of high fat/high sucrose diet induced metabolic syndrome on male Albino Wistar rats.

INTRODUCTION: Beilschmiedia (Lauraceae) is a pantropical genus of about 287 species, distributed in tropical Asia and Africa used in traditional medicines to cure many diseases. This study aimed to explore biological properties of Beilschmiedia obscura (B. obscura) on the prevention and management of metabolic syndrome (MetS) features induced by High Fat/High Sucrose (HF/HS) diet in rats as therapeutic option. METHODS: MetS was induced after administration of HF/HS diet followed by administration of B. Obscura powder at 5% or 10% for 21 days, while the control group received a chow diet and distilled water and the positive control group received the HF/HS diet and distilled water. At the end of the experiment, rats were sacrificed; the parameters of lipid profile, markers of oxidative stress, antioxidant status were evaluated. RESULTS: HF/HS diet successfully induced weight gain, oxidative stress and lipid profile disorders from rats. Treatment with powder of B. obscura at 10% than the 5% showed a reduction of body weight in treated groups and, anti-hyperlipidemic effect by improving lipid profile parameters. Triglycerides, Total cholesterol and LDL cholesterol levels were lower (p<0.05) and HDL-cholesterol levels higher in the treated groups compared to positive control. Inhibition of lipid peroxidation, and improvement protein thiols levels and catalase activity were also observed in treated groups. CONCLUSION: This study revealed that B. obscura whole plant was efficient in reducing biomarkers involved in metabolic syndrome and could efficiently help in its management by preventive effect.