Targeting Brain-Derived Neurotrophic Factor (BDNF) - An Important Strategy to Alzheimer's Disease

Many theories have been proposed to explain why candidate disease-modifying drugs (DMTs) for Alzheimer's disease (AD) failed. Late initiation of treatments during AD development, inappropriate drug dosages, incorrect selection of main therapeutic targets, and primarily inadequate understanding of the complex pathophysiology of AD are the most prominent ones. Reduced expression of Brain Derived Neurotrophic Factor (BDNF) is essential in the pathogenesis of Alzheimer's disease. BDNF plays important functions in cell survival and differentiation, neuronal outgrowth and plasticity. It can be a novel target for the treatment of the disease. In Alzheimer's disease, the hippocampus, parietal, entorhinal, and frontal cortex all have the most extreme BDNF deficits. Lower levels of BDNF can be linked to neuronal death, masking any gene-related effects. High BDNF levels have been attributed to a lower risk of dementia and Alzheimer's. Improvements in BDNF levels imparted by exercise, plant based drugs, trkB receptor agonist and BDNF enhancer drug have been proved to enhance cognitive performance. Plant-based products and nutraceuticals can boost BDNF levels. Polyphenols are essential plant compounds with a wide range of therapeutic potentials. Flavonoids like calycosin, genistein, isorhamnetin, and luteolin have been shown to affect the level of BDNF. Curcumin, a compound derived from spice turmeric (curcuma longa), has a variety of biological functions in the brain, including antidepressant properties which also increase BDNF level in the hippocampus. Riluzole is used to treat amyotrophic lateral sclerosis (ALS). In a depression model with chronic corticosteroid intake, riluzole also restores hippocampal BDNF levels. Evidence indicates that BDNF deficiency plays a role in the pathogenesis of Alzheimer's disease. Drugs used to treat Alzheimer's disease have the unintended property of modulating BDNF levels in brain regions specifically involved in the disease's pathophysiology. The discovery of molecules that precisely control BDNF in particular cellular phenotypes could increase the effectiveness of therapy against AD.

Subchronic Toxicity of Crinum jagus Extracts on Wistar Rats

Crinum jagus is used in Cameroon western and eastern regions folk medicine in detoxification, the management of diabetes and obesity and also as antivenomous and antipoison. The aim of this work was to evaluate the subchronic toxicity of Crinum jagus extracts on male and female Wistar rats. Subchronic toxicity of aqueous and hydroéthanolic Crinum jagus extracts was determined on two month old normal Wistar rats. Those rats, once daily orally received, hydroethanolic (75, 150 mg/kg b.w.) and aqueous (150 mg/kg b.w.) extracts, during 90 days (tree month). In both males and females animals, the C. jagus effects were investigated on the evolution of weight, food and water intakes, kidney and liver functioning markers (serum total cholesterol (TC), total proteins, creatinine and transaminase: AST and ALT). Both aqueous and hydroethanolic extracts in males as in females, did not cause any adverse changes in anthropometric (body mass, relative weight of liver and kidneys, food and water intakes) and seric parameters (total cholesterol, total proteins, creatinine AST and ALT activity). Instead, those extracts remarkably improved antropometric parameters, liver and kidney function and even protect again atherosclerosis. The results indicated that aqueous and hydroethanolic extracts of Crinum jagus did not induce toxic effect at the doses used in long term treatment; thus justifying its empiric use in detoxification and as antivenomous.

Hepatoprotective and Antioxidant Effects of Aqueous Extract of Rauwolfia vomitoria (Apocynaceae) Stem Bark in Wistar Rats

Rauwolfia vomitoria is used in Cameroon in indigenous medicine to treat liver diseases. The present study was carried out on the hepatoprotective and antioxidant effects of the plant aqueous extract. Liver toxicity was induced by oral route administration of CCl4 two times per week for four weeks. Rats were given concomitantly by oral route, aqueous extract at the doses of 100, 200 and 300 mg/kg or silymarin four days a week for four weeks. By the end, bloods were collected for liver functional parameters analyses. Liver tissues were removed, to assess to oxidative stress parameters and histological analyses. The extract (300 mg/kg) decreased enzyme activity of ALT, AST and the level of TG with the percentage 54.23%, 49.63% and 28.74% respectively while it increased the enzyme activity of SOD, CAT and level of MDA at about 67.16%, 71.42% and 43.80% respectively compared to control animals. These results suggested that aqueous extract has strong hepatoprotective effect on CCl4-induced liver damage and increase antioxidant defense system activity.

Acute and Subacute Toxicological Study of the Aqueous Extract of the Stem Bark of Khaya Grandifoliola (Meliaceae) in Wistar Rats

This study was carried out to investigate the possible toxic effects of the water extract from Khaya grandifoliola stem bark in Wistar rats. The acute assay used 9 females distributed into 3 groups of 3 rats each. A control group received distilled water and the two test groups received by oral gavage a unique dose of the extract at 2000 mg/kg. In subacute assay, 60 rats both sexes were distributed into 6 groups of 10 rats each (5 males and 5 females) and received the extract by oral gavage for 28 days consecutively. The tests groups received extract at 250, 500 and 1000 mg/kg. The controls and satellite test groups received respectively distilled water and extract at the dose of 1000 mg/kg. Some anthropometrical, hematological and biochemical parameters were measured and histological sections of some organs were realized. LD50 was superior at 2000 mg/kg in acute assay. In subacute toxicity assay, Khaya grandifoliola stimulated the haematopoetic and immune function, showed a significant decrease of alanine transaminase, aspartate transaminase and hypocholesterolaemic effects. Histopathology showed the presence of disturbances at the dose of 1000 mg/kg especially. K. grandifoliola stem bark could possess moderate toxicity at high doses and adequate caution should be exercised in its use in ethnomedicine.

Nano-Niosomal Formulation of Alkaloids from Vinca rosea for Improved Oral Delivery

Phytochemicals, the natural biochemical substances produced by plants possess a range of medicinal values. These phytochemicals get into our system through food and bring different physiological benefits. However, many of these phytochemicals lack essential physicochemical properties that can provide them effective drug-likeness properties. Vinca rosea alkaloids are known for their therapeutic values especially in the cancer treatment domain. However, the physiochemical properties of these molecules limit their bioavailability greatly. This current research aimed at improving the bioavailability of Vinca rosea alkaloids through the nanovector system, niosomes. Vinca alkaloids were extracted, purified, screened and quantified. Niosomal constructs of the alkaloids were made, characterized through scanning electron microscope and ex-vivo studies were carried out using goat intestine. The size of the niosomes was found to be in the range of 400 to 800 nm. Results shows that niosomal formulation can increase bioavailability of Vinca rosea alkaloids two folds compared to the native alkaloid extract.

A Short Communication on Indoor-Based Therapies to Reduce Stress During the COVID-19 Pandemic

Preserving mental health during the COVID-19 crisis should be a priority for individuals worldwide. In this regard, mental health professionals should advise the general public on the actions/activities that they can take to prevent mental health issues from becoming the next pandemic. However, the general public should also actively take measures to improve their mental wellbeing. Music therapy, aromatherapy or indoor nature therapy may or may not have the potential to preserve mental wellbeing, but individuals should experiment with them to ascertain the effects on themselves. Moreover, the guidelines provided by WHO should also be adhered to, as a healthy mind starts with a healthy body.

In Vivo Curative and Antacid Effects of Cameroonian Clay (MY41g) on Chronic and “Unhealed" Gastric Ulcers in Rats

This study evaluated the in vivo curative and antacid effects of MY41g clay on chronic and “unhealed" gastric ulcers in rats. Chronic gastric ulcers were induced by injecting 0.05 mL of acetic acid (30%) into the stomach wall. From day 5-14 after induction of ulcers, rats were treated daily with MY41g clay (125 and 250 mg/kg). For “Unhealed" gastric ulcers, from day 5-18 rats received MY41g clay orally concomitantly with indomethacin (1 mg/kg/day) subcutaneously. The ulcer index, percentage of healing, mucus secretion, histological parameters, oxidative stress parameters and gastric acidity were assessed. Treatment with clay solution for 10 days resulted in accelerated spontaneous healing of chronic gastric ulcers (83.69-90.2%). However, indomethacin administration did not induce significant variations in the percentage of healing (89.23-91.66%) in rats. For both ulcer models performed, ulcer healing was accompanied by a significant increase (p<0.001) of mucus secretion at the highest dose. Clay increased concentrations of antioxidant enzymes and decreased gastric acidity and lipid peroxidation. Administration of clay accelerated the spontaneous healing of both induction models. The mode of action of the clay could involve increased gastric mucus production, gastric mucosal re-epithelialization, improved antioxidant status and gastric acid neutralization. MY41g clay can be used as antacids in the ulcer treatment regime.