Resveratrol prevents akinesia and restores neuronal tyrosine hydroxylase immunoreactivity in the substantia nigra pars compacta of diabetic rats

Pharmacogenetic-based management of depression: Role of traditional Persian medicine

Depression is one of the most common mental disorders worldwide. The genetic factors are linked to depression and anti-depressant outcomes. Traditional Persian medicine (TPM) manuscripts have provided various anti-depressant remedies, which may be useful in depression management. This review has studied the bioactive compounds, underlying mechanisms, and treatment outcomes of the medicinal plants traditionally mentioned effective for depression from "The storehouse of medicament" (a famous pharmacopeia of TPM) to merge those with the novel genetics science and serve new scope in depression prevention and management. This review paper has been conducted in two sections: (1) Collecting medicinal plants and their bioactive components from "The storehouse of medicament," "Physician's Desk Reference (PDR) for Herbal Medicines," and "Google scholar" database. (2) The critical key factors and genes in depression pathophysiology, prevention, and treatment were clarified. Subsequently, the association between bioactive components' underlying mechanism and depression treatment outcomes via considering polymorphisms in related genes was derived. Taken together, α-Mangostin, β-carotene, β-pinene, apigenin, caffeic acid, catechin, chlorogenic acid, citral, ellagic acid, esculetin, ferulic acid, gallic acid, gentiopicroside, hyperoside, kaempferol, limonene, linalool, lycopene, naringin, protocatechuic acid, quercetin, resveratrol, rosmarinic acid, and umbelliferone are suitable for future pharmacogenetics-based studies in the management of depression.

Long-term liraglutide ameliorates nigrostriatal impairment via regulating AMPK/PGC-1a signaling in diabetic mice

Growing evidence indicates links between type 2 diabetes and Parkinson's disease. The glucagon-like peptide 1 analogue, liraglutide, a commonly used anti-diabetic drug, has protective effects on neurons. The goal of this study was to determine whether long-term liraglutide treatment could reduce the risk of adult type 2 diabetic mice developing Parkinson's disease. Male diabetic db/db mice (12 weeks old) were injected daily with liraglutide (n = 8), or saline (n = 8), and non-diabetic m/m littermates (n = 6) were included as controls. Motor function was assessed every 4 weeks and all mice were sacrificed after 8 weeks of drug intervention for further analysis. The results revealed that long-term treatment of liraglutide protected the db/db mice against the motor function decay and the dopaminergic neuron loss. Liraglutide also restored the impaired AMP kinase (AMPK)/peroxisome proliferator-activated receptor-γ coactivator 1a (PGC-1a) signaling in the striatum of db/db mice. Further experiments in SH-SY5Y cells supported that AMPK is involved in the neuroprotective effect of liraglutide. In summary, long-term liraglutide ameliorated motor dysfunction and dopaminergic neuron impairment in type 2 diabetic mice, probably via enhancing AMPK/PGC-1a signaling.

The antioxidant effect of mulberry and jamun fruit wines by ameliorating oxidative stress in streptozotocin-induced diabetic Wistar rats

Polyphenols act by scavenging reactive oxygen species during oxidative stress and hence are useful in the treatment of metabolic disorders including diabetes. This study describes the effect of polyphenol rich mulberry and jamun wines fed to streptozotocin-induced diabetic rats. To male adult Wistar rats, divided into groups (n = 10 per group) intraperitoneal injection was administered with streptozotocin at 38 mg per kg body weight for inducing diabetes. After confirmation of diabetes, rats divided into groups were fed each day with 5.7 milliliter per kg body weight of mulberry, jamun, white and red grape wines for 6 weeks. One group of animals received resveratrol at 20 mg per kg body weight. After six weeks of treatment, blood glucose, urinary profile, lipid profile, plasma, liver, kidney, brain and eye antioxidant enzyme activities, lipid peroxidation, non-esterified fatty acids (NEFA) and hepatic glutathione (GSH) content were determined. Though wine and resveratrol feeding did not improve the glycemic status of diabetic rats, increases in antioxidant enzymes and GSH content accompanied by reduced NEFA and lipid peroxidation were observed. The kidneys and brains of resveratrol fed rats showed significant reduction in malondialdehyde equivalents, exhibited an improved antioxidant status of tissues and an increased glutathione content. The findings suggested that the wines can ameliorate the consequences of diabetes due to their antioxidants.

Effect of natural products on diabetes associated neurological disorders

Diabetes mellitus, a metabolic disorder, is associated with neurological complications such as depression, anxiety, hypolocomotion, cognitive dysfunction, phobias, anorexia, stroke, pain, etc. Traditional system of medicine is long known for its efficient management of diabetes. The current review discusses the scope of some common medicinal herbs as well as secondary metabolites with a special focus on diabetes-mediated central nervous system complications. Literatures suggest that natural products reduce diabetes-mediated neurological complications partly by reducing oxidative stress and/or inflammation or apoptosis in certain brain regions. Natural products are known to modulate diabetes-mediated alterations in the level of acetylcholinesterase, choline acetyltransferase, monoamine oxidase, serotonin receptors, muscarinic receptors, insulin receptor, nerve growth factor, brain-derived neurotrophic factor, and neuropeptide in brain. Further, there are several natural products reported to manage diabetic complications with unknown mechanism. In conclusion, medicinal plants or their secondary metabolites have a wide scope and possess therapeutic potential to effectively manage neurological complications associated with chronic diabetes.

Resveratrol and pinostilbene confer neuroprotection against aging-related deficits through an ERK1/2-dependent mechanism

Age-related declines in motor function may be due, in part, to an increase in oxidative stress in the aging brain leading to dopamine (DA) neuronal cell death. In this study, we examined the neuroprotective effects of natural antioxidants resveratrol and pinostilbene against age-related DAergic cell death and motor dysfunction using SH-SY5Y neuroblastoma cells and young, middle-aged, and old male C57BL/6 mice. Resveratrol and pinostilbene protected SH-SY5Y cells from a DA-induced decrease in cell viability. Dietary supplementation with resveratrol and pinostilbene inhibited the decline of motor function observed with age. While DA and its metabolites (DOPAC and HVA), dopamine transporter, and tyrosine hydroxylase levels remain unchanged during aging or treatment, resveratrol and pinostilbene increased ERK1/2 activation in vitro and in vivo in an age-dependent manner. Inhibition of ERK1/2 in SH-SY5Y cells decreased the protective effects of both compounds. These data suggest that resveratrol and pinostilbene alleviate age-related motor decline via the promotion of DA neuronal survival and activation of the ERK1/2 pathways.

An evaluation of aversive memory and hippocampal oxidative status in streptozotocin-induced diabetic rats treated with resveratrol

The present study evaluated the effects of streptozotocin (STZ)-induced diabetes on aversive memory, free radical content and enzymatic antioxidant activity in the hippocampus of adult Wistar rats submitted to oral treatment with resveratrol. Animals were divided into eight groups: non-diabetic rats treated with saline (ND SAL), non-diabetic rats treated with resveratrol at a dose 5mg/kg (ND RSV 5), non-diabetic rats treated with resveratrol at a dose 10mg/kg (ND RSV 10), non-diabetic rats treated with resveratrol at a dose 20mg/kg (ND RSV 20), diabetic rats treated with saline (D SAL), diabetic rats treated with resveratrol at a dose 5mg/kg (D RSV 5), diabetic rats treated with resveratrol at a dose 10mg/kg (D RSV 10) and diabetic rats treated with resveratrol at a dose 20mg/kg (D RSV 20). The animals received oral gavage for 35days. The contextual fear conditioning task was performed to evaluate aversive-based learning and memory. The oxidative status was evaluated in the hippocampus, by measuring the free radical content - using a 2',7'-dichlorofluorescein diacetate probe - and enzymatic antioxidant activities, such as superoxide dismutase and glutathione peroxidase. Our main behavioral results demonstrated that rats from the D RSV 10 and D RSV 20 groups showed an increase in freezing behavior when compared, respectively, to the ND RSV 10 (p<0.01) and ND RSV 20 (p<0.05). Oxidative stress parameters remained unchanged in the hippocampus of all the experimental groups. In contrast to previous experimental findings, our study was unable to detect either cognitive impairments or oxidative stress in the hippocampus of the diabetic rats. We suggest additional long-term investigations be conducted into the temporal pattern of STZ-induced diabetic disruption in memory and hippocampal oxidative status, as well as the effects of resveratrol on these parameters, in a time and dose-dependent manner.