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Chronic D-galactose (D-gal) administration causes cognitive impairment and is used widely in animal models for anti-aging studies. Centella asiatica (CA), a traditional herbal medicine, has been used as a brain tonic to enhance memory. This study evaluates the neuroprotective role of an ethanolic extract of Centella asiatica (CAE) against D-gal-induced aging in rats. Healthy male rats were divided into three groups: Control, D-gal, and D-gal + CAE. The Control group received normal saline (i.p.), whereas the D-gal group received D-gal (120 mg/kg b.w., i.p.), and the D-gal + CAE group received D-gal (120 mg/kg b.w., i.p.) and CAE (300 mg/kg b.w., orally) daily for 42 days. Behavioral and brain biochemical and histopathological changes were assessed after treatment. The results of the behavioral study depicted that D-gal significantly reduces the spontaneous alternation and locomotor activity indicating behavioral and cognitive impairment. Biochemical studies showed that D-gal significantly increases the oxidative stress and acetylcholinesterase activity (AChE) in rat brain. Histopathological study showed that D-gal disturbs the normal architecture of hippocampal and cortical cells, indicating degeneration in these brain areas. D-gal and CAE co-treatment for 42 days attenuated the behavioral, biochemical, and neuroanatomical impairments caused by the D-gal; it markedly suppresses the D-gal-induced oxidative stress and AChE activity in the brain, and maintains the normal cellular architecture in hippocampal and cortical areas. Thus, this study shows that CAE can protect the brain from the adverse effects of D-gal (e.g., memory loss and cognitive impairment) by modulating AChE activity and oxidative stress. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is one of the widely reported neurodegenerative disorders affecting more than ten million people worldwide. Due to therapeutic limitations and several adverse effects associated with currently used drugs, it is crucial to search for safe and effective options for treatment of PD. Oxidative stress, mitochondrial dysfunction, α-synuclein oligomeric aggregates, and glucocerebrosidase (GCase) deficiency are involved in PD pathogenesis. Rebamipide, an anti-ulcer drug, is a proven free-radical scavenger and antioxidant. The drug has shown neuroprotective effects in cultured SH-SY5Y cells. Therefore, we investigated the pharmacological effect of rebamipide in 6-hydroxydopamine (6-OHDA)-induced experimental PD model. Rebamipide was given to adult male albino rats of Charles-Foster strain in 20, 40, and 80 mg/kg (R-20, R-40, and R-80) oral dose twice daily for 24 days (day 4 to day 27) after 6-OHDA intrastriatal injection. The drug inhibited 6-OHDA-induced motor deficits and nigral α-synuclein aggregates in dose-dependent manner. R-40 and R-80 dose dependently increased striatal mitochondrial complex I, II, IV, and V activities; mitochondrial bioenergetics; and nigral GCase activity. 6-OHDA-induced lipid peroxidation was decreased. Highest dose (R-80) also decreased apoptotic proteins and upregulated striatal dopamine concentration in 6-OHDA-induced hemiparkinson's rat model. Therefore, the anti-PD effect of rebamipide may involve stabilization of mitochondrial bioenergetics, enhancement of GCase enzymatic activity as well as decreased oxidative stress with α-synuclein pathology, and apoptosis in 6-OHDA-induced hemiparkinson's rat model. Hence, preclinical evidence indicates rebamipide to be a potential drug for management of PD. [ABSTRACT FROM AUTHOR]

Electromagnetic radiation (EMR) can induce or modulate several neurobehavioral disorders. Duration and frequency of exposure of EMR is critical to develop cognitive disorders. Even though EMR-2450 is widely used, its effects on cognition in relation to mitochondrial function and apoptosis would provide better understanding of its pathophysiological effects. Therefore, a comparative study of different frequencies of EMR exposure would give valuable information on effects of discrete frequencies of EMR on cognition. Male rats were exposed to EMR (900, 1800 and 2450 MHz) every day for 1 h for 28 consecutive days. The cognitive behavior in terms of novel arm entries in Y-maze paradigm was evaluated every week after 1 h to last EMR exposure. Animals exposed to EMR-2450 MHz exhibited significant cognitive deficits. EMR-2450 MHz caused loss of mitochondrial function and integrity, an increase in amyloid beta expression. There was release of cytochrome-c and activation of apoptotic factors such as caspase-9 and -3 in the hippocampus. Further, there was decrease in levels of acetylcholine, and increase in activity of acetyl cholinesterase, indicating impairment of cholinergic system. Therefore, exposure of EMR-2450 in rats caused cognitive deficit with related pathophysiological changes in mitochondrial and cholinergic function, and amyloidogenesis. [ABSTRACT FROM AUTHOR]

Context: Eugenol, an essential constituent found in plants such as Eugenia caryophyllata Thunb. (Myrtaceae) is reported to possess neuroprotective and anti-stress activities. These activities can potentially be useful in the treatment of stress-induced irritable bowel syndrome (IBS). Objective: The protective effect of eugenol was assessed against restraint stress (RS)-induced IBS-like gastrointestinal dysfunction in rats. Further, its centrally mediated effect was evaluated in this model. Materials and methods: Eugenol (12.5, 25, and 50 mg/kg), ondansetron (4.0 mg/kg, p.o.), and vehicle were administered to rats for 7 consecutive days before exposure to 1 h RS. One control group was not exposed to RS-induction. The effect of eugenol (50 mg/kg) with and without RS exposure was evaluated for mechanism of action and per se effect, respectively. The hypothalamic-pituitary-adrenal cortex (HPA)-axis function was evaluated by estimating the plasma corticosterone level. The levels of brain monoamines, namely serotonin, norepinephrine, dopamine, and their metabolites were estimated in stress-responsive regions such as hippocampus, hypothalamus, pre-frontal cortex (PFC), and amygdala. Oxidative damage and antioxidant defenses were also assessed in brain regions. Results: Eugenol (50 mg/kg) reduced 80% of RS-induced increase in fecal pellets similar to that of ondansetron. Eugenol attenuated 80% of stress-induced increase in plasma corticosterone and modulated the serotonergic system in the PFC and amygdala. Eugenol attenuated stress-induced changes in norepinephrine and potentiated the antioxidant defense system in all brain regions. Conclusion: Eugenol protected against RS-induced development of IBS-like gastrointestinal dysfunction through modulation of HPA-axis and brain monoaminergic pathways apart from its antioxidant effect. [ABSTRACT FROM AUTHOR]

Centella asiatica (L.) Urban, is a medicinal herb with rich history of traditional use in Indian subcontinent. This herb has been valued for its diverse range of medicinal properties including memory booster, and also as a folk treatment for skin diseases, wound healing and mild diuretic. Aging is a gradual and continuous process of natural decay in the biological systems, including the brain. This work aims to evaluate the effectiveness of ethanolic extract of Centella asiatica (CAE) on age-associated cognitive impairments in rats, as well as the underlying mechanism. Rats were allocated into five distinct groups of 5 animals each: Young rats (3 months old rats), middle-aged (m-aged) rats (13–14 months old), and the remaining three groups were comprised of m-aged rats treated with different concentrations of CAE, viz., 150, 300, and 450 mg/kg b. w., orally for 42 days. Y-maze, open field, novel object recognition, and elevated plus maze tests were used to assess animal behavior. The malondialdehyde (MDA), superoxide dismutase (SOD), and acetylcholinesterase (AChE) assays; and H&E staining were done in the rat brain to assess the biochemical and structural changes. CAE was also subjected to HPLC analysis, in vitro antioxidant and anti-cholinergic activity. The active compounds of CAE were docked with AChE and BuChE in molecular docking study. The results showed that CAE treatment improves behavioral performance; attenuates the age-associated increase in MDA content, SOD, and AChE activity; and reduces neuronal loss. In vitro study showed that CAE has concentration-dependent antioxidant and anti-AChE activity. Furthermore, the presence of Asiatic acid and Madecassic acid in CAE and their good binding with cholinergic enzymes (in silico) also suggest the anticholinergic effect of CAE. The findings of the current study show that the anticholinergic and antioxidant effects of CAE are attributable to the presence of Asiatic acid and Madecassic acid, which not only provide neuroprotection against age-associated cognitive decline but also reverse it. [Display omitted] • Aging has a major impact on the brain, affecting memory and cognitive function. • CA improves hippocampus and cortex associated cognitive functions in m-aged rats. • CA reduces oxidative stress and improves cholinergic activity in m-aged rats. • The presence of Asiatic and Madecassic acid contributes to CA's beneficial effect. [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological relevance: Shilajit has been used as a rejuvenator for ages in Indian ancient traditional medicine and has been validated for a number of pharmacological activities. Aim of the study: The effect of processed shilajit which was standardized to dibenzo-α-pyrones (DBPs;0.43% w/w), DBP-chromoproteins (DCPs; 20.45% w/w) and fulvic acids (56.75% w/w) was evaluated in a rat model of chronic fatigue syndrome (CFS). The mitochondrial bioenergetics and the activity of hypothalamus–pituitary–adrenal (HPA) axis were evaluated for the plausible mechanism of action of shilajit. Materials and Methods: CFS was induced by forcing the rats to swim for 15mins for 21 consecutive days. The rats were treated with shilajit (25, 50 and 100mg/kg) for 21 days before exposure to stress procedure. The behavioral consequence of CFS was measured in terms of immobility and the climbing period. The post-CFS anxiety level was assessed by elevated plus maze (EPM) test. Plasma corticosterone and adrenal gland weight were estimated as indices of HPA axis activity. Analysis of mitochondrial complex chain enzymes (Complex I, II, IV and V) and mitochondrial membrane potential (MMP) in prefrontal cortex (PFC) were performed to evaluate the mitochondrial bioenergetics and integrity respectively. Results: Shilajit reversed the CFS-induced increase in immobility period and decrease in climbing behavior as well as attenuated anxiety in the EPM test. Shilajit reversed CFS-induced decrease in plasma corticosterone level and loss of adrenal gland weight indicating modulation of HPA axis. Shilajit prevented CFS-induced mitochondrial dysfunction by stabilizing the complex enzyme activities and the loss of MMP. Shilajit reversed CFS-induced mitochondrial oxidative stress in terms of NO concentration and, LPO, SOD and catalase activities. Conclusion: The results indicate that shilajit mitigates the effects of CFS in this model possibly through the modulation of HPA axis and preservation of mitochondrial function and integrity. The reversal of CFS-induced behavioral symptoms and mitochondrial bioenergetics by shilajit indicates mitochondria as a potential target for treatment of CFS. [Copyright &y& Elsevier]