Atish Prakash

Protective effect of curcumin (Curcuma longa), against aluminium toxicity: Possible behavioral and biochemical alterations in rats.

Aluminium is a potent neurotoxin and has been associated with Alzheimers disease (AD) causality for decades. Prolonged aluminium exposure induces oxidative stress and increases amyloid beta levels in vivo. Current treatment modalities for AD provide only symptomatic relief thus necessitating the development of new drugs with fewer side effects. The aim of the study was to demonstrate the protective effect of chronic curcumin administration against aluminium-induced cognitive dysfunction and oxidative damage in rats. Aluminium chloride (100 mg/kg, p.o.) was administered to rats daily for 6 weeks. Rats were concomitantly treated with curcumin (per se; 30 and 60 mg/kg, p.o.) daily for a period of 6 weeks. On the 21st and 42nd day of the study behavioral studies to evaluate memory (Morris water maze and elevated plus maze task paradigms) and locomotion (photoactometer) were done. The rats were sacrificed on 43rd day following the last behavioral test and various biochemical tests were performed to assess the extent of oxidative damage. Chronic aluminium chloride administration resulted in poor retention of memory in Morris water maze, elevated plus maze task paradigms and caused marked oxidative damage. It also caused a significant increase in the acetylcholinesterase activity and aluminium concentration in aluminium treated rats. Chronic administration of curcumin significantly improved memory retention in both tasks, attenuated oxidative damage, acetylcholinesterase activity and aluminium concentration in aluminium treated rats (P<0.05). Curcumin has neuroprotective effects against aluminium-induced cognitive dysfunction and oxidative damage.

Naringin alleviates cognitive impairment, mitochondrial dysfunction and oxidative stress induced by d-galactose in mice

Role of mitochondrial dysfunction and oxidative stress has been well documented in aging and related disorders such as Alzheimers disease. Bioflavonoids have been reported to have a therapeutic potential against several age related processes. Bioflavonoids are being used as a neuroprotectants in the treatment of various neurological disorders including aging. Therefore, present study has been conducted in order to explore the possible role of naringin against D-galactose induced cognitive dysfunction, oxidative damage and mitochondrial dysfunction in mice. Chronic administration of D-galactose (100 mg/kg) for 6 weeks significantly impaired cognitive performance (both in Morris water maze and elevated plus maze), locomotor activity, oxidative defense and mitochondrial complex (I, II and III) enzymes activities as compared to sham group. Six weeks naringin (40 and 80 mg/kg) treatment significantly improved cognitive performance, oxidative defense and restored mitochondria complex enzyme activities as compared to control (D-galactose). Naringin treatment significantly attenuated acetylcholine esterase activity in D-galactose treated mice. In conclusion, present study highlights the potential role of naringin against D-galactose induced cognitive impairment, biochemical and mitochondrial dysfunction in mice.

Centella asiatica Attenuates D-Galactose-Induced Cognitive Impairment, Oxidative and Mitochondrial Dysfunction in Mice

D-galactose induced neurotoxicity is well known model for studying aging and related oxidative damage and memory impairment. Aging is a biological process, characterized by the gradual loss of physiological functions by unknown mechanism. Centella asiatica, Indian pennywort has been documented in the treatment of various neurological disorders including aging. Therefore, present study has been conducted in order to explore the possible role of Centella asiatica against D-galactose induced cognitive impairment, oxidative and mitochondrial dysfunction in mice. Chronic administration of D-galactose (100 mg/kg s.c.) for a period of six weeks significantly impaired cognitive task (both in both Morris water maze and elevated plus maze) and oxidative defense (Increased lipid peroxidation, nitrite concentration and decreased activity of superoxide dismutase, catalase and non-protein thiols) and impaired mitochondrial complex (I, II and III) enzymes activities as compared to sham group. Six weeks Centella asiatica (150 and 300 mg/kg, p.o) treatment significantly improved behavioral alterations, oxidative damage and mitochondrial enzyme complex activities as compared to contro l (D-galactose). Centella asiatica also attenuated enhanced acetylcholine esterase enzyme level in D-galactose senescence mice. Present study highlights the protective effect of Centella asiatica against D-galactose induced behavioral, biochemical and mitochondrial dysfunction in mice.

Neuroprotective Effects of Centella asiatica against Intracerebroventricular Colchicine-Induced Cognitive Impairment and Oxidative Stress

Oxidative stress appears to be an early event involved in the pathogenesis of Alzheimers disease. The present study was designed to investigate the neuroprotective effects of Centella asiatica against colchicine-induced memory impairment and oxidative damage in rats. Colchicine (15 μg/5 μL) was administered intracerebroventricularly in the lateral ventricle of male wistar rats. Morris water maze and plus-maze performance tests were used to assess memory performance tasks. Various biochemical parameters such as lipid peroxidation, nitrite, reduced glutathione, glutathione-S-transferase, superoxide dismutase, acetylcholinesterase were also assessed. ICV colchicine resulted marked memory impairment and oxidative damage. Chronic treatment with Centella asiatica extract (150 and 300 mg/kg, p.o.) for a period of 25 days, beginning 4 days prior to colchicine administration, significantly attenuated colchicine-induced memory impairment and oxidative damage. Besides, Centella asiatica significantly reversed colchicines administered increase in acetylcholinesterase activity. Thus, present study indicates protective effect of Centella asiatica against colchicine-induced cognitive impairment and associated oxidative damage.

Neuroprotective effect of carvedilol against aluminium induced toxicity: possible behavioral and biochemical alterations in rats

Aluminium, is a trace element available in the Earths crust naturally and has a toxic potential for humans. It has been suggested as a contributing factor in the pathogenesis of Alzheimers disease. β-Adrenoceptor blocking agents (β-blockers) have been established as therapeutics for the treatment of patients with hypertension, ischemic heart diseases, chronic heart failure, arrhythmias and glaucoma. Over the years, however, β-blockers have been associated with an incidence, albeit low, of central nervous system (CNS) side effects. In addition, noradrenergic receptors play a modulatory role in many nerve functions, including vigilance, attention, reward, learning and memory. Therefore, the present study has been designed to explore the possible role of carvedilol, an adrenergic antagonist against aluminium chloride-induced neurotoxicity in rats. Aluminium chloride (100 mg/kg) was administered daily for six weeks that significantly increased cognitive dysfunction in the Morris water maze and oxidative damage as indicated by a rise in lipid peroxidation and nitrite concentration and depleted reduced glutathione, superoxide dismutase, catalase and glutathione S-transferase activity compared to sham treatment. Chronic aluminium chloride treatment also significantly increased acetylcholinesterase activity and the aluminium concentration in brain compared to sham. Chronic administration of carvedilol (2.5 and 5 mg/kg, po) daily to rats for a period of 6 weeks significantly improved the memory performance tasks of rats in the Morris water maze test, attenuated oxidative stress (reduced lipid peroxidation, nitrite concentration and restored reduced glutathione, superoxide dismutase, catalase and glutathione S-transferase activity), decreased acetylcholinesterase activity and aluminium concentration in aluminium-treated rats compared to control rats (p < 0.05). Results of this study demonstrated the neuroprotective potential of carvedilol in aluminium chloride-induced cognitive dysfunction and oxidative damage.

Protective effect of curcumin (Curcuma longa) against D-galactose-induced senescence in mice

Brain senescence plays an important role in cognitive dysfunction and neurodegenerative disorders. Curcumin was reported to have beneficial effect against several neurodegenerative disorders including Alzheimers disease. Therefore, the present study was conducted in order to explore the possible role of curcumin against d-galactose-induced cognitive dysfunction, oxidative damage, and mitochondrial dysfunction in mice. Chronic administration of d-galactose for 6 weeks significantly impaired cognitive function (both in Morris water maze and elevated plus maze), locomotor activity, oxidative defense (raised lipid peroxidation, nitrite concentration, depletion of reduced glutathione and catalase activity), and mitochondrial enzyme complex activities (I, II, and III) as compared to vehicle treated group. Curcumin (15 and 30 mg/kg) and galantamine (5 mg/kg) treatment for 6 weeks significantly improved cognitive tasks, locomotor activity, oxidative defense, and restored mitochondrial enzyme complex activity as compared to control (d-galactose). Chronic d-galactose treatment also significantly increased acetylcholine esterase activity that was attenuated by curcumin (15 and 30 mg/kg) and galantamine (5 mg/kg) treatment. In conclusion, the present study highlights the therapeutic potential of curcumin against d-galactose induced senescence in mice.

Protective effect of naringin, a citrus flavonoid, against colchicine-induced cognitive dysfunction and oxidative damage in rats.

Alzheimers disease is a neurodegenerative disorder. Central administration of colchicine is well known to cause cognitive impairment and oxidative damage, which simulates sporadic dementia of the Alzheimer type in humans. The present study has been designed to investigate the protective effects of naringin against the colchicine-induced cognitive impairment and oxidative damage in rats. Colchicine (15 microg/5 microL), administered intracerebroventricularly, resulted in poor memory retention in both the Morris water maze and elevated plus maze task paradigms and caused marked oxidative damage. It also caused a significant decrease in acetylcholinesterase activity. Naringin (40 and 80 mg/kg, p.o.) treatment was given daily for a period of 25 days beginning 4 days prior to colchicine administration. Chronic treatment with naringin caused significant improvement in the cognitive performance and attenuated oxidative damage, as evidenced by lowering of malondialdehyde level and nitrite concentration and restoration of superoxide dismutase, catalase, glutathione S-transferase, and reduced glutathione levels, and acetylcholinesterase activity compared to control. The present study highlights the therapeutic potential of naringin against colchicine-induced cognitive impairment and associated oxidative damage.

Effect of N‐Acetyl Cysteine against Aluminium‐induced Cognitive Dysfunction and Oxidative Damage in Rats

Aluminium is a potent neurotoxin involved in the initiation and progression of various cognitive disorders like Alzheimers disease. Chronic aluminium exposure induces oxidative stress and increases amyloid beta levels in vivo. The role of oxidative stress has been well-suggested in these cognitive problems. Therefore, the present study was designed to explore the possible role of N-acetyl cysteine against aluminium mediating cognitive dysfunction and oxidative stress in rats. Aluminium chloride (100 mg/kg, p.o.) was given to rats daily for 6 weeks. N-acetyl cysteine (per se; 50 and 100 mg/kg, i.p.) pre-treatment was given 30 min. before aluminium daily for 6 weeks. On the third (21st day) and sixth week (42nd day) of the study, various behavioural tests (Morris water maze and elevated plus maze task paradigms) and locomotion (photoactometer) were done to evaluate cognitive tasks. The rats were killed on the 43rd day following the last behavioural test, and various biochemical tests were performed to assess the extent of oxidative damage. Chronic aluminium chloride administration resulted in poor retention of memory in Morris water maze, elevated plus maze task paradigms and caused marked oxidative damage. It also caused a significant increase in the acetylcholinesterase activity. Chronic administration of N-acetyl cysteine significantly improved memory retention in tasks, attenuated oxidative damage and acetylcholinesterase activity in aluminium-treated rats. The study suggests a neuroprotective effect of N-acetyl cysteine against aluminium-induced cognitive dysfunction and oxidative damage.

Effect of St. John's Wort (Hypericum perforatum) treatment on restraint stress-induced behavioral and biochemical alteration in mice

BackgroundA stressful stimulus is a crucial determinant of health and disease. Antidepressants are used to manage stress and their related effects. The present study was designed to investigate the effect of St. Johns Wort (Hypericum perforatum) in restraint stress-induced behavioral and biochemical alterations in mice.MethodsAnimals were immobilized for a period of 6 hr. St. Johns Wort (50 and 100 mg/kg) was administered 30 minutes before the animals were subjecting to acute immobilized stress. Various behavioral tests parameters for anxiety, locomotor activity and nociceptive threshold were assessed followed by biochemical assessments (malondialdehyde level, glutathione, catalase, nitrite and protein) subsequently.Results6-hr acute restraint stress caused severe anxiety like behavior, antinociception and impaired locomotor activity as compared to unstressed animals. Biochemical analyses revealed an increase in malondialdehyde, nitrites concentration, depletion of reduced glutathione and catalase activity as compared to unstressed animal brain. Five days St. Johns Wort treatment in a dose of 50 mg/kg and 100 mg/kg significantly attenuated restraint stress-induced behavioral (improved locomotor activity, reduced tail flick latency and antianxiety like effect) and oxidative damage as compared to control (restraint stress).ConclusionPresent study highlights the modest activity of St. Johns Wort against acute restraint stress induced modification.

Implicating the role of lycopene in restoration of mitochondrial enzymes and BDNF levels in β-amyloid induced Alzheimer׳s disease.

Lycopene has attracted significant research interest due to its beneficial therapeutic effects, which include anti-oxidant, neuro-protective and anti-cancer effects, but the mechanisms of its beneficial action are not clear so far. The present study was carried out to elucidate the neuroprotective effect of lycopene against the β-amyloid induced cognitive impairment and mitochondria oxidative damage in rats. β-amyloid (β-A1-42) was administered through intracerebroventricular (ICV) by using stereotaxic instrument in male Wistar rats. Lycopene (2.5 and 5mg/kg) was administrated for three weeks. Behavioral performances were conducted during the study. The rats were sacrificed on the 21st day following the last behavioral test and cytoplasmic fractions of hippocampus were prepared for the quantification of acetylcholinesterase, oxidative stress parameter, mitochondrial enzymes, and inflammatory mediator like TNF-α, Il-6 activities, caspase-3 and BDNF. ICV β-A1-42 resulted in poor memory retention in Morris water maze and caused marked oxidative stress as indicated by significant increase in oxidative, mitochondria damage, TNF-α, IL-6 and Caspase-3 activity. We also found that β-A1-42 induced animal altered BDNF level than control animals. Chronic administration of lycopene resulted in an improvement in memory retention, attenuation of mitochondrial-oxidative damage, reduced neuro-inflammation and restoration of BDNF level in β-A1-42 treated rats. These studies indicated that lycopene helps to protect β-A1-42 induced cognitive dysfunction and modulates amyloidogenesis.