piperine and Cognition-Disorders

Previous research has shown that resveratrol can increase cerebral blood flow (CBF) in the absence of improved cognitive performance in healthy, young human subjects during the performance of cognitively demanding tasks. This lack of cognitive effects may be due to low bioavailability and, in turn, reduced bioefficacy of resveratrol in vivo. Piperine can alter polyphenol pharmacokinetics, but previous studies have not investigated whether this affects the efficacy of the target compound. Therefore, the objective of the present study was to ascertain whether co-supplementation of piperine with resveratrol affects the bioavailability and efficacy of resveratrol with regard to cognition and CBF. The present study utilised a randomised, double-blind, placebo-controlled, within-subjects design, where twenty-three adults were given placebo, trans-resveratrol (250 mg) and trans-resveratrol with 20 mg piperine on separate days at least a week apart. After a 40 min rest/absorption period, the participants performed a selection of cognitive tasks and CBF was assessed throughout the period, in the frontal cortex, using near-IR spectroscopy. The presence of resveratrol and its conjugates in the plasma was confirmed by liquid chromatography-MS analysis carried out following the administration of the same doses in a separate cohort (n 6). The results indicated that when co-supplemented, piperine and resveratrol significantly augmented CBF during task performance in comparison with placebo and resveratrol alone. Cognitive function, mood and blood pressure were not affected. The plasma concentrations of resveratrol and its metabolites were not significantly different between the treatments, which indicates that co-supplementation of piperine with resveratrol enhances the bioefficacy of resveratrol with regard to CBF effects, but not cognitive performance, and does this without altering bioavailability.

Topics: Adult; Alkaloids; Benzodioxoles; Cerebrovascular Circulation; Cognition; Cognition Disorders; Cohort Studies; Cross-Over Studies; Dietary Supplements; Double-Blind Method; Female; Frontal Lobe; Humans; Intestinal Absorption; Male; Nootropic Agents; Pilot Projects; Piperidines; Polyunsaturated Alkamides; Resveratrol; Spectroscopy, Near-Infrared; Stilbenes; Task Performance and Analysis; Young Adult

Aging-related cholinergic dysfunction, extensive neuroinflammation and oxidative stress in brain are predominant pathogenic factors for dementia. In the present study, we aimed to evaluate the protective effects of piperine, an alkaloid nutrient component of Piper nigrum, against cognitive impairment in a senescent mouse model induced by D-galactose (D-Gal) and to explore the underlying mechanisms. Senescent mouse model was established by repeated subcutaneous injection of D-Gal (150 mg/kg, once daily for 42 days). Fourteen days after the first D-Gal exposure, piperine (2.5, 5, 10 mg/kg) or vehicle was intraperitoneally administered once daily for 28 days. The cognitive function of mice was evaluated by Morris water maze test (MWM). Twenty-four hours after behavioral test, the cholinergic function and oxidative stress level in mouse hippocampus were measured by spectrophotometric assays. In addition, the hippocampal levels of proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1β and interleukin-6, were quantified using enzyme-linked immunosorbent assay. Expressions of glycogen synthase kinase-3β (GSK-3β) and its upstream or downstream molecules including phosphatidylinositol 3-kinase (PI3K)，protein kinase B (AKT), protein kinase C (PKC), NF-E2-related factor 2, nuclear factor-κB and microtubule-associated protein tau in hippocampus were determined by western blotting, immunohistochemical or immunofluorescent staining. Our data revealed that chronic D-Gal exposure in mice led to cognitive impairment in MWM, along with cholinergic malfunction, extensive oxidative stress and neuroinflammation, as well as hyperphosphorylation of tau protein in hippocampus. All these neurochemical, neuroinflammatory and cognitive alterations could be ameliorated by 4-week repeated piperine administration. Moreover, piperine also reversed D-Gal-induced GSK-3β activation through modulating PKC and PI3K/AKT pathways in senescent mouse hippocampus, suggesting GSK-3β-related signaling might be involved in the benefits of piperine against D-Gal-induced cognitive decline in mice.

Topics: Aging; Alkaloids; Animals; Behavior, Animal; Benzodioxoles; Cellular Senescence; Cognition; Cognition Disorders; Cytokines; Galactose; Glutathione; Glycogen Synthase Kinase 3 beta; Hippocampus; Inflammation; Lipid Peroxidation; Male; Maze Learning; Mice; Models, Animal; Neurons; Oxidative Stress; Piperidines; Polyunsaturated Alkamides; Protein Kinase C; Reactive Oxygen Species; Signal Transduction

Piperine, the major alkaloid constituent of black pepper, has been reported to possess a wide range of pharmacological effects on the central nervous system, including antidepressant, anticonvulsant and anti-ischemic activities. In the present study, we aimed to investigate the therapeutic potential and neuroprotective mechanisms of piperine in an experimental mouse model of sporadic Alzheimer's disease (sAD) induced by intracerebroventricular (ICV) infusion of streptozotocin (STZ). STZ was infused bilaterally at a dose of 1.5 mg/kg/day on day 1 and day 3. From day 8, piperine (2.5-10 mg/kg body weight) was administered intraperitoneally once daily for 15 consecutive days. The locomotor activity and cognitive performance of mice were evaluated using open field test and Morris water maze test, respectively. On day 23, all animals were sacrificed, and the hippocampus was used for biochemical, neurochemical and neuroinflammatory determinations. Our data revealed that the ICV-STZ-infused sAD mouse showed an increased oxidative-nitrosative stress, an altered neurotransmission and an elevated neuroinflammation in hippocampus, as well as significant cognitive deficits. All these alterations can be ameliorated by piperine in a dose-dependent manner. In summary, our findings predict a therapeutic potential of piperine against cognitive deficits in sAD mouse. This effect might be due to its abilities to ameliorate oxidative-nitrosative stress, restore neurotransmission and reduce neuroinflammation.

Topics: Alkaloids; Alzheimer Disease; Animals; Benzodioxoles; Cognition Disorders; Disease Models, Animal; Hippocampus; Inflammation; Infusions, Intraventricular; Male; Maze Learning; Memory Disorders; Mice; Neuroprotective Agents; Nitrogen; Oxidative Stress; Piperidines; Polyunsaturated Alkamides; Streptozocin

Piperine has been shown to have antioxidant activity and a cognitive-enhancing effect following long-term oral administration. In a comparative study of memantine, the current investigation threw light on the cognitive benefits of piperine. Lipid peroxidation and the ferric reducing antioxidant power (FRAP) of cerebrospinal fluid (CSF) and hippocampus in streptozotocin (STZ)-induced experimental dementia of the Alzheimer's type was measured. After reaching a criterion in a memory test, STZ-induced rats received piperine [2.5, 5, and 10mg/kg, intraperitoneally (i.p.)], vehicle, and memantine (10mg/kg, i.p.) for two weeks after the first STZ administration, or two weeks before and one week after, as a preventive approach. After the behavioral studies, samples were taken for biochemical and histological assays. An appropriate concentration of piperine (2.5mg/kg), on a daily basis, effectively increased the number of correct (non-repeated) arm entries and repressed reentry to a previously visited arm, in terms of reference errors as well as memantine (10mg/kg, i.p.), irrespective of the dose administered. The cognitive-enhancing effect induced by piperine at a relevant dose was simultaneous with CSF and hippocampal malonaldehyde decrement, and the redox balance was established to some extent by maintaining the FRAP levels of CSF near to those of the control. Similarly, the neuroprotective properties of piperine are in accordance with histopathological outcomes, which have shown an increased number of live cresyl violet (CV)-positive neurons in a dentate gyrus (DG) subregion. Therefore, the effects of piperine on the redox balance of CSF and hippocampal neurons may certainly contribute to the cognitive-enhancing activity of the drug.

Topics: Alkaloids; Analysis of Variance; Animals; Antibiotics, Antineoplastic; Avoidance Learning; Benzodioxoles; Cognition Disorders; Cytochrome P-450 Enzyme Inhibitors; Dose-Response Relationship, Drug; Hippocampus; Lipid Peroxidation; Male; Malondialdehyde; Maze Learning; Memantine; Memory, Short-Term; Neurons; Piperidines; Polyunsaturated Alkamides; Rats; Rats, Wistar; Streptozocin

Life event stressors are the major vulnerability factors for the development of cognitive disorders. A vital therapeutic for stress related disorders is curcumin, derived from curry spice turmeric. Dietary phytochemicals are currently used as an adjuvant therapy to accelerate their therapeutic efficacy. Therefore, the present study was designed to investigate the effect of curcumin and its co-administration with piperine against chronic unpredictable stress (CUS)-induced cognitive impairment and oxidative stress in mice. Male Laca mice were subjected to undergo a battery of stressors for a period of 28 days. Vehicle/drugs were administered daily 30mins before CUS procedure. Chronic stress significantly impaired memory performance (delayed latency time to reach platform in Morris water maze as well as to reach closed arm in elevated plus maze test) and decreased locomotor activity along with sucrose consumption. Further, there was a significant impairment in oxidative parameters (elevated malondialdehyde, nitrite concentration and decreased reduced glutathione, catalase levels) and mitochondrial enzyme complex activities, along with raised acetylcholinesterase and serum corticosterone levels. Chronic treatment with curcumin (200 and 400mg/kg, p.o.) significantly improved these behavioral and biochemical alterations, restored mitochondrial enzyme complex activities and attenuated increased acetylcholinesterase and serum corticosterone levels. In addition, co-administration of piperine (20mg/kg; p.o.) with curcumin (100 and 200mg/kg, p.o.) significantly elevated the protective effect as compared to their effects alone. The results clearly suggest that piperine enhanced the bioavailability of curcumin and potentiated its protective effects against CUS induced cognitive impairment and associated oxidative damage in mice.

Topics: Alkaloids; Animals; Anti-Inflammatory Agents, Non-Steroidal; Benzodioxoles; Chronic Disease; Cognition Disorders; Corticosterone; Curcumin; Cytochrome P-450 Enzyme Inhibitors; Dietary Sucrose; Drug Synergism; Food Preferences; Male; Maze Learning; Mice; Mice, Inbred Strains; Mitochondria; Motor Activity; Neuroprotective Agents; Oxidative Stress; Piperidines; Polyunsaturated Alkamides; Stress, Psychological; Uncertainty

Recently, numerous medicinal plants possessing profound central nervous system effects and antioxidant activity have received much attention as food supplement to improve cognitive function against cognitive deficit condition including in Alzheimer's disease condition. Based on this information, the effect of piperine, a main active alkaloid in fruit of Piper nigrum, on memory performance and neurodegeneration in animal model of Alzheimer's disease have been investigated. Adult male Wistar rats (180-220 g) were orally given piperine at various doses ranging from 5, 10 and 20mg/kg BW at a period of 2 weeks before and 1 week after the intracerebroventricular administration of ethylcholine aziridinium ion (AF64A) bilaterally. The results showed that piperine at all dosage range used in this study significantly improved memory impairment and neurodegeneration in hippocampus. The possible underlying mechanisms might be partly associated with the decrease lipid peroxidation and acetylcholinesterase enzyme. Moreover, piperine also demonstrated the neurotrophic effect in hippocampus. However, further researches about the precise underlying mechanism are still required.

Topics: Acetylcholinesterase; Alkaloids; Alzheimer Disease; Animals; Aziridines; Benzodioxoles; Choline; Cognition Disorders; Donepezil; Hippocampus; Indans; Injections, Intraventricular; Lipid Peroxidation; Male; Malondialdehyde; Maze Learning; Nerve Degeneration; Neuromuscular Blocking Agents; Neuroprotective Agents; Nootropic Agents; Piper nigrum; Piperidines; Polyunsaturated Alkamides; Rats; Space Perception; Thailand

The effect of piperine, the main alkaloid from piper nigrum, on the central nervous system is not clearly known until now. In the present study, male Wistar rats were administered piperine at various doses ranging from 5, 10 and 20mg/kg BW once daily for 4 weeks and the animals were determined the neuropharmacological activity after single, 1, 2, 3 and 4 weeks of treatment. The results showed that piperine at all dosage range used in this study possessed anti-depression like activity and cognitive enhancing effect at all treatment duration. Therefore, piperine may be served as the potential functional food to improve brain function. However, further investigations about precise underlying mechanism are still required.

Topics: Alkaloids; Animals; Antidepressive Agents; Anxiety; Behavior, Animal; Benzodioxoles; Cognition Disorders; Food Analysis; Male; Maze Learning; Mood Disorders; Motor Activity; Piperidines; Polyunsaturated Alkamides; Rats; Rats, Wistar; Swimming