Oligomeric proanthocyanidins improve memory and enhance phosphorylation of vascular endothelial growth factor receptor-2 in senescence-accelerated mouse prone/8. Br J Nutr. 2010;103:479-489. [PMID: 19822031 DOI: 10.1017/S0007114509992005]

Neurocognitive effects of proanthocyanidin in Alzheimer's disease: a systematic review of preclinical evidence

Cognitive disorders and dementia largely influence individual independence and orientation. Based on the Alzheimer's Disease International (ADI) estimation, approximately 75% of individuals with dementia are undiagnosed. In fact, in some low- and middle-income countries, the percentage is as high as 90%. In this systematic review, which is based on PRISMA guidelines, we aim to identify the mechanism of action of proanthocyanidin. Finding a natural product alternative as a potential nootropic can help increase the number of armamentariums against dementia and other cognitive impairments. In this preclinical research, we determined the effect of proanthocyanidins on Alzheimer's disease (AD) by searching electronic bibliographic databases like Scopus, Proquest, ScienceDirect, PubMed, and Google. There was no imposed time limit. However, the search was limited to only English articles. The review protocol is registered on PROSPERO as CRD42022356301. A population, intervention, control, and outcomes (PICO) technique was utilized for report inclusion, and all reports were assessed for risk of bias by using the SYRCLE's RoB tool. The article's bibliographic information, induction model, type of proanthocyanidins, animal strain/weight/age, and outcome measurements were acquired from ten papers and are reported here. Further analysis was validated and determined for the review. The included studies met the review's inclusion criteria and suggested that proanthocyanidins have a neurocognitive effect against AD. Additionally, the effectiveness of proanthocyanidins in reducing oxidative stress, acetylcholinesterase activity, amyloid beta, its efficacy in alleviating superoxide dismutase, cognitive properties, and in facilitating cholinergic transmission in various models of AD has been collectively observed in ten studies.

Combination of tea polyphenols and proanthocyanidins prevents menopause-related memory decline in rats via increased hippocampal synaptic plasticity by inhibiting p38 MAPK and TNF-α pathway

OBJECTIVE

Many studies have examined the beneficial effects of tea polyphenols (TP) and proanthocyanidins (PC) on the memory impairment in different animal models. However, the combined effects of them on synaptic, memory dysfunction and molecular mechanisms have been poorly studied, especially in the menopause-related memory decline in rats.

METHODS

In this rat study, TP and PC were used to investigate their protective effects on memory decline caused by inflammation. We characterized the learning and memory abilities, synaptic plasticity, AMPAR, phosphorylation of the p38 protein, TNF-ɑ, structural synaptic plasticity-related indicators in the hippocampus.

RESULTS

The results showed that deficits of learning and memory in OVX + D-gal rats, which was accompanied by dendrites and synaptic morphology damage, and increased expression of Aβ1-42 and inflammation. The beneficial effects of TP and PC treatment were found to prevent memory loss and significantly improve synaptic structure and functional plasticity. TP+PC combination shows more obvious advantages than intervention alone. TP and PC treatment improved behavioral performance, the hippocampal LTP damage and the shape and number of dendrites, dendritic spines and synapses, reduced the burden of Aβ and decreased the inflammation in hippocampus. In addition, TP and PC treatment decreased the expressions of Iba-1, TNF-α, TNFR1, and TRAF2.

CONCLUSIONS

These results provided a novel evidence TP combined with PC inhibits p38 MAPK pathway, suppresses the inflammation in hippocampus, and increase the externalization of AMPAR, which may be one of the mechanisms to improve synaptic plasticity and memory in the menopause-related memory decline rats.

Proanthocyanidins: A comprehensive review

Proanthocyanidins are condensed tannins with various pharmacological properties. These phytochemicals are considered as 'offense and defense molecules because of their human health benefits. The validation of their diverse health aspects, namely, antioxidant, anticancer, antidiabetic, neuroprotective, and antimicrobial has earned them repute in thermochemistry. Proanthocyanidins are oligo- or polymers of monomeric flavan-3-ols produced as an end product of flavonoid biosynthetic pathway. Agricultural wastes and food processing wastes contain immense amount of proanthocyanidins, exploitation of which can be a sustainable source of dietary supplements and functional ingredients. The current review article discusses recent developments in the health promoting properties of proanthocyanidins and the associated hurdles.

Oligomeric proanthocyanidins protect myocardium by mitigating left ventricular remodeling in isoproterenol-induced postmyocardial infarction

Extracellular matrix (ECM) remodeling is a major pathophysiological process during post-myocardial infarction (MI). The activation, differentiation, and proliferation of cardiac fibroblasts to myofibroblasts regulate the expression of ECM proteins. The signaling by bone morphogenetic protein (BMP-4), an extracellular ligand of the TGF-β family, has recently been identified as an essential pathway in regulating cardiovascular dysfunctions including myocardial fibrosis. Oligomeric proanthocyanidins (OPC) are well known for their cardioprotective activity. The primary aim of the study was to investigate BMP-4-mediated ECM turnover in cardiac fibrosis during isoproterenol-induced post-MI and its downregulation by OPC. Myocardial injury was evaluated by assaying serum markers LDH and CK. Oxidative stress and the enzymatic and nonenzymatic antioxidant levels were assessed to support the cardioprotective nature of OPC. The total collagen level was analyzed by measuring hydroxyproline levels. The ISO-induced group showed a significant decrease in the levels of antioxidants due to severe oxidative stress and increased expression of BMP-4 which reflects the increased expression of MMP 2 and 9 with a concomitant increase and deposition of fibrillary collagens type I and III responsible for the fibrotic scar formation as evidenced in the histological analysis.BMP-4 activation, thus, is strongly associated with cardiac fibrosis which was downregulated upon OPC supplementation. This study provides an evidence supporting the antifibrotic effect of OPC via regulation of BMP-4-mediated ECM turnover and also substantiates the remarkable antioxidant efficacy of OPC against isoproterenol induced severe oxidative stress and subsequent post-MI cardiac fibrosis.

Protective Effect of Diospyros kaki against Glucose-Oxygen-Serum Deprivation-Induced PC12 Cells Injury

Ischemic cerebrovascular disease is one of the most common causes of death in the world. Recent interests have been focused on natural antioxidants and anti-inflammatory agents as potentially useful neuroprotective agents. Diospyros kaki (persimmon) has been shown to exert anti-inflammatory, antioxidant, and antineoplastic effects. However, its effects on ischemic damage have not been evaluated. Here, we used an in vitro model of cerebral ischemia and studied the effects of hydroalcoholic extract of peel (PeHE) and fruit pulp (PuHE) of persimmon on cell viability and markers of oxidative damage mainly intracellular reactive oxygen species (ROS) induced by glucose-oxygen-serum deprivation (GOSD) in PC12 cells. GOSD for 6 h produced significant cell death which was accompanied by increased levels of ROS. Pretreatment with different concentrations of PeHE and PuHE (0–500 μg/mL) for 2 and 24 h markedly restored these changes only at high concentrations. However, no significant differences were seen in the protection against ischemic insult between different extracts and the time of exposure. The experimental results suggest that persimmon protects the PC12 cells from GOSD-induced injury via antioxidant mechanisms. Our findings might raise the possibility of potential therapeutic application of persimmon for managing cerebral ischemic and other neurodegenerative disorders.

Persimmon (Diospyros kaki) fruit: hidden phytochemicals and health claims

Currently, nutrition and health linkages focused on emerging strategy of diet based regimen to combat various physiological threats including cardiovascular disorders, oxidative stress, diabetes mellitus, etc. In this context, consumption of fruits and vegetables is gaining considerable importance as safeguard to maintain human health. Likewise, their phytochemicals and bioactive molecules are also becoming popular as promising demulcent against various ailments. The current review is an effort to sum up information regarding persimmon fruit with special reference to its phytochemistry and associated health claims. Accordingly, the role of its certain bioactive molecules like proanthocyanidin, carotenoids, tannins, flavonoids, anthocyanidin, catechin, etc. is highlighted. Owing to rich phytochemistry, persimmon and its products are considered effective in mitigating oxidative damage induced by reactive oxygen species (ROS). The antioxidant potential is too responsible for anti-malignant and anti-melanogenic perspectives of persimmon functional ingredients. Additionally, they are effectual in soothing lifestyle related disparities e.g. cardiovascular disorders and diabetes mellitus. There are proven facts that pharmacological application of persimmon or its functional ingredients like proanthocyanidin may helps against hyperlipidemia and hyperglycemia. Nevertheless, astringent taste and diospyrobezoars formation are creating lacuna to prop up its vitality. In toto, persimmon and its components hold potential as one of effective modules in diet based therapy; however, integrated research and meta-analysis are still required to enhance meticulousness.

Improvement of cognitive deficits in SAMP8 mice by 3-n-butylphthalide

The herbal extract 3-n-butylphthalide (NBP) is used in clinical practice for ischemic patients in China. It has been shown to have various neuroprotective effects both in vitro and in vivo. In the present study, the effects of NBP on learning and memory decline in the senescence-accelerated mouse prone-8 (SAMP8) animal model were investigated. Intragastric NBP administration to 4-month-old SAMP8 mice for 2 months significantly improved spatial learning and memory ability. Moreover, the loss of choline acetyltransferase (ChAT)-positive neurons in the medial septal nucleus and the vertical limb of the diagonal band in SAMP8 mice was slowed down, as was the decline in the protein and mRNA expression of ChAT in the hippocampus, cerebral cortex, and forebrain. These results demonstrated that NBP treatment starting at the age of 4 months protected from the learning/memory deficits with aging of SAMP8 mice, and that this effect might be mediated by preventing the decline of the central cholinergic system.

Oligomeric proanthocyanidins from grape seeds protect against alcohol-induced liver injury and cerebral dysfunction in rats

AIM: To study the protective effects of oligomeric proanthocyanidins (OPC) from grape seeds against alcohol-induced liver injury and cerebral dysfunction in rats.

METHODS: Thirty-one Sprague-Dawley rats were randomly divided into four groups: A (treated with normal saline), B (treated with OPC), C (treated with OPC and alcohol), and D (treated with alcohol). Groups A and D were administered intragastrically with 0.9% NaCl [10 mL/(kg•d)], while groups B and C were administered with OPC solution [200 mg/(kg•d]. After three hours, groups A and B were intragastrically given 0.9% NaCl [10 mL/(kg•d)], while groups C and D were given 55% alcohol [10 mL/(kg•d)]. After 23 d, blood samples were collected from all animals via the inferior vena cava under general anesthesia, and liver and brain tissue samples were taken and fixed in 10% buffer formaldehyde. The level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the plasma was measured, and the histopathology of the liver and brain was assessed under an optical microscope.

RESULTS: Plasma levels of AST were 110.00 U/L ± 15.55 U/L, 98.38 U/L ± 17.86 U/L, 100.14 U/L ± 14.46 U/L and 176.00 U/L ± 49.60 U/L in groups A, B, C and D, respectively, and those of ALT were 57.25 U/L ± 9.04 U/L, 49.50 U/L ± 6.67 U/L, 50.28 U/L ± 5.37 U/L and 74.50 ± 9.69 in groups A, B, C and D. Both AST and ALT levels did not significantly differ between groups A, B and C (all P > 0.05); however, both AST and ALT levels were significantly elevated in group D compared to groups A, B, and C (all P < 0.001). No significant liver injury was found in groups A and B. The incidence of liver injury in group C was lower than that in group D (57.1% vs 100%, P = 0.077), and the area of injured liver was significantly less in group C than in group D (3.6% ± 3.2% vs 63% ± 28%, P < 0.001). The latent periods from alcohol administration to the onset of drunkenness was significantly longer in group C than in group D (16.43 min ± 2.71 min vs 10.67 min ± 2.38 min, P < 0.0001). No significant brain injury was found in all four groups by optical microscopy.

CONCLUSION: Pretreatment with OPC provides excellent protection against alcohol-induced liver injury and slows the onset of drunkenness in rats.

Neurodevelopmental disruption of cortico-striatal function caused by degeneration of habenula neurons

Background

The habenula plays an important role on cognitive and affective functions by regulating monoamines transmission such as the dopamine and serotonin, such that its dysfunction is thought to underlie a number of psychiatric conditions. Given that the monoamine systems are highly vulnerable to neurodevelopmental insults, damages in the habenula during early neurodevelopment may cause devastating effects on the wide-spread brain areas targeted by monoamine innervations.

Methodology/Principal Findings

Using a battery of behavioral, anatomical, and biochemical assays, we examined the impacts of neonatal damage in the habenula on neurodevelopmental sequelae of the prefrontal cortex (PFC) and nucleus accumbens (NAcc) and associated behavioral deficits in rodents. Neonatal lesion of the medial and lateral habenula by ibotenic acid produced an assortment of behavioral manifestations consisting of hyper-locomotion, impulsivity, and attention deficit, with hyper-locomotion and impulsivity being observed only in the juvenile period, whereas attention deficit was sustained up until adulthood. Moreover, these behavioral alterations were also improved by amphetamine. Our study further revealed that impulsivity and attention deficit were associated with disruption of PFC volume and dopamine (DA) receptor expression, respectively. In contrast, hyper-locomotion was associated with decreased DA transporter expression in the NAcc. We also found that neonatal administration of nicotine into the habenula of neonatal brains produced selective lesion of the medial habenula. Behavioral deficits with neonatal nicotine administration were similar to those caused by ibotenic acid lesion of both medial and lateral habenula during the juvenile period, whereas they were different in adulthood.

Conclusions/Significance

Because of similarity between behavioral and brain alterations caused by neonatal insults in the habenula and the symptoms and suggested neuropathology in attention deficit/hyperactivity disorder (ADHD), these results suggest that neurodevelopmental deficits in the habenula and the consequent cortico-striatal dysfunctions may be involved in the pathogenesis and pathophysiology of ADHD.