Reduction of apoptosis by proanthocyanidin-induced autophagy in the human gastric cancer cell line MGC-803

Dysregulation of autophagy in gastric carcinoma: Pathways to tumor progression and resistance to therapy

The considerable death rates and lack of symptoms in early stages of gastric cancer (GC) make it a major health problem worldwide. One of the most prominent risk factors is infection with Helicobacter pylori. Many biological processes, including those linked with cell death, are disrupted in GC. The cellular "self-digestion" mechanism necessary for regular balance maintenance, autophagy, is at the center of this disturbance. Misregulation of autophagy, however, plays a role in the development of GC. In this review, we will examine how autophagy interacts with other cell death processes, such as apoptosis and ferroptosis, and how it affects the progression of GC. In addition to wonderful its role in the epithelial-mesenchymal transition, it is engaged in GC metastasis. The role of autophagy in GC in promoting drug resistance stands out. There is growing interest in modulating autophagy for GC treatment, with research focusing on natural compounds, small-molecule inhibitors, and nanoparticles. These approaches could lead to breakthroughs in GC therapy, offering new hope in the fight against this challenging disease.

Insights into the Surface Binding and Structural Interference of Polyphenols with the Membrane Raft Domains in Relation to Their Distinctive Ability to Inhibit Preadipocyte Differentiation in 3T3-L1 Cells

Polyphenols with different structures have shown distinct variations in their ability to inhibit the differentiation of 3T3-L1 preadipocytes. However, the underlying mechanisms for these differences remain unclear. In the present study, the surface binding of polyphenols to different membrane domains was explored using coarse-grained molecular dynamics simulation (CG-MDs). Subsequently, this surface binding was confirmed in the liposome system by microscale thermophoresis. Additionally, the interference of polyphenols on the membrane raft's structure was studied through atomic force microscopy and high-content screening fluorescence microscopy. The results indicated that polyphenols with a differentiation-inhibitory ability, such as epicatechin-3-gallate (ECG) and epicatechin-3-gallate-(4β → 8, 2β → O → 7)-epicatechin-3-gallate (A-type ECG dimer), exhibited strong binding to ordered domains enriched in sphingolipids and cholesterol. This binding led to the structural disruption of membrane rafts by altering their size and shape, with the binding constant of 3.8 μM for ECG and 0.3 μM for A-type ECG dimer, respectively. In contrast, epicatechin (EC) with little differentiation-inhibitory ability had no effects on membrane rafts, and its binding constant with the ordered domain was 380.6 μM. Overall, the surface binding of polyphenols to ordered domains and the resulting disruption of membrane rafts structure might be a fundamental mechanism by which polyphenols inhibited the differentiation of 3T3-L1 preadipocytes.

Proanthocyanidin enhances the endogenous regeneration of alveolar bone by elevating the autophagy of PDLSCs

OBJECTIVE

This study aimed to investigate the effect of proanthocyanidin (PA) on osteogenesis mediated by periodontal ligament stem cells (PDLSCs) and endogenous alveolar bone regeneration.

BACKGROUND

Leveraging the osteogenic potential of resident stem cells is a promising strategy for alveolar bone regeneration. PA has been reported to be effective in osteogenesis. However, the effect and mechanism of PA on the osteogenic differentiation of PDLSCs remain elusive.

METHODS

Human PDLSCs were treated with various doses of PA to assess the cell proliferation using Cell Counting Kit-8. The osteogenic differentiation ability was detected by qRT-PCR analysis, western blot analysis, Alizarin red S staining, and Alkaline Phosphatase staining. The level of autophagy was evaluated by confocal laser scanning microscopy, transmission electron microscopy, and western blot analysis. RNA sequencing was utilized to screen the potential signaling pathway. The alveolar bone defect model of rats was created to observe endogenous bone regeneration.

RESULTS

PA activated intracellular autophagy in PDLSCs, resulting in enhanced osteogenic differentiation. Moreover, this effect could be abolished by the autophagy inhibitor 3-Methyladenine. Mechanistically, the PI3K/Akt/mTOR pathway was negatively correlated with PA-mediated autophagy activation. Lastly, PA promoted the alveolar bone regeneration in vivo, and this effect was reversed when the autophagy process was blocked.

CONCLUSION

PA may activate autophagy by inhibiting PI3K/Akt/mTOR signaling pathway to promote the osteogenesis of PDLSCs and enhance endogenous alveolar bone regeneration.

Eriodictyol Alleviated LPS/D-GalN-Induced Acute Liver Injury by Inhibiting Oxidative Stress and Cell Apoptosis via PI3K/AKT Signaling Pathway

Eriodictyol occurs naturally in a variety of fruits and vegetables, and has drawn significant attention for its potential health benefits. This study aims to look into the effects of eriodictyol on acute liver injury (ALI) induced by LPS/D-GalN and elucidate its potential molecular biological mechanisms. A total of 47 targets were predicted for the treatment of ALI with eriodictyol, and the PI3K/AKT signaling pathway played a key role in the anti-ALI processing of this drug. The in vivo experiment showed that eriodictyol can effectively reduce liver function-related biochemical indicators such as ALT, AST, and AKP. Eriodictyol can also up-regulate the levels of SOD and GSH, and inhibit the release of IL-1β, IL-6, and TNF-α. Additionally, TUNEL staining, immunohistochemistry, and RT-PCR experiments showed that eriodictyol activated the PI3K/AKT pathway and decreased the expression of Bax, caspase3, and caspase8 while increasing the expression of Bcl-2 m-RNA. Finally, molecular docking experiments and molecular dynamics simulations confirmed the stable binding between eriodictyol and PI3K, AKT molecules. This study showed that eriodictyol can activate the PI3K/AKT signaling pathway to alleviate ALI-related oxidative stress and apoptosis.

Anticancer applications of phytochemicals in gastric cancer: Effects and molecular mechanism

Gastric cancer (GC) is the fourth most common malignant cancer and is a life-threatening disease worldwide. Phytochemicals have been shown to be a rational, safe, non-toxic, and very promising approach to the prevention and treatment of cancer. It has been found that phytochemicals have protective effects against GC through inhibiting cell proliferation, inducing apoptosis and autophagy, suppressing cell invasion and migration, anti-angiogenesis, inhibit Helicobacter pylori infection, regulating the microenvironment. In recent years, the role of phytochemicals in the occurrence, development, drug resistance and prognosis of GC has attracted more and more attention. In order to better understand the relationship between phytochemicals and gastric cancer, we briefly summarize the roles and functions of phytochemicals in GC tumorigenesis, development and prognosis. This review will probably help guide the public to prevent the occurrence and development of GC through phytochemicals, and develop functional foods or drugs for the prevention and treatment of gastric cancer.

Grape seed proanthocyanidin extract induces apoptotic and autophagic cell death in rheumatoid arthritis fibroblast-like synoviocytes

Objectives

In this study, we aimed to evaluate the association between grape seed proanthocyanidin extract (GSPE) and rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLSs) and to investigate whether GSPE induces cell death in RA-FLSs.

Materials and methods

The FLSs were isolated from RA synovial tissues. Cell viability and cell cycle staging were analyzed using a hemocytometer and flow cytometry. Caspase 3 and poly (ADP-ribose) polymerase (PARP) proteins were analyzed using Western blotting with z-VAD-fmk. Protein LC3 and polyubiquitin-binding protein p62 that were degraded by autophagy were evaluated using Western blotting with 3-methyladenine and chloroquine. Reactive oxygen species (ROS) were also evaluated.

Results

When RA-FLSs were treated with GSPE, cell viability decreased, the number of cells in sub-G1 and G2/M phases increased, and the expression of pro-PARP and pro-caspase 3 proteins decreased in a concentration-dependent manner. This result was offset, when the cells were co-treated with the pan-caspase inhibitor z-VAD-fmk. The reduced cell viability, increased expression of LC3-II protein, and reduced expression of p62 protein with GSPE treatment were offset, when RA-FLSs were co-treated with GSPE and autophagy inhibitors 3-methyladenine and chloroquine. The level of ROS in RA-FLSs treated with GSPE was significantly lower than treatment with N-acetyl-cysteine, a ROS inhibitor.

Conclusion

Our study results show that GSPE induces apoptotic and autophagic cell death and inhibites reactive oxygen species in RA-FLSs.

Dietary proanthocyanidins on gastrointestinal health and the interactions with gut microbiota

Many epidemiological and experimental studies have consistently reported the beneficial effects of dietary proanthocyanidins (PAC) on improving gastrointestinal physiological functions. This review aims to present a comprehensive perspective by focusing on structural properties, interactions and gastrointestinal protection of PAC. In brief, the main findings of this review are summarized as follows: (1) Structural features are critical factors in determining the bioavailability and subsequent pharmacology of PAC; (2) PAC and/or their bacterial metabolites can play a direct role in the gastrointestinal tract through their antioxidant, antibacterial, anti-inflammatory, and anti-proliferative properties; (3) PAC can reduce the digestion, absorption, and bioavailability of carbohydrates, proteins, and lipids by interacting with them or their according enzymes and transporters in the gastrointestinal tract; (4). PAC showed a prebiotic-like effect by interacting with the microflora in the intestinal tract, and the enhancement of PAC on a variety of probiotics, such as Bifidobacterium spp. and Lactobacillus spp. could be associated with potential benefits to human health. In conclusion, the potential effects of PAC in prevention and alleviation of gastrointestinal diseases are remarkable but clinical evidence is urgently needed.

A natural derivative from ethnomedicinal mushroom potentiates apoptosis, autophagy and attenuates cell migration, via fine tuning the Akt signaling in human lung adenocarcinoma cells (A549)

Although comprehensive exertions have been made in late decades for treating advanced lung cancer with inclusive therapies but efficient anti-lung cancer therapeutics are statically inadequate in the clinics. Hence, compelling novel anti-lung cancer drugs are considerably desired. This backdrop enticed us to unveil anticancer efficacy of astrakurkurol, derivative of wild edible mushroom against lung cancer, whose effects have not yet been described. Mechanistic analysis disclosed that sensitizing effect of astrakurkurol is due to cell cycle arrest at G0/G1 phase, increased level of Fas, FADD, decreased ratio of Bax/Bcl-2, and increased cleaved form of caspase 9, 8, and 3. Apart from the induction of apoptosis, it was demonstrated for the first time that astrakurkurol induced an autophagic response as evidenced by the development of acidic vesicular organelles (AVOs) with up-regulation of beclin-1, Atg7, and downregulated p62. Apoptosis and autophagy can be sparked by the same stimuli, which was as evident from the astrakurkurol-induced inactivation of PI3K/AKT signaling. The thorough scanning of the mechanism of crosstalk between apoptosis and autophagy is requisite for prosperous anticancer remedy. Triterpenoid has evidently intensified cytotoxicity, induced apoptosis and autophagy on A549 cells. Besides astrakurkurol could also curb migration and regress the size of tumor in ex ovo xenograft model. All these findings put forth astrakurkurol as a convincing novel anti-cancer agent, for scrutinizing the lung cancer therapies and as a robust contender for future in vitro and in vivo analysis.

Galloyl Group in B-type Proanthocyanidin Dimers Was Responsible for Its Differential Inhibitory Activity on 3T3-L1 Preadipocytes due to the Strong Lipid Raft-Perturbing Potency

The effects of three B-type proanthocyanidin (PA) dimers covering procyanidin B2 (B-0g), procyanidin B2 3'-O-gallate (B-1g), and procyanidin B2 3,3'-di-O-gallate (B-2g) on 3T3-L1 preadipocyte differentiation and the underlying mechanisms were investigated. The results showed that digalloylated B-type PA dimers (B-2g) strongly inhibited 3T3-L1 preadipocyte differentiation through disrupting the integrity of the lipid raft structure and inhibiting the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (C/EBPα) and then downregulating the expression of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) factors, followed by B-1g, while B-0g had little effect. The different inhibitory effects were mainly due to the difference in the B-type PA dimer structure and the ability to interfere with lipid rafts. The greater the galloylation degree of B-type PA dimers, the stronger the ability to disrupt the lipid raft structure and oppose 3T3-L1 preadipocyte differentiation. In addition, galloylated B-type PA dimers had greater molecular hydrophobicity and topological polarity surface area and could penetrate into the lipid rafts to form multiple hydrogen bonds with the rafts by molecular dynamics simulation. These findings highlighted that the strong lipid raft-perturbing potency of galloylated B-type PA dimers was responsible for inhibition of 3T3-L1 preadipocyte differentiation.

A systems pharmacology approach to identify the autophagy-inducing effects of Traditional Persian medicinal plants

Aging is correlated with several complex diseases, including type 2 diabetes, neurodegeneration diseases, and cancer. Identifying the nature of this correlation and treatment of age-related diseases has been a major subject of both modern and traditional medicine. Traditional Persian Medicine (TPM) embodies many prescriptions for the treatment of ARDs. Given that autophagy plays a critical role in antiaging processes, the present study aimed to examine whether the documented effect of plants used in TPM might be relevant to the induction of autophagy? To this end, the TPM-based medicinal herbs used in the treatment of the ARDs were identified from modern and traditional references. The known phytochemicals of these plants were then examined against literature for evidence of having autophagy inducing effects. As a result, several plants were identified to have multiple active ingredients, which indeed regulate the autophagy or its upstream pathways. In addition, gene set enrichment analysis of the identified targets confirmed the collective contribution of the identified targets in autophagy regulating processes. Also, the protein-protein interaction (PPI) network of the targets was reconstructed. Network centrality analysis of the PPI network identified mTOR as the key network hub. Given the well-documented role of mTOR in inhibiting autophagy, our results hence support the hypothesis that the antiaging mechanism of TPM-based medicines might involve autophagy induction. Chemoinformatics study of the phytochemicals using docking and molecular dynamics simulation identified, among other compounds, the cyclo-trijuglone of Juglans regia L. as a potential ATP-competitive inhibitor of mTOR. Our results hence, provide a basis for the study of TPM-based prescriptions using modern tools in the quest for developing synergistic therapies for ARDs.

Proanthocyanidins Should Be a Candidate in the Treatment of Cancer, Cardiovascular Diseases and Lipid Metabolic Disorder

The conventional view of using medicines as routine treatment of an intractable disease is being challenged in the face of extensive and growing evidence that flavonoids in foods, especially proanthocyanidins (PAs), can participate in tackling fatal diseases like cancer, cardiovascular and lipid metabolic diseases, both as a precautionary measure or as a dietary treatment. Although medical treatment with medicines will remain necessary in some cases, at least in the short term, PAs’ function as antioxidant, anti-inflammatory drugs, signal pathway regulators remain critical in many diseases. This review article demonstrates the physical and biological properties of PAs, summarizes the health benefits of PAs found by researchers previously, and shows the possibility and importance of being a dietary treatment substance.

Procyanidin Compound (PC) Suppresses Lipopolysaccharide-Induced Cervical Cancer Cell Proliferation Through Blocking the TLR4/NF-κB Pathway

Purpose

Evidence suggested that procyanidin compound (PC) could inhibit the progression of cervical cancer (CC); however, the mechanism still remains unclear. We aimed to study the potential mechanism of PC acting on CC cells.

Patients and Methods

After a 24 hr incubation of lipopolysaccharide (LPS) (1 μg/mL), human CC SiHa and HeLa cells were cultured with various concentrations (20, 40, and 80 μg/mL) of PC for 24 hrs, then the cell viability was detected using Cell Counting Kit-8 (CCK-8). The migration and invasion abilities were assessed by scratch and Transwell assays. Apoptosis and cell cycle were detected using flow cytometry. Real-time quantitative PCR (RT-qPCR) and Western blot were used for expression analysis of the inflammatory cytokines. The pathway components were measured to evaluate the involvement of toll-like receptor 4/nuclear factor kappa-light-chain-enhancer of activated B cells (TLR4/NF-κB) pathway.

Results

PC inhibited the LPS-primed cell viability in a dose-dependent manner. After PC treatment, cell migration and invasion were inhibited, cell number at the G2/M phase was increased. The CC cell apoptosis was triggered through upregulating levels of cleaved caspase-3 and Bax and downregulating the level of B-cell lymphoma 2 protein. A significant reduction was shown in the levels of interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α. Furthermore, a remarkable reduction in the ratio of TLR4 and the p-P65/t-P65 and in the progression of P65 translocation into the nucleus was observed.

Conclusion

Our results revealed that the inhibitory effect of PC on CC cell proliferation relies on the induction of apoptosis and inhibition of inflammatory cytokines.

Oligomeric proanthocyanidins and epigallocatechin gallate aggravate autophagy of foam cells through the activation of Class III PI3K/Beclin1-complex mediated cholesterol efflux

Foam cells are specialized types of cells which predominate the necrotic core of atherosclerotic plaque. Recently, autophagy-mediated cholesterol efflux from foam cells has been proposed as a beneficial therapy for atherosclerosis. The purpose of this study was to delineate the underlying molecular mechanism of oligomeric proanthocyanidins (OPC) and epigallocatechin gallate (EGCG) induced autophagy of foam cells and associated cholesterol efflux. The oxidized low-density lipoprotein induced foam cells demonstrated impaired autophagy flux through the downregulated expressions of LC3BII/LC3BI, autophagy related gene-5, Class III phosphoinositide 3 kinase (Class III PI3K), Beclin1, ABCA1, and ABCG1 with concomitant increase in the expressions of protein 62, Class I phosphoinositide 3 kinase, Akt, and mammalian target of rapamycin. However, these effects were significantly abolished by treatment with OPC and EGCG through activation of autophagy flux via Class III PI3K/Beclin1 and with upregulated expression of transporter proteins ABCA1 and ABCG1. Furthermore, the cholesterol efflux process in the foam cells was activated by lysosomal acid lipase and cathepsin D facilitated lipolysis of lipid droplets. Taken together, our data demonstrate that OPC and EGCG treatment stimulated the coordinated activation of autophagy and cholesterol efflux through Class III PI3K/Beclin1 pathway in foam cells, suggesting a promising therapeutic strategy against atherosclerosis.

Apoptosis induction and cell cycle arrest induced by Sinkiangenone B, a novel phenylpropanoid derivative from the resin of Ferula sinkiangensis K. M. Shen

A new compound from Ferula sinkiangensis has the potential to treat gastric cancer through apoptosis induction and cell cycle arrest.

Curcumin suppresses AGEs induced apoptosis in tubular epithelial cells via protective autophagy

Renal tubular cell apoptosis and tubular dysfunction is an important process underlying diabetic nephropathy (DN). Understanding the mechanisms underlying renal tubular epithelial cell survival is important for the prevention of kidney damage associated with glucotoxicity. Curcumin has been demonstrated to possess potent anti-apoptotic properties. However, the roles of curcumin in renal epithelial cells are yet to be defined. The present study investigated advanced glycation or glycoxidation end-product (AGE)-induced toxicity in renal tubular epithelial cells via several complementary assays, including cell viability, cell apoptosis and cell autophagy in the NRK-52E rat kidney tubular epithelial cell line. The extent of apoptosis was significantly increased in the NRK-52E cells following treatment with AGEs. The results also indicated that curcumin reversed this effect by promoting autophagy through the phosphoinositide 3-kinase/AKT serine/threonine kinase signaling pathway. These conclusions suggested that curcumin exerts a renoprotective effect in the presence of AGEs, at least in part by activating autophagy in NRK-52E cells. Collectively, these findings indicate that curcumin not only exerts renoprotective effects, however may also act as a novel therapeutic strategy for the treatment of diabetic nephropathy.

Probiotic Mixture Golden Bifido Prevents Neonatal Escherichia coli K1 Translocation via Enhancing Intestinal Defense

Escherichia coli (E. coli) K1 sepsis and meningitis is a severe infection characterized by high mortality in neonates. Successful colonization and translocation across the intestinal mucosa have been regarded as the critical steps for E. coli K1 sepsis and meningitis. We recently reported that the probiotic mixture, Golden Bifido (containing live Lactobacillus bulgaricus, Bifidobacterium, and Streptococcus thermophilus, LBS) has a preventive role against neonatal E. coli K1 bacteremia and meningitis. However, the interaction between the neonatal gut barrier, probiotics and E. coli K1 is still not elucidated. The present study aims to investigate how LBS exerts its protective effects on neonatal gut barrier during E. coli K1 infection. The beneficial effects of LBS were explored in vitro and in vivo using human colon carcinoma cell lines HT-29 and rat model of neonatal E. coli K1 infection, respectively. Our results showed that stimulation with E. coli K1 was able to cause intestinal barrier dysfunction, which were reflected by E. coli K1-induced intestinal damage and apoptosis of intestinal epithelial cells, reduction of mucin, immunoglobulin A (IgA) and tight junction proteins expression, as well as increase in intestinal permeability, all these changes facilitate E. coli K1 intestinal translocation. However, these changes were alleviated when HT-29 cells were treated with LBS before E. coli K1 infection. Furthermore, we found that LBS-treated neonatal rats (without E. coli K1 infection) have showed higher production of mucin, ZO-1, IgA, Ki67 in intestinal mucosa as well as lower intestinal permeability than that of non-treated rats, indicating that LBS could accelerate the development of neonatal intestinal defense. Taken together, our results suggest that enhancement of the neonatal intestinal defense to fight against E. coli K1 translocation could be the potential mechanism to elucidate how LBS confers a protective effect against neonatal E. coli K1 bacteremia and meningitis. This indirect mechanism makes LBS exert preventive effect on most of gut-derived pathogenic infections rather than only E. coli.

Euptox A Induces G1 Arrest and Autophagy via p38 MAPK- and PI3K/Akt/mTOR-Mediated Pathways in Mouse Splenocytes

Euptox A (9-oxo-10, 11-dehydroageraphorone), the main toxin isolated from Eupatorium adenophorum, is known to induce immunotoxicity in animals. However, the precise mechanism underlying the effects of Euptox A on splenocytes is unclear. Here, we aimed to investigate the molecular mechanisms underlying the effect of Euptox A in mouse spleens after its intragastric administration and found that Euptox A exhibits proautophagic effects in splenocytes. Euptox A markedly arrested the splenocytes in the G0/G1 phase, which was accompanied by inhibition of the expression of the positive regulators CDK4, CDK2, cyclin D1, PCNA, and E2F1, and promotion of the expression of the negative regulators p53, p21 Waf1/Cip1, p27 Kip1, and Chk1. We also found that Euptox A did not markedly induce splenocyte apoptosis, but induced autophagy while increasing the subcellular localization of punctate LC3, ratio of LC3-II/LC3-I, and Beclin 1 levels, and decreasing p62 levels. Euptox A also significantly inhibited p-PI3K, p-p38 MAPK, p-Akt, and p-mTOR expression, but increased PTEN and p-AMPK expression. These results indicated that Euptox A induced splenocyte autophagy by inhibiting the PI3K/Akt/mTOR pathway, suppressing p38 MAPK expression, and activating AMPK. These findings provide new insights into the mechanisms involved in spleen toxicity caused by Euptox A in mice.

Immunohistochemical and biochemical alterations following administration of proanthocyanidin extract in rats hepatocellular carcinoma

Grape seed proanthocyanidin extract (GSPE) is known to be effective on broad spectrum of biological pathways in living organisms including oxidative stress. The present study aimed to investigate the effects of proanthocyanidin on preneoplastic lesions and liver cancer induced in rats by Diethylnitrosamine (DEN). 7-8 Week old male Sprague Dawley (S.D.) rats were divided into six groups: The 1st group received no treatment and were -ve controls, the 2nd were treated with a single dose of DEN 200mg/kg intraperitoneally (i.p.) and served as +ve control group. The 3rd and 4th groups were injected with the same dose of DEN as in group 2 and then post treated with 300 or 150mg/kg/b.wt./day GSPE by intrgastroluminal gavage (i.g.) respectively until the end after the 22 weeks. Groups 5 and 6 were treated with the same doses of GSPE as in groups 3 and 4 respectively without DEN administration. The results showed that the immunohistochemical Proliferating Cell Nuclear Antigen (PCNA) labeling indexes (PCNA LI%) were significantly inhibited in liver tissues and tumors by both treatments of GSPE. Furthermore, treatment with GSPE has modified the liver tissue oxidative stress markers levels of SOD, CAT, GSH, GST, GPx, GR and MDA changed by DEN. In conclusion, GSPE has a sufficient therapeutic effect against liver carcinogenesis through their free radical scavenging, inhibition of cellular proliferation.

Proanthocyanidin protects against acute zearalenone-induced testicular oxidative damage in male mice

Zearalenone (ZEN) exerts a major effect on human and animal health and has led to serious worldwide economic problems. In this study, we investigated whether proanthocyanidin (PC) can prevent ZEN-induced testicular oxidative damage in male mice and explored the underlying mechanism. Kunming mice were injected with ZEN (40 mg kg^-1) on the 11th day after intragastric administration of PC (75 or 150 mg/kg) for 10 days; the sperm quality of mice was then analysed statistically. Additionally, testicular morphology parameters related to oxidative damage, apoptosis and the expression of endoplasmic reticulum (ER) stress-related genes (GRP78, CHOP and XBP-1) were all measured. Results showed that ZEN exposure significantly reduced the sperm density, improved the sperm aberration rate, increased the MDA level and reduced SOD and GSH-Px activities. Meanwhile, ZEN was attributed to the downregulation of the expressions of the gene and protein of Bcl-2 and upregulation of the expressions of the gene and protein of Bax and caspase-3. ZEN exposure also upregulated the mRNA expression of GRP78, CHOP and XBP-1; however, PC pre-treatment reduced ZEN-induced oxidative damage and tended to maintain normal testicular morphology. Furthermore, PC pre-treatment substantially downregulated the expressions of the GRP78, CHOP and XBP-1 and upregulated the expression of the Bcl-2 gene. In conclusion, PC, due to its anti-oxidative ability, could ameliorate ZEN-induced testicular reproductive toxicity in male mice by decreasing ER stress and testicular cell apoptosis.

Recent Advances in Anticancer Activities and Drug Delivery Systems of Tannins

Tannins, polyphenols in medicinal plants, have been divided into two groups of hydrolysable and condensed tannins, including gallotannins, ellagitannins, and (-)-epigallocatechin-3-gallate (EGCG). Potent anticancer activities have been observed in tannins (especially EGCG) with multiple mechanisms, such as apoptosis, cell cycle arrest, and inhibition of invasion and metastases. Furthermore, the combinational effects of tannins and anticancer drugs have been demonstrated in this review, including chemoprotective, chemosensitive, and antagonizing effects accompanying with anticancer effect. However, the applications of tannins have been hindered due to their poor liposolubility, low bioavailability, off-taste, and shorter half-life time in human body, such as EGCG, gallic acid, and ellagic acid. To tackle these obstacles, novel drug delivery systems have been employed to deliver tannins with the aim of improving their applications, such as gelatin nanoparticles, micelles, nanogold, liposomes, and so on. In this review, the chemical characteristics, anticancer properties, and drug delivery systems of tannins were discussed with an attempt to provide a systemic reference to promote the development of tannins as anticancer agents.

Targeting mTOR signaling by polyphenols: A new therapeutic target for ageing

Current ageing research is aimed not only at the promotion of longevity, but also at improving ‎health span‎ through the‎ discovery and development‎ of new therapeutic strategies‎‏‎ by investigating ‎molecular and ‎cellular ‎pathways involved in cellular senescence.‎ Understanding the mechanism of action ‎of ‎polyphenolic compounds targeting mTOR (mechanistic target of rapamycin) and related pathways opens up new directions ‎‎to revolutionize ways to slow down the ‎onset and development of age-dependent degeneration. Herein, we will ‎discuss the mechanisms by which polyphenols can delay the‎ molecular ‎pathogenesis of ageing via manipulation or more specifically inhibition of mTOR-signaling pathways. We will also discuss the implications of polyphenols in targeting mTOR and its related ‎pathways‎‎ on ‎health life span extension and longevity.‎.