Epigallocatechin gallate enhances human lens epithelial cell survival after UVB irradiation via the mitochondrial signaling pathway

A Synergistic Therapy With Antioxidant and Anti-VEGF: Toward its Safe and Effective Elimination for Corneal Neovascularization

Corneal neovascularization (CNV) is one of the leading causes of blindness in the world. In clinical practice; however, it remains a challenge to achieve a noninvasive and safe treatment. Herein, a biocompatible shell with excellent antioxidant and antivascularity is prepared by co-assembly of epigallocatechin gallate/gallic acid and Cu (II). After loading glucose oxidase (GOx) inside, the shell is modified with dimeric DPA-Zn for codelivering vascular endothelial growth factor (VEGF) small interfering RNA (VEGF-siRNA). Meanwhile, the Arg-Gly-Asp peptide (RGD) peptide-engineered cell membranes coating improves angiogenesis-targeting and is biocompatible for the multifunctional nanomedicine (CEGs/RGD). After eye drops administration, CEGs/RGD targets enrichment in neovascularization and CEGs NPs enter cells. Then, the inner GOx consumes glucose with a decrease in local pH, which in turn leads to the release of EGCE and VEGF-siRNA. As a result, the nanomedicines significantly reduce angiogenesis and inhibit CNV formation through synergistic effect of antioxidant and antivascular via down-regulation of cluster of differentiation 31 and VEGF. The nanomedicine represents a safe and efficient CNV treatment through the combined effect of antioxidant/gene, which provides important theoretical and clinical significance.

Evaluation of enterotoxigenic Bacteroides fragilis correlation with the expression of cellular signaling pathway genes in Iranian patients with colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most common cancers all over the world, and dysbiosis in the gut microbiota may play a role in colorectal carcinogenesis. Bacteroides fragilis can lead to tumorigenesis by changing signaling pathways, including the WNT/β-catenin pathway. Therefore, in the present study, we investigated the correlation between the enterotoxigenic B. fragilis amount and the expression of signaling pathway genes involved in CRC.

MATERIALS AND METHODS

B. fragilis was determined in 30 tumors and adjacent healthy tissues by the qPCR method. Next, the relationship between enterotoxigenic B. fragilis and the expression of signaling pathway genes, including CCND1, TP53, BCL2, BAX, WNT, TCF, AXIN, APC, and CTNNB1 was investigated. Additionally, possible correlations between clinicopathological features of the tumor samples and the abundance of B. fragilis were analyzed.

RESULTS

The results showed that B. fragilis was detected in 100% of tumor samples and 86% of healthy tissues. Additionally, enterotoxigenic B. fragilis colonized 47% of all samples, and bft-1 toxin was the most frequently found isotype among the samples. The analysis showed that the high level of B. fragilis has a significant relationship with the high expression of AXIN, CTNNB1, and BCL2 genes. On the other hand, our results did not show any possible correlation between this bacterium and the clinicopathological features of the tumor sample.

CONCLUSION

B. fragilis had a higher abundance in the tumor samples than in healthy tissues, and this bacterium may lead to CRC by making changes in cellular signaling pathways and genes. Therefore, to better understand the physiological effects of B. fragilis on the inflammatory response and CRC, future research should focus on dissecting the molecular mechanisms by which this bacterium regulates cellular signaling pathways.

Lead toxicity and potential therapeutic effect of plant-derived polyphenols

BACKGROUND

Due to its unique physical and chemical properties, lead is still used worldwide in several applications, especially in industry. Both environmental and industrial lead exposures remain a public health problem in many developing and rapidly industrializing countries. Plant polyphenols are pleiotropic in their function and have historically made a major contribution to pharmacotherapy.

PURPOSE

To summarize available pre-clinical and limited clinical evidence on plant polyphenols as potential antidotes against lead poisoning and discuss toxic mechanisms of lead.

METHOD

A comprehensive search of peer-reviewed publications was performed from core collections of electronic databases such as PubMed, Web of Science, Google Scholar, and Science Direct. Articles written in English-language from inception until December 2022 were selected.

RESULTS

In this review, we review key toxic mechanisms of lead and its pathological effects on the neurological, reproductive, renal, cardiovascular, hematological, and hepatic systems. We focus on plant polyphenols against lead toxicity and involved mechanisms. Finally, we address scientific gaps and challenges associated with translating these promising preclinical discoveries into effective clinical therapies.

CONCLUSION

While preclinical evidence suggests that plant polyphenols exhibit bioprotective effects against lead toxicity, scant and equivocal clinical data highlight a need for clinical trials with those polyphenols.

The Role of Green Tea Catechin Epigallocatechin Gallate (EGCG) and Mammalian Target of Rapamycin (mTOR) Inhibitor PP242 (Torkinib) in the Treatment of Spinal Cord Injury

Spinal cord injury (SCI) is a devastating condition that has physical and psychological consequences for patients. SCI is accompanied by scar formation and systemic inflammatory response leading to an intense degree of functional loss. The catechin, epigallocatechin gallate (EGCG), an active compound found in green tea, holds neuroprotective features and is known for its anti-inflammatory potential. The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that exists in two functionally distinct complexes termed mTOR complex 1 and 2 (mTORC1; mTORC2). Inhibition of mTORC1 by rapamycin causes neuroprotection, leading to partial recovery from SCI. In this study the effects of EGCG, PP242 (an inhibitor of both complexes of mTOR), and a combination of EGCG and PP242 in SCI have been examined. It has been found that both EGCG and PP242 significantly improved sensory/motor functions following SCI. However, EGCG appeared to be more effective (BBB motor test, from 2 to 8 weeks after SCI, p = 0.019, p = 0.007, p = 0.006, p = 0.006, p = 0.05, p = 0.006, and p = 0.003, respectively). The only exception was the Von Frey test, where EGCG was ineffective, while mTOR inhibition by PP242, as well as PP242 in combination with EGCG, significantly reduced withdrawal latency starting from week three (combinatorial therapy (EGCG + PP242) vs. control at 3, 5, and 7 weeks, p = 0.011, p = 0.007, and p = 0.05, respectively). It has been found that EGCG was as effective as PP242 in suppressing mTOR signaling pathways, as evidenced by a reduction in phosphorylated S6 expression (PP242 (t-test, p < 0.0001) or EGCG (t-test, p = 0.0002)). These results demonstrate that EGCG and PP242 effectively suppress mTOR pathways, resulting in recovery from SCI in rats, and that EGCG acts via suppressing mTOR pathways.

Mitochondrial Modulators: The Defender

Mitochondria are widely considered the "power hub" of the cell because of their pivotal roles in energy metabolism and oxidative phosphorylation. However, beyond the production of ATP, which is the major source of chemical energy supply in eukaryotes, mitochondria are also central to calcium homeostasis, reactive oxygen species (ROS) balance, and cell apoptosis. The mitochondria also perform crucial multifaceted roles in biosynthetic pathways, serving as an important source of building blocks for the biosynthesis of fatty acid, cholesterol, amino acid, glucose, and heme. Since mitochondria play multiple vital roles in the cell, it is not surprising that disruption of mitochondrial function has been linked to a myriad of diseases, including neurodegenerative diseases, cancer, and metabolic disorders. In this review, we discuss the key physiological and pathological functions of mitochondria and present bioactive compounds with protective effects on the mitochondria and their mechanisms of action. We highlight promising compounds and existing difficulties limiting the therapeutic use of these compounds and potential solutions. We also provide insights and perspectives into future research windows on mitochondrial modulators.

Diosmetin attenuates oxidative stress-induced damage to lens epithelial cells via the mitogen-activated protein kinase (MAPK) pathway

Cataract is a global ophthalmic disease that blinds the eye, and oxidative stress is one of its primary causes. Apoptosis of lens epithelial cells (LECs) is considered the major cytological basis of many cataracts except congenital cataracts. The purpose of this study was to investigate whether diosmetin could reduce oxidative stress-induced damage to LECs, and explore its regulatory pathway. Lens epithelial cell line SRA01/04 was used as the object of study. Using ultraviolet B (UVB) and hydrogen peroxide (H₂O₂) as sources of oxidative stress, the protective effects of diosmetin at different concentrations on cells were investigated, including inhibition of proliferation, apoptosis, and oxidative stress. Molecular docking was then used to predict the target proteins and validation was performed at the cellular and protein levels. The oxidative stress of SRA01/04 was induced by UVB and H₂O₂, and inhibition of proliferation and apoptosis were observed. Here, diosmetin has a dose-dependent cell-protecting effect. This effect is achieved by targeting the MEK2 protein and inhibiting the MAPK signaling. In conclusion, diosmetin reduces H₂O₂- and UVB-induced inhibition of SRA01/04 proliferation and apoptosis by reducing oxidative stress-induced activation of the MAPK pathway.

Protocatechualdehyde Rescues Oxygen-Glucose Deprivation/Reoxygenation-Induced Endothelial Cells Injury by Inducing Autophagy and Inhibiting Apoptosis via Regulation of SIRT1

Background: Oxidative stress-induced endothelial cell death, such as apoptosis and autophagy, plays a critical role in ischemia-reperfusion injury. Protocatechualdehyde (PCA) is a major bioactive component of the traditional Chinese medicine Salvia miltiorrhiza Bunge (Lamiaceae), and it has been proved to be effective in the prevention and treatment of ischemic cardiovascular and cerebrovascular diseases. However, its role in oxidative stress-induced endothelial cell death and its underlying mechanisms remains unclear. This study aims to investigate the effects and mechanisms of PCA on endothelial cell apoptosis and autophagy induced by oxygen-glucose deprivation/reoxygenation (OGD/R) injury. Methods: After OGD/R induction, human umbilical vein endothelial cells (HUVECs) were treated with different concentrations of PCA. Cell viability, apoptosis, and autophagy were detected by Cell Counting Kit-8 assay, flow cytometry, and monodansylcadaverine assay, respectively. Western blot was applied to explore the effects of PCA on the expression levels of relevant protein factors. Results: The results show that PCA significantly promoted cell survival rate and cell proliferation and enhanced the antioxidant activity in OGD/R-induced HUVECs. PCA inhibited HUVECs apoptosis, as evidenced by decreased expression of cleaved-caspase-3, Bcl2-associated X (BAX), and increased expression of Bcl-2. PCA induced autophagy by reducing the expression of P62 while increasing the expression of Beclin-1 and LC3 II/I. Meanwhile, PCA enhanced the expression of Sirtuin 1 (SIRT1) and suppressed the expression of P53. When SIRT1 was inhibited by selisistat or SIRT1 small-interfering RNA, the anti-apoptotic and pro-autophagy abilities of PCA were attenuated. Conclusion: These results demonstrated that PCA rescued HUVECs from OGD/R-induced injury by promoting autophagy and inhibiting apoptosis through SIRT1 and could be developed as a potential therapeutic agent against ischemic diseases.