Yifuning postpones ovarian aging through antioxidant mechanisms and suppression of the Rb/p53 signal transduction pathway

Fluorometholone inhibits high glucose-induced cellular senescence in human retinal endothelial cells

Diabetic retinopathy (DR) is a common diabetic complication that severely impacts the life quality of diabetic patients. Recently, cellular senescence in human retinal endothelial cells (HRECs) induced by high glucose has been linked to the pathogenesis of DR. Fluorometholone (FML) is a glucocorticoid drug applied in the treatment of inflammatory and allergic disorders of the eye. The objective of the present study is to investigate the protective function of FML on high glucose-induced cellular senescence in HRECs. The in vitro injury model was established by stimulating HRECs with 30 mm glucose. After evaluating the cytotoxicity of FML in HRECs, 0.05% and 0.1% FML were used as the optimal concentration in the entire experiment. It was found that the excessive released inflammatory factors including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8) in HRECs induced by high glucose were significantly suppressed by FML, accompanied by the inhibitory effects on the expression levels of vascular endothelial growth factor (VEGF) and tissue factor (TF). Declined telomerase activity and enhanced senescence-associated β-galactosidase (SA-β-gal) activity were found in high glucose-challenged HRECs, which were dramatically alleviated by FML, accompanied by the inactivation of the p53/p21 and retinoblastoma (Rb) signaling. Interestingly, FML ameliorated high glucose-induced dephosphorylation of Akt. Lastly, the protective effects of FML against high glucose-induced cellular senescence in HRECs were abolished by the co-treatment of the PI3K/Akt signaling inhibitor LY294002, suggesting the involvement of this pathway. Taken together, these data revealed that FML-inhibited high glucose-induced cellular senescence mediated by Akt in HERCs, suggesting a novel molecular mechanism of FML.

Redox imbalance in age-related ovarian dysfunction and perspectives for its prevention

The age at which women have their first child is increasing. This change represents a major health problem to society because advanced maternal age is related with a decay in fertility and an increase in the incidence of a variety of pregnancy complications and offspring health issues. The ovary stands as the main contributor for female reproductive ageing because of the progressive age-related decrease in follicle number and oocyte quality. Loss of redox homeostasis and establishment of an ovarian oxidative microenvironment are seen as major underlying causes for such downfall and impairment of ovarian function. Thus, the use of antioxidants to preserve fertility became an important field of research. In this review, new insights on mechanisms underlying the establishment of oxidative stress and its repercussions on ovarian ageing are addressed, along with the current state of knowledge on antioxidant supplementation and its contribution for healthy ageing and extension of ovarian lifespan.

Can ovarian aging be delayed by pharmacological strategies?

Aging has been regarded as a treatable condition, and delaying aging could prevent some diseases. Ovarian aging, a special type of organ senescence, is the earliest-aging organ, as ovaries exhibit an accelerated rate of aging with characteristics of gradual declines in ovarian follicle quantity and quality since birth, compared to other organs. Ovarian aging is considered as the pacemaker of female body aging, which drives the aging of multiple organs of the body. Hence, anti-ovarian aging has become a research topic broadly interesting to both biomedical scientists and pharmaceutical industry. A marked progress has been made in exploration of possible anti-ovarian agents or approaches, such as calorie restriction mimetics, antioxidants, autophagy inducers etc., over the past years. This review is attempted to discuss recent advances in the area of anti-ovarian aging pharmacology and to offer new insights into our better understanding of molecular mechanisms underlying ovarian aging, which might be informative for future prevention and treatment of ovarian aging and its related diseases.

Ginsenoside Rg1 ameliorates testicular senescence changes in D‑gal‑induced aging mice via anti‑inflammatory and antioxidative mechanisms

With the growing population, aging, extended lifespans and anti-aging have become popular areas of research in the life and social sciences. With increasing age, the structure and function of the testes, the spermatogenetic and androgen-producing organ in the male reproductive system, gradually declines. Ginsenoside Rg1 is an extract of Panax ginseng in traditional Chinese medicine. The extract facilitates anti-aging through its anti-inflammatory and antioxidant properties. However, it has not been reported whether ginsenoside Rg1 delays testicular aging. The present study established D-galactose (D-gal)-induced aging mouse models to examine the protective effects of ginsenoside Rg1 on the structure and function of the testes, and the underlying mechanism. A total of 60 healthy specific pathogen-free male C57BL/6 mice were randomly divided into four groups: Control group; Rg1 group; D-gal + Rg1 group; and D-gal group. The tissues of the mice were used for further experiments. The present study further investigated the effects of Rg1 on the volume of serum testosterone, the testicular index, testicular microscopic structures, the senescence of spermatogenetic cells, the apoptosis of spermatogenetic cells, the activity of the antioxidant enzymes, the levels of inflammatory cytokines, and the levels of S-phase kinase-associated protein (p19), cyclin-dependent kinase inhibitor 1 (p21) and cellular tumor antigen p53 (p53) in D-gal-induced aging mice. In general, compared with the D-gal group, the treatment of Rg1 increased the testis index, serum testosterone level and the active content of superoxide dismutase and the total antioxidant capacity. The percentage of senescence-associated β-galactosidase-positive cells, the level of apoptosis and the volume of methane dicarboxylic aldehyde, tumor necrosis factor-α, interleukin (IL)-1β and IL-6 in testicular tissues were significantly decreased, and the expression of p19, p53 and p21 was downregulated due to the treatment with Rg1. The results of the present study demonstrated that ginsenoside Rg1 was able to protect the testes against D-gal-induced aging in mice. In addition, the protective effect of Rg1 may be achieved via antioxidation and downregulation of the p19/p53/p21 signaling pathway.

Protective effects of Oviductus Ranae-containing serum on oxidative stress-induced apoptosis in rat ovarian granulosa cells

ETHNOPHARMACOLOGICAL RELEVANCE

Oviductus Ranae (OR) is a traditional Chinese medicine derived from Rana temporaria chensinensis David, and is known to have a wide variety of pharmacological effects.

AIM OF THE STUDY

To investigate the function and mechanism of OR-containing serum in protecting rat ovarian granulosa cells from hydrogen peroxide (H₂O₂)-induced oxidative damage.

MATERIALS AND METHODS

H₂O₂-treated granulosa cells were pretreated with OR-containing serum, and viability and proliferation assays were carried out using Cell Counting Kit-8 (CCK-8). Apoptotic granulosa cells were observed microscopically using 4',6-diamidino-2-phenylindole (DAPI), and the apoptotic ratio was quantified via Annexin V/ propidium iodide (PI) staining combined with flow cytometry. The levels of reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) in the cells were measured using 2,7-dichlorofluorescein diacetate (DCFH-DA) and rhodamine 123, respectively, and analyzed by flow cytometry. Mitogen-activated protein kinases (MAPKs), including ERK1/2, JNK, and p38, and other apoptosis-related proteins (p53, Bcl-2, Bax, caspase-9, caspase-3), were detected by western blot analysis, and the related mRNA levels were detected using reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

The results revealed that treatment with OR-containing serum reduced apoptosis and mitochondrial membrane damage in H₂O₂-treated granulosa cells. The OR-containing serum interfered with H₂O₂-induced intracellular generation of ROS and loss of ΔΨm, which typically lead to apoptosis. Furthermore, the OR-containing serum down-regulated pro-apoptotic proteins such as p53, Bax, caspase-9, and caspase-3, while up-regulating the anti-apoptotic protein Bcl-2. Finally, the OR-containing serum increased phosphorylation of ERK1/2, and reduced JNK and p38 phosphorylation.

CONCLUSIONS

OR-containing serum protected rat ovarian granulosa cells against H₂O₂-induced apoptosis, by reducing ROS production and improving mitochondrial membrane potential, through down-regulation of negative regulators of proliferation, activation of ERK1/2, and inhibition of the activity of JNK and p38.