Hesperidin Exhibits Protective Effects against PM2.5-Mediated Mitochondrial Damage, Cell Cycle Arrest, and Cellular Senescence in Human HaCaT Keratinocytes

Hyperoside reduced particulate matter 2.5-induced endoplasmic reticulum stress and senescence in skin cells

Particulate matter 2.5 (PM2.5) causes skin aging, inflammation, and impaired skin homeostasis. Hyperoside, a flavanol glycoside, has been proposed to reduce the risk of diseases caused by oxidative stress. This study evaluated the cytoprotective potential of hyperoside against PM2.5-induced skin cell damage. Cultured human HaCaT keratinocytes were pretreated with hyperoside and treated with PM2.5. Initially, the cytoprotective and antioxidant ability of hyperoside against PM2.5 was evaluated. Western blotting was further employed to investigate endoplasmic reticulum (ER) stress and cellular senescence and for evaluation of cell cycle regulation-related proteins. Hyperoside inhibited PM2.5-mediated ER stress as well as mitochondrial damage. Colony formation assessment confirmed that PM2.5-impaired cell proliferation was restored by hyperoside. Moreover, hyperoside reduced the activation of PM2.5-induced ER stress-related proteins, such as protein kinase R-like ER kinase, cleaved activating transcription factor 6, and inositol-requiring enzyme 1. Hyperoside promoted cell cycle progression in the G0/G1 phase by upregulating the PM2.5-impaired cell cycle regulatory proteins. Hyperoside significantly reduced the expression of PM2.5-induced senescence-associated β-galactosidase and matrix metalloproteinases (MMPs), such as MMP-1 and MMP-9. Overall, hyperoside ameliorated PM2.5-impaired cell proliferation, ER stress, and cellular senescence, offering potential therapeutic implications for mitigating the adverse effects of environmental pollutants on skin health.

Protective effect of luteolin against oxidative stress‑mediated cell injury via enhancing antioxidant systems

Physiological stress such as excessive reactive oxygen species (ROS) production may contribute normal fibroblasts activation into cancer‑associated fibroblasts, which serve a crucial role in certain types of cancer such as pancreatic, breast, liver and lung cancer. The present study aimed to examine the cytoprotective effects of luteolin (3',4',5,7‑tetrahydroxyflavone) against hydrogen peroxide (H2O2)‑generated oxidative stress in lung fibroblasts. To examine the effects of luteolin against H2O2‑induced damages, cell viability, sub‑G1 cell population, nuclear staining with Hoechst 33342, lipid peroxidation and comet assays were performed. To evaluate the effects of luteolin on the protein expression level of apoptosis, western blot assay was performed. To assess the antioxidant effects of luteolin, detection of ROS using H2DCFDA staining, O2‑ and ·OH using electron spin resonance spectrometer and antioxidant enzyme activity was performed. In a cell‑free chemical system, luteolin scavenges superoxide anion and hydroxyl radical generated by xanthine/xanthine oxidase and the Fenton reaction (FeSO4/H2O2). Furthermore, Chinese hamster lung fibroblasts (V79‑4) treated with H2O2 showed a significant increase in cellular ROS. Intracellular ROS levels and damage to cellular components such as lipids and DNA in H2O2‑treated cells were significantly decreased by luteolin pretreatment. Luteolin increased cell viability, which was impaired following H2O2 treatment and prevented H2O2‑mediated apoptosis. Luteolin suppressed active caspase‑9 and caspase‑3 levels while increasing Bcl‑2 expression and decreasing Bax protein levels. Additionally, luteolin restored levels of glutathione that was reduced in response to H2O2. Moreover, luteolin enhanced the activity and protein expressions of superoxide dismutase, catalase, glutathione peroxidase, and heme oxygenase‑1. Overall, these results indicated that luteolin inhibits H2O2‑mediated cellular damage by upregulating antioxidant enzymes.

Protective effects of astaxanthin on particulate matter 2.5‑induced senescence in HaCaT keratinocytes via maintenance of redox homeostasis

Particulate matter 2.5 (PM2.5) imposes a heavy burden on the skin and respiratory system of human beings, causing side effects such as aging, inflammation and cancer. Astaxanthin (ATX) is a well-known antioxidant widely used for its anti-inflammatory and anti-aging properties. However, few studies have investigated the protective effects of ATX against PM2.5-induced senescence in HaCaT cells. In the present study, the levels of reactive oxygen species (ROS) and antioxidant enzymes were measured after treatment with PM2.5. The results revealed that PM2.5 generated excessive ROS and reduced the translocation of nuclear factor erythroid 2-related factor 2 (NRF2), subsequently reducing the expression of antioxidant enzymes. However, pretreatment with ATX reversed the ROS levels as well as the expression of antioxidant enzymes. In addition, ATX protected cells from PM2.5-induced DNA damage and rescued PM2.5-induced cell cycle arrest. The levels of senescence-associated phenotype markers, such as interleukin-1β, matrix metalloproteinases, and β-galactosidase, were increased by exposure to PM2.5, however these effects were reversed by ATX. After interfering with NRF2 mRNA expression and exposing cells to PM2.5, the levels of ROS and β-galactosidase were higher compared with siControl RNA cells exposed to PM2.5. However, ATX inhibited ROS and β-galactosidase levels in both the siControl RNA and the siNRF2 RNA groups. Thus, ATX protects HaCaT keratinocytes from PM2.5-induced senescence by partially inhibiting excessive ROS generation via the NRF2 signaling pathway.

Accelerated biological aging mediated associations of ammonium, sulfate in fine particulate matter with liver cirrhosis

BACKGROUND

Although both air pollution and aging are related to the development of liver cirrhosis, the role of biological aging in association of the mixture of fine particulate matter (PM2.5) and its constituents with liver cirrhosis was unknown.

METHODS

This case-control retrospective study included 100 liver cirrhosis patients and 100 control subjects matched by age and sex. The concentrations of PM2.5 and its constituents were estimated for patients using machine-learning methods. The clinical biomarkers were used to calculate biological age using the Klemera-Doubalmethod (KDM) algorithms. Individual associations of PM2.5 and its constituents or biological age with liver cirrhosis were analyzed by generalized linear models. WQS and BKMR were applied to analyze association of mixture of PM2.5 and its constituents with liver cirrhosis. The mediation effect of biological age on associations of PM2.5 and its constituents with liver cirrhosis was further explored.

RESULTS

we found that each 1-unit increment in NH4+, NO3-, SO42- and biological age were related to 3.618-fold (95%CI: 1.896, 6.904), 1.880-fold (95%CI: 1.319, 2.680), 2.955-fold (95%CI: 1.656, 5.272) and 1.244-fold (95%CI: 1.093, 1.414) increased liver cirrhosis. Both WQS and BKMR models showed that the mixture of PM2.5 and its constituents was related to increased liver cirrhosis. Furthermore, the mediated proportion of biological age on associations of NH4+ and SO42- with liver cirrhosis were 14.7 % and 14.6 %, respectively.

CONCLUSIONS

Biological aging may partly explain the exposure to PM2.5 and its constituents in association with increased risk for liver cirrhosis, implying that delaying the aging process may be a key step for preventing PM2.5-related liver cirrhosis risk.

PM2.5-induced cellular senescence drives brown adipose tissue impairment in middle-aged mice

Airborne fine particulate matter (PM2.5) exposure is closely associated with metabolic disturbance, in which brown adipose tissue (BAT) is one of the main contributing organs. However, knowledge of the phenotype and mechanism of PM2.5 exposure-impaired BAT is quite limited. In the study, male C57BL/6 mice at three different life phases (young, adult, and middle-aged) were simultaneously exposed to concentrated ambient PM2.5 or filtered air for 8 weeks using a whole-body inhalational exposure system. H&E staining and high-resolution respirometry were used to assess the size of adipocytes and mitochondrial function. Transcriptomics was performed to determine the differentially expressed genes in BAT. Quantitative RT-PCR, immunohistochemistry staining, and immunoblots were performed to verify the transcriptomics and explore the mechanism for BAT mitochondrial dysfunction. Firstly, PM2.5 exposure caused altered BAT morphology and mitochondrial dysfunction in middle-aged but not young or adult mice. Furthermore, PM2.5 exposure increased cellular senescence in BAT of middle-aged mice, accompanied by cell cycle arrest, impaired DNA replication, and inhibited AKT signaling pathway. Moreover, PM2.5 exposure disrupted apoptosis and autophagy homeostasis in BAT of middle-aged mice. Therefore, BAT in middle-aged mice was more vulnerable to PM2.5 exposure, and the cellular senescence-initiated apoptosis, autophagy, and mitochondrial dysfunction may be the mechanism of PM2.5 exposure-induced BAT impairment.

Protective effect of 3-bromo-4,5-dihydroxybenzaldehyde against PM2.5-induced cell cycle arrest and autophagy in keratinocytes

Particulate matter 2.5 (PM2.5) poses a serious threat to human health and is responsible for respiratory disorders, cardiovascular diseases, and skin disorders. 3-Bromo-4,5-dihydroxybenzaldehyde (3-BDB), abundant in marine red algae, exhibits anti-inflammatory, antioxidant, and antidiabetic activities. In this study, we investigated the protective mechanisms of 3-BDB against PM2.5-induced cell cycle arrest and autophagy in human keratinocytes. Intracellular reactive oxygen species generation, DNA damage, cell cycle arrest, intracellular Ca2+ level, and autophagy activation were tested. 3-BDB was found to restore cell proliferation and viability which were reduced by PM2.5. Furthermore, 3-BDB reduced PM2.5-induced reactive oxygen species levels, DNA damage, and attenuated cell cycle arrest. Moreover, 3-BDB ameliorated the PM2.5-induced increases in cellular Ca2+ level and autophagy activation. While PM2.5 treatment reduced cell growth and viability, these were restored by the treatment with the autophagy inhibitor bafilomycin A1 or 3-BDB. The findings indicate that 3-BDB ameliorates skin cell death caused by PM2.5 via inhibiting cell cycle arrest and autophagy. Hence, 3-BDB can be exploited as a preventive/therapeutic agent for PM2.5-induced skin impairment.

PM2.5-induced premature senescence in HUVECs through the SIRT1/PGC-1α/SIRT3 pathway

Vascular endothelial cell senescence plays a pivotal role in the development of atherosclerosis. Recent studies have demonstrated that ambient fine particulate matter (PM2.5) induces stress-induced premature senescence (SIPS) in vascular endothelial cells. However, the precise mechanisms underlying this process remain to be fully elucidated. Cellular senescence is closely associated with reactive oxygen species (ROS), and emerging research has established a strong connection between the SIRT1/PGC-1α/SIRT3 signaling pathway and the antioxidant system in vascular endothelial cells. In this study, we aimed to investigate the impact of PM2.5 on vascular endothelial cell senescence and to elucidate the underlying mechanisms. Our findings revealed that PM2.5 exposure led to an increase in senescence-associated β-galactosidase (SA-β-gal) activity and the expression of the cell cycle-blocking proteins P53/P21 and P16 in human umbilical vein endothelial cells (HUVECs). Flow cytometry analysis demonstrated an elevated proportion of cells arrested in the G0/G1 phase after PM2.5 exposure. In addition, PM2.5-induced cellular senescence was attributed to the disruption of the cellular antioxidative defense system through the SIRT1/PGC-1α/SIRT3 signaling pathway. The expression of cellular senescence markers was reduced after targeted scavenging of mitochondrial ROS using MitoQ. Moreover, treatment with SRT1720, a SIRT1-specific activator, upregulated the SIRT1/PGC-1α/SIRT3 signaling pathway, restored the antioxidant system, and attenuated the expression of cellular senescence markers. Taken together, our results suggest that PM2.5 downregulates the SIRT1/PGC-1α/SIRT3 signaling pathway, resulting in impaired antioxidant defenses in HUVECs. This, in turn, allows for the accumulation of ROS, leading to inhibition of endothelial cell cycle progression and the onset of stress-induced senescence in HUVECs.

Hesperidin from Orange Peel as a Promising Skincare Bioactive: An Overview

The pursuit for better skin health, driven by collective and individual perceptions, has led to the demand for sustainable skincare products. Environmental factors and lifestyle choices can accelerate skin aging, causing issues like inflammation, wrinkles, elasticity loss, hyperpigmentation, and dryness. The skincare industry is innovating to meet consumers' requests for cleaner and natural options. Simultaneously, environmental issues concerning waste generation have been leading to sustainable strategies based on the circular economy. A noteworthy solution consists of citrus by-product valorization, as such by-products can be used as a source of bioactive molecules. Citrus processing, particularly, generates substantial waste amounts (around 50% of the whole fruit), causing unprecedented environmental burdens. Hesperidin, a flavonoid abundant in orange peels, is considered to hold immense potential for clean skin health product applications due to its antioxidant, anti-inflammatory, and anticarcinogenic properties. This review explores hesperidin extraction and purification methodologies as well as key skincare application areas: (i) antiaging and skin barrier enhancement, (ii) UV radiation-induced damage, (iii) hyperpigmentation and depigmentation conditions, (iv) wound healing, and (v) skin cancer and other cutaneous diseases. This work's novelty lies in the comprehensive coverage of hesperidin's promising skincare applications while also demonstrating its potential as a sustainable ingredient from a circular economy approach.

Rosmarinic Acid Protects Skin Keratinocytes from Particulate Matter 2.5-Induced Apoptosis

Background: The exposure of the human skin to particulate matter 2.5 (PM2.5) results in adverse health outcomes, such as skin aging, wrinkle formation, pigment spots, and atopic dermatitis. It has previously been shown that rosmarinic acid (RA) can protect keratinocytes from ultraviolet B radiation by enhancing cellular antioxidant systems and reducing oxidative damage; however, its protective action against the adverse effects of PM2.5 on skin cells remains unclear. Therefore, in this study, we explored the mechanism underlying the protective effects of RA against PM2.5-mediated oxidative stress in HaCaT keratinocytes. Methods: HaCaT keratinocytes were pretreated with RA and exposed to PM2.5. Thereafter, reactive oxygen species (ROS) production, protein carbonylation, lipid peroxidation, DNA damage, and cellular apoptosis were investigated using various methods, including confocal microscopy, western blot analysis, and flow cytometry. Results: RA significantly inhibited PM2.5-induced lipid peroxidation, protein carbonylation, DNA damage, increases in intracellular Ca2+ level, and mitochondrial depolarization. It also significantly attenuated PM2.5-induced apoptosis by downregulating Bcl-2-associated X, cleaved caspase-9, and cleaved caspase-3 protein levels, while upregulating B-cell lymphoma 2 protein level. Further, our results indicated that PM2.5-induced apoptosis was associated with the activation of the mitogen-activated protein kinase (MAPK) signaling pathway and that MAPK inhibitors as well as RA exhibited protective effects against PM2.5-induced apoptosis. Conclusion: RA protected HaCaT cells from PM2.5-induced apoptosis by lowering oxidative stress.

The Neuroprotective Effect of Sophocarpine against Glutamate-Induced HT22 Cell Cytotoxicity

Neuronal cell death and dysfunction of the central nervous system can be caused by oxidative stress, which is associated with the development of neurodegenerative diseases. Sophocarpine, an alkaloid compound derived from Sophora moorcroftiana (Benth.) Baker seeds, has a wide range of medicinal value. This study sought to determine how sophocarpine exerts neuroprotective effects by inhibited oxidative stress and apoptosis in mouse hippocampus neuronal (HT22) cells. 20mM glutamate-induced HT22 cells were used to develop an in vitro model of oxidative stress damage. The Cell Counting Kit-8 (CCK-8) assay was used to assess cell viability. According to the instructions on the kits to detect reactive oxygen species (ROS) levels and oxidative stress indicators. HT22 cells were examined using immunofluorescence and Western Blotting to detect Nuclear Factor Erythroid 2-related Factor 2 (Nrf2) expression. The expression of proteins and messenger RNA (mRNA) for heme oxygenase-1 (HO-1) was examined by Western Blotting and Quantitative real time polymerase chain reaction (qRT-PCR). Mitochondrial membrane potential (MMP) and Cell apoptosis were used by 5, 5', 6, 6'-Tetrachloro-1, 1', 3, 3'-tetraethyl-imidacarbocyanine iodide (JC- 1) kit and Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick-End Labeling (TUNEL) apoptosis assay kit, respectively. Finally, the expression of pro-apoptotic proteins was detected by Western Blotting. The result demonstrated that sophocarpine (1.25 μM-10 μM) can significantly inhibit glutamate-induced cytotoxicity and ROS generation, improve the activity of antioxidant enzymes. Sophocarpine increased the expression of HO-1 protein and mRNA and the nuclear translocation of Nrf2 to play a cytoprotective role; however, cells were transfected with small interfering RNA targeting HO-1 (si-HO-1) reversed the above effects of sophocarpine. In addition, sophocarpine significantly inhibited glutamate induced mitochondrial depolarization and further inhibited cell apoptosis by reducing the expression level of caspase-related proteins.

Particulate matter and inflammatory skin diseases: From epidemiological and mechanistic studies

Epidemiological and toxicological studies have confirmed that exposure to atmospheric particulate matter (PM) could affect our cardiovascular and respiratory systems. Recent studies have shown that PM can penetrate the skin and cause skin inflammation, but the evidence is limited and contradictory. As the largest outermost surface of the human body, the skin is constantly exposed to the environment. The aim of this study was to assess the relationship between PM and inflammatory skin diseases. Most epidemiological studies have provided positive evidence for outdoor, indoor, and wildfire PM and inflammatory skin diseases. The effects of PM exposure during pregnancy and inflammatory skin diseases in offspring are heterogeneous. Skin barrier dysfunction, Oxidative stress, and inflammation may play a critical role in the underlying mechanisms. Finally, we summarize some interventions to alleviate PM-induced inflammatory skin diseases, which may contribute to public health welfare. Overall, PM is related to inflammatory skin diseases via skin barrier dysfunction, oxidative stress, and inflammation. Appropriate government interventions are beneficial.

Comparison of Pollutant Effects on Cutaneous Inflammasomes Activation

The skin is the outermost layer of the body and, therefore, is exposed to a variety of stressors, such as environmental pollutants, known to cause oxinflammatory reactions involved in the exacerbation of several skin conditions. Today, inflammasomes are recognized as important modulators of the cutaneous inflammatory status in response to air pollutants and ultraviolet (UV) light exposure. In this study, human skin explants were exposed to the best-recognized air pollutants, such as microplastics (MP), cigarette smoke (CS), diesel engine exhaust (DEE), ozone (O3), and UV, for 1 or 4 days, to explore how each pollutant can differently modulate markers of cutaneous oxinflammation. Exposure to environmental pollutants caused an altered oxidative stress response, accompanied by increased DNA damage and signs of premature skin aging. The effect of specific pollutants being able to exert different inflammasomes pathways (NLRP1, NLRP3, NLRP6, and NLRC4) was also investigated in terms of scaffold formation and cell pyroptosis. Among all environmental pollutants, O3, MP, and UV represented the main pollutants affecting cutaneous redox homeostasis; of note, the NLRP1 and NLRP6 inflammasomes were the main ones modulated by these outdoor stressors, suggesting their role as possible molecular targets in preventing skin disorders and the inflammaging events associated with environmental pollutant exposure.

Hesperidin via maintenance of mitochondrial function and antioxidant activity protects lithium toxicity in rat heart isolated mitochondria

Lithium is commonly used in the treatment of bipolar disorders (BD) and consumer electronics. It has been reported that lithium exposure is associated with mitochondrial dysfunction and oxidative stress in isolated cardiac mitochondria. Mitochondrial protection has a key role in myocardial tissue homeostasis, cardiomyocyte survival and inhibition of cardiotoxicity. Hesperidin as a flavanone and cardioprotective agent has shown high potential in antioxidant activity and restoration of mitochondrial dysfunction in different models. Therefore, we aimed to evaluate the ameliorative effects of hesperidin against lithium-induced mitochondrial toxicity in rat cardiac mitochondria. Isolated mitochondria were classified into six groups; control, lithium carbonate (125 µM), three groups of lithium + hesperidin-treated received lithium (125 µM) and hesperidin with various concentrations (10, 50, and 100 µM) and hesperidin (100 µM). Succinate dehydrogenases (SDH) activity, mitochondrial swelling, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), mitochondrial glutathione (GSH) and lipid peroxidation (LPO) were measured. The mitochondria received lithium showed a significant reduction of SDH activity, MMP collapse, mitochondrial swelling, induction of ROS formation and lipid peroxidation. However, we observed that the administration of hesperidin (50 and 100 µM) resulted in the increase of SDH activity, improved MMP collapse, mitochondrial swelling, and reduced ROS formation and lipid peroxidation. Also, there were no obvious changes in cardiac mitochondria received of hesperidin. These findings suggest that hesperidin could reduce lithium-induced mitochondrial dysfunction through antioxidant activities in cardiac mitochondria, may be beneficial for prevention and treatment of lithium toxicities, either as a drug to treat BD or as an environmental pollutant.

3-Bromo-4,5-dihydroxybenzaldehyde Protects Keratinocytes from Particulate Matter 2.5-Induced Damages

Cellular senescence can be activated by several stimuli, including ultraviolet radiation and air pollutants. This study aimed to evaluate the protective effect of marine algae compound 3-bromo-4,5-dihydroxybenzaldehyde (3-BDB) on particulate matter 2.5 (PM_2.5)-induced skin cell damage in vitro and in vivo. The human HaCaT keratinocyte was pre-treated with 3-BDB and then with PM_2.5. PM_2.5-induced reactive oxygen species (ROS) generation, lipid peroxidation, mitochondrial dysfunction, DNA damage, cell cycle arrest, apoptotic protein expression, and cellular senescence were measured using confocal microscopy, flow cytometry, and Western blot. The present study exhibited PM_2.5-generated ROS, DNA damage, inflammation, and senescence. However, 3-BDB ameliorated PM_2.5-induced ROS generation, mitochondria dysfunction, and DNA damage. Furthermore, 3-BDB reversed the PM_2.5-induced cell cycle arrest and apoptosis, reduced cellular inflammation, and mitigated cellular senescence in vitro and in vivo. Moreover, the mitogen-activated protein kinase signaling pathway and activator protein 1 activated by PM_2.5 were inhibited by 3-BDB. Thus, 3-BDB suppressed skin damage induced by PM_2.5.

Biometabolites of Citrus unshiu Peel Enhance Intestinal Permeability and Alter Gut Commensal Bacteria

Flavanones in Citrus unshiu peel (CUP) have been used as therapeutic agents to reduce intestinal inflammation; however, the anti-inflammatory effects of their biometabolites remain ambiguous. Here, we identified aglycone-type flavanones, such as hesperetin and naringenin, which were more abundant in the bioconversion of the CUP than in the ethanol extracts of the CUP. We found that the bioconversion of the CUP induced the canonical nuclear factor-κB pathway via degradation of IκB in Caco-2 cells. To check the immune suppressive capacity of the aglycones of the CUP in vivo, we orally administered the bioconversion of the CUP (500 mg/kg) to mice for two weeks prior to the 3% dextran sulfate sodium treatment. The CUP-pretreated group showed improved body weight loss, colon length shortage, and intestinal inflammation than the control mice. We also found a significant decrease in the population of lamina propria Th17 cells in the CUP-pretreated group following dextran sodium sulfate (DSS) treatment and an increase in mRNA levels of occludin in CUP-treated Caco-2 cells. Pyrosequencing analysis revealed a decreased abundance of Alistipes putredinis and an increased abundance of Muribaculum intestinale in the feces of the CUP-pretreated mice compared to those of the control mice. Overall, these findings suggest that the pre-administration of CUP biometabolites may inhibit the development of murine colitis by modulating intestinal permeability and the gut microbiome.

In Vitro Determination of the Skin Anti-Aging Potential of Four-Component Plant-Based Ingredient

The beauty industry is actively searching for solutions to prevent skin aging. Some of the crucial elements protecting cells from the aging process are telomere shortening, telomerase expression, cell senescence, and homeostasis of the redox system. Modification of these factors using natural antioxidants is an appealing way to support healthy skin aging. Therefore, in this study, we sought to investigate the antiaging efficacy of a specific combination of four botanical extracts (pomegranate, sweet orange, Cistanche and Centella asiatica) with proven antioxidant properties. To this end, normal human dermal fibroblasts were used as a cell model and the following studies were performed: cell proliferation was established by means of the MTT assay and the intracellular ROS levels in stress-induced premature senescence fibroblasts; telomere length measurement was performed under standard cell culture conditions using qPCR and under oxidative stress conditions using a variation of the Q-FISH technique; telomerase activity was examined by means of Q-TRAP; and AGE quantification was completed by means of ELISA assay in UV-irradiated fibroblasts. As a result, the botanical blend significantly reversed the H2O2-induced decrease in cell viability and reduced H2O2-induced ROS. Additionally, the presence of the botanical ingredient reduced the telomere shortening rate in both stressed and non-stressed replicating fibroblasts, and under oxidative stress conditions, the fibroblasts presented a higher median and 20th percentile telomere length, as well as a lower percentage of short telomeres (<3 Kbp) compared with untreated fibroblasts. Furthermore, the ingredient transiently increased relative telomerase activity after 24 h and prevented the accumulation of UVR-induced glycated species. The results support the potential use of this four-component plant-based ingredient as an antiaging agent.

Participation of the Serotonergic System and Brain-Derived Neurotrophic Factor in the Antidepressant-like Effect of Flavonoids

Depressive disorders are among the most disabling diseases experienced around the world, and their incidence has significantly increased over the last few decades due to multiple environmental, social, and biological factors. The search for new pharmacological alternatives to treat depression is a global priority. In preclinical research, molecules obtained from plants, such as flavonoids, have shown promising antidepressant-like properties through several mechanisms of action that have not been fully elucidated, including crossing of the blood brain barrier (BBB). This review will focus on discussing the main findings related to the participation of the serotonergic system and brain-derived neurotrophic factor (BDNF) on the antidepressant-like effect of some flavonoids reported by behavioral, neurochemical, and molecular studies. In this sense, evidence shows that depressive individuals have low levels of serotonin and BDNF, while flavonoids can reverse it. Finally, the elucidation of the mechanism used by flavonoids to modulate serotonin and BDNF will contribute to our understanding of the neurobiological bases underlying the antidepressant-like effects produced by these natural compounds.

Ambient PM2.5 exposure causes cellular senescence via DNA damage, micronuclei formation, and cGAS activation

Ambient PM2.5 is one of the environmental risk factors and was correlated with senescence-related diseases based on the epidemiologic investigation. However, little is known about senescence induced by PM2.5 as well as the underlying mechanisms. In this study, we demonstrated that PM2.5 exposure aggravated cellular senescence in vivo and in vitro, and disrupted micronuclei (MN) played a vital role in this process. Our results suggested that the nuclear envelope (NE) of PM2.5-induced MN was ruptured. Subsequently, cGAS was found to localize to approximately 80% of the disrupted MN but few for intact MN. Upon examination of cGAMP and SA-β-Gal, the cGAS-STING pathway was found activated and related to cellular senescence induced by PM2.5. Taken together, we reported a novel finding that PM2.5 exposure causes cellular senescence via DNA damage, MN formation, and cGAS activation. These results revealed the potential toxicity of PM2.5 and its related mechanisms in cellular senescence.