Regulatory Effect on Skin Differentiation by Mevastatin in Psoriasis Model Using TNF-α and IL-17 Induced HaCaT Cells

Mechanistic prospective and pharmacological attributes of quercetin in attenuation of different types of arthritis

Arthritis is a frequent autoimmune disease with undefined etiology and pathogenesis. Scientific community constantly fascinating quercetin (QUR), as it is the best-known flavonoid among others for curative and preventive properties against a wide range of diseases. Due to its multifaceted activities, the implementation of QUR against various types of arthritis namely, rheumatoid arthritis (RA), osteoarthritis (OA), gouty arthritis (GA) and psoriotic arthritis (PsA) has greatly increased in recent years. Many research evidenced that QUR regulates a wide range of pathways for instance NF-κB, MAK, Wnt/β-catenine, Notch, etc., that are majorly associated with the inflammatory mechanisms. Besides, the bioavailability of QUR is a major constrain to its therapeutic potential, and drug delivery techniques have experienced significant development to overcome the problem of its limited application. Hence, this review compiled the cutting-edge experiments on versatile effects of QUR on inflammatory diseases like RA, OA, GA and PsA, sources and bioavailability, therapeutic challenges, pharmacokinetics, clinical studies as well as toxicological impacts. The use of QUR in a health context would offer a tearing and potential therapeutic method, supporting the advancement of public health, particularly, of arthritic patients worldwide.

Diallyl trisulfide inhibits monosodium urate-induced NLRP3 inflammasome activation via NOX3/4-dependent mitochondrial oxidative stress in RAW 264.7 and bone marrow-derived macrophages

BACKGROUND

Monosodium urate (MSU) crystals are associated with gouty inflammatory diseases. MSU-associated inflammation is majorly triggered by NOD-like receptor protein 3 (NLRP3) inflammasome that promotes interleukin (IL)-1β secretion. Although diallyl trisulfide (DATS) is well-known polysulfide garlic compounds with anti-inflammatory effects, its action in MSU-induced inflammasome activation has not been known yet.

PURPOSE

The objective of the current study was to investigate anti-inflammasome effects and mechanisms of DATS in RAW 264.7 and bone marrow-derived macrophages (BMDM).

METHODS

The concentrations of IL-1β were analyzed with enzyme-linked immunosorbent assay. The MSU-induced mitochondrial damage and reactive oxygen species (ROS) production were detected by fluorescence microscope and flow cytometry. The protein expressions of NLRP3 signaling molecules, NADPH oxidase (NOX) 3/4 were assessed with Western blotting.

RESULTS

DATS suppressed MSU-induced IL-1β and caspase-1 accompanied by decreased inflammasome complex formation in RAW 264.7 and BMDM. In addition, DATS restored mitochondrial damage. DATS downregulated NOX 3/4 that were upregulated by MSU as predicted by gene microarray and confirmed by Western blotting.

CONCLUSION

This study first reports mechanistic finding that DATS alleviates MSU-induced NLRP3 inflammasome by mediating NOX3/4-dependent mitochondrial ROS production in macrophages in vitro and ex vivo, suggesting DATS could be effective therapeutic candidate for gouty inflammatory condition.

Current evidence on the role of lipid lowering drugs in the treatment of psoriasis

Background

Abnormal lipid distribution is observed in patients with psoriasis, which increases their risk for atherosclerosis. Lipid-lowering drugs have a certain curative effect in the treatment of psoriasis, but there is no relevant evidence-based medical evaluation.

Objective

The purpose of this systematic evaluation was to assess the efficacy, safety, and potential mechanisms of action of lipid-lowering drugs for the treatment of psoriasis.

Methods

The PubMed, Embase, Cochrane Central Register of Controlled Trials, Clinical Trial, Chinese National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database, and Wanfang Database were searched for relevant articles from inception to 31 December 2021. The RevMan 5.3 and Cochrane risk-of-bias tool were used for data analysis and risk assessment, respectively. The psoriasis area and severity index (PASI) score is the primary outcome indicator in clinical studies. Based on preclinical studies, we elucidated and mapped the action mechanisms of lipid-lowering drugs in the treatment of psoriasis.

Results

The study included eight randomized controlled studies, four single-arm studies, and four in vitro studies. The results showed that lipid-lowering drugs, particularly statins, administered both orally and topically, can significantly improve psoriatic skin lesions and reduce the PASI scores [standardized mean difference, (SMD): −0.94; 95% CI: [−1.58, −0.31]; p = 0.004]. Oral statins performed best at week eight (SMD: −0.92; 95% CI: [−1.39, −0.44]; p = 0.0001). The mechanism of lipid-lowering drugs in the treatment of psoriasis may be related to the inhibition of keratinocyte proliferation, inhibition of CCL20–CCR6 interaction, and reduction in the levels of inflammatory factors.

Limitations

There are few studies on lipid-lowering drugs and psoriasis, and their small sample sizes may render the evidence unconvincing.

Conclusion

The present findings suggest that lipid-lowering drugs are relieving symptoms in psoriasis. Lipid-lowering drugs, particularly statins, can be used to treat psoriasis with good efficacy and few side effects.

Fisetin Attenuated Oxidative Stress-Induced Cellular Damage in ARPE-19 Human Retinal Pigment Epithelial Cells Through Nrf2-Mediated Activation of Heme Oxygenase-1

Fisetin is a kind of bioactive flavonol, widely present in various fruits such as strawberries and apples, and is known to act as a potent free radical scavenger. However, the mechanism of action related to the antioxidant activity of this compound in human retinal pigment epithelial (RPE) cells is not precisely known. In this study, we aimed to investigate whether fisetin could attenuate oxidative stress-induced cytotoxicity on human RPE ARPE-19 cells. To mimic oxidative stress, ARPE-19 cells were treated with hydrogen peroxide (H₂O₂), and fisetin significantly inhibited H₂O₂-induced loss of cell viability and increase of intracellular reactive oxygen species (ROS) production. Fisetin also markedly attenuated DNA damage and apoptosis in H₂O₂-treated ARPE-19 cells. Moreover, mitochondrial dysfunction in H₂O₂-treated cells was alleviated in the presence of fisetin as indicated by preservation of mitochondrial membrane potential, increase of Bcl-2/Bax expression ratio, and suppression of cytochrome c release into the cytoplasm. In addition, fisetin enhanced phosphorylation and nuclear translocation of nuclear factor erythroid 2 related factor 2 (Nrf2), which was associated with increased expression and activity of heme oxygenase-1 (HO-1). However, the HO-1 inhibitor, zinc protoporphyrin, significantly reversed the protective effect of fisetin against H₂O₂-mediated ARPE-19 cell injury. Therefore, our results suggest that Nrf2-mediated activation of antioxidant enzyme HO-1 may play an important role in the ROS scavenging activity of fisetin in RPE cells, contributing to the amelioration of oxidative stress-induced ocular disorders.

The preventive effect of loganin on oxidative stress-induced cellular damage in human keratinocyte HaCaT cells

Loganin is a type of iridoid glycosides isolated from Corni fructus and is known to have various pharmacological properties, but studies on its antioxidant activity are still lacking. Therefore, in this study, the preventive effect of loganin on oxidative stress-mediated cellular damage in human keratinocyte HaCaT cells was investigated. Our results show that loganin pretreatment in a non-toxic concentration range significantly improved cell survival in hydrogen peroxide (H₂O₂)-treated HaCaT cells, which was associated with inhibition of cell cycle arrest at the G2/M phase and induction of apoptosis. H₂O₂-induced DNA damage and reactive oxygen species (ROS) generation were also greatly reduced in the presence of loganin. Moreover, H₂O₂ treatment enhanced the cytoplasmic release of cytochrome c, upregulation of the Bax/Bcl-2 ratio and degradation of cleavage of poly (ADP-ribose) polymerase, whereas loganin remarkably suppressed these changes. In addition, loganin obviously attenuated H₂O₂-induced autophagy while inhibiting the increased accumulation of autophagosome proteins, including as microtubule-associated protein 1 light chain 3-II and Beclin-1, and p62, an autophagy substrate protein, in H₂O₂-treated cells. In conclusion, our current results suggests that loganin could protect HaCaT keratinocytes from H₂O₂-induced cellular injury by inhibiting mitochondrial dysfunction, autophagy and apoptosis. This finding indicates the applicability of loganin in the prevention and treatment of skin diseases caused by oxidative damage.