Exploring the link between metformin use and adhesive capsulitis of the shoulder: a retrospective cohort study in Taiwan

The risk of adhesive capsulitis of shoulder in diabetic patients taking metformin has not been evaluated. We aimed for evaluating the relative risk of adhesive capsulitis of shoulder in diabetic patients taking metformin at the level of the whole country population. We conducted a retrospective cohort study using a national health insurance database in Taiwan from 2000 to2015. We used International Classification of Diseases, Ninth Revision, to categorise the medical condition for study group and comparison group. We used Cox proportional hazard regression analyses to determined adjusted hazard ratios (aHRs) of adhesive capsulitis of shoulder between study and comparison group after adjusting for sex, age, and comorbidities.Among 30,412 diabetic patients using metformin, 3020 patients were diagnosis with adhesive capsulitis of shoulder during follow up. Of the 121,648 patients without the use of metformin, 11,375 patients developed adhesive capsulitis of shoulder. Adhesive capsulitis of shoulder risk was elevated in patients taking metformin than in non-metformin group (adjusted hazard ratio [HR] 1.179, 95% confidence interval [95% CI] 1.022 to 1.268; p = 0.039). Risk of adhesive capsulitis of shoulder among the diabetic patients taking metformin was higher than those did not taking metformin.

Modulation of autophagy, apoptosis and oxidative stress: a clue for repurposing metformin in photoaging

Long-term sun exposure is the commonest cause of photoaging, where mutual interplay between autophagy, oxidative stress, and apoptosis is incriminated. In combating photoaging, pharmacological approaches targeted to modulate autophagy are currently gaining more ground. This study aimed to examine repurposing metformin use in such context with or without the antioxidant coenzyme Q10 (coQ10) in ultraviolet A (UVA) irradiation-induced skin damage. The study was conducted on 70 female CD1 mice that were randomly assigned into seven groups (10/group): normal control, vehicle-treated-UVA-exposed mice, three metformin UVA-exposed groups (Topical 1 and 10%, and oral 300 mg/kg), topical coQ10 (1%)-treated mice, and combined oral metformin with topical coQ10-treated UVA-exposed mice. After UVA-exposure for 10 weeks (3 times/week), macroscopic signs of photoaging were evaluated. Mice were then euthanized, and the skin was harvested for biochemical estimation of markers for oxidative stress, inflammation, matrix breakdown, and lysosomal function. Histopathological signs of photoaging were also evaluated with immunohistochemical detection of associated changes in autophagic and apoptotic markers. Metformin, mainly by topical application, improved clinical and histologic signs of photoaging. This was associated with suppression of the elevated oxidative stress, IL-6, matrix metalloproteinase 1, and caspase, with induction of cathepsin D and subsequent change in anti-LC3 and P62 staining in skin tissue. In addition to metformin antioxidant, anti-inflammatory, and antiapoptotic activities, its anti-photoaging effect is mainly attributed to enhancing autophagic flux by inducing cathepsin D. Its protective effect is boosted by coQ10, which supports their potential use in photoaging.

Inhibitory Effect of Seawater Pearl Hydrolysate on UVA-Induced Photoaging of Human Skin Fibroblasts

This study is an investigation into the inhibitory effect of seawater pearl hydrolysate (SPH) on the UVA-induced photoaging of human skin fibroblast (HSF) cells, and the mechanism thereof. HSF cells were cultured and irradiated with a UVA 0–50 J·cm⁻² dose gradient. The cell inhibition rate was detected using the CCK8 method, and the half-inhibitory dose was determined. Based on this, the dose of UVA irradiation for the follow-up experiment was selected to establish a photoaging model of the HSF cells. The cells were divided into a normal (N) group, UVA-irradiated (UVA) group, SPH low dose (SPHL) group, SPH medium dose (SPHM) group, and SPH high dose (SPHH) group. The photoaging model of HSF cells was established by UVA irradiation in the UVA, SPHL, SPHM, and SPHH groups; the SPHL, SPHM, and SPHH groups were treated with SPH at concentrations of 50, 100, and 200 mg·L⁻¹, respectively, at the same time. After 24 and 48 h of culture, the reactive oxygen species (ROS) level of the HSF cells was detected by flow cytometry, and the required culture time of the HSF cells for the follow-up experiment was selected. The malondialdehyde and glutathione contents, as well as the activities of the superoxide dismutase, catalase, and glutathione peroxidase in the HSF cells, were detected by biochemical methods. The levels of expression of MMP-1 and collagen I protein in HSF cells were detected by the western blot test, the extent of aging of HSF cells was detected by β-galactosidase staining, and the apoptosis level of HSF cells was detected by flow cytometry. The results show that SPH inhibits the UVA-induced photoaging of HSF cells in a dose-dependent manner within a certain concentration range, and the effect of a concentration of 200 mg·L^–1 was the most significant. The mechanism is related to improving the antioxidant activity of photoaging HSF cells to eliminate excessive ROS. It can inhibit apoptosis, reduce the protein expression of MMP-1, and effectively control the degradation of collagen I protein in photoaging HSF cells. Therefore, SPH offers potential for use in sunscreen cosmetics.

Keratinocyte Carcinoma and Photoprevention: The Protective Actions of Repurposed Pharmaceuticals, Phytochemicals and Vitamins

Simple Summary

Keratinocyte carcinoma is the most common type of cancer. Sun exposure and ultraviolet radiation are significant contributors to the development of carcinogenesis, mediated by DNA damage, increased oxidative stress, inflammation, immunosuppression and dysregulated signal transduction. Photoprevention involves using different compounds to delay or prevent ultraviolet radiation-induced skin cancer. In this review, we look at new avenues for systemic photoprevention that are based on pharmaceuticals, plant-derived phytochemicals and vitamins. We also investigate the mechanisms underlying these strategies for preventing the onset of carcinogenesis.

Abstract

Ultraviolet radiation (UVR) arising from sun exposure represents a major risk factor in the development of keratinocyte carcinomas (KCs). UVR exposure induces dysregulated signal transduction, oxidative stress, inflammation, immunosuppression and DNA damage, all of which promote the induction and development of photocarcinogenesis. Because the incidence of KCs is increasing, better prevention strategies are necessary. In the concept of photoprevention, protective compounds are administered either topically or systemically to prevent the effects of UVR and the development of skin cancer. In this review, we provide descriptions of the pathways underlying photocarcinogenesis and an overview of selected photoprotective compounds, such as repurposed pharmaceuticals, plant-derived phytochemicals and vitamins. We discuss the protective potential of these compounds and their effects in pre-clinical and human trials, summarising the mechanisms of action involved in preventing photocarcinogenesis.