No abstract

Type 1 diabetes mellitus (T1DM) is caused by the insulin deficiency resulting from the progressive destruction of pancreatic β cells. Thiazolidine-2,4-diones (TZDs) activate the peroxisome proliferator-activated receptor-γ (PPARγ) and enhance the actions of insulin. 5-((6-methyl-4-oxo-4Hchromen-3-yl)methylene)-3-(2-(4-nitrophenyl)-2-oxoethyl)-thiazolidine-2,4-dione (TZDd) is a heterocyclic derivative synthesized in our laboratory. The purpose of this study was to examine whether TZDd has hypoglycemic and antioxidant effects in diabetic rats. Its effects were compared with those of quercetin (Que), a potent antioxidant, and with pioglitazone (Pio), a well-known antidiabetic drug. Type 1 DM was induced in Wistar rats by the intraperitoneal administration of streptozotocin (STZ) (60 mg/kg). The non-diabetic and diabetic rats were treated with Que (30 mg/kg/day), pioglitazone (30 mg/kg/day), or TZDd (30 mg/kg/day), for 5 weeks. The serum levels of malondialdehyde (MDA) and protein carbonyl (PC) groups, and the superoxide dismutase (SOD) and catalase (CAT) activities in the blood were then assessed. The results indicated that the TZDd decreased the blood oxidative stress parameters in the treated diabetic rats, compared to Que and pioglitazone. In conclusion, the hypoglycemic and antioxidant effects of TZDd in diabetic rats, suggest its therapeutic properties for the clinical treatment of T1DM.

Bioactive glasses (BGs), also known as bioglasses, are very attractive and versatile materials that are increasingly being used in dentistry. For this study, two new bioglasses—one with boron (BG1) and another with boron and vanadium (BG2)—were synthesized, characterized, and tested on human dysplastic keratinocytes. The in vitro biological properties were evaluated through pH and zeta potential measurement, weight loss, Ca2+ ions released after immersion in phosphate-buffered saline (PBS), and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) analysis. Furthermore, biocompatibility was evaluated through quantification of lactate dehydrogenase activity, oxidative stress, transcription factors, and DNA lesions. The results indicate that both BGs presented the same behavior in simulated fluids, characterized by high degradation, fast release of calcium and boron in the environment (especially from BG1), and increased pH and zeta potential. Both BGs reacted with the fluid, particularly BG2, with irregular deposits covering the glass surface. In vitro studies demonstrated that normal doses of the BGs were not cytotoxic to DOK, while high doses reduced cell viability. Both BGs induced oxidative stress and cell membrane damage and enhanced NFkB activation, especially BG1. The BGs down-regulated the expression of NFkB and diminished the DNA damage, suggesting the protective effects of the BGs on cell death and efficacy of DNA repair mechanisms.