Evaluation of the Effects of Favipiravir Combined with Vitamin C on Alveolar Bone in Rats

Introduction: Favipiravir and Vitamin C (Vit C) were used together in the treatment of the COVID-19 pandemic. However, the effects of favipiravir on the periodontium are still unknown. Therefore, the aim of this study was to investigate the effects of Favipiravir and Vit C treatment on alveolar bone metabolism. Experimental: Fifty healthy adult male Sprague-Dawley rats (2–3 months old) were randomly divided into five equal groups (n = 10): Control, Favi 20, Favi 100, Favi 20+Vit C, Favi 100+Vit C. Favipiravir (20 mg/kg and 100 mg/kg, i.m.) and Vit C (150 mg/kg/day, oral) were administered to the rats for 14 days. Alveolar bone loss (ABL) and histopathological changes were examined using a light microscope. Immunohistochemistry was used to determine levels of receptor activator of nuclear factor kappa-B ligand (RANKL), caspase-3, bone morphogenic protein 2 (BMP-2) and alkaline phosphatase (ALP) in the bone tissues. Results: Favipiravir increased the levels of RANKL and caspase-3 expression but decreased BMP-2 and ALP levels in a dose-dependent manner. Favi 20+Vit C and Favi 100 +Vit C groups showed decreased RANKL and caspase-3 levels in addition to increased BMP-2 and ALP levels. Conclusion: Favipiravir can cause histopathological damage to the periodontium, but administration of favipiravir combined with Vit C can provide a protective effect against this damage.

Synthesis, crystal structure, spectroscopic, fluorescent, thermal properties and EPR spectra of doped Cu2+ ions in [Cd(sac)2(H2O)2(meim)2] single crystal

The crystal structures of the six-coordinate complexes [Cd(sac)2(H2O)2(meim)2] (complex 1) formed by reaction of 4-methylimidazole(meim) with [Cd(sac)2(H2O)4]·2H2O (saccharinate=sac), was synthesized and characterized by elemental analysis, infrared (IR) and electron paramagnetic resonance (EPR) spectroscopy, thermal analysis and X-ray single crystal diffraction. X-ray diffraction analysis revealed that complex 1 crystallized in the monoclinic crystal system with space group P21/c. The Cd(II) center was six-coordinated with four nitrogen atoms from two sac and two 4-meim ligands, two oxygen atoms from two aqua ligands. Spectral and thermal analysis data for complex 1 was in agreement with the crystal structures. In addition complex 1 displayed blue fluorescent emission in the solid state at room temperature. Single crystal EPR spectra at room temperature are resolved and have exhibited that two different Cu(2+) complexes were located in different chemical environments which contained two magnetically nonequivalent Cu(2+) sites. In low temperature EPR spectra down to 110 °C did show no considerable change. At higher temperatures, however, both thermo gravimetric analyses (TGA) and EPR spectra showed detectable changes around 140 °C; the causes and the mechanisms of changes are discussed.