RESUMO
Pharmaceuticals and personal care products (PPCPs) have a significant impact on the environment and human health, due to their sometimes toxic and carcinogenic characteristics. Therefore, an innovative chemosensor was constructed for ultrasensitive determination of two typical PCCPs (hydroquinone (HQ) and catechol (CC)) in several minutes. The homemade chemosensor (UiO-67@GO/MWCNTs) consisted of MOF(UiO-67), graphene oxide (GO), and multi-walled carbon nanotubes (MWCNTs) composites; it was a networked, structurally sparse, porosity-rich, homogeneous octahedral composite, and had ultra-high electrical conductivity, which provided lots of active adsorption sites, promote charge transfer, and enrich lots of molecules to be measured in a few minutes. The prepared electrochemical sensor showed good long-term stability, applicability, reproducibility, and immunity to interference for the determination of HQ and CC, with a wide linear range of response of 5.0 ~ 940 µM for both HQ and CC, and a low limit of detection with satisfactory recoveries. In addition, a new strategy of using MOF composites as the basis for electrochemical determination of organic small molecules was established, and a new platform was constructed for the quantitative determination of organic small molecules in various environmental samples.
RESUMO
Apigenin (APG) is a plant-based flavonoid that possesses antioxidants, anti-inflammatory, and modulates P38 MAPK as well as tyrosinase. Hydroquinone (HQ), a phenolic compound was used to induce vitiligo in C57BL/6 mice. The present study was performed to check the therapeutic potential of apigenin in HQ-induced vitiligo via targeting P38 MAPK pathway. In the present study, 41 C57BL/6 mice were divided into six groups containing seven animals per group except normal group. (I) normal group, (II) HQ group, (III) to (IV) APG with (1%, 2.5%, 5%), and (VI) tacrolimus (TAC) group. Topical application of HQ was performed from day 1 to day 20 to, (II), (III) to (IV) APG with (1%, 2.5%, 5%), (VI) tacrolimus (TAC) group, and then APG; tacrolimus (TAC) was applied from day 21 to day 60 after removing the hair. In the case of (I) normal group and (II) HQ group, we smeared them with water for 60 days and HQ for 20 days in their individual group. On day 61 after anesthesia, a part of the target skin was peeled and blood serum was taken to check the level of malondialdehyde, cholinesterase, catalase, tyrosinase, pro-inflammatory cytokines, and expression of P38 MAPK, histology of melanin containing hair follicles and depigmentation evaluation. Applying HQ topically had a noticeable impact on depigmentation, inflammatory indicators, oxidative stress, and lowered tyrosinase activity. Further HQ reduced melanin containing hair follicles and increased expression of P38 MAPK was confirmed by histopathology and immunohistochemistry. Furthermore, application of APG and TAC after day 21 to 60 significantly reduced depigmentation, inflammatory markers, oxidative stress, and increased tyrosinase. Furthermore, APG increased melanin containing hair follicles and decreased expression of non-phosphorylated P38 MAPK, as confirmed by histopathology and immunohistochemistry. Our finding demonstrated that APG significantly prevented HQ-induced vitiligo by acting as an anti-inflammatory, increasing tyrosine, and reducing the expression of non-phosphorylated P38 MAPK.