Background: Recently, several studies demonstrate the possible role of zinc oxide (ZnO) in the protection of several skin diseases, but less is known about the role of ZnO nanoparticles in the inflammatory skin disease. So, this study was designed to confirm the pivotal role of the nano zinc oxide cream in the alleviation of lead oxide (PbO) induced-allergic dermatitis in rats. Materials and methods: Two concentrations (1% and 6%) of ZnONPs creams were prepared and characterized prior to being used in the study. A total number of 30 male Wistar rats were randomly divided into six groups. Group 1 (negative control), groups 2&3 (either 1% or 6% ZnONPs control groups), group 4 (PbO), groups 5&6 (co-treatment of each ZnONPs concentration+PbO). All rats in different groups were observed daily to determine the severity of dermal gross lesions. Histopathological studies, mRNA analysis, and oxidative stress evaluations were performed on the affected skin tissue. Immunohistochemical studies were performed to evaluate the expression of cluster of differentiation CD4, CD8 and intercellular adhesion molecules ICAM-1 in different groups. Results: PbO caused extensive skin oxidative damage manifested by a significant increase in MDA level with a decrease in GSH content and CAT activity. The results of histopathological and immunohistochemical examinations revealed that topical application of PbO for 14 days led to severe allergic dermatitis with remarkable elevations in the number of CD4+ T-helper, CD8+ T-cytotoxic lymphocytes, and ICAM-1 expression. On the other hand, noticeable improvements were recorded in all the previous toxicopathological parameters among the groups treated by either 1% or 6% ZnO-NPs cream. However, the best results were observed in the group treated with 1% ZnO-NPs cream. Conclusion: Our findings suggest that 1% of ZnO-NPs cream is safe when applied topically on the inflamed skin. Moreover, it had anti-inflammatory and antioxidant effects so that, it is recommended to use the 1% ZnO-NPs cream to avert the dermal toxicity-induced by PbO.

Background: Acute pancreatitis is a significant global disease. This study investigated the phytochemical composition and potential protective effects of Equisetum arvense L. (horsetail) ethanol extract and Olea europaea L. (olive leaves) aqueous extract against metronidazole (MTZ)-induced pancreatic damage in rats. Materials and Methods: Rats were randomly divided into six groups: Group I (control) received saline; Group II (Metronidazole) received only MTZ (400 mg/kg). Group III (Equisetum arvense group) received E. arvense 100 mg/kg. Group IV (Olea europaea) received 400 mg/kg of O. europaea. Group V (MTZ + E. arvense) received both MTZ (400 mg/kg) and E. arvense (100 mg/kg). Group VI (MTZ + O. europaea) received MTZ (400 mg/kg) and O. europaea (400 mg/kg). All treatments were delivered daily via the oral route. After 60 days, serum amylase, lipase, protease, and glucose levels, oxidative parameters “malondialdehyde (MDA), catalase (CAT), mRNA relative expression of pancreatic Pik3ca (phosphatidylinosi-tol-4,5-bisphosphate 3-kinase, catalytic subunit alpha), AKT (AKT Serine/Threonine Kinase 1), Nrf-2 (Nuclear factor, erythroid 2-like 2), TNFα (tumor necrosis factor alpha), and IL-1β (interleukin-1 beta genes, an apoptotic marker “caspase-3,” and histopathological changes were estimated. Results: HPLC analysis revealed that horsetail extract contained caffeic acid, catechin, rutin, and kaempferol, while olive leaf extract was dominated by oleuropein. MTZ administration significantly elevated serum levels of pancreatic enzymes (lipase, amylase, and protease) and glucose and increased oxidative stress markers, such as MDA, while reducing catalase (CAT) activity. Co-treatment with MTZ and horsetail, or MTZ and olive extracts, mitigated these effects, especially horsetail, which restored CAT levels and reduced MDA concentrations. qPCR analysis showed MTZ upregulated inflammatory genes (TNFα, IL-1β) and downregulated antioxidant and survival-related genes (Pik3ca, AKT, Nrf-2). Horsetail co-treatment significantly reversed these gene expression patterns. Histopathological and immunohistochemical analyses confirmed MTZ-induced pancreatic tissue degeneration and increased cleaved caspase-3 expression, both of which were notably alleviated by horsetail extract. Conclusions: These findings highlight the superior protective efficacy of Equisetum arvense over Olea europaea in ameliorating MTZ-induced pancreatic toxicity, potentially through anti-inflammatory, antioxidant, and anti-apoptotic mechanisms.