Recently, the self-assembly property of nonionic surfactants has been utilized to create vesicles as alternatives to liposomes. The aims of the present study were to investigate the impact of cholesterol on niosome bilayer properties and to evaluate niosome solubilization by Triton X-100 (TR) in the presence and absence of cholesterol. Niosomes were prepared using Span 80 and Tween 80 with or without cholesterol, and several structural studies were done. We compared both types of niosomes in their rigidity, permeability, surface tension, thermal properties, toxicity profile, and solubilization by the addition of several aliquots of TR. Efforts to achieve solubilizing parameters are also discussed. Our results indicate that cholesterol in niosomes increases membrane stability, decreases the fluidity of the membrane and also alters membrane permeability. Additionally, the solubilization process is illustrated by a three-stage model, in which the vesicle-to-micelle transition for niosomes is induced by the stepwise addition of TR. We show that cholesterol-containing niosomes need a higher amount of TR concentration for solubilization. To our best knowledge, this is the first report on niosome solubilization with TR. The results revealed the similarity of niosomal to liposomal systems, and we hope this encourages researchers to design more solubilization and protein reconstitution studies with niosomes.

The major side effect of gentamicin (GEN) is nephrotoxicity which in turn restricts the clinical use of this drug. In this study, the effect of gallic acid (GA) on gentamicin-induced nephrotoxicity was studied. A total number of 28 male Wistar rats were randomly divided into four experimental groups: control, GEN (100 mg/kg/day), GEN + GA (30 mg/kg/day), GA (30 mg/kg/day). All drug administrations were done intraperitoneally (i.p) for eight consecutive days. Twenty-four hours after the last administration, blood samples were collected to determine serum creatinine (Cr), blood urea nitrogen (BUN). The right kidney was used for histological examination. Malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) levels and catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activity were assayed in left renal tissue. Results showed a significant increase in the levels of MDA, NO, Cr, and BUN and decrease of GSH, CAT, GPx, and SOD by GEN administration. Co-administration with GA showed reduction in the levels of MDA, NO, Cr, and BUN and increase in GSH, CAT, GPx, and SOD. Also, the nephroprotective effect of GA was confirmed by the histological examination of the kidneys. The results of our study showed that GA exerts a significant nephroprotective effect against GEN-induced nephrotoxicity.