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Background and purpose: Adsorption is considered as one of the promising treatment methods for removal of heavy metals from aqueous solutions. The aim of this study was to determine the efficiency of Padina sanctae crucis in removal of manganese (Mn) from aqueous solutions.

Materials and methods: Biosorption was studied in a series of batch experiments at room temperature and the effects of experimental parameters such as biosorbent dose (0.1-10 g/L), contact time (3–120 min), pH (3, 5, 7, 8) and initial Mn concentration (0.5–100 mg/L) were studied.

Results: The highest removal biosorption of Mn was reached at 5 g/L biosorbent dose, 20 min contact time, and 20 mg/L initial Mn concentration (100% removal). Langmuir model was better fitted than Freundlich model that showed homogeneous biosorption surface and the possibility of monolayer biosorption of Mn by biosorbent. The biosorption kinetics was controlled by the pseudo-second order.

Conclusion: According to the results, Padina sanctae crucis could be used as an effective and low-cost biosorbent for Mn removal from aqueous solutions.

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Background and purpose: Ischemia-reperfusion injuries (I/RI) are the major causes of liver failure after various types of liver surgeries, particularly liver transplantation. Reactive oxygen species (ROS) are the major causes of such injuries, therefore, antioxidant therapy to attenuate hepatic lesions is preferred. We aimed to evaluate the effects of silibinin, a potent radical scavenger, on liver damages and endothelial and inducible nitric oxide synthase (eNOS and iNOS) genes expression after liver I/R.
Materials and methods: In this experimental study, the rats were divided into four groups (n=8 per group). Group1 Vehicle: the rats underwent laparotomy and received DMSO10%, Group 2 SILI: the animals received silibinin alongside laparotomy, Group3 I/R: the rats received DMSO10% and subjected to liver I/R procedure, and group 4 I/R+SILI: this group received both silibinin and liver I/R simultaneously. Silibinin (50 mg/kg I.P) was administered twice in all rats. After 1 h ischemia and 5 h reperfusion, blood samples were collected to evaluate serum AST and ALT levels and liver sections were taken to analyze the eNOS and iNOS gene expressions and histological examinations.
Results: There were no significant differences in all parameters between Vehicle and SILI groups (p>0.05). But serum AST and ALT increased significantly in I/R group compared with those in vehicle group. Treatment with silibinin could considerably reduce these markers. Histological damages during I/R improved by silibinin. The iNOS gene was found to be overexpressed whereas eNOS expression decreased in I/R group compared with those in the vehicle group. Silibinin treatment could decline iNOS expression but could not significantly affect eNOS expression (p>0.05).
Conclusion: Silibinin protects liver from I/RI. It may decrease iNOS adverse effects by suppressing its expression.