RESUMO
The use of Colistin, a last-resort antimicrobial drug, carries the risk of acute kidney injury. The objective of the study was to assess the effectiveness of colistin-encapsulated liposomes (CL) in reducing nephrotoxicity. Additionally, a liposomal preparation of colistimethate sodium was formulated using the reverse phase evaporation method with a 3:1 ratio of phospholipids to cholesterol. The liposomal properties were evaluated using scanning electron microscopy, photon correlation spectroscopy, and release kinetic assay. The killing kinetics of the formulations on embryonic kidney cells were assessed using in vitro MTT reduction assay. The nephrotoxicity of CL and colistimethate sodium solution (CS) was evaluated in vivo by administering a dose of 20 mg/kg to rats every 12 h for 3 days, with a negative control group receiving a 0.9% saline solution (NSS). The study results revealed that monodisperses of CL showed a smooth surface and distinct boundaries, with an average size of 151.50 ± 0.46 nm and a narrow size distribution of 0.25 ± 0.01. The liposomal particles showed high entrapment efficiency of 96.45% ± 0.41%, with a ζ-potential of -60.80 ± 1.01 mV and a release rate of 50% of colistimethate sodium within the first 480 min. The CL induced nephrocytotoxicity in a concentration- and time-dependent manner. However, CS had notably lower IC50 values compared to its liposome preparations at 48 and 72 h (p < 0.05). In vivo study results show that serum levels of symmetric dimethylarginine (SDMA) and total white blood cell count (WBC) were significantly lower in the CL group (SDMA = 8.33 ± 1.70 µg/dL; WBC = 7.29 ± 0.99 log10 cells/mL) compared to the CS group (SDMA = 15.00 ± 1.63 µg/dL; WBC = 9.73 ± 0.51 log10 cells/mL). Our study findings enhance the understanding of the safety profile of CL and its potential to improve patient outcomes through the use of liposomal colistin medication. Additional clinical studies are necessary to establish the optimal safety regiment in humans.
RESUMO
Despite its nutritional values, rice also contains arsenic. There has been increasing concern about health implications associated with exposure to arsenic through rice consumption. The present study evaluated arsenic accumulation and its speciation in selected organs of Wistar rats after 28 day repeated oral administrations of polished or unpolished rice and their control arsenic compounds (sodium arsenite or dimethylarsinic acid; DMA). Only the treatment of sodium arsenite (2 µg/kg body weight), significantly increased total arsenic concentrations in blood when compared to the distilled water control group. In all groups, total arsenic concentrations were highest in kidney (1.54-1.90 mg/kg) followed by liver (0.85-1.52 mg/kg), and the predominant arsenic form in these organs was DMA. However, there was no significant difference in arsenic accumulation in the measured organs among the control and rice-treated groups. Therefore, the repeated 28 day administration of arsenic-contaminated rice did not cause significant arsenic accumulation in the animal organs.
