In-vitro and in-vivo evaluation of silymarin nanoliposomes against isolated methicillin-resistant staphylococcus aureus

Staphylococcus aureus is an opportunistic pathogen and remains a common cause of burn wound infections. Different studies have shown that entrapment of plant-derived compounds into liposomes could increase their anti-Staphylococcus aureus activity. Silymarin is the bioactive extract from the known plant Silybum marianum L. The objective of this study was to evaluate efficacy of silymarin in free and nanoliposomal forms against isolated methicillinresistant Staphylococcus aureus [MRSA] strain. Silymarin-loaded nanoliposomes were prepared by extrusion method. The minimum inhibitory concentrations [MICs] of silymarin in free and nanoliposomal forms against MRSA were determined by broth dilution method. The killing rate of free and nanoliposomal forms of silymarin were analyzed. Ultimately, invivo therapeutic efficacy of nanoliposomes in burned mice infected by isolated MRSA was examined. The MICs of free and nanoliposomal forms of silymarin against isolated strain were 500 and 125 mg/L, respectively. The killing rate of silymarin-loaded nanoliposomes was higher than those of free silymarin. Topically treatment by silymarin in free and nanoliposomal forms resulted in almost 20 and 100% survival rates, respectively. The results suggest that silymarinloaded nanoliposomes may provide a basis for future treatment of MRSA infections

[In vitro evaluation of efficacy and toxicity of Amphotericin Bloaded nanocapsules]

Amphotericin B [AmB] is an ancient antifungal drug and proper for treatment of systemic fungal infection. Unfortunately, this antibiotic has shown some side effects such as nephrotoxicity. Therefore, recently new AmB formulated has been prepared for reduced toxicity and increased effectiveness. AmB nanocapsules prepared from polymers such as poly D, L-lactide-coglycolide by means of a solvent displacement technique. Then, the dried nanocapsules prepared by using SiO2 and entrapment efficacy of AmB was measured by spectrophotometry technique. The MICs of these nanocapsules to Candida albicans [ATCC 90028] was also determined by using microdilution method. Then, in vitro toxicity [haemolysis] of the AmB-loaded nanocapsules determined on human red blood cells. The data shows AmB entrapment efficacy for nanocapsules were 75% +/- 0.13.The MICs of AmB-loaded nanocapsules against C. albicans tested were significantly reduced compared to that of free antibiotic. Also, the AmB-loaded nanocapsules found to be 5.89 times less toxic than free AmB on human red blood cells. The results suggest that prepared AmB-loaded nanocapsules in this research may be an appropriate delivery system for AmB to be used in the treatment of fungal infections