Biomedical potential of chitosan-silver nanoparticles with special reference to antioxidant, antibacterial, hemolytic and in vivo cutaneous wound healing effects.

The aim of the present study was to prepare chitosan-PVA-silver nanoparticles (CS-AgNPs) through green method. Chitosan and PVA polymers acted as stabilizing agents. DLS and TEM analyses showed that CS-AgNPs were homogeneously dispersed in matrix with an average size of 190-200 nm. The CS-AgNPs were tested for their antioxidant and antibacterial properties and the results revealed that they exhibited higher antioxidant activity than CS powder. Moreover, CS-AgNPs were characterized by a low cytotoxicity effect at 5-200 µg/ml against Chinese Hamster Ovary (CHO-K1) cells. In addition, the prepared CS-Ag NPs were found to promote significantly the wound healing, as determined by the wound contraction ratio and histological examination. A significant improvement in wound healing progression and in oxidative stress damage were observed for CS, CS-PVA and CS-AgNPs-treated wound tissues, when compared to control and CICAFLORA®-treated groups. The wound healing effect could be attributed to the antibacterial and antioxidant synergy of AgNPs and CS. Results strongly support the possibility of using CS-AgNPs for wound care applications.

Chemoprotective role of ethanol extract of Urtica urens L. against the toxicity of imidacloprid on endocrine disruption and ovarian morphometric in female rats, GC/MS analysis.

Imidacloprid (IMI) is a widely used in Tunisia and abroad, and high doses of IMI have been known to cause endocrine disruption. Some reports claim that Urtica urens L. (UU) can reduce toxicity thanks to it anti-inflammatory and antioxidant activities, but there is no scientific evidence justifying its use, which lets us think to its direct effect on the metabolism of the ovarian tissue. The present study was undertaken to evaluate the protective effect of UU against the toxicity of Confidor®, whose active substance is imidacloprid (IMI), in female rat, as well as the chemical compositions of UU ethanol (EtOH) extract by GC-MS. Female rats were divided into control group, 3 groups treated with IMI at 50, 200 or 300mg/kg/day and three groups co-treated with IMI (50, 200 or 300mg/kg/day)+100mg/kg/day of UU, for 60days. Blood samples were collected for the dosage of 17ß-estradiol levels. Ovaries were removed for tissular dosage of malondialdehyde (MDA), advanced oxidation protein products (AOPP), glutathione (GSH), vitamin E, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Histological and histomorphometric examinations were performed as well. IMI caused an acute ovary injury, increased the ovary tissue levels of MDA and AOPP, and decreased the levels of GSH, vitamin E, and antioxidant enzyme activities. The number and the diameter of follicles were markedly diminished together with a reduction of the relative weight of ovaries. Compared with controls, the treated rats exhibited a significant reduction in serum 17b-estradiol levels. These results suggest an endocrine disruption by IMI which may interfere with ovarian follicles development in rat. The injection of UU EtOH extract improved the histological and all biochemical parameters cited above. In conclusion, IMI induced an acute ovary injury accompanied with disturbance of oxidant status and causes follicular atresia. Significant antioxidant activities were also observed in UU EtOH and a total of 31 compounds were identified. The injection of UU EtOH provided a significant protection which might be due to its antioxidant activities.

Protective effect of ethanolic extract of Urtica urens L. against the toxicity of imidacloprid on bone remodeling in rats and antioxidant activities.

Imidacloprid (IMI) is very harmful to human health and cause problems. Recently, plants have been considered as potential agents for protection against these disorders. Urtica urens L. (UU) is very useful for relieving rheumatic pains and there is no scientific evidence justifying its use, which lets us think of its direct effect on the bone. This study aimed to investigate the protective effect of UU against toxicity effects of IMI in female rat. Rats were divided into control group, 3 groups treated with IMI at 50, 200 or 300mg/kg/day and 3 groups co-treated with IMI (50, 200 or 300mg/kg/day)+100mg/kg/day of UU. We studied bone remodeling through histological, histomorphometry and biochemical analyses. In IMI- treated groups, we have noted, following histomorphomotric analysis, significant decreases in cortical, trabecular thicknesses and osteoid surfaces. Elsewhere, IMI intoxication significantly decreased serum vitamin D and hydroxyproline levels in the groups treated for 60days. IMI intoxication increased significantly calcium, phosphorus contents, MDA and AOPP levels and the rate of calcification. It decreased significantly GSH, GPx, SOD, CAT, 17b-Estradiol and vitamin E levels, induces a tendency of rarefaction and increases of intrabecular spaces. The co-treatment with UU improved all biochemical parameters (hydroxyproline, MDA, AOPP, GSH, GPx, SOD, CAT, 17b-Estradiol, vitamin D, vitamin E calcium, phosphorus). UU leads to a significant increase in cortical, trabecular thicknesses, osteoid surfaces, a decrease in the intrabecular spaces and the rarefaction of bone. In conclusion, IMI inhibits bone remodeling and enhances bone formation. A significant antioxidant activity was also observed in UU and a total of 6 compounds were identified. Co-administration of UU provided a significant protection which might be due to its antioxidant property.

The healing effect of Pistacia lentiscus fruit oil on laser burn.

CONTEXT: Since antiquity, Pistacia lentiscus L. (Anacardiaceae) fruit oil (PLFO) has been used as a remedy for primary health care such as burn treatment. OBJECTIVE: This study assesses the healing effect of PLFO on CO2 laser fractional burn in a rat model. MATERIALS AND METHODS: The study was carried out on 18 adult male Wistar rats. A second-degree laser burn (wound area = 2.2 cm2) was inflicted in the dorsal region by the application of CO2 fractional laser within the following parameters; Energy level: 25 MJ and Depth level: 4. After applying laser, the rats were divided into three groups: the first was treated with saline solution, the second with a reference cream 'CYTOL BASIC®' (0.13 µg/mm2) and the third with PLFO (0.52 µL/mm2). All treatments were topically administered for eight days. The healing effect was assessed using macroscopic, histological and biochemical parameters. RESULTS: After eight days, the higher percentage of wound healing contraction was observed among the PLFO-treated group (100%) followed by the 'CYTOL BASIC®' treated group (61.36%) and untreated group (32.27%). During the treatment, the PLFO-treated group showed less erythema, less crusting/scabbing, higher general wound appearance scores and a high content of collagen (220.67 ± 7.48 mg/g of tissue) than the other groups. DISCUSSION AND CONCLUSION: The current study has shown, for the first time, the healing effect of PLFO on CO2 laser fractional burn. Their wound healing effect could be attributed to their antimicrobial, anti-inflammatory and antioxidant effects.