Lipid-core nanocapsules containing simvastatin improve the cognitive impairment induced by obesity and hypercholesterolemia in adult rats.

The development of cognitive impairment may be related to high levels of plasma cholesterol and obesity. Simvastatin (SV) and lovastatin (LV) are drugs that can potentially be used for the treatment of cognitive deficit. This study aimed to develop and characterize lipid-core nanocapsules (LNC) containing SV (SV-LNC) or LV (LV-LNC), evaluating the effects of SV-LNC in an animal model of cognitive deficit. The formulations SV-LNC and LV-LNC presented a particle average size around 200 nm, a low-polydispersity index, and negative zeta potential. Analysis of differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy showed that there is no reaction among LNC components: LV was crystallized in the suspensions, and SV was molecularly dispersed. The encapsulation efficiency of the SV was high (98.9 ± 1.4%), while that of the LV was low (21.5 ± 1.5%).Based on these results, SV-LNC was used in the preclinical studies. Animals fed with a hyperlipidic diet (HD) developed obesity, hypercholesterolemia, and cognitive impairment, which was corroborated by the brain lesions indicated by histological analysis of some of the animals that received the high-fat diet. We observed that free simvastatin (CS3) was able to reduce the enzymatic activity of pyruvate kinase, an important enzyme for brain energy homeostasis, without affecting the memory of the animals that received a standard diet. However, it failed to improve the cognitive damage caused by a diet high in cholesterol and saturated fats. On the other hand, when simvastatin is "camouflaged" in the lipid-core nanocapsules (HNS3), this cognitive impairment improves. Thus, SV-LNC is a promising alternative therapy for the treatment of cognitive impairment.

Preliminary study of coconut water for graft tissues preservation in transplantation.

OBJECTIVE: to verify the effectiveness of coconut water in preserving tissues for transplant. METHODS: Fifty male Wistar rats were randomly distributed in five groups, according to the following preservation solutions for tissue grafts: Group 1: Lactated Ringer; Group 2: Belzer solution; Group 3: mature coconut water; Group 4: green coconut water; Group 5: modified coconut water. In Group 5, the green coconut water has been modified like the Belzer solution. From each animal we harvested the spleen, ovaries and skin of the back segment. These tissues were preserved for six hours in one of the solutions. Then, the grafts were reimplanted. The recovery of the function of the implanted tissues was assessed 90 days after surgery, by splenic scintigraphy and blood exam. The implanted tissues were collected for histopathological examination. RESULTS: The serum levels did not differ among groups, except for the animals in Group 5, which showed higher levels of IgG than Group 1, and differences in relation to FSH between groups 1 and 2 (p <0.001), 4 and 2 (p = 0.03) and 5 and 2 (p = 0.01). The splenic scintigraphy was not different between groups. The ovarian tissue was better preserved in mature coconut water (p <0.007). CONCLUSION: the coconut water-based solutions preserves spleen, ovary, and rat skin for six hours, maintaining their normal function.