Nano-hesperetin enhances the functional recovery and endogenous remyelination of the optic pathway in focal demyelination model.

Our recent report demonstrated that hesperetin (Hst) as a citrus flavonoid, significantly reduces the levels of demyelination in optic chiasm of rats. Previous evidence also indicated that nano-hesperetin (nano-Hst) possesses beneficial impacts in experimental models of Alzheimer's disease and autism. In this study, the effects of nano-Hst on latency of visual signals, demyelination levels, glial activation, and expression of Olig2 and MBP were evaluated in lysolecithin (LPC)-induced demyelination model. Focal demyelination was induced by injection of LPC (1%, 2 µL) into the rat optic chiasm. Animals received oral administration of nano-Hst at dose of 20 mg/kg for 14 or 21 days post LPC injection. Visual evoked potential (VEP) recording showed that nano-Hst reduces the latency of visual signals and ameliorates the extent of demyelination areas and glial activation. Expression levels of the Olig2 and MBP were also significantly increased in nano-Hst treated rats. Overall, our data suggest that nano-Hst reduces the latency of visual signals through its protective effects on myelin sheath, amelioration of glial activation, and enhancement of endogenous remyelination.

Protective Effects of Curcumin and its Nano-Phytosome on Carrageenan-Induced Inflammation in Mice Model: Behavioral and Biochemical Responses.

BACKGROUND AND PURPOSE: Natural compounds are used for prevention of inflammation. Curcumin has antioxidant and anti-inflammatory properties, and loading it into nano-phytosomes may improve its efficiency. The present study investigates the effects of curcumin and its nano-phytosome on behavioral and biochemical responses in carrageenan-induced inflammation in the mice model. METHODS: The mice were divided into six groups and received oral administration of curcumin or its nano-phytosome at a dose of 15 mg/kg for seven days before the administration of carrageenan. Acute inflammation in the mice was induced by administration of carrageenan (1%) into the subplantar region of the left paw. Antioxidant activity and behavioral responses were then evaluated. RESULTS: The results showed that the serum concentrations of antioxidant enzymes were significantly higher in the sal+sal group compared to the cara+sal group (P<0.05). Using nanophytosome, separately and in combination with indomethacin, increased the levels of antioxidant enzymes compared to the cara+sal group (P<0.05). Latency was significantly lower in the cara+sal group compared to the cara+sal group (P<0.05), but it was considerably higher in other groups, especially in the cara+nano.ph.cur+indo group (P<0.05). CONCLUSION: It can be stated that the nano-phytosome of curcumin could improve antioxidant and behavioral responses in inflamed mice.

Hesperetin reduces myelin damage and ameliorates glial activation in lysolecithin-induced focal demyelination model of rat optic chiasm.

Visual impairment is considered as the most common initial manifestation of multiple sclerosis (MS) patients. It has been shown that hesperetin (Hst), a flavonoid of citrus fruit, possesses anti-inflammatory and antioxidant effects both in vitro and in vivo. The present study was designed to evaluate the pharmacological/medicinal effects of Hst treatment on myelin repair and glial activation in lysolecithin (LPC)-induced focal demyelination model. In order to induce local demyelination model, LPC 1% (2 µL) was injected into the optic chiasm of rats. Animals received oral administration of Hst at dose of 20 mg/kg for 14 or 21 days post lesion induction. Visual evoked potential (VEP) recordings were conducted before and also on days 7, 14 and 21 post LPC injection. Glial activation and myelination of optic chiasm were evaluated by immunostaining on brain sections. Analysis of VEPs data revealed that oral administration of Hst effectively reduced the latency of N1 waves. Immunostaining results showed the reduced number of astrocytes and microglia in animal which were treated with Hst. Furthermore, the extent of demyelination area was decreased in animals treated by Hst. Taken together; our results suggest that Hst treatment significantly protects and repairs myelin sheath, therefore it might be regarded as effective supplementary agent in demyelinating disorders, particularly MS.

Querectin improves myelin repair of optic chiasm in lyolecithin-induced focal demyelination model.

Although the beneficial effects of quercetin on oligodendrocyte precursor cell (OPCs) population has been evaluated in-vitro, there are few studies about the effects of quercetin on myelin repair in the context of demyelination. The aim of this study was to investigate the effects of querectin on functional recovery and myelin repair of optic chiasm in lysolecithin (LPC)-induced demyelination model. Demyelination was induced by local injection of LPC 1% (2 µl) into rat optic chiasm. Querectin at doses 25 or 50 mg/kg was administrated daily by oral gavage for 7 or 14 days post LPC. Visual evoked potential (VEPs) recordings were used to assess the functional property of the optic pathway. Immunostaining and myelin staining were performed on brain sections 7 or 14 days post lesion. Electrophysiological data indicated that LPC injection increased the latency of VEPs waves and quercetin effectively reduced the delay of visual signals. The level of glial activation was alleviated in animals under treatment of quercetin compared to vehicle group. Furthermore, quercetin treatment decreased the extent of demyelination areas and increased the remyelination process following LPC injection. Overall, our findings indicate that quercetin could remarkably improve the functional recovery of the optic pathway by its protective effects on myelin sheath and attenuation of glial activation.