In the present study, 6-hr restraint-stressed animal showed significant loss of memory and anxiety behavior, impaired memory activity indicating stress-induced neurobehavioral alterations.[27
] Extracts of the medicinal plant HPE has been widely used in the therapy of various neurochemical disorders and have been reported to antidepressant, anxiolytic and cognitive effect.[28
] In the present study the anxiety was assessed by mirror chamber test. After the administration of HPE and HPGNPs the improvement was better.[29
] Khalifa et al
. reported that significant improvement of the recognition and recall memory in rats treated with the crude preparation of HPE, the nootropic action,[30
] was qualitatively comparable with that produced by piracetam.[31
] and improved of cognitive functions,[32
] learning and spatial memory[33
] by the plant extract have also been reported. El –Sherbiny et al
] reported that HPE could be a novel type of antidepressant with memory-enhancing properties. So it is evident from this study as well as previous reports that HPE extract has definite neuroprotective action. Present study suggests its therapeutic potential against these stress-related altered behavioral states.
The study also reveals the existence of quantitative behavioral responses in 21 days stress-induced animals for the administration of HPE and HPGNPs. Stress-induced mice, subjected to the T-maze test and mirror chamber test, revealed a significant loss of spatial working memory and anxiety behavior. HPE and HPGNPstreatment for 21 days significantly improved behavior alterations, suggesting its neuroprotective effect against stressful conditions.
In the present study, stress-treated groups increase level of lipid per oxidation is indicated that the stress caused significant oxidative damage and depletes SOD, catalase, Gpx. and GSH activity. Tsuboi et al
. reported an increased oxidative damage and weak antioxidant defense events are implicated in major depression.[35
] Silva et al
] have reported that ethanolic extract of HPE contains many phenolic compounds namely flavonoids and phenolic acid suggesting that could have potent antioxidant property. Super oxide dismutase, catalase, glutathione peroxidase, reduced glutathione levels were significantly restored to significant levels. It suggests the possible role of HPE as an antioxidant and has been reported earlier by Hunt et al
] about the antioxidant effect of HPE against superoxide anion. They observed a free radical scavenging effect for most of the concentrations tested and postulated that this effect could not relate to its content in hypericin among other compounds. Flavonids, specifically quearcetin and its glycoside derivatives, are a major class of compounds present in the total ethanolic extract. These types of compounds are well-known antioxidants.[36
] Sloley and Urichuk[38
] reported that different standardized extracts of HPE demonstrated a free radical scavenging activity. Such free radical scavenging capacity was found to correlate with the content of several flavanodis including quercetin and hyperoside.[38
] In the present study HPE and HPGNPs improved the antioxidant status in stressed mice.
In the present study, HPE and HPGNPs were effectively improved the antioxidant enzyme activities such as SOD, CAT, GPx and GSH in stress-treated animals. So, it is concluded that both the HPE and HPGNPs can exert a significant behavior and neuroprotective effect. But, the HPGNPs has a significant behavior and neuroprotective effect than compared to the HPE.