Abelmoschus esculentusL. (ladies finger, okra) is a well-known tropical vegetable, widely planted from Africa to Asia and from South Europe to America. In the present study, we investigated thein vitroantioxidant capacity andin vivoprotective effect of the aqueous and methanolic seed extracts ofAbelmoschus esculentusagainst scopolamine-induced cognitive impairment using passive avoidance task and acute restraining stress-induced behavioural and biochemical changes using elevated plus maze (EPM) and forced swimming test (FST) in mice. Our results demonstrated that the pretreatment of mice with aqueous and methanolic seed extracts ofAbelmoschus esculentus(200 mg/kg, p.o.) for seven days significantly(P< 0.01)attenuated scopolamine-induced cognitive impairment in the passive avoidance test. In addition, these extracts significantly reduced the blood glucose, corticosterone, cholesterol, and triglyceride levels elevated by acute restraint stress and also significantly increased the time spent in open arm in EPM and decreased the immobility time in FST. It has also been revealed that these extracts showed a significant antioxidant activity and no signs of toxicity or death up to a dose of 2000 mg/kg, p.o. These results suggest that the seed extracts ofAbelmoschus esculentusL. possess antioxidant, antistress, and nootropic activities which promisingly support the medicinal values of ladies finger as a vegetable.

Memory impairment (MI) is one of the predominant criteria generally used to identify schizophrenia, dementia and amnesia that are associated with neurodegenerative disorders by evaluating patient’s cognitive symptoms. To date, there is no available treatment that can completely mitigate MI. Currently, there is a trend in recent investigations towards symptomatic therapy approaches using a variety of natural compounds. Mangiferin is one of them that have been investigated extensively. Mangiferin is a naturally occurring potent glucoxilxanthone and is mainly isolated from the Mangifera indica (Mango) plant. This review is aimed at providing a comprehensive overview on the efficacy of mangiferin on MI, based on in-vivo animal studies. After screening through articles identified from Scopus and PubMed based on the inclusion and exclusion criteria, a total of 11 articles between 2009 and 2019 were included. The minimum and maximum dose of mangiferin were 10 and 200 mg/kg respectively and administered over the period of 12–154 days. The results of 11 articles showed that mangiferin effectively improved spatial recognition, episodic aversive events, short- and long-term memories primarily occurring via its antioxidant and anti-inflammatory effects. The outcomes of the review revealed that mangiferin improves memory and cognitive impairment in different animal models, indicating that it has potential preventive and therapeutic roles in MI.

Chronic stress has been associated with impairment of memory, learning, and social cognition. In animal studies, chronic stress has been shown to impair rodent sociability behaviour which mimics social withdrawal as observed in depression patients. The effect of chronic stress on social recognition, however, is uncertain. Moreover, with reference to spatial learning and memory, the effect of chronic stress is dependent on the type of behavioural task: an appetitively or aversively motivated tasks. The effect of chronic stress was consistent in impairing spatial learning and memory in the appetitive task; however, the effect was inconsistent in an aversive task like the Morris water maze. Thus, we aimed to investigate the effect of chronic restraint stress on sociability and social recognition by using a modified protocol of the three-chamber paradigm and the effect of chronic restraint stress on spatial learning and memory by using the Morris water maze test in young adult C57BL/6J male mice. The present report also describes a modified protocol of the three-chamber paradigm. Our modification is based on measurement of sniffing behaviour, which is a direct social interaction that represents sociability. We used the chronic restraint stress paradigm for 6hours/day for 21 days to induce depression-like symptoms in male C57BL/6J mice which were validated by forced-swim test. We observed that the stressed group had impairments in their sociability behaviour but that social recognition was not affected. Furthermore, we confirmed that chronic stress produced no significant impairment in spatial learning and memory of the mice in the water maze.