Ethanolic extract of Erythrina velutina Willd ameliorate schizophrenia-like behavior induced by ketamine in mice

An extract from the stem bark of the plant Erythrina velutina (EEEV), known as “mulungu,” reversed schizophrenia-like behaviors in mice that had been induced by repeated ketamine injections. Mice given ketamine for 14 days showed deficits in prepulse inhibition of the startle reflex, hyperlocomotion, and impaired social interaction. When EEEV extract (200 or 400 mg/kg) was given alongside ketamine from days 8 to 14, it reversed these behavioral changes, similar to the effects of the antipsychotic olanzapine. The results suggest EEEV may offer a new avenue for developing schizophrenia treatments.

Study at a glance

Abstract

Abstract Background Schizophrenia is a chronic mental disorder, characterized by positive, negative and cognitive symptoms. In general, several plants have shown activity in diseases related to the central nervous system (e.g., Erythrina velutina (EEEV), also known as “mulungu”). For this reason, we aimed to investigate the effects of standardized ethanol extract obtained from the stem bark of EEEV on the schizophrenia-like behaviors induced by ketamine (KET) administration. Methods Swiss mice were treated with KET (20 mg/kg, i.p.) or saline for 14 days. In addition, from 8th to 14th days, saline, EEEV (200 or 400 mg/kg, p.o.) or olanzapine (OLAN 2 mg/kg, p.o.) were associated to the protocol. On the 14th day of treatment, schizophrenia-like symptoms were evaluated by the prepulse inhibition of the startle reflex (PPI), locomotor activity evaluated by the open field test (OFT), spatial recognition memory evaluated by the Y-maze task and social interaction test (SIT). Results KET has caused deficits in PPI, and it has also has caused hyperlocomotion in OFT and deficits in SIT as compared to control. EEEV in both doses used, reversed behavioral changes induced by KET, likewise results obtained with the administration of OLAN. Conclusions Taken together, the results demonstrate that the standard extract of EEEV was able to revert schizophrenia-like symptoms, due to the administration in repeated doses of ketamine. Thus, our findings lead to a new perspective for the use of EEEV an interesting alternative for drug discovery in schizophrenia.