Ameliorative effect of Cassia singueana extract against acute ketamine induced cognitive impairment in murine models of schizophrenia

Introduction: In the quest for search of novel pharmacotherapy from medicinal plants for psychiatric disorders, it has progressed appreciably for the past few decades and their therapeutic potential has been evaluated in a variety of murine models. Cassia singueana Del. is a commonly used medicinal plant in Nigeria for management of insanity and as lactation enhancer.

Aim: The main aim of this study was to evaluate the cognitive potential of Cassia singueana extract against ketamine-induced cognitive impairment in mice.

Methods: The phytochemicals and elemental minerals present in the extract were determined using standard protocol and antioxidant potential of the extract was evaluated using TBA-TCAA protocols, while its oral median lethal dose (LD₅₀) in mice was estimated by OECD protocol. The effect of Cassia singueana extract (100, 200 and 400 mg/kg) on neurobehavioral deficit was evaluated in mice using behavioural paradigms: Y- maze, novel object recognition, forced swim test, open field test and catalepsy test.

Results: The phytochemical constituents of Cassia singueana were alkaloids, cardiac glycosides, tannins, flavonoids, saponins, steroids and triterpenes. The extract also significantly decreased the level of MDA and increased the level of SOD and GSH. Oral LD₅₀ was estimated to be >5000 mg/kg. Cassia singueana extract significantly (P< 0.05) increased the exploration time of novel object and percentage recognition index during the retention phase of the NORT. In Y-maze test, the extract significantly (p<0.05) increased the number of actual alternation and the percentage spontaneous alternation. It also significantly (p<0.05) decreased the duration of immobility in forced swim test. The extract also significantly (p<0.05) increased the number of central and peripheral square cross in open field. The extract also did not prolong the duration of catalepsy induced by haloperidol in glass bar test.

Conclusion: Cassia singueana extract contained phytochemicals that could ameliorate cognitive impairment and negative symptoms of schizophrenics.