Neuroprotective effects of aqueous extract of Caricapapaya, vitamin E and dexamethasonc on traumatic brain injury-induced oxidative damage in adult male Wistar rats.

Abstract

Background: Traumatic brain injury, TBI (blunt or penetrating) induces oxidative stress by generation of free radicals which triggers a cascade of events resulting in cellular dysfunctions and death. The neuroprotective effects of ripe aqueous extract of Carica papaya (paw-paw) (CP) fruit, vitamin E and dexamethasonc, respectively, on traumatized cerebral cortex of Wistar rats was studied. Method: Fifty adult male Wistar rats were divided into six groups; control, trauma control (TC), Carica papaya control (CPC), Carica papaya+trauma (CPT), vitamin E+ trauma (VET) and dexamethasone+trauma (DET) groups. Two hundred (200) mg/kg body weight of CP and vitamin E were administered orally, while dexamethasonc was administered at 0.005 ml of 4 mg/ml intraperitoneally. Rats were treated for 14 days pre-trauma induction and sacrificed 7 days post-trauma. Body, brain and cerebral weights as well as the behavior of the rats were studied. Blood and brain tissues were processed for haematological parameters, oxidative stress markers and histomorphological evaluations. Results: A decreased body weight was seen in all the traumatized rats compared with the control rats (p<0.05) Increased body weight was observed in the CPC, CPT and VET rats, respectively, compared with the TC rats (p<0.05) An increased brain weight was observed in the TC and VET rats compared with the control rats at p<0.05. In behavioral studies, trauma significantly (p<0.05) reduced the hang time (forelimb grip) and delayed time of re-orientation (negative geotaxis). Carica papaya and DET increased the time of re-orientation. A decreased percentage lymphocyte in the DET rats and an increased percentage neutrophil was seen in the TC and DET rats compared with the control rats at p<0.05.