ABSTRACT
This study aimed to evaluate the neuroprotective effects of the ethanolic leaf extract of Crassocephalum crepidioides (Cc) on diazepam-induced amnesia in mice. Thirty mice distributed into six groups of five mice each were used. The normal control and negative control groups received 2% ethanol per os, the positive control group received piracetam (150 mg/kg, p.o), and three experimental groups were treated with three doses of ethanolic leaf extract of Cc (100, 200, and 400 mg/kg, p.o). All groups except the normal control group were co-treated with diazepam (3 mg/kg, i.p) daily for 14 days. The memory effects were evaluated using the Radial Arm Maze (RAM) and the Novel Object Recognition (NOR) tests, while the anti-depressive effects were evaluated using the tail suspension test. All animals were sacrificed at the end of the study. Hippocampi, isolated from the right hemisphere, were used to prepare a homogenate for the determination of oxidative stress biomarkers. The ethanolic leaf extract of cc significantly (p < 0.001) decreased the number of working and reference memory errors in the RAM test and induced a significant (p < 0.01) increase in the time spent exploring the novel object in the NOR test. The extract also induced a significant (p < 0.001) increase in the mobility time in tail suspension. Moreover, compared to the negative control group, the extract significantly (p < 0.01) increased superoxide dismutase activity and significantly (p < 0.01) decreased malondialdehyde levels. The histopathological analysis of hippocampi showed that the cc extract increased cell density when compared with the negative control. These results suggest that the ethanolic left extract of cc could have neuroprotective properties, which could be attributed to its antioxidant properties.
ABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Antrocaryon klaineanum is used by traditional healers to treat many disorders including pain and inflammatory diseases. This study aimed to evaluate the analgesic and antiinflammatory activities of methanol extract of A. klaineanum in mice and rats. MATERIALS AND METHODS: Reverse phase high-performance liquid chromatography (RP-HPLC) was performed to establish the chromatographic fingerprint and to identify various chemical components of the plant extract. The anti-nociceptive activity of methanol extract of A. klaineanum was assessed using the acetic acid-induced abdominal constriction model, formalin test, capsaicin and cinnamaldehyde induced-neurogenic pain and hot plate test. Anti-inflammatory activity was assessed on carrageenan-induced inflammation. Extract was administrated orally at 200, 400 and 600mg/kg. RESULTS: Phytochemical analysis indicated the presence of proanthocyanidins, phenolic acids and flavonoids. The results of anti-nociceptive and anti-inflammatory activities showed that methanol extract significantly (p<0.01) reduced the pain induced by acetic acid with an inhibition percentage of 45.49% (600mg/kg). In the formalin test, the extract also significantly (p<0.01) reduced linking time in both phase (neurogenic and inflammatory) of the test with inhibition percentage of 56.28% and 60.73% respectively at the dose of 600mg/kg. The methanol extract of A. klaineanum significantly (P<0.001) reduced neurogenic pain linking time induced by capsaicin and cinnamaldehyde by 82.54% and 75.94% at the highest dose (600mg/kg) respectively. More over the extract significantly increase the reaction time in hot plate test. In the inflammatory test, the plant extract significantly reduced the carrageen induced rat paw oedema from 30min to 6h with a maximum percentage inhibition of 89.88% (6h) at the dose of 600mg/kg. CONCLUSION: These results demonstrate that the methanol extract of A. klaineanum may possess analgesic and anti-inflammatory effects and provide support of the traditional use of this plant in the treatment of different pain and inflammatory conditions. Further investigation could reveal metabolites of the extract responsible for the observed effects.
