Studies On the Pharmacognostic Profiling And Anticonvulsant Activity Of Morinda lucida Leaves Benth (Rubiaceae)

The anticonvulsant activity of the methanol extract of Morinda lucida, a tropical shrub which have shown great medicinal value was evaluated using the suppression test against pentylenetetrazole (PTZ) and isoniazid (INH) induced convulsion. The pharmacognostic and acute toxicity studies were also carried out. This research is to evaluate anticonvulsant effectiveness in line with one of its ethnomedicinal use and also to establish the standards for the leaf for proper identification as well as its safety margin. The extract at the studied doses (200, 400 and 800 mg/kg) showed a significant dose-dependent delay of the time of onset, peak of seizure, recovery and mortality from seizure. The percentage animal survival for PTZ- induced convulsion for 200, 400 and 800 mg/kg extract is 60, 40 and 60 % while diazepam (standard drug) gave 100 %. INH -induced convulsion also showed a significant delay as the dose increase for the time of onset, peak of seizure and mortality but there was no recovery for all the dose of extract used but 800 mg of the extract gave a significant delay in peak of seizure from the onset that was more than the peak of seizure of the standard drug (diazepam) used. The anticonvulsant activity of M. lucida may be attributed to the presence of alkaloids, flavonoids, saponins, steroids, terpenoids and tannins, which have been found in phytochemical investigation of the methanol extract of the plant. The acute toxicity test on the crude extract showed no toxic effect at the higher dose of 5000 mg/kg which indicate the safety of the extract. The data obtained from pharmacognostic studies gave 11.00, 8.5, 1.00, 2.00, 6.50, 6.00 and 3.40 % of moisture content, total ash value, acid insoluble ash, water soluble ash, water soluble extractive and alcohol soluble extractive yield respectively. From the study, it shows that Morinda lucida do possess anticonvulsant activity and justifies its use in folkloric medicine. The pharmacognostic features can be used in the standardization of M. lucida for proper identification of the plant and for possible inclusion in the Pharmacopoeia. Keywords: Morinda lucida, Phytochemical analysis, Pharmacognostic analysis, Acute toxicity, Anticonvulsant