Faculty: Pharmaceutical Sciences
Department: Pharmaceutical And Medicinal Chemistry
Ezeanokete C. Celestina
Okoye F. B. C.
Osadebe P. O.
Morinda lucida (Rubiaceae) is a widely used plant with lots of claims in ethnopharmacology. Although this plant has been investigated for immunomodulatory activity, the chemical constituents associated with this activity have not yet been isolated.Methanol leaf extract and fractions of the plant were investigated for immunomodulatory activity using the following models, the cyclophosphamide induced myelosuppression, total white blood count (WBC) and differential leukocyte count (DLC); delayed type hypersensitivity (DTH) and haemagglutination titre. Ethyl acetate fraction was further purified using vacuum liquid chromatography (VLC), Gel chromatography using Sephadex LH-20 and semi preparative HPLC leading to the isolation of two major compounds, whose structures were elucidated using a combination of HPLC-DAD and NMR spectroscopy. The crude extract, ethyl acetate and butanol fractions of M. lucida administered orally at different doses of 50, 100 and 200 mg/kg/day exhibited significant increase in the cyclophosphamide-induced myelosuppression, and circulating antibody titre.The percentage inhibition of the haemagglutination test was 75.01, while that of delayed hypersensitivity test was 46.15 for ethyl acetate fraction. The two isolated compounds, molucidine and desmethyl molucidine, were identified to be tetracyclic iridoids. The ethyl acetate fraction of M. lucida leaf showed immunomodulatory activity, which may be attributed to the two major compounds isolated, molucidine and desmethyl molucidine. These two compounds may represent “lead” molecules for further development of novel immunomodulatory drugs.