Molluscicidal and Antimalarial Properties and Isolation of Alkaloids from Crinum jagus (Thomps) Dandy.

Crinum jagus fresh bulb and leaf methanol extracts were subjected to molluscicidal test using adult Biomphalaria glabrata snails and antimalarial prophylactic and suppressive tests in-vivo against chloroquine-sensitive (NK 65) Plasmodium berghei according to established experimental protocols (1, 2). The more active bulb extract was fractionated by vacuum liquid chromatography (VLC) into alkaloidal and non-alkaloidal fractions and also investigated for antimalarial property. The active alkaloidal fraction was further purified using various chromatographic techniques. The isolated alkaloids were identified using spectroscopic methods including NMR, FTIR and MS. The oral median lethal dose (LD50) of both leaf and bulb extracts were greater than 10000 mg/kg body weight (b.wt.) according to Lorke's 1983 (3) acute toxicity test. The leaf extract showed weak antimalarial and molluscicidal activities (40% snail mortality) at 1000 mg/L while reference niclosamide (0.5 mg/L) gave 100% mortality. The bulb extract had a chemo-suppression of 76.55 ± 2.76% and prophylactic effects of 90.49 ± 2.70% (p < 0.05) at the maximum concentration (1000 mg/kg b.wt). Similarly, the alkaloidal fraction had a chemo-suppression of 71.36 ± 12.54% while the non-alkaloidal fraction was 51.49 ± 10.46% (p > 0.05). Chloroquine and pyrimethamine standards had 80.26 ± 3.09% chemosuppression and 50.39 ± 6.80% prophylactic effects respectively. The two alkaloids isolated from the antimalarial active fraction were identified as lycorine [1] and crinamine [2].

[1] Duncan J. and Sturrock R. F. (1987). Laboratory Evaluation of Potential Plant Molluscicides. In: Mott K. E. (ed.). Plant Molluscicides. A Wiley medical publication. ISBN 0471 91228 X. Chapter 9, 251 – 265.

[2] Peters W. (1980). Chemotherapy of Malaria. In: Malaria. Kreier J. P. (ed.), Vol. 1. Academic, New York, Pp 145 – 283.

[3] Lorke D. Archives Toxicology. 1983, 54:275 – 287