Antiplasmodial Effect of Crude Ethanol and Alkaloidal Extracts of Sida acuta Leaf in mice.

Abstract

Antiplasmodial effect of extracts of crude ethanol and alkaloid of Sida acuta leaf were investigated in Plasmodium berghei infected mice. Acute toxicity and LD50 of the extracts of crude and alkaloid Sida acuta leaf were determined using the Lorkes method. Forty mice were intraperitoneally inoculated with blood of Plasmodium bergei infected mice and were divided into eight groups of five animals each. Groups 1-3 mice were treated with 200, 400 and 800 mg/kg body weight of crude ethanol leaf extract of Sida acuta, respectively. Groups 4 - 6 mice were treated with 200, 400 and 800 mg/kg body weight of crude alkaloid extract of Sida acuta leaf, respectively. Group 7 mice were treated with standard chloroquine at 5 mg/kg body weight, while group 8 served as control which were infected but not treated. Plasmodium parasite level was determined microscopically. Inhibition concentration, mean survival period, packed cell volume and body weights of the animals were determined. No death was recorded for the crude ethanol extract of Sida acuta leaf while the LD50 calculated for crude alkaloid extract of Sida acuta leaf was 2154 mg/kg body weight. By the 4th day of treatment the Plasmodium parasite level for the crude ethanol extract and extracted crude alkaloids from Sida acuta leaf at 800 mg/kg body weight were reduced to 18.0 and 5.0 parasite per field respectively compared to chloroquine (8.2 parasite level per field). The control untreated group showed increased parasitemia level of 110 parasites per field by the 4th day. The inhibition concentration was highest for chloroquine and comparable to the alkaloid extract which was not significantly different (p>0.05). The mean survival period was significantly higher for the chloroquine (30 days) compared to the 26.45 days for the animals that received 800 mg/kg body weight of crude alkaloid extract of Sida acuta leaf. The packed cell volume (PCV) significantly (p<0.05) decreased more for the control (17.7±1.8) compared to the treated groups (29.2±1.4 and 31.6±0.4), this was however comparable to the standard drug (31.5±1.0 %). There was no significant difference (p>0.05) between the decrease in weights of the animals treated with the plant extracts and the chloroquine drug. Based on the results obtained, it can be concluded that the crude ethanol and alkaloidal leaf extracts of Sida acuta leaf have a potency in mice comparable to chloroquine and this may be the rationale for its use in malaria treatment among the indigenous Nigerians.