Effect of Solanum erianthum aqueous leaf extract on Plasmodium berghei in mice.

The aqueous leaf extract of Solanum erianthum collected in May was administered orally to albino Swiss mice infected with Plasmodium berghei berghei. The schizontocidal activity on early infection was assessed by administering the extract of S. erianthum, chloroquine, or distilled water as single daily dose from the day of infection for 4 days. Microscopic examination made on the fifth day from all the mice, showed S. erianthum extract producing a dose-related schizontocidal effect, with the highest having a chloroquine equivalent of 1.7 mg/kg. The residual activity of this extract was assessed by administering it to mice for 3 days prior to the day of inoculation with parasites. Seventy-two hours after infecting the mice, microscopic examination of the blood smears was made from all the mice. The extract produced dose-related activity. The highest dose and 1.2 mg/kg pyrimethamine produced 78.9 and 80.5% chemosuppression, respectively. Its effect on the established infection was studied by administering the drugs daily 72 h after infecting the mice, and for 5 days. The level of parasitaemia was assessed daily. The results show that the extract did not produce any significant suppression of infection. The observations are interesting and promising in view of the fact that the crude extract was used and also because controversy exists as to its usefulness as an anti-malarial agent.

Screening of Morinda lucida leaf extract for antimalarial action on Plasmodium berghei berghei in mice.

The leaf extract of Morinda lucida collected in August was administered subcutaneously to albino Swiss mice infected with P. berghei berghei. The schizontocidal activity on early infection was assessed by administering chloroquine (standard) distilled water or Morinda lucida as single daily dose on day 0-3 to infected mice. On day 4 the degree of parasitaemia and percentage was determined in relation to control. Its schizontocidal activity was also observed on an established infection by administering the drugs 72 h after infecting the mice and the degree of parasitaemia was determined daily. The repository action of pyrimethamine was also compared with Morinda lucida. On the early infection, the chloroquine equivalent of Morinda lucida was found to be 1.0 mg/kg. In established infection a daily increase in parasitaemia was observed in control group while the animals that received chloroquine (5 mg/kg) and 1/6 dilution of the stock of Morinda lucida extract showed a sharp fall in parasitaemia from the second day of treatment. For the prophylactic test, 1.2 mg/kg of pyrimethamine and 1/6 dilution of stock of extract produced 80.5% and 70% chemosuppression respectively. It is interesting to note that Morinda lucida leaves extract appears to have schizontocidal and repository effects in mice infected with P. berghei berghei.

Lack of schizontocidal activity of three herbal decoctions on Plasmodium berghei berghei in mice.

This work reports the effects of three herbal decoctions on Plasmodium berghei berghei in mice. The schizontocidal activity of each decoction was determined on an established infection using chloroquine as a standard and distilled water as control. Also a repository study of the decoction was carried out in another group of mice. The three decoctions neither reduced parasitaemia nor prolonged the life of infected mice that received them.

Effect of Azadirachta indica on Plasmodium berghei berghei in mice.

Azadirachta indica leaf extract has been investigated for antimalarial activity against drug sensitive strain of P. berghei berghei in mice. On administering the extract subcutaneously to infected mice in the "4-day schizontocidal test' 41.2% suppression of parasitaemia was observed. A similar observation was made when the extract was injected for 3 days before the animals were infected with the parasites, 21.7% chemosuppression was obtained. When treatment commenced after the infection had already established, there was no demonstrable suppression of parasitaemia.

Investigations of various extracts of Morinda lucida for antimalarial actions on Plasmodium berghei berghei in mice.

Morinda lucida extracts, the stem bark, the root bark and the leaves were screened for antimalarial activity in a "4-day schizontocidal test' against a chloroquine-sensitive strain of P. berghei berghei in mice. Each extract was administered as a single daily dose on days 0, 1, 2 and 3 to mice that had received an intraperitoneal inoculum of 1 X 10(7) infected erythrocytes. Each extract produced a degree of suppression of parasitaemia. The most promising result was obtained with chromatographic fractions of the stem bark extracts, the highest dose producing 96.4% suppression of parasitaemia.

The sensitivity of Plasmodium falciparum to chloroquine and amodiaquine in Ibadan, Nigeria.

An extended in vivo test of the sensitivity of Plasmodium falciparum to antimalarial drugs in Nigerian children showed no evidence of resistance to chloroquine and amodiaquine. However, the results of a small number of in vitro tests suggest a decreased sensitivity of the parasite to chloroquine when compared with the results of earlier studies in the same locality.

Use and misuse of 4-aminoquinoline antimalarials in tropical Africa and re-examination of itch reaction to these drugs.

PIP: A total of 1059 persons from 14 different locations in Ibadan (the most populous city in tropical Africa) were interviewed to determine whether they had had itch reaction with each of the 12 4-aminoquinoline preparations (one amodiaquine hydrochloride, 11 chloroquine). The various trade and pharmacological names are listed in a table. Respondents were asked for what purpose the listed drugs were used: treatment of an attack of malaria fever; prevention of malaria; and other conditions or illnesses. The respondents were also asked how often each subject had an attack of malaria: monthly, every 3 months, every 6 months, once a year, once every 2-3 years, less often than this, never. Inquiry was made regarding details of the itch reaction since there was particular interest in the pruritus which, judging from previous studies, constitutes the 1 reaction most likely to make 4-aminoquinolines unpopular. Chloroquine sulphate tablets, the 8th most popular preparation, was the 6th on the list of itching incidence. There appeared to be no difference in the incidence of itching after chloroquine sulphate injection. Avloclor tablets, chloroquine phosphate injection tablets and Malarex and Aralen tablets gave a comparatively low incidence of itch reaction--3.4% and 1.4% respectively within the population studied. The incidence of itching after these 4-aminoquinoline preparations may also be estimated in the population sampled by finding the mean percentage of the subjects who itch within those who admitted taking each preparation mentioned in the questionnaire. The corrected percentage incidence gave an estimated mean of 28% compared with a mean incidence of 11% when projected to the whole population sampled. Most of the people (90%) used the 4-aminoquinoline antimalarials to treat an attack of malaria fever; 23% take them for prophylaxis and 7% in the population used the drugs for nonmalarial ailments. The misuse of the drugs for nonmalarial ailments may be related to their potency in treating malaria. In sum, the itch reaction failed to conform to a simple clinical pattern.^ieng