S. O. Awe

Pharmacological studies on the leaf of Psidium guajava

The methanol extract of the leaves of Psidium guajava was found to inhibit paw oedema induced by carrageenan in rats and pain induced by acetic acid in mice, and exhibited an antipyretic effect. Oral administration of the extract reduced intestinal transit time and prevented castor oil-induced diarrhoea in mice. A CNS depressant activity was exhibited by the extract by potentiating the phenobarbitone sleeping time in mice.

Antimalarial Activity of Cryptolepine and Some Other Anhydronium Bases

Eight naturally occurring anhydronium bases and the synthetic quaternary compound Nb‐methylharmalane were tested against Plasmodium falciparum (strain K1) in vitro. Cryptolepine was found to have similar activity to that of chloroquine but alstonine, 5,6‐dihydroflavopereirine, matadine, Nb‐methylharmalane, melinonine F, normelinonine F, strychnoxanthine and serpentine were found to have little activity. Cryptolepine, given orally to mice infected with Plasmodium berghei berghei was found to have moderate antimalarial activity; parasitaemia was suppressed by 80% at 50 mg/kg/day.

Antiplasmodial and antipyretic screening of Mangifera indica extract

The stem bark extract of Mangifera indica was evaluated for antiplasmodial activity against Plasmodium yoelii nigeriensis. The extract was also screened for antipyretic activity in mice. The extract exhibited a schizontocidal effect during early infection, and also demonstrated repository activity. A reduction in yeast‐induced hyperpyrexia was also produced by the extract.

Cathartic effect of the leaf extract of Vernonia amygdalina

A methanol extract of Vernonia amygdalina leaves was evaluated for cathartic effect. The extract exhibited a significant promotion of intestinal motility on charcoal meal test in mice. Frequency of defecation and of faeces were markedly increased following administration of the extract which also promoted gastric emptying in rats. Preliminary studies on the isolated rat fundus strip showed a contractile effect, which was blocked by atropine.

Diuretic and antidiuretic diuretic of the leaf extracts ofVernonia cinerea (Less) (Fam. Compositae)

The diuretic and anti‐diuretic potency of the leaf extracts of Vernonia cinerea was studied in albino rats. The chloroform extract of the leaf induced significant diuresis, while the methanol and aqueous extracts induced significant antidiuresis in rats. In both cases, the observed effects on urine volume and electrolyte excretion were dose dependent. The trend was a significant increase (in the case of diuresis) in natriuretic and kaliuretic activity and a significant decrease (in the case of antidiuresis) in natriuresis and kaliuresis.

Purgative effect of the methanol extract of Morinda lucida

Abstract The purgative effect of a methanol extract of the leaves of Morinda lucida is reported. The oral treatment (12.5–100 mg/kg) caused a pronounced increase in the number of wet faeces in rats and a potentiated castor oil-induced diarrhoea in mice.

Central nervous system depressant effect of Hoslundia opposita Vahl

The chloroform extract of the dried root of Hoslundia opposita has been evaluated for effects on the central nervous system (CNS). The extract significantly potentiated the phenobarbitone sleeping time in mice and produced a 60% protection against leptazol‐induced convulsion. Neuropharmacological screening revealed CNS depression. Copyright

Effects of Allium sativum and Vernonia amygdalina on thrombosis in mice

Extracts of Allium sativum and Vernonia amygdalina have been evaluated for antithrombotic activity in mice. Both plant extracts offered protection against thrombosis produced by an intravenous injection of a mixture of ADP and adrenaline, with Allium sativum showing a stronger activity.

Pharmacological evaluation of Hoslundia opposita extract in rodents

A chloroform extract of the dried root of Hoslundia opposita was studied for its analgesic, antipyretic and antiinflammatory activities. A significant protection against the acetic acid‐induced writhing response in mice, and a marked lowering of the body temperature of hyperthermic mice was observed. A significant inhibition of the carrageenan‐induced rat hind paw oedema was also produced. Our preliminary screening thus confirms the folklore use of Hoslundia opposita in various ailments.

Phytotherapy Research, Vol. 11 (6), pp. 454-456 (1997). Diuretic and antidiuretic activity of the leaf extracts ofVernonia cinerea. (Less) (Fam. Compositae)

A typesetting error occurred in the caption to Table 2 on page 455. The caption to Table 2 should read: ‘Table 2. Dose response study of antidiuretic effects of Vernonia cinerea methanol leaf extract (VCMLE) in rats’ rather than: ‘Table 2. Dose response study of diuretic effects of Vernonia cinerea chloroform leaf extract (VCMLE) in rats’