Paul A. Nwafor

Antidiarrhoeal and antiulcerogenic effects of methanolic extract of Asparagus pubescens root in rats

The effect of methanolic extract of Asparagus pubescens root on experimentally-induced diarrhoea and ulceration was investigated in rats. The extract (500-1500 mg/kg) dose-dependently, reduced significantly the intestinal propulsive movement, castor oil-induced diarrhoea and intestinal fluid accumulation. Yohimbine an alpha(2)-adrenoceptor blocker attenuated the antidiarrhoeal effect of the extract. The extract also reduced the ulcer indices induced by indomethacin and ethanol in a dose-related manner. The results indicate that its antidiarrhoeal and antiulcerogenic effects might in part be due to its alpha(2)-adrenoceptor stimulation and its active constituents respectively.

Antiplasmodial activity of root extract and fractions of Croton zambesicus

AIM OF THE STUDY Antiplasmodial activity of root extract and fractions of Croton zambesicus were evaluated to ascertain the folkloric claim of its antimalarial activity and elucidate its antiplasmodial mechanism of action. MATERIAL AND METHOD The crude ethanolic root extract (27-81 mg/kg) and gradient fractions (n- hexane, chloroform, ethyl acetate and methanol; 54 mg/kg) of Croton zambesicus were investigated for antiplasmodial activity against chloroquine--sensitive Plasmodium berghei infections in mice. The antiplasmodial activity during early and established infections as well as the prophylactic activity were investigated. Chloroquine (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Thin films made from tail blood of each mouse were used to assess the level of parasitaemia of the mice. Oxidant generation potentials of the crude extract and fractions was also evaluated to elucidate their mechanism of action. RESULTS The crude root extract (27-81 mg/kg) demonstrated significant (P<0.01-0.001) schizonticidal activity during early and established infections and also had prophylactic activity. The activity was comparable to that of the standard drug used (chloroquine 5 mg/kg, pyrimethamine 1.2 mg/kg). Methanol, ethyl acetate and chloroform fractions had comparative in vivo antiplasmodial activity and oxidant generation potentials. CONCLUSION The antiplasmodial activity of this root extract and fractions which is likely to be through peroxidation confirms the folkloric use of this plant.

Anti-nociceptive and anti-inflammatory effects of methanolic extract of Asparagus pubescens root in rodents

The effect of methanolic extract of Asparagus pubescens was investigated on chemical, thermal-induced pain as well as fresh egg albumin-induced inflammation and pentylenetetrazol (PTZ)-induced convulsion in rodents. The extract dose-dependently (0.25-1.5 g/kg) inhibited acetic acid-induced writhing, formalin-induced pain licking and hot plate-induced pain in mice. The extract significantly inhibited both the fresh egg albumin-induced inflammation in rats as well as PTZ-induced convulsion in mice. These inhibitions were statistically significant (P < 0.02-0.001). It increased the latencies of both clonic and tonic convulsions and delayed their mortalities. Its ability to reduce both neurogenic and non-neurogenic pains may be related to its active constituents such as tannins, saponins, steroid and flavonoids.

Contraceptive and non-estrogenic effects of methanolic extract of Asparagus pubescens root in experimental animals

The methanolic extract of Asparagus pubescens Bak root was investigated for its contraceptive activity in mice, rats and rabbits. The extract dose-dependently (0.5-1.5 g/kg) protected the animals from conception for 4-14 gestational periods in rabbits, rats and mice. It inhibited fetal implantation, as was confirmed by laparotomy on day 10 of pregnancy. The pups showed significant change in weight and length (P < 0.05-0.001) with 1.5 g/kg compared to the control fetal defects. In ovariectomized immature young rats and mice, there was a dose-dependent decrease in uterine wet weight (P < 0.001). The extract did not induce any uterotrophic effects or immature vaginal opening when compared to estrogen treated groups. Its contraceptive effect may in part be due to its anti-implantation and/or a direct effect on the uterus.

Analgesic and antimalarial activities of crude leaf extract and fractions of Acalypha wilkensiana.

AIM OF THE STUDY Antiplasmodial and analgesic activities of leaf extract and fractions of Acalypha wilkensiana were evaluated to ascertain the folkloric claim of its antimalarial and analgesic activities. MATERIALS AND METHODS The crude leaf extract (220-659 mg/kg) and fractions (chloroform and aqueous; 440 mg/kg) of Acalypha wilkensiana were investigated for antiplasmodial activity against chloroquine sensitive Plasmodium berghei infections in mice and for analgesic activity against chemical and heat-induced pains. The antiplasmodial activity during early and established infections as well as prophylactic activity were investigated. Chloroquine (5mg/kg) and pyrimethamine (1.2mg/kg) were used as positive controls. Thin films made from tail blood of each mouse were used to assess the level of parasitaemia of the mice. Analgesic activity of the crude extract was also evaluated against acetic acid, formalin and heat-induced pains. RESULTS The extract and its fractions dose-dependently reduced parasitaemia induced by chloroquine sensitive Plasmodium berghei infection in prophylactic, suppressive and curative models in mice. These reductions were statistically significant (p<0.001). They also improved the mean survival time (MST) from 16 to 22 days relative to control (p<0.01-0.001). The activities of extract/fractions were incomparable to that of the standard drugs used (chloroquine and pyrimethamine). On chemically and thermally induced pains, the extract inhibited acetic acid and formalin-induced inflammation as well as hot plate-induced pain in mice. These inhibitions were statistically significant (p<0.001) and in a dose-dependent fashion. CONCLUSION The antiparasitaemic and analgesic effects may in part be mediated through the chemical constituents of the plant.

Effect of methanolic extract of Cassia nigricans leaves on rat gastrointestinal tract

The effects of the methanolic extract of Cassia nigricans leaves were investigated on experimentally-induced diarrhoea and ulceration in rat. The extract dose-dependently reduced both the small intestinal propulsive movement (P<0.01-0.001), and castor oil-induced fluid accumulation (P<0.05-0.001). Its inhibitory effects on intestinal propulsive movement and fluid accumulation were significantly (P<0.05) antagonised by yohimbine. However, castor oil-induced diarrhoea was increased. The extract also reduced significantly (P<0.05-0.001) the ulcers induced by both indomethacin and ethanol. The results indicate that the observed antidiarrhoeal effect might in part be due to alpha(2)-adrenoceptor stimulation.

Antipyretic and antimalarial activities of crude leaf extract and fractions of Enicostema littorale

Abstract Objective To evaluate the antiplasmodial and antipyretic activities of whole plant extract and fractions of Enicostemma littorale (E. littorale) for ascertaining the folkloric claim of its antimalarial and antipyretic activities. Methods The crude extract (260 – 780 mg/kg) and fractions (chloroform and acqeous; 520 mg/kg) of E. littorale were investigated for antiplasmodial activity against chloroquine-sensitive Plasmodium berghei (P. berghei) infections in mice and for antipyretic activity against dinitrophenol, amphetamine and yeast-induced pyrexia. The antiplasmodial activity during early and established infections as well as prophylactic were investigated. Artesunate (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Antipyretic activity of the crude extract was also evaluated against dinitrophenol, amphetamine and yeast-induced pyrexia. Results The extract and fractions dose-dependently reduced parasitaemia induced by chloroquine-sensitive P. berghei infection in prophylactic, suppressive and curative models in mice. These reductions were statistically significant (P Conclusions These plant extracts possess considerable antiplasmodial and antipyretic activities, which justify its use in ethnomedicine.

Nephroprotective effect of Croton zambesicus root extract against gentimicin-induced kidney injury

OBJECTIVE To evaluate the kidney protective effect of ethanolic root extract of Croton zambesicus (C. zambesicus) against gentimicin-induced kidney injury in rats. METHODS The root extract (27-81 mg/kg) was administered to rats for eight days with concurrent administration of gentimicin (100 mg/kg) daily for the same period of time. Protective effect of the extract was evaluated in serum levels of creatinine, urea, and uric acid as well as some ions like sodium, potassium and chloride. Histological examination of the kidneys from different treatment groups were also carried out. RESULTS Administration of the root extract significantly reduced histopathological changes in the kidneys of the extract-treated rats especially in the rats treated with lower doses of the extract (27 and 54 mg/kg). The levels of serum urea and creatinine were also reduced significantly (P<0.01) at these doses with no observable effect on the levels of uric acid and ions. CONCLUSIONS The kidney - protective activity of this extract could be due to its antioxidant and free radical scavenging activities.

In Vivo Antiplasmodial Potentials of the Combinations of Four Nigerian Antimalarial Plants

Various combinations of Nauclea latifolia root, Artocarpus altilis stem bark, Murraya koenigii leaf and Enantia chlorantha stem bark used in African ethnomedicine as decoctions for malaria and fevers, and combinations with standard drugs, were investigated for antiplasmodial activities using Plasmodium berghei berghei-infected mice. The respective prophylactic and curative ED50 values of 189.4 and 174.5 mg/kg for N. latifolia and chemosuppressive ED50 value of 227.2 mg/kg for A. altilis showed that they were the best antimalarial herbal drugs. A 1.6-fold increase of the survival time given by the negative control was elicited by M. koenigii, thereby confirming its curative activity. Pyrimethamine with an ED50 of 0.5 ± 0.1 mg/kg for the prophylactic, and chloroquine with ED50 = 2.2 ± 0.1 and 2.2 ± 0.0 mg/kg for the chemosuppressive and curative tests, respectively, were significantly (p < 0.05) more active. Co-administrations of N. latifolia with the standard drugs significantly reduced their prophylactic, chemosuppressive and curative actions, possibly increasing the parasites’ resistance. Binary combinations of N. latifolia or M. koenigii with any of the other plants significantly increased the prophylactic and suppressive activities of their individual plants, respectively. Also, E. chlorantha with A. altilis or N. latifolia enhanced their respective prophylactic or curative activities, making these combinations most beneficial against malaria infections. Combinations of three and four extracts gave varied activities. Hence, the results justified the combinations of ethnomedicinal plants in antimalarial herbal remedies and showed the importance of the three in vivo models in establishing antimalarial activity.

Contraceptive and Estrogenic Effect of a Methanol Extract of Cassia nigricans Leaves in Experimental Animals

The methanol extract of Cassia nigricans Vadl leaves was investigated for its contraceptive activity in mice and rats. The extract dose-dependently (0.5–1.0 g/kg) protected the animals from conception for 1–4 gestational periods in mice and rats. It inhibited fetal implantation, as was confirmed by laparotomy on day 10 of pregnancy. The pups showed significant change in weight and length (p < 0.01) with 0.75 g/kg, compared to control fetal defects. In ovariectomized immature young rats and mice, there was a dose-dependent increase in uterine wet weight (p < 0.001). The extract induced uterotrophic effects or immature vaginal opening and cornification when compared with estrogen-treated groups. Its anticonceptive effect may be due in part to its anti-implantation, estrogenic and/or direct effect on the uterus.