Ibrahim Abdu-Aguye

Euphorbia hirta leaf extracts increase urine output and electrolytes in rats.

Euphorbia hirta is locally used in Africa and Australia to treat numerous diseases, including hypertension and edema. The diuretic effect of the E. hirta leaf extracts were assessed in rats using acetazolamide and furosemide as standard diuretic drugs. The water and ethanol extracts (50 and 100 mg/kg) of the plant produced time-dependent increase in urine output. Electrolyte excretion was also significantly affected by the plant extracts. The water extract increased the urine excretion of Na+, K+ and HCO3-. In contrast, the ethanol extract increased the excretion of HCO3- decreased the loss of K+ and had little effect on renal removal of Na+. Acetazolamide, like the water extract, increased urine output and enhanced the excretion of Na+, K+ and HCO3-. The high-ceiling diuretic, furosemide, increased the renal excretion of Na+ and Cl-; but had no effect on K+ and HCO3- loss. This study suggests that the active component(s) in the water extract of E. hirta leaf had similar diuretic spectrum to that of acetazolamide. These results validate the traditional use of E. hirta as a diuretic agent by the Swahilis and Sukumas.

Analgesic effect of Irvingia gabonensis stem bark extract

Irvingia gabonensis is used medicinally in most parts of tropical Africa for the treatment of a number of ailments. In West Africa the Mende tribe of Sierra Leone uses the stem bark to relieve pain. In order to establish a pharmacological rationale for the traditional use of this plant as a remedy for pain, the water and ethanol extracts of the powdered stem bark were screened for analgesic activity and compared with standard analgesic drugs. The water extract and morphine protected the mice from heat-induced pain. In contrast, the ethanol extract and metamizole sodium showed very low level of analgesic activity in this test. However, using tail pressure as a source of pain, the water and ethanol extracts, metamizole sodium and morphine offered protection to the mice against pain stimuli. Morphine and the water extract were more potent as analgesic agents in heat than non-heat pain test. The analgesic effects of the water extract and morphine were blocked by a non-selective opioid receptor antagonist, naloxone in both tests, whereas the analgesic effects of the ethanol extract and metamizole sodium were not antagonized by the same dose of the opioid antagonist. The data presented in this study suggest that the active principle(s) in the water extract has analgesic profile similar to that of the narcotic analgesic and the ethanol extract might contain compound(s) that behave like non-narcotic analgesic agent. These findings provide for the first time the pharmacological basis for the folkloric use of Irvingia gabonensis in the relief of pain.

Psychopharmacological properties of saponins from Randia nilotica stem bark

Abstract Context: Decoctions of Randia nilotica Stapf. (Rubiaceae) have been used in the Nigerian traditional medicine for the management of epilepsy, anxiety, depression and psychosis for many years and their efficacies are widely acclaimed among the rural communities of Northern Nigeria. Objective: The aim of this study is to establish whether the saponins present in R. nilotica are responsible for its acclaimed beneficial effects in Nigerian traditional medicine. Materials and methods: The behavioural properties of the saponin-rich fraction (SFRN) of R. nilotica stem bark were studied on hole-board, diazepam-induced sleep, rota-rod and beam-walking in mice. The anticonvulsant properties of SFRN were also examined on maximal electroshock, pentylenetetrazole- and strychnine-induced seizures in mice. Results: The intraperitoneal LD50 of SFRN in mice and rats were estimated to be 11.1 and 70.7 mg/kg, respectively. SFRN significantly prolonged the duration of diazepam-induced sleep; diminished head dip counts in the hole-board test and protected mice against maximal electroshock seizures. SFRN failed to protect mice against pentylenetetrazole- and strychnine-induced seizures; and had no effect on motor coordination on the rota-rod treadmill at the doses tested. SFRN significantly decreased the number of foot slips in the beam-walking assay in mice with no effect on time to reach the goal box. Discussion and conclusion: This study provides evidence of the psychopharmacological effects of SFRN, thus supporting further development of the psychoactive components as remedies for epilepsy.

Central depressant activity of butanol fraction of Securinega virosa root bark in mice

ETHNOPHARMACOLOGICAL RELEVANCE Securinega virosa is a commonly used medicinal plant in African traditional medicine in the management of epilepsy and mental illness. Previous studies in our laboratory showed that the crude methanol root bark extract of the plant possesses significant behavioral effect in laboratory animals. In an attempt to isolate and characterize the biological principles responsible for the observed activity, this study is aimed at evaluating the central depressant activity of the butanol fraction of the methanol root bark extract of Securinega virosa. MATERIALS AND METHODS The medial lethal dose of the butanol fraction was estimated using the method of Lorke. Preliminary phytochemical screening was conducted on the butanol fraction using standard protocol. The behavioral effect of the butanol fraction (75, 150 and 300mg/kg) was evaluated using diazepam induced sleep test, hole-board test, beam walking assay, staircase test, open field test and elevated plus maze assay, all in mice. RESULTS The median lethal dose of the butanol fraction was estimated to be 1256.9mg/kg. The preliminary phytochemical screening revealed the presence of tannins, saponins, alkaloids, flavonoids, cardiac glycosides, similar to those found in the crude methanol extract. The butanol fraction significantly (P<0.001) reduced the mean onset of sleep in mice and doubled the mean duration of sleep in mice at the dose of 75mg/kg. The butanol fraction and diazepam (0.5mg/kg) significantly (P<0.01-0.001) reduced the number of head dips in the hole-board test suggesting sedative effect. The sedative effect of the butanol fraction was further corroborated by its significant (P<0.01-0.001) reduction of the number of step climbed and rearing in the staircase test. The butanol fraction did not significantly increase the time taken to complete the task and number of foot slips in the beam walking assay, suggesting that it does not induce significant motor coordination deficit. Diazepam (2mg/kg), the standard agent used significantly (P<0.01) increased the number of foot slips. In the open field test, the butanol fraction significantly reduced the number of square crossed as well as the number of rearing. However, the butanol fraction did not significantly alter the behavior of mice in the elevated plus maze assay, while diazepam (0.5mg/kg) significantly (P<0.05) increased the time spent in the open arm and reduced the number of closed arm entry. CONCLUSION The findings of this study suggest that the butanol fraction of Securinega virosa root bark contains some bioactive principles that are sedative in nature.

Drug use pattern in out-patient children: A comparison between primary and secondary health care facilities in Northern Nigeria

Children are more vulnerable to adverse events related to use of drugs. It is therefore important to study drug use in children in order to optimize pharmacotherapy. The aim of this study was to compare drug utilization in paediatric outpatient departments of primary and secondary health care facilities. The patient and drug information of 600 patients was analyzed for World Health Organization (WHO) recommended prescribing indicators. The average number of drugs per prescription was significantly (p < 0.0005) lower in secondary (2.97) compared to primary (3.62) facilities, while average consultation time was shorter (p < 0.0005) in primary than secondary facilities. Percentages of drugs prescribed from Nigerian Essential Drug List (EDL, primary {89.78%}; secondary {91.79%}) and by generic name (primary {55.04%}; secondary {57.88%}) were insignificantly different between the facilities. The use of injectables was low (8.32% in primary versus 3.74% in secondary facilities) while antibiotic use was high (54.14% in primary to 60.28% in secondary facilities). Analysis of the dispensing indicators showed that the secondary facilities were significantly (p < 0.05) better than the primary facilities, even though not a single drug was adequately labeled in both the primary and secondary facilities. Prescription from EDL was found to be fair in the study area while use of injections was low. There is a need for improvement in case of medicines prescribed by generic name.

Anti-histaminic and bronchodilatory activities of aqueous and methanol extracts of Calotropis procera (Ait) R.Br. root bark on allergic asthma in rodents

The root bark of Calotropis procera ( C. procera ) (Asclepiadaceae) has been reported to be a part of herbal remedies for the management of allergic conditions including asthma. However, there is paucity of data on its anti-histaminic and bronhodilatory activity in asthma. This study therefore aimed to provide some pharmacological rationale for the ethnomedical use of C. procera as an anti-histamine and bronchodilator in asthma. The aqueous and methanol extracts of C. procera were investigated for anti-histaminic and bronchodilatory activities using histamine induced contraction of isolated guinea pig tracheal chain (at 0.5 ml, 1 ml and 2 ml, and stock concentration of 0.5 mg/ml), histamine induced contraction of isolated guinea pig ileum strip test (at 0.1, 0.2, 0.4, 0.8 and 1 ml, and stock concentration of 10 mg/ml), and haloperidol induced catalepsy test in rats (at 200 mg/kg and 300 mg/kg doses). Both extracts of C. procera significantly relaxed (p˂0.01) histamine induced contraction of isolated guinea pig trachea. The extracts also significantly inhibited (p˂0.001) histamine induced contraction of isolated guinea pig ileum. The aqueous extract did not significantly inhibit haloperidol-induced catalepsy. However, methanol extract significantly inhibited (p˂0.05) haloperidol-induced catalepsy at 300 mg/kg. The aqueous and methanol root bark extract of C. procera was found to poses anti-histaminic and bronchodilatory activities in in vivo and in vitro antiasthmatic test on animal models, with the methanol extract having greater activity than the aqueous extract, thus support the folkloric use of the plant in inflammatory and allergic conditions including asthma. Keywords: Calotropis procera , Anti-histaminic, Bronchorelaxant, Anti-asthmatic, Histamine