Smooth muscle relaxant evaluation of Jatropha curcas Linn (Euphorbiaceae) and isolation of triterpenes

Jatropha curcas is a herbal preparation used in the tropics for the treatment of threatened abortion and related problems associated with pregnancy. The Stem bark of Jatropha curcas is used ethno medicinally in Nigeria especially in the eastern part of the country for the treatment of infertility and spontaneous abortion (miscarriage). The present study was undertaken in order to validate the folkloric claim, using scientific experimental procedures and bioassay guided fractionation. The crude powdered sample was subjected to phytochemical screening testing for the presence of alkaloids, tannins, saponins and carbohydrates. Chromatographic analysis (TLC and VLC) were carried out using various solvent systems. The effect of methanolic extracts on rat uterine contractions was studied in vitro, in 40ml organ baths containing physiological salt solution of De Jalon maintained at 370C, aerated with 95% O2 and 5% CO2 with an isometric transducer connected an UgoBasile recorder under a resting tension of 750mg. The result of the phytochemical screening revealed the presence of glycosides, tannins, saponins and alkaloids. The extract abolished significantly the spontaneous contraction of the uterus and reduced acetylcholine induced uterine contractions at a dose of 50mg/ml. The tocolytic effects indicate the presence of active principle(s) which would explain the ethno medicinal use of the stem bark of Jatropha curcas to treat spontaneous abortion.

Antidiarrheal evaluation of the ethanol extract of Nauclea latifolia root bark

Nauclea latifolia (Rubiaceae) is a medicinal plant used in Nigeria folk medicine for the treatment of gastrointestinal disorders. The root bark of the plant was extracted with 70% ethanol and the extract screened for antidiarrheal activity by investigating castor oil-induced diarrhea and small intestinal motility in mice. The effects of the extract on isolated rat ileum were also investigated. The extract (125, 250 and 500 mg/kg) caused a significant decrease in the frequency of diarrhea and conferred protection following castor oil administration (P < 0.05). It also significantly (P < 0.0001) inhibited small intestinal motility in mice at the same doses. Its activity was dose-dependent and when compared to atropine, its antidiarrheal effects at 500 mg/kg were 179% and 165% respectively, in castor oil-induced diarrhea and small intestinal motility experiments. Extract effects on rat ileum revealed a significant (P < 0.0001) inhibition of acetylcholine-induced contractions at 0.2 and 2 mg/mL final bath concentrations used. These findings confirm the antidiarrheal activity of the root bark extract of N. latifolia.

Antidiarrheal evaluation of the ethanol extract of Musanga cecropioides stem bark

The ethnomedicinal uses of Musanga cecropioides R. Apud Tedlie (Cecropiaceae) as a hypotensive agent have been scientifically investigated and reported. This work examines its effect on various models of diarrhea based on the ethnomedicinal use of the plant for this indication. The stem bark of the plant, used locally by soaking in gin (alcoholic), was treated with absolute ethanol and the extract screened for antidiarrheal activity using the castor oil-induced diarrhea and small intestinal motility models in mice. Its effects on the isolated rat ileum were also investigated. In the castor oil-induced diarrhea, the extract at 100, 200, and 400 mg/kg significantly (P < 0.05 at all doses) showed dose-related antidiarrheal effects as indicated by reduction in the number and weight of fecal material produced. The extract at all doses used also significantly (P < 0.05, P < 0.0001 and P < 0.0001 at 100, 200, and 400 mg/kg doses, respectively) decreased the intestinal motility of the treated mice as compared to controls and inhibited acetylcholine-induced contractions (P < 0.0001). In the isolated rat ileum the extract at 5 and 10 mg/mL, remarkably inhibited acetylcholine induced contractions, indicating a probable antimuscarinic effect of the extract. The results obtained confirmed that the stem bark of M cecropioides has antidiarrheal activity as used in folkloric medicine.

In vitro determination of the mechanism of the uterine stimulatory effect of Newbouldia laevis

The uterine stimulatory effect of the ethanol leaf extract of Newbouldia laevis (Beauv.) Seemann ex Bureau (Bignoniaceae) was evaluated in the presence of some antagonists in vitro in an attempt to elucidate the mechanism of action of the extract. The extract was tested in the presence and absence of phentolamine (4.09 and 40.91 nM), diphenhydramine (4.45 and 44.47 nM), atropine (1.18 and 11.91 nM), and verapamil (2.03 and 20.35 nM). The effect of the antagonists on the extract and on oxytocin used as a reference drug in this study was evaluated. The EC(50) and E(max) were determined and statistically analyzed using one way ANOVA and Dunnett's post hoc test. There was no significant difference in the EC(50) and E(max) of the extract and oxytocin in the presence of phentolamine. Diphenhydramine and atropine significantly inhibited (p <0.01) the extract but both drugs had no effect on oxytocin. However, significant differences (p <0.01) were observed in the EC(50) and E(max) of the extract and oxytocin in the presence of verapamil. These results suggest that the leaf extract of N. laevis contracts the uterus by opening voltage-operated calcium channels and/or by activation of muscarinic receptors.

Inhibitory effect of 3-carboethoxypyridine and 3-carbobutoxypyridine on isolated rat uterus

3-Carbomethoxypyridine (CMP) was isolated and characterized from the leaves of Pyrenacantha staudtii Hutch and Dalz, family Icacinaceae, in our earlier study and was found to possess an inhibitory activity on the isolated rat uterus. In order to study the structure - activity relationship, derivatives of CMP were obtained synthetically, purified and characterized by spectroscopic techniques such as infra red spectroscopy (IR), nuclear magnetic resonance (1H- and 13C-NMR) and mass spectrometry (MS). The synthesized compounds were subjected to pharmacological testing using isolated rat uterine preparation in oestrus suspended in an organ bath containing De Jalon physiological salt solution (PSS). The force of contraction was recorded via an isometric transducer connected to an Ugo Basile recorder. The effects of these two compounds were compared with salbutamol as a positive control. 3-Carboethoxypyridine (ECP) demonstrated very significant (p < 0.005) inhibitory activity on the uterus with a total elimination of the spontaneous contractility at a dose of 0.4 mg/mL. Carbobutoxypyridine (BCP) also demonstrated a marked reduction of oxytocin-induced contractions and elimination of spontaneous activity. The study lends support to the potential use of these agents as tocolytics.

Phytochemical components of Hunteria umbellata (K. Schum) and its effect on isolated non-pregnant rat uterus in oestrus

Hunteria umbellate plant is used by West African traditional midwives as phytomedicine in herbal remedies to treat pregnancy related ailment and most especially to augment or induce labour in gravid uterus. The purpose of this study was to investigate this claim with view to validating scientifically the ethno - medicinal usage. The phytochemical analysis of the crude medicinal plant extract revealed the presence of saponin, saponin glycosides, steroid, tannins, volatile oils, phenols and copious amount of alkaloids. The aqueous extract obtained by maceration technique was subjected to pharmacological testing in vitro on a piece of isolated rat uterus previously pretreated with stilbesterol, suspended in De Jalon at 37 degrees C and aerated with 95% Oxygen and 5% CO(2). The oxytocic activity of the aqueous pulp extract of the pulp of Hunteria umbellata was compared with uterine stimulant like oxytocin. The extract affected the contractility of the uterus significantly (P<0.05) in a dose dependent manner. The effect of 10mg/ml extract was blocked by 0.1 ml of 0.1mg/ml atropine. The extract also potentiated the response shown by various doses of oxytocin. This preliminary investigation revealed that Hunteria umbellata has oxytocic effect thus justifying the use by the traditional birth attendants.

Phytochemical and active column fractions of Pyrenacantha staudtii leaf extracts on isolated rat uterus

Four methanolic leaf fraction extracts of Pyrenacantha staudtii obtained from accelerated gradient chromatography (AGC) were tested on the isolated rat uterus. Various fractions--M1, M2, M3 and M4 through bioassay guided isolation were obtained. Fractions M(2) and M(4), containing saponins and alkaloids respectively, significantly (P<0.05) exerted high smooth muscle relaxant activity on the uterus. Fractions M(1) and M(3) containing fatty acids and tannins respectively did not exhibit significant effect on the isolated rat uterus. The results indicate the presence of active principles in the leaf extracts of P. staudtii which may be responsible for some of the applications in traditional medicines as remedy against threatened abortion and dysmenorrheal.