BackgroundPhyllanthus amarus (Schum & Thonn), a plant belonging to the family of Euphorbiaceae is used in Ivorian traditional medicine to treat cardiovascular disorders such as hypertension. However, although this plant has been described as a diuretic agent, the underlying mechanism remains unclear. Therefore, the aim of the present study was to investigate the mechanism action of diuretic effects of an ethanolic fraction of Phyllanthus amarus (EFPA) in rats.MethodsEffects of EFPA on urinary excretion were carried out for doses ranging from 5 to 80 mg/kg given by intraperitoneal injection (i.p.) and compared with that induced by furosemide (5 mg/kg) after 8 h. Thereafter, the diuretic activity of EFPA was also evaluated in the presence of indomethacin (5 mg/kg, i.p.) in order to determine the involvement of prostaglandins, after 24 h.ResultsBetween 5 and 80 mg/kg, EFPA induced a significant urinary excretion. The profile of urinary excretion showed that after 2 h, the highest dose of 80 mg/kg induced a urinary volumetric excretion (UVE), which was similar to that induced by furosemide. After 24 h, EFPA at 10 mg/kg increased significantly UVE, Na+ (43 mEq) and Cl¯ (97 mEq) urinary excretions without promoting kaliuresis. In rats pretreated with indomethacin, the urinary excretion and the natriuretic response of EFPA were significantly reduced.ConclusionAltogether, this study has shown that EFPA promotes a significant urinary excretion of water and Na+, confirming its diuretic activity. Moreover, the increased diuresis could be attributed, at least in part, to the involvement of prostaglandins.Electronic supplementary materialThe online version of this article (10.1186/s12906-018-2158-0) contains supplementary material, which is available to authorized users.

BackgroundDichrostachys cinerea (L.) Wight et Arn. (Mimosaceae) is largely used in ethno-medically across Africa, and mainly employed for the treatment of asthma in Ivory Coast and Gabon. The paper analyses the relaxation induced by the methanolic extract of D. cinerea (Edici) in the guinea-pig trachea preparations (GPTPs). Purpose: This study aimed to bring out the scientific basis to the use of this plant leading to the validation of this phytomedicine.MethodThe aorta obtained from guinea-pigs was immediately placed in a Mac Ewen solution. Experiments were performed in preparations suspended between two L-shaped stainless steel hooks in a 10 ml organ bath containing Mac Ewen solution. The isometric contractile force of the aorta strips of guinea-pig were recorded by using a strain gauge. The different drugs were directly administered into the organ bath and the magnitude of GPTPs was evaluated.ResultsPhytochemical analysis of the methanolic extract of Dichrostachys cinerea (Edici) using chemical methods revealed the presence of flavenoids, tannins, sterols, triterpenes and polyphenols. Pharmacological studies performed in GPTPs show that of Dichrostachys cinerea (0.1 mg/ml - 2 mg/ml) evoked a broncho-constriction in GPTPs. Whereas, at concentration up to 2 mg/ml, Edici induced a significant dose-dependent relaxation in the GPTPs. KCl-, ACh- or histamine-evoked contractions of isolated trachea was significantly inhibited by increasing concentrations of Edici (3.5-10 mg/ml). Edici (10 mg/ml) as well as promethazine (0.25 mg/ml) significantly inhibited contractions induced by increasing concentrations of histamine (1×10-7-1×10-4mg/ml). In the presence of atropine at a concentration of 10-6mg/ml, contractile response curve (CRC) evoked by ACh (1×10-5-1×10-2 mg/ml) was significantly abolished in concentration-dependent manner. Edici did not significantly reduced ACh evoked contraction (10-5-10-2mg/ml).ConclusionThese observations suggest that Edici could act through two mechanisms: firstly by activation of β-adrenergic or histaminergic receptors; and secondly muscarinic receptors may not be greatly involved, that justifying the use of the extract in traditional Medicine in Africa.

This study was carried to examine the effects of the aqueous leaf extract of Sesamum radiatum,a laxative plant on the contractile activity of Taenia caeci, an intestinal smooth muscle. Strips of Taenia caeci were rapidly removed from guinea-pig and were suspended between two L-shaped stainless steel hooks in a 10 ml organ bath with Mac Ewen solution. The isometric contractile force of the Taenia caeci strips were recorded by using a strain gauge. S. radiatum aqueous leaf extract (ESera) is a spasmogenic substance. This myostimulant effect is characterized by the increase of the rhythm and the amplitude of isolated guinea-pig Taenia caeci smooth muscle in normal solution and by the development of contracture in modified solution and in solution without calcium. A similar effect was observed with ACh which caused a graded increase of the contractile activity of Taenia caeci. The effects induced by ESera and ACh were reversed in the presence of atropine. The spasmogenic effect induced by ESera could justify partially the use of S. radiatum as laxative in traditional medicine.

The aim of the present study was to compare the effect of Phyllanthus amarus extracts and its fractions on urinary excretion. Aqueous extract of Phyllanthus amarus was prepared by decoction of the whole plant and lyophilized. Ethanolic fraction and chloroformic fraction of Phyllanthus amarus were obtained from aqueous extract. Animal were divided into 5 groups of 6 rats and placed individually in metabolic cages. The control group received normal water. A positive control group received furosemide (5 mg/kg, i.p.), used as a reference loop diuretic drug. Three other groups were treated with aqueous extract or ethanolic fraction or chloroformic fraction of Phyllanthus amarus by intraperitoneal injection at the same dose of 40 mg/kg. Urine volumes were collected each 2 h during 8 h period. The diuretic action was obtained by a ratio of urinary excretion of treated group and that of control group. Phyllanthus amarus extracts increased urinary excretion. This effect was time dependant and significant, compared to control group (p < 0.001). During all experiments, ethanolic fraction increased urinary excretion, more than other extracts. After 8h period, it had eliminated about 2.44 ± 0.27 mL, however this value remained less than that of furosemide (3.01 ± 0.17 mL). The urinary excretion induced by furosemide was significantly high (p < 0.05), compared to ethanolic fraction, but the ratio was similar. This study showed that, like furosemide, ethanolic fraction seemed to be the most potent extract for diuresis. Further studies might be carried out to identify the actives molecules and its mechanisms.