Effects of 6 weeks oral administration of Phyllanthus acidus leaf water extract on the vascular functions of middle-aged male rats

Sulfonic Acid-Containing Flavonoids from the Roots of Phyllanthus acidus

Six new sulfonic acid-containing flavonoids, acidoflavanone (1), acidoauronol (2), 5- O-methylacidoauronol (3), acidoaurone (4), acidoisoflavone (5), and acidoflavonol (6), were isolated from the EtOH extract of the roots of Phyllanthus acidus. Their structures were unambiguously established by interpretation of their HRESIMS and 1D and 2D NMR data, single-crystal X-ray diffraction analysis, and comparison to the literature data. These new structures represent the first examples of sulfonic acid-containing flavanones, auronols, aurones, and isoflavones.

The acute diuretic effect of an ethanolic fraction of Phyllanthus amarus (Euphorbiaceae) in rats involves prostaglandins

Background

Phyllanthus 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.

Methods

Effects 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.

Results

Between 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.

Conclusion

Altogether, 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 material

The online version of this article (10.1186/s12906-018-2158-0) contains supplementary material, which is available to authorized users.

Increased vascular eNOS and cystathionine-γ-lyase protein after 6 weeks oral administration of 3, 5, 7, 3', 4'-pentamethoxyflavone to middle-aged male rats

Effects of treatment of middle-aged male rats with 3, 5, 7, 3', 4'-pentamethoxyflavone (PMF) on vascular and perivascular adipose tissue (PVAT) functions and blood chemistry were investigated. Rats received PMF (22 mg/kg), orally or vehicle, twice a day for 6 weeks. The PMF-treated rats had lower serum glucose, higher HDL-C levels, but no change in other parameters. Thoracic aortic and mesenteric rings of PMF treated rats produced lower maximal contraction to phenylephrine that was normalized by N^G-nitro-L-arginine (L-NA) or endothelial removal. The aortic- and mesenteric rings of the PMF treated rats showed improved relaxation to acetylcholine, but not to glyceryl trinitrate, and had higher eNOS protein. DL-propargylglycine (PAG) caused greater increase in the baseline tension of the PMF-treated aortic ring and higher contraction to low concentrations of phenylephrine. PVAT lowered the contractile response of the L-NA pretreated aortic rings to phenylephrine for both groups, but PAG had no effect. The cystathionine-γ-lyase (CSE) protein of the thoracic rings, but not of the PVAT, shows increased expression after PMF treatment. Overall, PMF treatment of middle aged rats appeared to increase production of NO and H₂S from the blood vessels by upregulating the expression of eNOS and CSE. PMF also decreased fasting serum glucose and increased HDL-C levels, with no toxicity to liver and kidney functions. Thus, PMF is a novel compound for possible use as a health product to prevent and/or to reduce the development of diabetes type II and/or cardiovascular disease.