Role of cGMP signals in tetramethylpyrazine induced relaxation of the isolated rat aortic strip

Preventive effect of tetramethylpyrazine on nitroglycerin-tolerance in rats by improving oxidative stress and ribosome homeostasis

Nitroglycerin (NTG) is recommended as the first-line drug in angina pectoris though its prolonged use impacts nitroglycerin tolerance. In this study, we investigated the preventive effect of Tetramethylpyrazine (TMP), a famous Chinese medicine used for cardiovascular diseases, on NTG-induced tolerance and further explained the underlying mechanism of its action. The results revealed that pretreatment of TMP improved NTG-induced tolerance in vitro thoracic aorta rings and in rats. Proteomic analysis showed oxidative stress and ribosome proteins dyshomeostasis in NTG-tolerance vessels. TMP attenuated the oxidative stress by enhancing the protein expression of ALDH2, Nrf2 and HO-1. In addition, TMP recovered the down-regulated expression of RpL10a induced by nitroglycerin. Therefore, TMP could prevent nitroglycerin tolerance in rats, which may be mediated by up-regulation of ALDH2 and Nrf2/HO-1 signaling pathway and involved in the restoration of ribosome homeostasis. These findings indicate the potential of TMP as a promising medicine for preventing the development of nitroglycerin-induced tolerance.

Efficacy and safety of tetramethylpyrazine phosphate on pulmonary hypertension: study protocol for a randomized controlled study

BACKGROUND

Tetramethylpyrazine (TMP), an active ingredient in the traditional Chinese herbal medicine Rhizoma Chuanxiong, has been used clinically for the prevention and treatment of cardiovascular disease. The benefits of TMP are largely attributed to its anti-oxidative and vasodilative properties. However, the efficacy of TMP in the treatment of pulmonary hypertension (PH) is unknown. We hypothesized that TMP may have a therapeutic effect in patients with PH.

METHODS/DESIGN

A randomized, single-blinded, clinical study with a TMP treatment group and a control group will be conducted to evaluate the efficacy and safety of TMP intervention in patients with PH. The recruitment target is 120 subjects meeting the following criteria: (i) at rest and at sea level, mean pulmonary artery pressure above 20 mmHg and pulmonary capillary wedge pressure below 15 mmHg; (ii) type 1 or 4 PH in the stable phase; (iii) age 15-70 years; (iv) 6-min walk distance between 100 and 450 m; (v) World Health Organization (WHO) functional classification of pulmonary hypertension of II, III, or IV. Subjects will be assigned randomly into two groups at a ratio of 1:2 (control:TMP). Both groups will receive routine treatment, and the treatment group will also receive oral TMP (100 mg) three times a day for 16 weeks. All patients will be followed up for 4, 8, 12, and 16 weeks; symptoms and patient compliance will be recorded.

DISCUSSION

We aimed to determine the efficacy and safety of TMP for the treatment of PH.

TRIAL REGISTRATION

Chinese Clinical Trial Register, ChiCTR1800018664. Registered on 2 October 2018.

Relaxation effects of ligustilide and senkyunolide A, two main constituents of Ligusticum chuanxiong, in rat isolated aorta

Ligusticum chuanxiong Hort. (Umbelliferae) is a widely prescribed traditional Chinese medicinal herb for cardiovascular diseases in China. However, the cardiovascular actions of ligustilide and senkyunolide A, two of the most abundant Ligusticum chuanxiong constituents, have yet to be examined. The objective of the present study was to investigate the vasorelaxation effects of ligustilide and senkyunolide A and their underlying mechanisms in rat isolated aorta. Both constituents had similar relaxation potencies against contractions to 9,11-dideoxy-9alpha,11alpha-methanoepoxyprostaglandin F(2alpha), phenylephrine, 5-hydroxytryptamine and KCl. Their vasorelaxation effects were not affected by endothelium removal, the adenylate cyclase inhibitor 9-(tetrahydro-2-furanyl)-9H-purin-6-amine, the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, or the non-selective K+ channel blocker tetraethylammonium. This is the first report to demonstrate the vasorelaxation activities of ligustilide and senkyunolide A in contractions to various contractile agents in rat isolated aorta. The underlying mechanisms await further investigations.