Osthole improves pulmonary artery hypertension by inducing apoptosis in pulmonary artery smooth muscle cells.

OBJECTIVES: The objectives of this study were to explore the effect of Osthole (Ost) on apoptosis in pulmonary artery smooth muscle cells (PASMCs) and investigate the potential mechanism of this effect. METHODS: Rats were injected subcutaneously with monocrotaline (MCT) to establish a PAH model, and Ost were intragastrically administrated from day 1 to day 35. After 35 days administration, the mean pulmonary artery pressure and lung weight index were measured. HE and TUNEL staining were used to observe the morphology of pulmonary artery and the apoptosis of PASMCs. In addition, the apoptosis of PASMCs were detected by flow cytometry in cultured PASMCs. The proteins of Bax and Bcl-2, and the levels of p-ASK1 and cleaved caspase 3 were measured by Western blot. KEY FINDINGS: Ost decreased the mean pulmonary artery pressure and lung weight index in MCT-induced rats, and promoted apoptosis in PASMCs in MCT-induced rats and PDGF-BB stimulated PASMCs. Ost increased the ratio of Bax/Bcl-2 and the levels of p-ASK1, cleaved caspase 3 in MCT-induced rats and PDGF-BB stimulated PASMCs. CONCLUSION: Ost promoted apoptosis in PASMCs in vivo and in vitro, and the mechanism may be associated with upregulation of ASK1 and the Bax/Bcl-2-caspase 3 signalling pathway.

Icariside II attenuates myocardial fibrosis by inhibiting nuclear factor-κB and the TGF-ß1/Smad2 signalling pathway in spontaneously hypertensive rats.

Studies have demonstrated that icariin plays important roles in preventing hypertension and improving myocardial hypertrophy, inflammatory and infiltration. Icariside (ICS II) is the main metabolite of icariin, which has anti-inflammatory and anti-oxidant activities and protects against ischaemic brain injury. Whether ICS II improves myocardial fibrosis in spontaneously hypertensive rats (SHRs) and the related mechanism remain unknown. Some studies have suggested that TGF-ß and the nuclear factor κB signalling pathway play a key role in the progression of myocardial fibrosis. Therefore, in the current study, we aimed to evaluate the effects of ICS II on induced myocardial fibrosis in SHRs and explore the mechanism underlying this activity. The SHRs were treated with ICS II (4, 8, and 16 mg/kg) via daily gavage for 12 weeks. Left ventricular function was detected using the Vevo2100 system, and the collagen area was measured by Masson staining. The results indicated that ICS II markedly improved left ventricular function and decreased the left ventricular myocardial collagen area compared with the SHR group. To further investigate the mechanism underlying this activity, we measured the protein expression of interleukin-1ß (IL-1ß), tumour necrosis factor-α (TNF-α), transforming growth factor-ß1 (TGF-ß1), Smad2, inhibitory κB (IκB), and nuclear factor κB (NF-κB) p65 by Western blot. The results showed that ICS II inhibited NF-κB p65 expression and the TGF-ß1/Smad2 signalling pathways. In conclusion, the present results suggest that ICS II suppresses myocardial fibrosis in SHRs, and this effect might be at least partially mediated through suppression of NF-kB signalling and the TGF-ß1/Smad2 signalling pathway.

Osthole inhibits intimal hyperplasia by regulating the NF-κB and TGF-ß1/Smad2 signalling pathways in the rat carotid artery after balloon injury.

Osthole (7-methoxy-8-isopentenoxy-coumarin), a compound extracted from Cnidiummonnieri (L.) Cusson seeds, has been found to exhibit potent therapeutic effects in cancer due to its ability to inhibit inflammation and cell proliferation. However, its effects on arterial wall hypertrophy-related diseases remain unclear. Therefore, in this study, we aimed to investigate the effects of Osthole on intimal hyperplasia in a rat model of carotid artery balloon injury. We established the balloon-induced carotid artery injury rat model in male Sprague-Dawley rats, after which we administered Osthole (20mg/kg/day or 40mg/kg/day) or volume-matched normal saline orally by gavage for 14 consecutive days. Intimal hyperplasia and the degree of vascular smooth muscle cell proliferation were then evaluated by histopathological examination of the changes in the carotid artery, as well as by examination of proliferating cell nuclear antigen (PCNA) expression. Tumour necrosis factor-ɑ (TNF-α), interleukin-1ß (IL-1ß), transforming growth factor-beta (TGF-ß1) and PCNA mRNA expression levels were examined by real-time RT-PCR, while nuclear factor-κB (NF-κB (p65)), IκB-α, TGF-ß1 and phospho-Smad2 (p-Smad2) protein expression levels were analysed by immunohistochemistry or western blot analysis. We found that Osthole significantly attenuated neointimal thickness and decreased the elevations in PCNA protein expression induced by balloon injury. Moreover, Osthole down-regulated the pro-inflammatory factors TNF-α and IL-1ß and NF-κB (p65), whose expression had been upregulated after balloon injury. Moreover, IκB-α protein expression levels increased following Osthole treatment. In addition, the elevations in TGF-ß1 and p-Smad2 protein expression induced by balloon injury were both significantly attenuated by Osthole administration. We concluded that Osthole significantly inhibited neointimal hyperplasia in balloon-induced rat carotid artery injury and that the mechanism by which this occurs may involve NF-κB, IL-1ß and TNF-ɑ down-regulation, which alleviates the inflammatory response, and TGF-ß1/Smad2 signalling pathway inhibition.

Icariin prevents hypertension-induced cardiomyocyte apoptosis through the mitochondrial apoptotic pathway.

A prior study demonstrated that icariin (ICA) could repress angiotensin II-induced apoptosis in H9c2 cells. The activation of mitochondrial apoptotic pathways may play a crucial role in this phenomenon. In this study, we explored the potential protective roles of ICA in apoptosis in cardiomyocytes, cardiac remodelling, and the underlying mechanisms with regard to the mitochondrial apoptotic pathway in rats with spontaneous hypertension. The oral administration of ICA (20 and 40mg/kg/d) inhibited cardiomyocyte apoptosis and ameliorated left heart ventricle remodelling and abnormal mitochondria. ICA also decreased the blood pressure of model rats. ICA treatment increased the expression of Bcl-2 and decreased the expression of p53, Bax, Bok and cleaved caspase 3 in model rats, which suggests the potential mechanism underlying this effect. In summary, ICA inhibits the apoptosis of cardiomyocytes and ameliorates cardiac remodelling. The potential mechanism may relate to the inhibition of the mitochondrial apoptotic pathway.