Puerarin attenuates angiotensin II-induced cardiac fibroblast proliferation via the promotion of catalase activity and the inhibition of hydrogen peroxide-dependent Rac-1 activation

Puerarin exhibits antiinflammatory properties in gunpowder smog-induced acute lung injury in rats via regulation of the renin-angiotensin system and the NFκB signaling pathway

Puerarin, which is a widely used in Traditional Chinese Medicine, was previously demonstrated to regulate the subsets of CD4⁺ lymphocytes in gunpowder smog-induced acute lung injury (ALI). However, the underlying mechanism remains largely unknown. Previous studies on autoimmune diseases have revealed that the renin-angiotensin system (RAS) and NF-κB participate in regulating the levels of CD4⁺ T lymphocytes. The aim of the present study was to further investigate the mechanisms underlying the protective effects of puerarin. Wistar rats were randomly divided into four groups as follows: Normal control, puerarin control, smoke inhalation injury and puerarin treatment plus smoke inhalation injury groups. The levels of angiotensin II (Ang II) in lung tissue and in the circulation, and the levels of interleukin (IL)-6, IL-1β, IL-17A and tumor necrosis factor (TNF)-α in the bronchoalveolar lavage fluid (BALF) were assayed using ELISA kits. The expression of Ang II type 1 receptor (AT1-R), angiotensin-converting enzyme (ACE) and ACE2 were examined by immunohistochemical analysis and western blotting. Phosphorylated (p-) NF-κB p65 and NF-κB inhibitor α (IκB-α) protein expression levels were also determined using western blotting. Puerarin treatment reduced the levels of inflammatory cytokines in the BALF. Furthermore, puerarin treatment significantly decreased the levels of Ang II, AT1-R and ACE, which were increased following smoke inhalation. Conversely, puerarin treatment upregulated the expression of ACE2, which was downregulated following smoke inhalation. Additionally, puerarin decreased the expression of p-NF-κB p65 and increased that of IkB-α. Thus, the antiinflammatory effects of puerarin were partly mediated via the RAS and via regulation of the NFĸB signaling pathway in rats with gunpowder smog-induced ALI.

Scoparone alleviates Ang II-induced pathological myocardial hypertrophy in mice by inhibiting oxidative stress

Long‐term poorly controlled myocardial hypertrophy often leads to heart failure and sudden death. Activation of ras‐related C3 botulinum toxin substrate 1 (RAC1) by angiotensin II (Ang II) plays a pivotal role in myocardial hypertrophy. Previous studies have demonstrated that scoparone (SCO) has beneficial effects on hypertension and extracellular matrix remodelling. However, the function of SCO on Ang II‐mediated myocardial hypertrophy remains unknown. In our study, a mouse model of myocardial hypertrophy was established by Ang II infusion (2 mg/kg/day) for 4 weeks, and SCO (60 mg/kg bodyweight) was administered by gavage daily. In vitro experiments were also performed. Our results showed that SCO could alleviate Ang II infusion‐induced cardiac hypertrophy and fibrosis in mice. In vitro, SCO treatment blocks Ang II‐induced cardiomyocyte hypertrophy, cardiac fibroblast collagen synthesis and differentiation to myofibroblasts. Meanwhile, we found that SCO treatment blocked Ang II‐induced oxidative stress in cardiomyocytes and cardiac fibroblasts by inhibiting RAC1‐GTP and total RAC1 in vivo and in vitro. Furthermore, reactive oxygen species (ROS) burst by overexpression of RAC1 completely abolished SCO‐mediated protection in cardiomyocytes and cardiac fibroblasts in vitro. In conclusion, SCO, an antioxidant, may attenuate Ang II‐induced myocardial hypertrophy by suppressing of RAC1 mediated oxidative stress.

Puerarin alleviates coronary heart disease via suppressing inflammation in a rat model

BACKGROUND

Puerarin shows inhibitory effects on inflammation in chronic heart failure (CHF), but its efficacy in coronary heart disease (CHD) remained vague.

METHODS

Rat CHD model was constructed, and serum parameters were determined using a blood liquid biochemical analyzer. Also, contents of creatine kinase (CK), creatine kinase MB isoenzyme (CK-MB), lactate dehydrogenase (LDH) and cardiac troponin (cTnT) were measured using colorimetry. Histological examination was conducted with Hematoxylin-Eosin (H&E) staining, and cardiac function was assessed by Echocardiography. Cell apoptosis was detected using Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Relative expressions were measured using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot as needed.

RESULTS

In CHD rats, the levels of TC, LDL and TG and the expressions of matrix metalloproteinase-9 (MMP-9), CD40 ligand (CD40L), tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) were increased while HDL level was decreased, accompanied with inflammatory cell infiltration and cardiac malfunction. Also, the contents of CK, CK-MB, LDH and cTnT, the percentage of apoptotic cells, the expressions of Bcl-2 associated X protein (Bax), cleaved Caspase-3, TNF-α, Interleukin-β (IL-β), IL-6 and Lipoprotein-associated Phospholipase A2 (Lp-PLA2) expressions and the levels of oxidized-(ox-)LDL and malondialdehyde (MDA) were upregulated, while the level of super oxidase dismutase (SOD) and the expressions of B cell lymphoma-2 (Bcl-2) and vascular endothelial growth factor (VEGF) were downregulated. However, Puerarin ameliorated the effects of CHD model construction, suppressed nuclear factor-(NF-)κB expression, and enhanced the expressions of Farnesoid X Receptor (FXR), phosphorylated-AKT (p-AKT) and phosphorylated-signal transducer and activator of transcription 3 (p-STAT3).

CONCLUSION

Puerarin alleviated CHD in rats via inhibiting inflammation, providing possible method for CHD treatment.

Caspase/AIF/apoptosis pathway: a new target of puerarin for diabetes mellitus therapy

Pancreatic β cell damage is one of the crucial factors responsible for the development of type 2 diabetes mellitus (T2DM). Previous studies have suggested that puerarin (PR) could regulate the activities of the mitochondrial respiratory chain complex in diabetic nephropathy (DN); however, whether PR can inhibit pancreatic β-cell apoptosis in T2DM remains to be elucidated. In the present study, T2DM mice induced by high-fat diet and streptozotocin (STZ) injection were used as a working model to investigate the mechanism of PR on pancreatic β cell apoptosis. The results showed that PR decreased the serum fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG) and low-density lipoprotein (LDL) levels but significantly increased the fasting blood insulin (FINS) and high-density lipoprotein (HDL) levels. Furthermore, decreased caspase-3, 8, 9 and apoptosis-inducing factor (AIF) proteins in the pancreas were detected by Western blot analysis. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining demonstrated that the pancreatic β cell apoptosis was inhibited by PR. Furthermore, PR improved the histopathological changes in pancreatic tissue in T2DM mice. Collectively, the data show that PR can protect the β cells from apoptotic death in a mouse model of T2DM through regulating the expression of apoptosis-related protein-AIF and caspase family proteins.