Protection of Shengmai Recipe on Improving Cardiac Function and Attenuating Kidney Injury in Pressure Overload Rats

Cardiac sympathetic overdrive, M2 macrophage activation and fibroblast heterogeneity are associated with cardiac remodeling in a chronic pressure overload rat model of HFpEF

Heart failure with preserved ejection fraction (HFpEF) is a multifaceted pathogenesis disease and the exact mechanisms driving HFpEF have not been completely elucidated. Pressure overload hypertrophy (POH) related fibroblasts and M2 macrophages in HFpEF myocardium have been recently identified and are now of great interest. Sympathetic overdrive has also been implicated in HFpEF. This study is designed to dynamically observe the potential roles of aforementioned mechanisms in pathological remodeling and cardiac dysfunction in chronic PO rats. Surgical constriction of the abdominal aorta was used for induction of HFpEF. Echocardiography, electrocardiogram, hemodynamic measurement, hematoxylin and eosin staining, Masson staining, immunohistochemistry and immunofluorescence were performed to assess the changes in heart dysfunction, cardiac remodeling and driving mechanisms at different time points (2, 18, 24 weeks). The PO induced HFpEF model was well established, which was confirmed by the persistent increase in carotid artery systolic and diastolic blood pressure, and left ventricle hypertrophy at the corresponding postoperative stage. Meanwhile, PO hypertrophy gradually developed into HFpEF, associated with QT and QTc intervals prolongation, normal systolic (EF was maintained at >50%) but impaired diastolic function (increasing LVEDP and LV -dP/dtmin, abnormal E/A ratio), increased myocytes size, and observed relatively slight inflammatory infiltration but robust reactive fibrosis. IHC staining further confirmed that macrophages (CD68) but not neutrophils (MPO) or T cells (CD3) accounted for a predominant proportion of infiltrating cells. Mechanistically, we found that the infiltrating macrophages in the heart expressed high levels of CD206 which was simultaneously adjacent to POH fibroblasts appeared to overexpression of α-SMA in PO rats at late stages. Interestingly, we distinguished two different POHF sub-populations during PO induced HFpEF development, according to non overlapping signals of α-SMA and PDGFRα/β proteins. Additionally, PO led to a pronounced exaggeration in sympathetic fibers at all time points. These findings suggest that the establishing model here begins with cardiac sympathetic overdrive, subsequently along with immune cells especially M2 macrophage accumulation and fibroblast heterogeneity at later stages is associated with the development of cardiac maladaptive remodeling and diastolic dysfunction thus further progression to HFpEF.

A Strategy for Selecting "Q-Markers" of Chinese Medical Preparation via Components Transfer Process Analysis with Application to the Quality Control of Shengmai Injection

Chinese medical preparation has complicated chemical constituents. Consequently, the proper quality control methods for these Chinese medical preparations have been great challenges to the traditional Chinese medicine modernization and internationalization. What components should be chosen for quality control is a big challenge in the development of traditional Chinese medicine. A new concept of "Quality Marker" was proposed by Liu et al. to solve this problem and established a new research paradigm for traditional Chinese medicine quality study. Several strategies were proposed by the researchers in traditional Chinese medicine, here, we used Shengmai injection as an example to discuss a strategy for selecting "Quality Markers" of Chinese medical preparation by the components transfer process analysis in the Shengmai injection manufacturing process. Firstly, a total of 87 compounds were identified or partially characterized in shengmai injection. Secondly, referenced to the quality control method in China pharmacopeia and considered the biomarkers in the original medicines and representative components in the manufacturing process, four ginsenosides in Panax ginseng (Hongshen), two compounds in Schisandra chinensis (Wuweizi), and a sugar from Ophiopogon japonicas (Maidong) were quantified. As a result, these seven representative compounds exhibited an acceptable transitivity throughout the Shengmai injection manufacturing process. Finally, combined with the active ingredients, components transfer process analysis, and comprehensive evaluation by "Spider-web" analysis, six compounds were selected as the quality markers for the quality control of Shengmai injection. Through this strategy of optimization for quality markers of Shengmai injection, we found that these six compounds could represent the main bioactive substances and be easily detected in the whole process of production. Furthermore, the quality control method was developed for quality assessment and control of these six quality markers in the Shengmai injection. The total content range of the selected quality markers in the 10 batches of the Shengmai injection is 13.844-22.557 mg/mL.

PKA/β2-AR-Gs/Gi signaling pathway is associated with anti-inflammatory and pro-apoptotic effects of Fuzi and Banxia combination on rats subjected to pressure overload

ETHNOPHARMACOLOGICAL RELEVANCE

Either Aconite Lateralis Radix Praeparata (Fuzi) or Pinelliae Rhizoma (Banxia) exerts anti-inflammatory activity and their combination has long been used in China for treating cardiovascular diseases. However, combination of two drugs is controversially prohibited in clinical prescriptions because it serves a representative incompatible pairs in "eighteen antagonisms". Up to date, whether the combination of Fuzi and Banxia could be used for treating heart failure with preserved ejection fraction (HFpEF) especially charactered by systemic inflammation and the potential mechanisms have not been elucidated.

AIM OF THE STUDY

The pros and cons of Fuzi in combination with Banxia were evaluated in pressure overload (PO) rat models of HF in vivo.

MATERIALS AND METHODS

Male Sprague Dawley rats were subjected to abdominal aorta constriction or sham-operated procedure. From week 12, rats were administered with low dose Fuzi (5.4 g kg^-1 d^-1), Banxia (5.4 g kg^-1 d^-1), combination (5.4 g kg^-1 d^-1 + 5.4 g kg^-1 d^-1), high dose Fuzi (10.8 g kg^-1 d^-1) or with vehicle (n = 15 per group) orally for additional 6 weeks.

RESULTS

Fuzi alone treatment led to exaggerated cardiac-renal response to PO, and occurred dramatically at high dose as manifested by markedly exacerbated cardiac-renal inflammation and myocardial fibrosis. Further studies revealed that cardiotoxicity of Fuzi may be associated with highly expression levels of β2-AR and PKA. In contrast, coadministration of Fuzi and Banxia restored cardiac function, as indicated by relieving inflammation and fibrosis as well as normalizing electrocardiogram parameters, which were accompanied by PKA down-regulation. More importantly, both high dose Fuzi and combination treatment enhanced induction of apoptosis, which could be partially associated with inhibition of β2-AR-Gi signaling.

CONCLUSION

Thus, combination of Fuzi and Banxia elicited concurrent protective and toxic effects in PO induced HF. The protective effect appeared to predominate and was associated with suppression of PKA/β2-AR-Gs signaling pathway. Unlike the eighteen antagonisms theory where Fuzi and Banxia combination was considered incompatible, in the present study, this herb pairs appeared to be benefit, and probably had potential therapeutic prospect in treating HFpEF and diseases associated with inflammation.