In silico analysis and experimental validation of molecular mechanisms of salvianolic acid A-inhibited LPS-stimulated inflammation, in RAW264.7 macrophages

Salvianolic acid A prevents UV-induced skin damage by inhibiting the cGAS-STING pathway

DNA damage resulting from UV irradiation on the skin has been extensively documented in numerous studies. In our prior investigations, we demonstrated that UVB-induced DNA breakage from keratinocytes can activate the cGAS-STING pathway in macrophages. The cGAS-STING signaling pathway serves as the principal effector for detecting and responding to abnormal double-stranded DNA in the cytoplasm. Expanding on our previous findings, we have further validated that STING knockout significantly diminishes UVB-induced skin damage, emphasizing the critical role of cGAS-STING activation in this context. Salvianolic acid A, a principal active constituent of Salvia miltiorrhiza Burge, has been extensively studied for its therapeutic effects in conditions such as coronary heart disease, angina pectoris, and diabetic peripheral neuropathy. However, its effect on cGAS-STING pathway and its ability to alleviate skin damage have not been previously reported. In a co-culture system, supernatant from UVB-treated keratinocytes induced IRF3 activation in macrophages, and this activation was inhibited by salvianolic acid A. Our investigation, employing photodamage and photoaging models, establishes that salvianolic acid A effectively mitigates UV-induced epidermal thickening and collagen degeneration. Treatment with salvianolic acid A significantly reduced skin damage, epidermal thickness increase, and keratinocyte hyperproliferation compared to the untreated photo-damage and photoaging model groups. In summary, salvianolic acid A emerges as a promising candidate for preventing UV-induced skin damage by inhibiting cGAS-STING activation. This research enhances our understanding of the intricate mechanisms underlying skin photodamage and provides a potential avenue for the development of therapeutic interventions.

Integrated network pharmacology analysis, molecular docking, LC-MS analysis and bioassays revealed the potential active ingredients and underlying mechanism of Scutellariae radix for COVID-19

Scutellariae radix ("Huang-Qin" in Chinese) is a well-known traditional herbal medicine and popular dietary supplement in the world, extensively used in prescriptions of TCMs as adjuvant treatments for coronavirus pneumonia 2019 (COVID-19) patients in China. According to the differences in its appearance, Scutellariae radix can be classified into two kinds: ZiQin (1∼3 year-old Scutellariae baicalensis with hard roots) and KuQin (more than 3 year-old S. baicalensis with withered pithy roots). In accordance with the clinical theory of TCM, KuQin is superior to ZiQin in cooling down the heat in the lung. However, the potential active ingredients and underlying mechanisms of Scutellariae radix for the treatment of COVID-19 remain largely unexplored. It is still not clear whether there is a difference in the curative effect of ZiQin and KuQin for the treatment of COVID-19. In this research, network pharmacology, LC-MS based plant metabolomics, and in vitro bioassays were integrated to explore both the potential active components and mechanism of Scutellariae radix for the treatment of COVID-19. As the results, network pharmacology combined with molecular docking analysis indicated that Scutellariae radix primarily regulates the MAPK and NF-κB signaling pathways via active components such as baicalein and scutellarin, and blocks SARS-CoV-2 spike binding to human ACE2 receptors. In vitro bioassays showed that baicalein and scutellarein exhibited more potent anti-inflammatory and anti-infectious effects than baicalin, the component with the highest content in Scutellariae radix. Moreover, baicalein inhibited SARS-CoV-2's entry into Vero E6 cells with an IC₅₀ value of 142.50 μM in a plaque formation assay. Taken together, baicalein was considered to be the most crucial active component of Scutellariae radix for the treatment of COVID-19 by integrative analysis. In addition, our bioassay study revealed that KuQin outperforms ZiQin in the treatment of COVID-19. Meanwhile, plant metabolomics revealed that baicalein was the compound with the most significant increase in KuQin compared to ZiQin, implying the primary reason for the superiority of KuQin over ZiQin in the treatment of COVID-19.

In vitro evaluation of selligueain A effects on the proinflammatory mediators production in RAW264.7 murine macrophages

Introduction: Selligueain A derived from the roots of Polypodium feei was shown to have anti-inflammatory activity, which was tested in vivo on the rats’ paw edema induced by carrageenan. The aim of this study was to evaluate the anti-inflammatory mechanism of selligueain A in vitro against the production of pro-inflammatory mediators. Methods: In this study, RAW264.7 cells were used as an inflammatory cell model, and observations were made on the inflammatory mediators nitric oxide (NO), inducible nitric oxide synthase (iNOS), and tumour necrosis factor-α (TNF-α). The NO concentration was measured by the Griess reaction, and the iNOS enzyme and the TNF-α concentrations were determined by the ELISA method. Cell viability was assessed by the [3-(4,5-dimethylthiazol-2yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] (MTS) test. Results: Selligueain A at concentrations of 100 and 150 µM suppressed the production of NO, iNOS, and TNF-α in RAW264.7 cells stimulated by lipopolysaccharide (LPS). The concentration of 150 µM showed the highest inhibition of NO, iNOS, and TNF-α mediators with the percentage inhibition of 64.85, 55.01, and 48.54%, respectively. Conclusion: This study shows that selligueain A has anti-inflammatory activity through inhibition of NO, iNOS, and TNF-α production in RAW264.7 macrophage cells.

The Effect of Salvianolic Acid on Vascular Protection and Possible Mechanisms

Salvia miltiorrhiza (Danshen), as an important traditional Chinese medicinal plant, has been used in China for the treatment of cardiovascular diseases for hundreds of years. Salvianolic acids (salvianolic acid A and salvianolic acid B) as the most abundant water-soluble component extracted from Salvia miltiorrhiza have attracted more and more attention from cardiovascular scientists due to its comprehensive cardiovascular actions. In vivo and in vitro studies have rendered salvianolic acid an excellent drug candidate for the treatment and prevention of cardiovascular diseases. In this review, we surveyed the protective effects of salvianolic acid A and salvianolic acid B against cardiovascular diseases and the pharmacological basis, providing a strong scientific rationale for elucidating the important role of Salvia miltiorrhiza in cardiovascular therapy. More importantly, we also hope to provide new inspiration and perspectives on the development and innovation of small-molecule cardiovascular drugs based on salvianolic acid.

Salvianolic Acid A Has Anti-Osteoarthritis Effect In Vitro and In Vivo

Osteoarthritis (OA) is a degenerative disease found in middle-aged and elderly people, which seriously affects their quality of life. The anti-inflammatory and anti-apoptosis pharmacological effects of salvianolic acid A (SAA) have been shown in many studies. In this study, we intended to explore the anti-inflammatory and anti-apoptotic effects of SAA in OA. We evaluated the expression of pro-inflammatory mediators and cartilage matrix catabolic enzymes in chondrocytes by ELISA, Griess reaction, immunofluorescence, and Western blot, which includes nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), MMPs (MMP-3, MMP-13), and ADAMTS-5. Bax, Bcl-2, and cleaved caspase-3 were also measured by Western blot methods. The results of this experiment in vitro showed that SAA not only inhibited the production of inflammatory mediators induced by IL-1β and the loss of cartilage matrix but also reduced the apoptosis of mouse chondrocytes induced by IL-1β. According to the results of immunofluorescence and Western blot, SAA inhibited the activation of the NF-κB pathway and MAPK pathway. The results of these in vitro experiments revealed for the first time that SAA down-regulated the production of inflammatory mediators and inhibited the apoptosis of mouse chondrocytes and the degradation of extracellular matrix (ECM), which may be attributed to the inhibition of the activation of NF-κB and MAPK signaling pathways. In the in vivo experiments, 45 mice were randomly divided among three groups (the sham group, OA group, and OA + SAA group). The results of animal experiments showed that SAA treatment for eight consecutive weeks inhibited further deterioration of OA. These results demonstrate that SAA plays an active therapeutic role in the development of OA.

Salvianolic Acid Alleviated Blood-Brain Barrier Permeability in Spontaneously Hypertensive Rats by Inhibiting Apoptosis in Pericytes via P53 and the Ras/Raf/MEK/ERK Pathway

Objective

To investigate the effect of salvianolic acid A (SA) on the permeability of blood–brain barrier (BBB) and brain microvascular pericyte apoptosis in spontaneously hypertensive rats (SHR).

Methods

Evans Blue was used to determine the BBB permeability in control rats and SHR. Western blotting was used to evaluate the expression levels of relevant proteins in the pericytes isolated from the differentially treated animals. An in vitro model of hypertension was established by stimulating pericytes with angiopoietin-2 (Ang2). MTT assay was used to assess cell viability, and apoptosis and cell cycle distribution were analyzed by flow cytometry.

Results

SA attenuated BBB permeability in SHR in a dose-dependent manner. It downregulated pro-apoptotic proteins including p53, p21, Fas, FasL, cleaved-caspase 3/caspase 3 and Bax in the pericytes of SHR and upregulated CDK6, cyclin D1, CDK2, cyclin E and Bcl2. In addition, SA activated the Ras/Raf/MEK/ERK pathway in a dose-dependent manner by increasing the levels of Ras, Raf, p-MEK1, p-MEK2, p-ERK1 and p-ERK2. Finally, SA reduced Ang2-induced apoptosis of cerebral microvessels pericytes and decreased the proportion of cells in the G0/G1 phase of the cell cycle by inhibiting the p53 pathway and activating the Ras/Raf/MEK/ERK pathway.

Conclusion

SA reduced BBB permeability in spontaneously hypertensive rats, possibly by inhibiting Ang2-induced apoptosis of pericytes by activating the Ras/Raf/MEK/ERK pathway.

Salvia miltiorrhizaBurge (Danshen): a golden herbal medicine in cardiovascular therapeutics

Salvia miltiorrhiza Burge (Danshen) is an eminent medicinal herb that possesses broad cardiovascular and cerebrovascular protective actions and has been used in Asian countries for many centuries. Accumulating evidence suggests that Danshen and its components prevent vascular diseases, in particular, atherosclerosis and cardiac diseases, including myocardial infarction, myocardial ischemia/reperfusion injury, arrhythmia, cardiac hypertrophy and cardiac fibrosis. The published literature indicates that lipophilic constituents (tanshinone I, tanshinone IIa, tanshinone IIb, cryptotanshinone, dihydrotanshinone, etc) as well as hydrophilic constituents (danshensu, salvianolic acid A and B, protocatechuic aldehyde, etc) contribute to the cardiovascular protective actions of Danshen, suggesting a potential synergism among these constituents. Herein, we provide a systematic up-to-date review on the cardiovascular actions and therapeutic potential of major pharmacologically active constituents of Danshen. These bioactive compounds will serve as excellent drug candidates in small-molecule cardiovascular drug discovery. This article also provides a scientific rationale for understanding the traditional use of Danshen in cardiovascular therapeutics.

Effects of the Nrf2 Protein Modulator Salvianolic Acid A Alone or Combined with Metformin on Diabetes-associated Macrovascular and Renal Injury

Nuclear factor E2-related factor 2 (Nrf2) is considered a promising target against diabetic complications such as cardiovascular diseases and diabetic nephropathy. Herein, we investigated the effects of a potential Nrf2 modulator, salvianolic acid A (SAA), which is a natural polyphenol, on diabetes-associated macrovascular and renal injuries in streptozotocin-induced diabetic mice. Given that lowering glucose is the first objective of diabetic patients, we also examined the effects of SAA combined with metformin (MET) on both complications. Our results showed that SAA significantly increased the macrovascular relaxation response to acetylcholine and sodium nitroprusside in diabetic mice. Interestingly, treatment with SAA alone only provided minor protection against renal injury, as reflected by minor improvements in impaired renal function and structure, despite significantly reduced oxidative stress observed in the diabetic kidney. We demonstrated that decreased oxidative stress and NF-κB p65 expression were associated with SAA-induced expression of Nrf2-responsive antioxidant enzymes heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase (quinone) 1 (NQO-1), and glutathione peroxidase-1 (GPx-1) in vivo or in vitro, which suggested that SAA was a potential Nrf2 modulator. More significantly, compared with treatment with either SAA or MET alone, we found that their combination provided further protection against the macrovascular and renal injury, which was at least partly due to therapeutic activation of both MET-mediated AMP-activated protein kinase and SAA-mediated Nrf2/antioxidant-response element pathways. These findings suggested that polyphenol Nrf2 modulators, especially combined with drugs activating AMP-activated protein kinase, including hypoglycemic drugs, are worthy of further investigation to combat diabetic complications.

CEMTDD: The database for elucidating the relationships among herbs, compounds, targets and related diseases for Chinese ethnic minority traditional drugs

China has different ethnic minorities that establish their own medical systems and practice experience for thousand years, thereafter named Chinese Ethnic Minority Traditional Drugs (CEMTDs) (http://www.cemtdd.com/index.html). Since many compounds from CEMTDs have been reported to perturb human's dysfunction network and restore human normal physiological conditions, the relationships amongst a series of compounds from specific herbs, their targets and relevant diseases have become our main focus in CEMTD modernization. Herein, we have constructed the first Chinese Ethnic Minority Traditional Drug Database (CEMTDD) mainly from Xinjiang Uygur Autonomous Region (XUAR), retrieving CEMTD-related information from different resources. CEMTDD contains about 621 herbs, 4, 060 compounds, 2, 163 targets and 210 diseases, among which most of herbs can be applied into gerontology therapy including inflammation, cardiovascular disease and neurodegenerative disease. Gerontology is highly occurred in XUAR, and has abundant experience in treating such diseases, which may benefit for developing a new gerontology therapeutic strategy. CEMTDD displays networks for intricate relationships between CEMTDs and treated diseases, as well as the interrelations between active compounds and action targets, which may shed new light on the combination therapy of CEMTDs and further understanding of their herb molecular mechanisms for better modernized utilizations of CEMTDs, especially in gerontology.