Effects of Tilianin on Proliferation, Migration and TGF-β/Smad Signaling in Rat Vascular Smooth Muscle Cells Induced with Angiotensin II

An efficient flavonoid glycosyltransferase NjUGT73B1 from Nardostachys jatamansi of alpine Himalayas discovered by structure-based protein clustering

Tilianin and linarin, two rare glycosylated flavonoids in the aromatic endangered medicinal plant Nardostachys jatamansi (D.on)DC., play an important role in the fields of medicine, cosmetics, food and dye industries. However, there remains a lack of comprehensive understanding regarding their biosynthetic pathway. In this study, the phytochemical investigation of N. jatamansi resulted in the isolation of linarin. With help of AlphaFold2 to cluster the entire glycosyltransferase family based on predicted structure similarities, we successfully identified a flavonoid glycosyltransferase NjUGT73B1, which could efficiently catalyze the glucosylation of acacetin at 7-OH to produce tilianin, also the key precursor in the biosynthesis of linarin. Additionally, NjUGT73B1 displayed a high degree of substrate promiscuity, enabling glucosylation at 7-OH of many flavonoids. Molecular modeling and site-directed mutagenesis revealed that H19, H21, H370, F126, and F127 play the crucial roles in the glycosylation ability of NjUGT73B1. Notably, comparation with the wild NjUGT73B1, mutant H19K led to a 50% increase in the activity of producing tilianin from acacetin.

Dracocephalum moldavica L.: An updated comprehensive review of its botany, traditional uses, phytochemistry, pharmacology, and application aspects

Dracocephalum moldavica, known as Xiang-qing-lan (in Chinese), is a traditional folk medicine, which was commonly used by Mongolian and Xinjiang Uyghurs area. Dracocephalum moldavica has the effects of purging liver fire, clearing stomach heat, hemostasis. It is used for treating insufficient heart and blood, weakened brain function, weak feeling and spirit disease etc. This review aimed to summarize the botany, traditional uses, phytochemistry, pharmacology and application of Dracocephalum moldavica, which expected to provide theoretical support for future utilization and highlight the further investigation of this vital plant. In addition to the essential oil, approximately 154 compounds have been isolated and identified from aerial parts of the Dracocephalum moldavica, including flavonoids, terpenoids, lignans, phenylpropanoids, phenols, glycosides, polysaccharide and other compounds. Extensive pharmacological activities of the extracts or compounds of Dracocephalum moldavica in vivo and in vitro were confirmed including cardiovascular protection, antioxidative, antimicrobial, antifungal, anti-complementary and chronic mountain sickness. Moreover, Dracocephalum moldavica is used in a wide range of applications in food, biological pesticides and cosmetics. In the future, Dracocephalum moldavica needs further study, such as paying more attention to quality control, toxicity, pharmacological mechanism and pharmacokinetics.

Flavones, Flavonols, Lignans, and Caffeic Acid Derivatives from Dracocephalum moldavica and Their In Vitro Effects on Multiple Myeloma and Acute Myeloid Leukemia

Phenolic plant constituents are well known for their health-promoting and cancer chemopreventive properties, and products containing such constituents are therefore readily consumed. In the present work, we isolated 13 phenolic constituents of four different compound classes from the aerial parts of the Moldavian dragonhead, an aromatic and medicinal plant with a high diversity on secondary metabolites. All compounds were tested for their apoptotic effect on myeloma (KMS-12-PE) and AML (Molm-13) cells, with the highest activity observed for the flavone and flavonol derivatives. While diosmetin (6) exhibited the most pronounced effects on the myeloma cell line, two polymethylated flavones, namely cirsimaritin (1) and xanthomicrol (3), were particularly active against AML cells and therefore subsequently investigated for their antiproliferative effects at lower concentrations. At a concentration of 2.5 µM, cirsimaritin (1) reduced proliferation of Molm-13 cells by 72% while xanthomicrol (3) even inhibited proliferation to the extent of 84% of control. In addition, both compounds were identified as potent FLT3 inhibitors and thus display promising lead structures for further drug development. Moreover, our results confirmed the chemopreventive properties of flavonoids in general, and in particular of polymethylated flavones, which have been intensively investigated especially over the last decade.

Tilianin: A Potential Natural Lead Molecule for New Drug Design and Development for the Treatment of Cardiovascular Disorders

Cardiovascular disorders (CVDs) are the leading risk factor for death worldwide, and research into the processes and treatment regimens has received a lot of attention. Tilianin is a flavonoid glycoside that can be found in a wide range of medicinal plants and is most commonly obtained from Dracocephalum moldavica. Due to its extensive range of biological actions, it has become a well-known molecule in recent years. In particular, numerous studies have shown that tilianin has cardioprotective properties against CVDs. Hence, this review summarises tilianin’s preclinical research in CVDs, as well as its mechanism of action and opportunities in future drug development. The physicochemical and drug-likeness properties, as well as the toxicity profile, were also highlighted. Tilianin can be a natural lead molecule in the therapy of CVDs such as coronary heart disease, angina pectoris, hypertension, and myocardial ischemia, according to scientific evidence. Free radical scavenging, inflammation control, mitochondrial function regulation, and related signalling pathways are all thought to play a role in tilianin’s cardioprotective actions. Finally, we discuss tilianin-derived compounds, as well as the limitations and opportunities of using tilianin as a lead molecule in drug development for CVDs. Overall, the scientific evidence presented in this review supports that tilianin and its derivatives could be used as a lead molecule in CVD drug development initiatives.

Dracocephalum moldavica Ethanol Extract Suppresses LPS-Induced Inflammatory Responses through Inhibition of the JNK/ERK/NF-κB Signaling Pathway and IL-6 Production in RAW 264.7 Macrophages and in Endotoxic-Treated Mice

The excessive synthesis of interleukin-6 (IL-6) is related to cytokine storm in COVID-19 patients. Moreover, blocking IL-6 has been suggested as a treatment strategy for inflammatory diseases such as sepsis. Sepsis is a severe systemic inflammatory response syndrome with high mortality. In the present study, we investigated the anti-inflammatory and anti-septic effects and the underlying mechanisms of Dracocephalum moldavica ethanol extract (DMEE) on lipopolysaccharide (LPS)-induced inflammatory stimulation in RAW 264.7 macrophages along with septic mouse models. We found that DMEE suppressed the release of inflammatory mediators NO and PGE₂ and inhibited both the mRNA and protein expression levels of iNOS and COX-2, respectively. In addition, DMEE reduced the release of proinflammatory cytokines, mainly IL-6 and IL-1β, in RAW 264.7 cells by inhibiting the phosphorylation of JNK, ERK and p65. Furthermore, treatment with DMEE increased the survival rate and decreased the level of IL-6 in plasma in LPS-induced septic shock mice. Our findings suggest that DMEE elicits an anti-inflammatory effect in LPS-stimulated RAW 264.7 macrophages and an anti-septic effect on septic mouse model through the inhibition of the ERK/JNK/NF-κB signaling cascades and production of IL-6.

Tilianin Ameliorates Cognitive Dysfunction and Neuronal Damage in Rats with Vascular Dementia via p-CaMKII/ERK/CREB and ox-CaMKII-Dependent MAPK/NF-κB Pathways

Vascular dementia (VaD) is a common cause of cognitive decline and dementia of vascular origin, but the precise pathological mechanisms are unknown, and so effective clinical treatments have not been established. Tilianin, the principal active compound of total flavonoid extract from Dracocephalum moldavica L., is a candidate therapy for cardio-cerebrovascular diseases in China. However, its potential in the treatment of VaD is unclear. The present study is aimed at investigating the protective effects of tilianin on VaD and exploring the underlying mechanism of the action. A model of VaD was established by permanent 2-vessel occlusion (2VO) in rats. Human neurons (hNCs) differentiated from human-induced pluripotent stem cells were used to establish an oxygen-glucose deprivation (OGD) model. The therapeutic effects and potential mechanisms of tilianin were identified using behavioral tests, histochemistry, and multiple molecular biology techniques such as Western blot analysis and gene silencing. The results demonstrated that tilianin modified spatial cognitive impairment, neurodegeneration, oxidation, and apoptosis in rats with VaD and protected hNCs against OGD by increasing cell viability and decreasing apoptosis rates. A study of the mechanism indicated that tilianin restored p-CaMKII/ERK1/2/CREB signaling in the hippocampus, maintaining hippocampus-independent memory. In addition, tilianin inhibited an ox-CaMKII/p38 MAPK/JNK/NF-κB associated inflammatory response caused by cerebral oxidative stress imbalance in rats with VaD. Furthermore, specific CaMKIIα siRNA action revealed that tilianin-exerted neuroprotection involved increase of neuronal viability, inhibition of apoptosis, and suppression of inflammation, which was dependent on CaMKIIα. In conclusion, the results suggested the neuroprotective effect of tilianin in VaD and the potential mechanism associated with dysfunction in the regulation of p-CaMKII-mediated long-term memory and oxidation and inflammation involved with ox-CaMKII, which may lay the foundation for clinical trials of tilianin for the treatment of VaD in the future.

Qingda granule inhibits angiotensin Ⅱ induced VSMCs proliferation through MAPK and PI3K/AKT pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The abnormal increase in vascular smooth muscle cell (VSMC) proliferation is widely accepted as the pivotal process in the vascular remodeling of hypertension. Qingda granule (QDG) is simplified from Qingxuan Jiangya Decoction (QXJYD) which has been in usage for a long time as a traditional Chinese medicine formula to treat hypertension based on the theory of traditional Chinese medicine. However, its underlying molecular mechanisms of action remain largely unknown.

AIM OF STUDY

To investigate the therapeutic efficacy of QDG in the attenuation of elevation of blood pressure and proliferation of VSMCs in vivo and in vitro and explore its possible mechanism of action.

MATERIALS AND METHODS

In vivo, we established an angiotensin Ⅱ (Ang Ⅱ)-mediated hypertension model in C57BL/6 mice and orally administered 1.145 g/kg/day of QDG. The systolic and diastolic blood pressures of all mice were measured at the end of the treatment by using the tail-cuff plethysmograph method and CODA™ noninvasive blood pressure system. VSMC proliferation within the aorta was determined by immunohistochemistry. In vitro, primary rat VSMCs were cultured to further verify the effects of QDG on Ang Ⅱ induced VSMC proliferation. Cell proliferation was investigated using cell counting and MTT assays. The protein expression was determined by western blotting.

RESULTS

We found that oral administration of QDG significantly attenuated the elevation of blood pressure and proliferation of VSMCs in Ang Ⅱ-induced hypertensive mice. Moreover, QDG remarkably inhibited Ang Ⅱ-induced primary rat VSMCs proliferation and decreased mitogen-activated protein kinase (MAPK) and PI3K/AKT activity by attenuating the expression of phospho-extracellular signaling-regulated kinase 1/2, phospho-p38, phospho-c-Jun N-terminal kinase and phospho-protein kinase B.

CONCLUSION

Collectively, our findings suggest that QDG attenuates Ang Ⅱ-induced elevation of blood pressure and proliferation of VSMCs through a decrease in the activation of MAPK and PI3K/AKT pathways. Based on this study, we postulate this could be one of the mechanisms whereby QDG effectively controls hypertension.

Wnt Signaling Modulates Routes of Retinoic Acid-Induced Differentiation of Embryonic Stem Cells

Smooth muscle cells (SMCs) are important cell type for regenerative medicine. Previous studies showed that retinoic acid (RA) induces differentiation of SMCs from monolayer-cultured embryonic stem cells (ESCs) with high efficiency. However, the underlying mechanisms are still poorly defined. Here, we identified Wnt signaling as a primary regulator for RA-induced ESC differentiation. The activation of Wnt signaling inhibited the epithelial-mesenchymal transition during ESC differentiation, leading to inhibition of RA-induced SMC differentiation and promoting differentiation of ESCs toward primitive endoderm (PrE) lineage instead, while the inhibition of Wnt signaling promoted RA-induced SMC differentiation. Loss-of-function studies revealed that 7-like 2 (Tcf7l2) was the key transcription factor that Wnt operate through during RA-induced differentiation. Thus, this study revealed that the Tcf7l2-mediated Wnt signaling is a switch in determining the mesoderm/PrE fates in RA-induced ESC differentiation.

[The renin-angiotensin-aldosterone system as a potential target for therapy in patients with calcific aortic stenosis: a literature review]

Calcific aortic valve stenosis (CAVS) is a serious socio-economic problem in developed countries because this disease is the most common indication for aortic valve replacement. Currently, there are no methods for non-invasive treatment of CAVS. Nevertheless, it is assumed that effective drug therapy for CAVS can be developed on the basis of modulators of the renin-angiotensin-aldosterone system (RAAS), which is involved in the pathogenesis of this disease. The purpose of this paper is to compile and analyze current information on the role of RAAS in the CAVS pathophysiology. Recent data on the effectiveness of RAAS inhibition are reviewed.