Effect of Scutellarin inhibits collagen‑induced arthritis through TLR4/NF‑κB‑mediated inflammation

Scutellarin: pharmacological effects and therapeutic mechanisms in chronic diseases

Scutellarin (SCU), a flavonoid glucuronide derived from Scutellaria barbata and Erigeron breviscapus, exhibits broad pharmacological effects with promising therapeutic potential in treating various chronic diseases. It has demonstrated efficacy in modulating multiple biological pathways, including antioxidant, anti-inflammatory, anti-apoptotic, and vasodilatory mechanisms. These protective roles make SCU a valuable compound in treating chronic diseases such as cerebrovascular diseases, cardiovascular diseases, neurodegenerative disorders, and metabolic diseases. Despite its multi-targeted effects, SCU faces challenges such as low bioavailability and limited clinical data, which hinder its widespread therapeutic application. Current research supports its potential to prevent oxidative stress, reduce inflammatory responses, and enhance cell survival in cells and rats. However, more comprehensive studies are required to clarify its molecular mechanisms and to develop strategies that enhance its bioavailability for clinical use. SCU could emerge as a potent therapeutic agent for the treatment of chronic diseases with complex pathophysiological mechanisms. This review examines the current literature on Scutellarin to provide a comprehensive understanding of its pharmacological activity, mechanisms of action, and therapeutic potential in treating chronic diseases.

Pharmacological effects and the related mechanism of scutellarin on inflammation-related diseases: a review

Inflammation is a biological response of multicellular organisms caused by injuries, pathogens or irritants. An excessive inflammatory response can lead to tissue damage and various chronic diseases. Chronic inflammation is a common feature of many diseases, making the search for drugs to treat inflammation-related diseases urgent. Scutellarin, a natural flavonoid metabolite, is widely used in the treatment of various inflammation-related diseases for its anti-inflammatory, anti-oxidant and anti-cancer activities. Scutellarin can inhibit key inflammatory pathways (PI3K/Akt, MAPK, and NF-κB, etc.) and activate the anti-oxidant related pathways (Nrf2, ARE, ect.), thereby protecting tissues from inflammation and oxidative stress. Modern extraction technologies, such as microwave-assisted, ultrasound assisted, and supercritical fluid extraction, have been utilized to extract scutellarin from Scutellaria and Erigeron genera. These technologies improve efficiency and retain biological activity, making scutellarin suitable for large-scale production. Scutellarin has significant therapeutic effects in treating osteoarthritis, pulmonary fibrosis, kidney injury, and cardiovascular diseases. However, due to its low bioavailability and short half-life, its clinical application is limited. Researchers are exploring innovative formulations (β-cyclodextrin polymers, triglyceride mimetic active ingredients, and liposome precursors, etc.) to improve stability and absorption rates. Despite these challenges, the potential of scutellarin in anti-inflammatory, anti-oxidant, and anti-cancer applications remains enormous. By optimizing formulations, exploring combination therapies, and conducting in-depth mechanistic research, scutellarin can play an important role in treating various inflammatory diseases, providing patients with more and effective treatment options.

Scutellarin Alleviates Ovalbumin-Induced Airway Remodeling in Mice and TGF-β-Induced Pro-fibrotic Phenotype in Human Bronchial Epithelial Cells via MAPK and Smad2/3 Signaling Pathways

Asthma is a chronic inflammatory disease characterized by airway hyperresponsiveness (AHR), inflammation, and remodeling. Epithelial-mesenchymal transition (EMT) is an essential player in these alterations. Scutellarin is isolated from Erigeron breviscapus. Its vascular relaxative, myocardial protective, and anti-inflammatory effects have been well established. This study was designed to detect the biological roles of scutellarin in asthma and its related mechanisms. The asthma-like conditions were induced by ovalbumin challenges. The airway resistance and dynamic compliance were recorded as the results of AHR. Bronchoalveolar lavage fluid (BALF) was collected and processed for differential cell counting. Hematoxylin and eosin staining, periodic acid-Schiff staining, and Masson staining were conducted to examine histopathological changes. The levels of asthma-related cytokines were measured by enzyme-linked immunosorbent assay. For in vitro analysis, the 16HBE cells were stimulated with 10 ng/mL transforming growth beta-1 (TGF-β1). Cell migration was estimated by Transwell assays and wound healing assays. E-cadherin, N-cadherin, and α-smooth muscle actin (α-SMA) were analyzed by western blotting, real-time quantitative polymerase chain reaction, immunofluorescence staining, and immunohistochemistry staining. The underlying mechanisms of the mitogen-activated protein kinase (MAPK) and Smad pathways were investigated by western blotting. In an ovalbumin-induced asthmatic mouse model, scutellarin suppressed inflammation and inflammatory cell infiltration into the lungs and attenuated AHR and airway remodeling. Additionally, scutellarin inhibited airway EMT (upregulated E-cadherin level and downregulated N-cadherin and α-SMA) in ovalbumin-challenged asthmatic mice. For in vitro analysis, scutellarin prevented the TGF-β1-induced migration and EMT in 16HBE cells. Mechanistically, scutellarin inhibits the phosphorylation of Smad2, Smad3, ERK, JNK, and p38 in vitro and in vivo. In conclusion, scutellarin can inactivate the Smad/MAPK pathways to suppress the TGF-β1-stimulated epithelial fibrosis and EMT and relieve airway inflammation and remodeling in asthma. This study provides a potential therapeutic strategy for asthma.

The efficacy and safety of mecobalamin combined with Chinese medicine injections in the treatment of diabetic peripheral neuropathy: A systematic review and Bayesian network meta-analysis of randomized controlled trials

Background: In recent years, people pay more and more attention to diabetic peripheral neuropathy (DPN). As a neurotrophic agent, mecobalamin is able to repaire nerves, which has already become a consensus among experts. However, it has been found that mecobalamin has poor effect to increase nerve conduction velocity, which is an important indicator. Clinical data have shown that Chinese medicine injection, combined with mecobalamin injection, can significantly improve nerve conduction velocity of the limbs. Nevertheless, several kinds of Chinese medicine injections have been used to treat DPN. The effect of these Chinese medicine injections for DPN are various. Therefore, it is necessary to evaluate the effectiveness of Chinese medicine injections combined with mecobalamin in the treatment of DPN.

Methods: All relevant articles published before 12 March 2022 were searched in eight electronic databases. Randomized controlled trials (RCTs) on Chinese medicine injections plus Mecobalamin for DPN were identified according to inclusion criteria, and were assessed using the revised Cochrane risk of bias tool (ROB2.0). R software and stata15 was used to create the ranking probabilities and network meta-analysis.

Results: A total of 80 RCTs involving 6,980 patients were included. The results showed that mecobalamin plus Dengzhanxixin injection (ME + DZXX) ranked first in overall response rate [RR = 1.64, 95% CI (1.26, 2.21)] and median motor nerve conduction velocity [MD = 9.46, 95% CI (5.67, 13.28)]. Then, mecobalamin plus Kudiezi Injection (ME + KDZ) had the best effect in median sensory nerve conduction velocity [MD = 10.41, 95% CI (−13.31, −7.52)], and mecobalamin plus Honghua injection (ME + HH) ranked highest in common peroneal motor nerve conduction velocity [MD = 6.8, 95% CI (4.13, 9.49)] and common peroneal sensory nerve conduction velocity [MD = −6.25, 95% CI (−8.85, −3.65)].

Conclusion: This study determined the efficacy of different Chinese medicine injections combined with mecobalamin. DZXX may be the best adjunctive Chinese medicine injection for DPN patients. However, due to potential risk of bias and limited RCTs, our results need to be treated with reservations.

Breviscapine alleviates NASH by inhibiting TGF-β-activated kinase 1-dependent signaling

BACKGROUND AND AIMS

NAFLD is a key component of metabolic syndrome, ranging from nonalcoholic fatty liver to NASH, and is now becoming the leading cause of cirrhosis and HCC worldwide. However, due to the complex and unclear pathophysiological mechanism, there are no specific approved agents for treating NASH. Breviscapine, a natural flavonoid prescription drug isolated from the traditional Chinese herb Erigeron breviscapus, exhibits a wide range of pharmacological properties, including effects on metabolism. However, the anti-NASH efficacy and mechanisms of breviscapine have not yet been characterized.

APPROACH AND RESULTS

We evaluated the effects of breviscapine on the development of hepatic steatosis, inflammation, and fibrosis in vivo and in vitro under metabolic stress. Breviscapine treatment significantly reduced lipid accumulation, inflammatory cell infiltration, liver injury, and fibrosis in mice fed a high-fat diet, a high-fat/high-cholesterol diet, or a methionine- and choline-deficient diet. In addition, breviscapine attenuated lipid accumulation, inflammation, and lipotoxicity in hepatocytes undergoing metabolic stress. RNA-sequencing and multiomics analyses further indicated that the key mechanism linking the anti-NASH effects of breviscapine was inhibition of TGF-β-activated kinase 1 (TAK1) phosphorylation and the subsequent mitogen-activated protein kinase signaling cascade. Treatment with the TAK1 inhibitor 5Z-7-oxozeaenol abrogated breviscapine-mediated hepatoprotection under metabolic stress. Molecular docking illustrated that breviscapine directly bound to TAK1.

CONCLUSION

Breviscapine prevents metabolic stress-induced NASH progression through direct inhibition of TAK1 signaling. Breviscapine might be a therapeutic candidate for the treatment of NASH.

Oral Scutellarin Treatment Ameliorates Retinal Thinning and Visual Deficits in Experimental Glaucoma

Purpose: Intraocular pressure (IOP) is currently the only modifiable risk factor for glaucoma, yet glaucoma can continue to progress despite controlled IOP. Thus, development of glaucoma neurotherapeutics remains an unmet need. Scutellarin is a flavonoid that can exert neuroprotective effects in the eye and brain. Here, we investigated the neurobehavioral effects of scutellarin treatment in a chronic IOP elevation model. Methods: Ten adult C57BL/6J mice were unilaterally injected with an optically clear hydrogel into the anterior chamber to obstruct aqueous outflow and induce chronic IOP elevation. Eight other mice received unilateral intracameral injection of phosphate-buffered saline only. Another eight mice with hydrogel-induced unilateral chronic IOP elevation also received daily oral gavage of 300 mg/kg scutellarin. Tonometry, optical coherence tomography, and optokinetics were performed longitudinally for 4 weeks to monitor the IOP, retinal nerve fiber layer thickness, total retinal thickness, visual acuity, and contrast sensitivity of both eyes in all three groups. Results: Intracameral hydrogel injection resulted in unilateral chronic IOP elevation with no significant inter-eye IOP difference between scutellarin treatment and untreated groups. Upon scutellarin treatment, the hydrogel-injected eyes showed less retinal thinning and reduced visual behavioral deficits when compared to the untreated, hydrogel-injected eyes. No significant difference in retinal thickness or optokinetic measures was found in the contralateral, non-treated eyes over time or between all groups. Conclusion: Using the non-invasive measuring platform, oral scutellarin treatment appeared to preserve retinal structure and visual function upon chronic IOP elevation in mice. Scutellarin may be a novel neurotherapeutic agent for glaucoma treatment.

Scutellarin ameliorates high glucose-induced vascular endothelial cells injury by activating PINK1/Parkin-mediated mitophagy

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellarin (Scu) is one of the main active ingredients of Erigeron breviscapus (Vant.) Hand.-Mazz which has been used to treat cardiovascular disease including vascular dysfunction caused by diabetes. Scu also has a protective effect on vascular endothelial cells against hyperglycemia. However, molecular mechanisms underlying this effect are not clear.

AIM OF THE STUDY

This aim of this study was to investigate the effect of Scu on human umbilical vein endothelial cells (HUVECs) injury induced by high glucose (HG), especially the regulation of PTEN-induced kinase 1 (PINK1)/Parkin-mediated mitophagy.

MATERIALS AND METHODS

HUVECs were exposed to HG to induce vascular endothelial cells injury in vitro. Cell viability was assessed by MTT assay. The extent of cell apoptosis was measured by Hoechst staining and flow cytometry. Mitophagy was assayed by fluorescent immunostaining, transmission electron microscope and immunoblot. Besides, virtual docking was conducted to validate the interaction of PINK1 protein and Scu.

RESULTS

We found that Scu significantly increased cell viability in HG-treated HUVECs. Scu reduces the expression of Bcl-2, Bax and cytochrome C (Cyt.c) to inhibit apoptosis through a mitochondria-dependent pathway. Meanwhile, Scu improved the overload of reactive oxygen species (ROS), superoxide dismutase (SOD) activity and SOD2 protein expression, and reversed the collapse of mitochondrial membrane potential. Besides, Scu increased autophagic flux, improved the expression of microtubule-associated protein 1 light chain 3 Ⅱ (LC3 II), Beclin 1 and autophagy-related gene 5 (Atg 5) and decreased the expression of Sequestosome1/P62 in HG-treated HUVECs. Furthermore, Scu improved the expressions of PINK1, Parkin, and Mitofusin2, which revealed the enhancement of mitophagy. Moreover, the beneficial effects of Scu on HG-induced low expression of Parkin, overproduction of ROS, and over expressions of P62, Cyt.c and Cleaved caspase-3 were weakened by PINK1 gene knockdown. Molecular docking suggested good interaction of Scu and PINK1 protein.

CONCLUSION

These results suggest that Scu may protect vascular endothelial cells against hyperglycemia-induced injury by up-regulating mitophagy via PINK1/Parkin signal pathway.

Scutellarin Inhibits the Growth and EMT of Gastric Cancer Cells through Regulating PTEN/PI3K Pathway

Gastric cancer is one of the most common malignancies with a high mortality rate world. This study intends to make clear the role and mechanism of the Scutellarin (Scu), a flavonoid isolated from Erigeron breviscapus (Vant.) Hand.-Mazz, in regulating the evolvement of gastric cancer. We selected different doses of Scu to treat gastric cancer cells (MGC-803 and AGS). Then, cell counting kit-8 (CCK8) assay was conducted to verify the proliferation of tumor cells, while flow cytometry was adopted to test the apoptosis rate. Meanwhile, Western blot was conducted to examine epithelial-mesenchymal transition (EMT) markers and the expression of phosphatase and tensin homolog (PTEN)/phosphatidylinositol 3-kinase (PI3K) and apoptosis-related proteins (Bax, Bcl2 and Caspase3). Moreover, xenograft tumor experiment in nude mice was established to verify the effect of Scu on tumor growth. Furthermore, the knockdown model of PTEN was constructed, and the influence of PTEN on the anti-tumor effect of Scu was investigated. As a result, Scu inhibited cell proliferation, EMT and promoted the apoptosis in gastric cancer dose-dependently. Additionally, Scu attenuated tumor cell growth in vivo. Besides, Scu enhanced the expression of PTEN while reduced the phosphorylated level of PI3K. Moreover, the mechanistic study proved that Scu inactivated PI3K by up-regulating PTEN, thus dampening tumor progression. In conclusion, Scu dampened the growth and EMT of gastric cancer by regulating the PTEN/PI3K pathway.

Scutellarin Reduce the Homocysteine Level and Alleviate Liver Injury in Type 2 Diabetes Model

Scutellarin (SCU) is an active ingredient extracted from Erigeron breviscapus (Vaniot) Hand.-Mazz. Its main physiological functions are anti-inflammatory and antioxidant. In this study, we established a STZ-induced model of type 2 diabetes (T2DM) and a homocysteine (Hcy)-induced apoptosis model of LO2 to investigate whether SCU can alleviate liver damage by regulating Hcy in type 2 diabetes. Biochemical analysis indicated that SCU could improve the lipid metabolism disorder and liver function in diabetic rats by downregulating the levels of triglycerides (TG), cholesterol (CHO), low-density lipoprotein (LDL), alanine transaminase (ALT) and aspartate transaminase (AST), and by upregulating the level of high-density lipoprotein (HDL). Interestingly, SCU also could down-regulate the levels of Hcy and insulin and enhance the ability of type 2 diabetic rats to regulate blood glucose. Mechanistically, our results indicated that SCU may control the level of Hcy through regulating the levels of β-Cystathionase (CBS), γ-Cystathionase (CSE) and 5,10-methylenetetrahydrofolate (MTHFR) in liver tissue, and up-regulate folic acid, VitB₆ and VitB₁₂ levels in serum. Furthermore, SCU inhibits apoptosis in the liver of T2DM rats and in cultured LO2 cells treated with Hcy. Together, our findings suggest that SCU may alleviate the liver injury thorough downregulating the level of Hcy in T2DM rats.

Antibiofilm activity of flavonoids on staphylococcal biofilms through targeting BAP amyloids

The opportunistic pathogen Staphylococcus aureus is responsible for causing infections related to indwelling medical devices, where this pathogen is able to attach and form biofilms. The intrinsic properties given by the self-produced extracellular biofilm matrix confer high resistance to antibiotics, triggering infections difficult to treat. Therefore, novel antibiofilm strategies targeting matrix components are urgently needed. The Biofilm Associated Protein, Bap, expressed by staphylococcal species adopts functional amyloid-like structures as scaffolds of the biofilm matrix. In this work we have focused on identifying agents targeting Bap-related amyloid-like aggregates as a strategy to combat S. aureus biofilm-related infections. We identified that the flavonoids, quercetin, myricetin and scutellarein specifically inhibited Bap-mediated biofilm formation of S. aureus and other staphylococcal species. By using in vitro aggregation assays and the cell-based methodology for generation of amyloid aggregates based on the Curli-Dependent Amyloid Generator system (C-DAG), we demonstrated that these polyphenols prevented the assembly of Bap-related amyloid-like structures. Finally, using an in vivo catheter infection model, we showed that quercetin and myricetin significantly reduced catheter colonization by S. aureus. These results support the use of polyphenols as anti-amyloids molecules that can be used to treat biofilm-related infections.

Treatment of tibial dyschondroplasia with traditional Chinese medicines: "Lesson and future directions"

Tibial dyschondroplasia (TD) is a metabolic tibiotarsal bone disease in rapidly growing birds throughout the world, which is characterized by gait disorders, reduced growth, and in an unrecoverable lameness in many cases. The short production cycle in chickens, long metabolism cycle in most of the drugs with the severe drug residue, and high treatment cost severely restrict the enthusiasm for the treatment of TD. Traditional Chinese medicine (TCM) has been used for the prevention, treatment, and cure of avian bone diseases. Previously, a couple of traditional Chinese medicines has been reported being useful in treating TD. This review will discuss the TCM used in TD and the alternative TCM to treat TD. Selecting a TCM approach and its pharmacologic effects on TD chickens mainly focused on the differentiation, proliferation, and apoptosis of chondrocytes, angiogenesis, matrix metabolism, oxidative damage, cytokines, and calcification of cartilage in tibia.

Loganin attenuates intestinal injury in severely burned rats by regulating the toll-like receptor 4/NF-κB signaling pathway

Severe burns may lead to intestinal inflammation and oxidative stress, resulting in intestinal barrier damage and gut dysfunction. Loganin, an iridoid glycoside compound, has been isolated from Cornus officinalis Sieb. et Zucc; however, its role in the treatment of burn injury is yet to be fully elucidated. Therefore, the present study examined the effect of loganin administration on burn-induced intestinal inflammation and oxidative stress after severe burns in male Sprague-Dawley rats. Histological injury was assessed by hematoxylin and eosin staining. Furthermore, cytokine expression in intestinal tissues was measured by ELISA and reverse transcription-quantitative PCR. Antioxidative activities were assessed by determining the levels of reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA). Apoptosis was detected by flow cytometry. Apoptosis-related proteins, toll-like receptor 4 (TLR4) protein and NF-κB translocation were examined by western blotting. Immunohistochemical staining was used to observe TLR4 and NF-κB p65 expression in intestinal tissues. The present study suggested that loganin administration significantly reduced burn injury-induced intestinal histological changes, tumor necrosis factor-α, interleukin (IL)-6 and IL-1β production and oxidative stress, evidenced by decreased ROS levels and MDA content (P<0.05). Furthermore, loganin increased SOD, CAT and GSH-Px levels and intestinal epithelial cell apoptosis. Loganin treatment also significantly inhibited activation of the TLR4/NF-κB signaling pathway in the intestine of severely burned rats (P<0.05). In conclusion, loganin reduced burns-induced intestinal inflammation and oxidative stress, potentially by regulating the TLR4/NF-κB signaling pathway.

Scutellarin Attenuates the IL-1β-Induced Inflammation in Mouse Chondrocytes and Prevents Osteoarthritic Progression

Osteoarthritis (OA) is a chronic degenerative disease wherein the articular cartilage exhibits inflammation and degradation. Scutellarin (SCU) is a flavonoid glycoside with a range of pharmacological activities, as shown in previous studies demonstrating its anti-inflammatory activity. How SCU impacts the progression of OA, however, has not been explored to date. Herein, we assessed the impact of SCU on murine chondrocytes in an OA model system. In in vitro assays, we measured chondrocyte expression of key OA-associated factors such as matrix metalloproteinase 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) via qRT-PCR and Western blotting, the expression of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) were detected by qRT-PCR. Our results showed that the downregulation of MMP-13, ADAMTS-5, COX-2, and iNOS expression by SCU and the overproduction of IL-6, TNF-α, and PGE2 induced by IL-1β were all inhibited by SCU in a concentration-dependent manner. Moreover, SCU was able to reverse aggrecan and collagen II degradation and nuclear factor-κB (NF-κB) and nuclear factor erythroid-derived 2-like 2 (Nrf2) signaling pathway activation both in vivo and in vitro. We further used a destabilization of the medial meniscus (DMM) murine model of OA to explore the therapeutic benefits of SCU in vivo. Together, our findings suggest SCU to be a potentially valuable therapeutic agent useful for treating OA.

Scutellarin suppresses cartilage destruction in osteoarthritis mouse model by inhibiting the NF-κB and PI3K/AKT signaling pathways

Osteoarthritis (OA), a common and severe disease, is predominantly characterized by cartilage destruction, which results in the degeneration of joint surfaces. Nowadays, it is accepted that TNFα plays a critical role in OA. Scutellarin, the main bioactive flavonoid glycoside extracted form Erigeron breviscapus, has been reported to exert positive effects on anti-inflammatory reactions. However, the effect of scutellarin in OA is still unknown. In this study, we isolated and cultured primary murine chondrocytes, stimulating TNF-α, in the presence or absence of scutellarin treatment. We found that the inflammatory response stimulated by TNF-α was significantly inhibited by the addition of scutellarin. Moreover, we established OA mouse models induced by surgery. In this mouse model, both inflammatory reaction and cartilage degeneration were markedly inhibited by oral administration of scutellarin. Furthermore, the cellular mechanism underlying the protective effect of scutellarin in OA was clearly associated with the NF-κB and PI3K/AKT signaling pathways. Collectively, this study proposes scutellarin as a potential therapeutic to treat joint degenerative diseases, including OA.

Kaempferol-3-O-glucorhamnoside inhibits inflammatory responses via MAPK and NF-κB pathways in vitro and in vivo

Klebsiella pneumoniae causes severe infections including pneumonia and sepsis and treatments are complicated by increased levels of antibiotic resistance. We have identified a flavonoid kaempferol-3-O-glucorhamnoside derived from the plant Thesium chinense Turcz that possessed potent anti-inflammatory effects in K. pneumoniae infected mice. Administration of kaempferol-3-O-glucorhamnoside before bacterial challenge effectively suppressed expression of the major inflammatory cytokines TNF-α, IL-6, IL-1β and PGE2 and ameliorated lung edema. In addition, administration of this compound to cultured RAW macrophages or Balb/c mice resulted in the suppression of NFκB and MAP kinase phosphorylation indicating an inhibitory effect on inflammation in vitro and in vivo. Kaempferol-3-O-glucorhamnoside also decreased ROS levels and overall oxidative stress in lungs and in cultured cells generated by K. pneumoniae exposure. Taken together, kaempferol-3-O-glucorhamnoside is a potent anti-inflammatory in vitro and in vivo and is a promising therapeutic agent for treating K. pneumoniae infections in the clinic.