Baicalin attenuates bleomycin-induced pulmonary fibrosis via adenosine A2a receptor related TGF-β1-induced ERK1/2 signaling pathway

Novel therapeutic strategies and drugs for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease of unknown etiology. Currently, drugs used to treat IPF in clinical practice exhibit severe side effects and limitations. To address these issues, this paper discusses the therapeutic effects of preclinical targeted drugs (such as STAT3 and TGF-β/Smad pathway inhibitors, chitinase inhibitors, PI3K and phosphodiesterase inhibitors, etc.) and natural products on IPF. Through a summary of current research progress, it is found that natural products possess multitarget effects, stable therapeutic efficacy, low side effects, and nondrug dependence. Furthermore, we discuss the significant prospects of natural product molecules in combating fibrosis by influencing the immune system, expecting that current analytical data will aid in the development of new drugs or the investigation of active ingredients in natural products for potential IPF treatments in the future.

Therapeutic effects of flavonoids on pulmonary fibrosis: A preclinical meta-analysis

BACKGROUND

The efficacy of flavonoid supplementation in animal models of pulmonary fibrosis has been demonstrated.

PURPOSE

We conducted a systematic review and meta-analysis to evaluate the efficacy and underlying mechanisms of flavonoids in animal models of bleomycin-induced pulmonary fibrosis.

STUDY DESIGN

Relevant studies (n = 45) were identified from English- and Chinese-language databases from the inception of the database until October 2023.

METHODS

Methodological quality was evaluated using the SYRCLE risk of bias tool. Statistical analyses were conducted using RevMan 5.3 and Stata 17.0. Lung inflammation and fibrosis score were the primary outcome indicators.

RESULTS

Flavonoids can alleviate pathological changes in the lungs. The beneficial effects of flavonoids on pulmonary fibrosis likely relate to their inhibition of inflammatory responses, restoration of oxidative and antioxidant homeostasis, and regulation of fibroblast proliferation, migration, and activation by transforming growth factor β1/mothers against the decapentaplegic homologue/AMP-activated protein kinase (TGF-β1/Smad3/AMPK), inhibitor kappa B alpha/nuclear factor-kappa B (IκBα/NF-κB), phosphatidylinositol 3-kinase (PI3K)/AKT, interleukin 6/signal transducer/activator of transcription 3 (IL6/STAT3), and nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathways.

CONCLUSION

Flavonoids are potential candidate compounds for the prevention and treatment of pulmonary fibrosis. However, extensive preclinical research is necessary to confirm the antifibrotic properties of natural flavonoids.

Flavonoids for treating pulmonary fibrosis: Present status and future prospects

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with an unknown underlying cause. There is no complete cure for IPF; however, two anti-fibrotic agents (Nintedanib and pirfenidone) are approved by the USFDA to extend the patient's life span. Therefore, alternative therapies supporting the survival of fibrotic patients have been studied in recent literature. The abundance of phenolic compounds, particularly flavonoids, has gathered attention due to their potential health benefits. Various flavonoids, like naringin, quercetin, baicalin, baicalein, puerarin, silymarin, and kaempferol, exhibit anti-inflammatory and anti-oxidant properties, which help decrease lung fibrosis. Various databases, including PubMed, EBSCO, ProQuest, and Scopus, as well as particular websites, such as the World Health Organisation and the National Institutes of Health, were used to conduct a literature search. Several mechanisms of action of flavonoids are reported with the help of in vivo and cell line studies emphasizing their ability to modulate oxidative stress, inflammation, and fibrotic processes in the lungs. They are reported for the restoration of biomarkers like hydroxyproline, cytokines, superoxide dismutase, malondialdehyde and others associated with IPF and for modulating various pathways responsible for the progression of pulmonary fibrosis. Yet, flavonoids have some drawbacks, such as poor solubility, challenging drug loading, stability issues, and scarce bioavailability. Therefore, novel formulations of flavonoids are explored, including liposomes, solid lipid microparticles, polymeric nanoparticles, nanogels, and nanocrystals, to enhance the therapeutic efficacy of flavonoids in pulmonary fibrosis. This review focuses on the role of flavonoids in mitigating idiopathic pulmonary fibrosis, their mode of action and novel formulations.

Monomeric compounds from natural products for the treatment of pulmonary fibrosis: a review

Pulmonary fibrosis (PF) is the end stage of lung injury and chronic lung diseases that results in diminished lung function, respiratory failure, and ultimately mortality. Despite extensive research, the pathogenesis of this disease remains elusive, and effective therapeutic options are currently limited, posing a significant clinical challenge. In addition, research on traditional Chinese medicine and naturopathic medicine is hampered by several complications due to complex composition and lack of reference compounds. Natural product monomers, possessing diverse biological activities and excellent safety profiles, have emerged as potential candidates for preventing and treating PF. The effective anti-PF ingredients identified can be generally divided into flavonoids, saponins, polysaccharides, and alkaloids. Specifically, these monomeric compounds can attenuate inflammatory response, oxidative stress, and other physiopathological processes of the lung through many signaling pathways. They also improve pulmonary factors. Additionally, they ameliorate epithelial-mesenchymal transition (EMT) and fibroblast-myofibroblast transdifferentiation (FMT) by regulating multiple signal amplifiers in the lungs, thereby mitigating PF. This review highlights the significant role of monomer compounds derived from natural products in reducing inflammation, oxidative stress, and inhibiting EMT process. The article provides comprehensive information and serves as a solid foundation for further exploration of new strategies to harness the potential of botanicals in the treatment of PF.

Anti-ROS and NIR-II-Responsive Hyaluronic Acid Microneedle Loaded With Baicalin Nanoparticles for Treatment of Psoriasis

In this work, a natural medicine, baicalin, is designed for the treatment of psoriasis with the aid of hyaluronic acid (HA)-based MNs patches. This is also to improve the solubility of baicalin and increase its residence time in infected part, which is made into nanoparticles by complexation with humic acid and Eu2+. The baicalin nanoparticles loaded-MNs exhibit satisfactory rigidity, minimum injury, and controlled drug delivery. The anti-reactive oxygen species (anti-ROS) and anti-inflammatory action are verified by the effective scavenging oxygen and nitrogen radicals. In addition, the loading of baicalin nanoparticles brings remarkable photothermic effect to the MNs, enabling the device to release a controlled drug under near-infrared region II (NIR-II) laser irradiation. With the aid of NIR-II laser, the baicalin-mediated treatment of psoriasis is significantly improved by expediting radical scavenging and suppressing inflammation. The design of baicalin MNs provides a new idea for the treatment of chronic disease.

A Chinese classical prescription Maimendong decoction in treatment of pulmonary fibrosis: an overview

Pulmonary fibrosis (PF) is a chronic and progressive disease characterized by fibrosis and interstitial pneumonia. It has similar clinical symptoms to "Fei Bi" and "Fei Wei" as described in the traditional Chinese medicine (TCM) classic Jingui Yaolue written by Zhang Zhongjing in the Han Dynasty. This study explored the potential of Maimendong Decoction (MMDD). MMDD consists of Ophiopogon japonicus (L.f) (ophiopogonis), Pinellia ternata (Thunb.) Breit. (pinellia), Panax ginseng C. A. Mey. (ginseng), Glycyrrhiza uralensis Fisch. (glycyrrhiza), Zizi phus jujuba Mill. (jujuba), and Oryza sativa L. (oryza sativa), with the function of nourishing the lung and stomach, and reducing the effect of reverse qi. It has been used clinically for over two thousand years to treat conditions like "Fei Bi" and "Fei Wei". Previous research suggests that MMDD and its individual herbal extracts have anti-fibrotic effects. The main focus of MMDD in treating PF is to reduce inflammatory cytokines, inhibit pro-fibrotic factors and oxidative stress, promote differentiation and homing of bone marrow mesenchymal stem cells, and enhance cell autophagy activity. This review summarized the clinical applications, mechanisms, and pharmacological effects of MMDD in treating PF based on existing clinical applications and experimental research. It also discussed current issues and prospects, aiming to provide a reference for further research on the mechanism of PF, drug development, and clinical trials.

Advances in Flavonoid Research: Sources, Biological Activities, and Developmental Prospectives

At present, the occurrence of a large number of infectious and non-communicable diseases poses a serious threat to human health as well as to drug development for the treatment of these diseases. One of the most significant challenges is finding new drug candidates that are therapeutically effective and have few or no side effects. In this respect, the active compounds in medicinal plants, especially flavonoids, are potentially useful compounds with a wide range of pharmacological activities. They are naturally present in nature and valuable in the treatment of many infectious and non-communicable diseases. Flavonoids are divided into fourteen categories and are mainly derived from plant extraction, chemical synthesis and structural modification, and biosynthesis. The structural modification of flavonoids is an important way to discover new drugs, but biosynthesis is currently considered the most promising research direction with the potential to revolutionize the new production pipeline in the synthesis of flavonoids. However, relevant problems such as metabolic pathway analyses and cell synthesis protocols for flavonoids need to be addressed on an urgent basis. In the present review, new research techniques for assessing the biological activities of flavonoids and the mechanisms of their biological activities are elucidated and their modes of interaction with other drugs are described. Moreover, novel drug delivery systems, such as nanoparticles, bioparticles, colloidals, etc., are gradually becoming new means of addressing the issues of poor hydrophilicity, lipophilicity, poor chemical stability, and low bioavailability of flavonoids. The present review summarizes the latest research progress on flavonoids, existing problems with their therapeutic efficacy, and how these issues can be solved with the research on flavonoids.

Baicalin and lung diseases

Studies focusing on natural products have been conducted worldwide, and the results suggest that their natural ingredients effectively treat a wide range of illnesses. Baicalin (BIA) is a glycoside derived from the flavonoid baicalein present in Scutellaria baicalensis of the Lamiaceae family. Interestingly, BIA has been shown to protect the lungs in several animal models used in numerous studies. Therefore, we fully analyzed the data of the studies that focused on BIA's lung protective function against various injuries and included them in this review. Interestingly, BIA exhibits promising effects against acute lung injury, lung fibrosis, pulmonary embolism, and lung remodelling associated with COPD, LPS, and paraquat insecticide. BAI exhibits anticancer activity against lung cancer. Additionally, BIA potently attenuates lung damage associated with infections. BIA primarily exerts its therapeutic effects by suppressing inflammation, oxidative stress immune response, and apoptosis pathways. Nrf2/HO-1, PI3K/Akt, NF-κB, STAT3, MAPKs, TLR4, and NLRP3 are important targets in the pulmonary therapeutic effects of BIA on different lung disease models. Consequently, we recommend using it in future potential clinical applications, its contribution to treatment guidelines, and translating its promising effects to clinical practice in lung diseases.

Improved Bioavailability and Hepatoprotective Activity of Baicalein Via a Self-assembled Solutol HS15 Micelles System

BACKGROUND

Baicalein (BA) is a flavonoid extract from the root of Scutellaria baicalensis Georgi with excellent biological activities, such as antioxidant and anti-inflammatory activities. However, its poor water solubility limits its further development.

OBJECTIVE

This study aims to prepare BA-loaded Solutol HS15 (HS15-BA) micelles, evaluate the bioavailability, and explore protective effects on carbon tetrachloride (CCl4) induced acute liver injury.

METHODS

The thin-film dispersion method was used to prepare HS15-BA micelles. The physicochemical, in vitro release, pharmacokinetics, and hepatoprotective effects of HS15-BA micelles were studied.

RESULTS

The optimal formulation showed a spherical shape by characterization of the transmission electron microscope (TEM) with an average small size (12.50 nm). The pharmacokinetic results illustrated that HS15-BA increased the oral bioavailability of BA. The in vivo results showed that HS15-BA micelles significantly inhibited the activity of the CCl4-induced liver injury marker enzymes aspartate transaminase (AST) and alanine transaminase (ALT). Also, CCl4 induced oxidative damage to liver tissue, leading to increased L-glutathione (GSH) and superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) activity, while HS15-BA significantly reversed the above changes. Moreover, BA also had a hepatoprotective effect through anti-inflammatory activity; the results of ELISA and RT-PCR revealed that HS15-BA pretreatment significantly inhibited the increase in the expression of inflammatory factors induced by CCl4.

CONCLUSION

In summary, our study confirmed that HS15-BA micelles enhanced the bioavailability of BA, and showed hepatoprotective effects through antioxidant and anti-inflammatory activities. HS15 could be considered a promising oral delivery carrier in treating liver disease.

Astragaloside IV protects against lung injury and pulmonary fibrosis in COPD by targeting GTP-GDP domain of RAS and downregulating the RAS/RAF/FoxO signaling pathway

BACKGROUND

Pulmonary fibrosis is a chronic progressive interstitial lung disease characterized by the replacement of lung parenchyma with fibrous scar tissue, usually as the final stage of lung injury like COPD. Astragaloside IV (AST), a bioactive compound found in the Astragalus membranaceus (Fisch.) used in traditional Chinese medicine, has been shown to improve pulmonary function and exhibit anti-pulmonary fibrosis effects. However, the exact molecular mechanisms through which it combats pulmonary fibrosis, especially in COPD, remain unclear.

PURPOSE

This study aimed to identify the potential therapeutic target and molecular mechanisms for AST in improving lung injury especially treating COPD type pulmonary fibrosis both in vivo and in vitro.

METHODS

Multi lung injury models were established in mice using lipopolysaccharide (LPS), cigarette smoke (CS), or LPS plus CS to simulate the processes of pulmonary fibrosis in COPD. The effect of AST on lung function protection was evaluated, and proteomic and metabolomic analysis were applied to identify the signaling pathway affected by AST and to find potential targets of AST. The interaction between AST and wild-type and mutant RAS proteins was studied. The RAS/RAF/FoxO signaling pathway was stimulated in BEAS-2B cells and in mice lung tissues by LPS plus CS to investigate the anti-pulmonary fibrosis mechanism of AST analyzed by western blotting. The regulatory effects of AST on the RAS/RAF/FoxO pathway dependent on RAS were further confirmed using RAS siRNA.

RESULTS

RAS was predicted and identified as the target protein of AST in anti-pulmonary fibrosis in COPD and improving lung function. The administration of AST was observed to impede the conversion of fibroblasts into myofibroblasts, reduce the manifestation of inflammatory factors and extracellular matrix, and hinder the activation of epithelial mesenchymal transition (EMT). Furthermore, AST significantly suppressed the RAS/RAF/FoxO signaling pathway in both in vitro and in vivo settings.

CONCLUSION

AST exhibited lung function protection and anti-pulmonary fibrosis effect by inhibiting the GTP-GDP domain of RAS, which downregulated the RAS/RAF/FoxO signaling pathway. This study revealed AST as a natural candidate molecule for the protection of pulmonary fibrosis in COPD.

Asarinin attenuates bleomycin-induced pulmonary fibrosis by activating PPARγ

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease that lacks effective treatment modalities. Once patients are diagnosed with IPF, their median survival is approximately 3-5 years. PPARγ is an important target for the prevention and treatment of pulmonary fibrosis. Asarinin is a lignan compound that can be extracted from food plant Asarum heterotropoides. In this study, we investigated the therapeutic effects of asarinin in a pulmonary fibrosis model constructed using bleomycin in mice and explored the underlying mechanisms. Intraperitoneal administration of asarinin to mice with pulmonary fibrosis showed that asarinin effectively attenuated pulmonary fibrosis, and this effect was significantly inhibited by the PPARγ inhibitor GW9662. Asarinin inhibited TGF-β1-induced fibroblast-to-myofibroblast transition in vitro, while GW9662 and PPARγ gene silencing significantly inhibited this effect. In addition, asarinin inhibited not only the canonical Smad pathway of TGF-β but also the non-canonical AKT and MAPK pathways by activating PPARγ. Our study demonstrates that asarinin can be used as a therapeutic agent for pulmonary fibrosis, and that PPARγ is its key target.

Natural plant resource flavonoids as potential therapeutic drugs for pulmonary fibrosis

Pulmonary fibrosis is an enduring and advancing pulmonary interstitial disease caused by multiple factors that ultimately lead to structural changes in normal lung tissue. Currently, pulmonary fibrosis is a global disease with a high degree of heterogeneity and mortality rate. Nitidine and pirfenidone have been approved for treating pulmonary fibrosis, and the quest for effective therapeutic drugs remains unabated. In recent years, the anti-pulmonary fibrosis properties of natural flavonoids have garnered heightened attention, although further research is needed. In this paper, the resources, structural characteristics, anti-pulmonary fibrosis properties and mechanisms of natural flavonoids were reviewed. We hope to provide potential opportunities for the application of flavonoids in the fight against pulmonary fibrosis.

An overview of anti-SARS-CoV-2 and anti-inflammatory potential of baicalein and its metabolite baicalin: Insights into molecular mechanisms

The current Coronavirus Disease 2019 (COVID-19) pandemic, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is highly contagious infection that breaks the healthcare systems of several countries worldwide. Till to date, no effective antiviral drugs against COVID-19 infection have reached the market, and some repurposed drugs and vaccines are prescribed for the treatment and prevention of this disease. The currently prescribed COVID-19 vaccines are less effective against the newly emergent variants of concern of SARS-CoV-2 due to several mutations in viral spike protein and obviously there is an urgency to develop new antiviral drugs against this disease. In this review article, we systematically discussed the anti-SARS-CoV-2 and anti-inflammatory efficacy of two flavonoids, baicalein and its 7-O-glucuronide, baicalin, isolated from Scutellaria baicalensis, Oroxylum indicum, and other plants as well as their pharmacokinetics and oral bioavailability, for development of safe and effective drugs for COVID-19 treatment. Both baicalein and baicalin target the activities of viral S-, 3CL-, PL-, RdRp- and nsp13-proteins, and host mitochondrial OXPHOS for suppression of viral infection. Moreover, these compounds prevent sepsis-related inflammation and organ injury by modulation of host innate immune responses. Several nanoformulated and inclusion complexes of baicalein and baicalin have been reported to increase oral bioavailability, but their safety and efficacy in SARS-CoV-2-infected transgenic animals are not yet evaluated. Future studies on these compounds are required for use in clinical trials of COVID-19 patients.

Protective role of baicalin in the dynamic progression of lung injury to idiopathic pulmonary fibrosis: A meta-analysis

BACKGROUND AND PURPOSE

The pathological progression of lung injury (LI) to idiopathic pulmonary fibrosis (IPF) is a common feature of the development of lung disease. At present, effective strategies for preventing this progression are unavailable. Baicalin has been reported to specifically inhibit the progression of LI to IPF. Therefore, this meta-analysis aimed to assess its clinical application and its potential as a therapeutic drug for lung disease based on integrative analysis.

METHODS

We systematically searched preclinical articles in eight databases and reviewed them subjectively. The CAMARADES scoring system was used to assess the degree of bias and quality of evidence, whereas the STATA software (version 16.0 software) was used for statistical analysis, including a 3D analysis of the effects of dosage frequency of baicalin in LI and IPF. The protocol of this meta-analysis is documented in the PROSPERO database (CRD42022356152).

RESULTS

A total of 23 studies and 412 rodents were included after several rounds of screening. Baicalin was found to reduce the levels of TNF-α, IL-1β, IL-6, HYP, TGF-β and MDA and the W/D ratio and increase the levels of SOD. Histopathological analysis of lung tissue validated the regulatory effects of baicalin, and the 3D analysis of dosage frequency revealed that the effective dose of baicalin is 10-200 mg/kg. Mechanistically, baicalin can prevent the progression of LI to IPF by modulating p-Akt, p-NF-κB-p65 and Bcl-2-Bax-caspase-3 signalling. Additionally, baicalin is involved in signalling pathways closely related to anti-apoptotic activity and regulation of lung tissue and immune cells.

CONCLUSION

Baicalin at the dose of 10-200 mg/kg exerts protective effects against the progression of LI to IPF through anti-inflammatory and anti-apoptotic pathways.

The Pharmacological Efficacy of Baicalin in Inflammatory Diseases

Baicalin is one of the most abundant flavonoids found in the dried roots of Scutellaria baicalensis Georgi (SBG) belonging to the genus Scutellaria. While baicalin is demonstrated to have anti-inflammatory, antiviral, antitumor, antibacterial, anticonvulsant, antioxidant, hepatoprotective, and neuroprotective effects, its low hydrophilicity and lipophilicity limit the bioavailability and pharmacological functions. Therefore, an in-depth study of baicalin's bioavailability and pharmacokinetics contributes to laying the theoretical foundation for applied research in disease treatment. In this view, the physicochemical properties and anti-inflammatory activity of baicalin are summarized in terms of bioavailability, drug interaction, and inflammatory conditions.

Baicalin/ambroxol hydrochloride combined dry powder inhalation formulation targeting lung delivery for treatment of idiopathic pulmonary fibrosis: fabrication, characterization, pharmacokinetics, and pharmacodynamics

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and often fatal lung disease caused by multiple factors. Currently, safe, and effective drugs for the treatment of IPF have been extremely scarce. Baicalin (BA) is used to treat pulmonary fibrosis, IPF, chronic obstructive pulmonary disease, and other lung diseases. Ambroxol hydrochloride (AH), a respiratory tract lubricant and expectorant, is often used to treat chronic respiratory diseases, such as bronchial asthma, emphysema, tuberculosis, and cough. The combination of BA and AH can relieve cough and phlegm, improve lung function, and potentially treat IPF and its symptoms. However, given the extremely low solubility of BA, its bioavailability for oral absorptions is also low. AH, on the other hand, has been associated with certain side effects, such as gastrointestinal tract and acute allergic reactions, which limit its applicability. Therefore, an efficient drug delivery system is urgently needed to address the mentioned problems. This study combined BA and AH as model drugs with L-leucine (L-leu) as the excipient to prepare BA/AH dry powder inhalations (BA/AH DPIs) using the co-spray drying method. We the performed modern pharmaceutical evaluation, which includes particle size, differential scanning calorimetry analysis, X-ray diffraction, scanning electron microscope, hygroscopicity, in vitro aerodynamic analysis, pharmacokinetics, and pharmacodynamics. Notably, BA/AH DPIs were found to be advantageous over BA and AH in treating IPF and had better efficacy in improving lung function than did the positive drug pirfenidone. The BA/AH DPI is a promising preparation for the treatment of IPF given its lung targeting, rapid efficacy, and high lung bioavailability.

Tanreqing injection protects against bleomycin-induced pulmonary fibrosis via inhibiting STING-mediated endoplasmic reticulum stress signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Idiopathic pulmonary fibrosis (IPF), characterized by excessive collagen deposition, is a progressive and typically fatal lung disease without effective therapeutic methods. Tanreqing injection (TRQ), a Traditional Chinese Patent Medicine, has been widely used to treat inflammatory respiratory diseases clinically.

AIM OF THE STUDY

The present work aims to elucidate the therapeutic effects and the possible mechanism of TRQ against pulmonary fibrosis.

METHODS

The pulmonary fibrosis murine model were constructed by the intratracheal injection of bleomycin (BLM). 7 days later, TRQ-L (2.6 ml/kg) and TRQ-H (5.2 ml/kg) were administered via intraperitoneal injection respectively for 21 days. The efficacy and underlying molecular mechanism of TRQ were investigated.

RESULTS

Here, we showed that TRQ significantly inhibited BLM-induced lung edema and pulmonary function. TRQ markedly reduced BLM-promoted inflammatory cell infiltration in BALF and inflammatory cytokines release (TNF-α, IL-6, and IL-1β) in serum and lung tissues. Meanwhile, TRQ also alleviated BLM-induced collagen synthesis and deposition. Simultaneously, TRQ attenuated BLM-induced pulmonary fibrosis through regulating the expression of fibrotic hallmarks, manifested by down-regulated α-SMA and up-regulated E-cadherin. Moreover, we found that TRQ significantly prevented STING, p-P65, BIP, p-PERK, p-eIF2α, and ATF4 expression in lung fibrosis mice.

CONCLUSIONS

Taken together, our results indicated that TRQ positively affects inflammatory responses and lung fibrosis by regulating STING-mediated endoplasmic reticulum stress (ERS) signal pathway.

Berberine attenuates epithelial mesenchymal transition in bleomycin-induced pulmonary fibrosis in mice via activating A2aR and mitigating the SDF-1/CXCR4 signaling

AIMS

Berberine is endowed with anti-oxidant, anti-inflammatory and anti-fibrotic effects. This study explored the role of adenosine A_2a receptor (A_2aR) activation and SDF-1/CXCR4 signaling suppression in the protective effects of berberine in bleomycin-induced pulmonary fibrosis in mice.

MAIN METHODS

Pulmonary fibrosis was generated in mice by injecting bleomycin (40 U/kg, i.p.) on days 0, 3, 7, 10 and 14. Mice were treated with berberine (5 mg/kg, i.p.) from day 15 to day 28.

KEY FINDINGS

Severe lung fibrosis and increased collagen content were observed in the bleomycin-challenged mice. Pulmonary A_2aR downregulation was documented in bleomycin-induced pulmonary fibrosis animals and was accompanied by enhanced expression of SDF-1/CXCR4. Moreover, TGF-β1elevation and pSmad2/3 overexpression were reported in parallel with enhanced epithelial mesenchymal transition (EMT) markers expression, vimentin and α-SMA. Besides, bleomycin significantly elevated the inflammatory and pro-fibrogenic mediator NF-κB p65, TNF-α and IL-6. Furthermore, bleomycin administration induced oxidative stress as depicted by decreased Nrf2, SOD, GSH and catalase levels. Interestingly, berberine administration markedly ameliorated the fibrotic changes in lungs by modulating the purinergic system through the inhibition of A_2aR downregulation, mitigating EMT and effectively suppressing inflammation and oxidative stress. Strikingly, A_2aR blockade by SCH 58261, impeded the pulmonary protective effect of berberine.

SIGNIFICANCE

These findings indicated that berberine could attenuate the pathological processes of bleomycin-induced pulmonary fibrosis at least partially via upregulating A_2aR and mitigating the SDF-1/CXCR4 related pathway, suggesting A_2aR as a potential therapeutic target for the management of pulmonary fibrosis.

The protective effects of baicalin for respiratory diseases: an update and future perspectives

Background: Respiratory diseases are common and frequent diseases. Due to the high pathogenicity and side effects of respiratory diseases, the discovery of new strategies for drug treatment is a hot area of research. Scutellaria baicalensis Georgi (SBG) has been used as a medicinal herb in China for over 2000 years. Baicalin (BA) is a flavonoid active ingredient extracted from SBG that BA has been found to exert various pharmacological effects against respiratory diseases. However, there is no comprehensive review of the mechanism of the effects of BA in treating respiratory diseases. This review aims to summarize the current pharmacokinetics of BA, baicalin-loaded nano-delivery system, and its molecular mechanisms and therapeutical effects for treating respiratory diseases.

Method: This review reviewed databases such as PubMed, NCBI, and Web of Science from their inception to 13 December 2022, in which literature was related to “baicalin”, “Scutellaria baicalensis Georgi”, “COVID-19”, “acute lung injury”, “pulmonary arterial hypertension”, “asthma”, “chronic obstructive pulmonary disease”, “pulmonary fibrosis”, “lung cancer”, “pharmacokinetics”, “liposomes”, “nano-emulsions”, “micelles”, “phospholipid complexes”, “solid dispersions”, “inclusion complexes”, and other terms.

Result: The pharmacokinetics of BA involves mainly gastrointestinal hydrolysis, the enteroglycoside cycle, multiple metabolic pathways, and excretion in bile and urine. Due to the poor bioavailability and solubility of BA, liposomes, nano-emulsions, micelles, phospholipid complexes, solid dispersions, and inclusion complexes of BA have been developed to improve its bioavailability, lung targeting, and solubility. BA exerts potent effects mainly by mediating upstream oxidative stress, inflammation, apoptosis, and immune response pathways. It regulates are the NF-κB, PI3K/AKT, TGF-β/Smad, Nrf2/HO-1, and ERK/GSK3β pathways.

Conclusion: This review presents comprehensive information on BA about pharmacokinetics, baicalin-loaded nano-delivery system, and its therapeutic effects and potential pharmacological mechanisms in respiratory diseases. The available studies suggest that BA has excellent possible treatment of respiratory diseases and is worthy of further investigation and development.

Pharmacological effects of baicalin in lung diseases

The flavonoids baicalin and baicalein were discovered in the root of Scutellaria baicalensis Georgi and are primarily used in traditional Chinese medicine, herbal supplements and healthcare. Recently, accumulated investigations have demonstrated the therapeutic benefits of baicalin in treating various lung diseases due to its antioxidant, anti-inflammatory, immunomodulatory, antiapoptotic, anticancer, and antiviral effects. In this review, the PubMed database and ClinicalTrials website were searched with the search string "baicalin" and "lung" for articles published between September 1970 and March 2023. We summarized the therapeutic role that baicalin plays in a variety of lung diseases, such as chronic obstructive pulmonary disease, asthma, pulmonary fibrosis, pulmonary hypertension, pulmonary infections, acute lung injury/acute respiratory distress syndrome, and lung cancer. We also discussed the underlying mechanisms of baicalin targeting in these lung diseases.

Baicalin Ameliorates Radiation-Induced Lung Injury by Inhibiting the CysLTs/CysLT1 Signaling Pathway

Objective

Radiation-induced lung injury (RILI) is a common complication of radiotherapy for thoracic tumors. This study investigated the alleviating effect of baicalin (BA) on RILI and its possible mechanism.

Methods

RILI model was established by chest irradiation (IR) of C57BL/6 mice for 16 weeks. Different concentrations of BA were administered, and dexamethasone (DXM) was used as a positive control. Then, the lung pathological changes were observed by HE and Masson staining. The levels of TGF-β, TNF-α, IL-1β, IL-6, CysLT, LTC4, and LTE4 were measured by ELISA. The CysLT1 expression was detected by qPCR, immunohistochemistry, and western blot. Type II AEC cells were pretreated with LTD-4 to establish the RILI cell model and intervened with different concentrations of BA. Then, the collagen I protein level was measured by ELISA. The CysLT1 and α-SMA expression were detected by qPCR, immunofluorescence, and western blot.

Results

BA could effectively improve lung histopathological changes and pulmonary fibrosis. In vivo, BA could inhibit the levels of TGF-β, TNF-α, IL-1β, and IL-6 and reduce the levels of CysLT, LTC4, and LTE4. In vitro, different concentrations of LTD4 could reduce the viability of type II AEC cells, which could be reversed by the administration of different concentrations of BA. In addition, BA could reduce CysLT1 mRNA, as well as CysLT1 and α-SMA protein levels in vitro and in vivo.

Conclusion

BA attenuated lung inflammation and pulmonary fibrosis by inhibiting the CysLTs/CysLT1 pathway, thereby protecting against RILI.

Scutellaria baicalensis and its constituents baicalin and baicalein as antidotes or protective agents against chemical toxicities: a comprehensive review

Scutellaria baicalensis (SB), also known as the Chinese skullcap, has a long history of being used in Chinese medicine to treat a variety of conditions ranging from microbial infections to metabolic syndrome and malignancies. Numerous studies have reported that treatment with total SB extract or two main flavonoids found in its root and leaves, baicalin (BA) and baicalein (BE), can prevent or alleviate the detrimental toxic effects of exposure to various chemical compounds. It has been shown that BA and BE are generally behind the protective effects of SB against toxicants. This paper aimed to review the protective and therapeutic effects of SB and its main components BA and BE against chemical compounds that can cause intoxication after acute or chronic exposure and seriously affect different vital organs including the brain, heart, liver, and kidneys. In this review paper, we had a look into a total of 221 in vitro and in vivo studies from 1995 to 2021 from the scientific databases PubMed, Scopus, and Web of Science which reported protective or therapeutic effects of BA, BE, or SB against drugs and chemicals that one might be exposed to on a professional or accidental basis and compounds that are primarily used to simulate disease models. In conclusion, the protective effects of SB and its flavonoids can be mainly attributed to increase in antioxidants enzymes, inhibition of lipid peroxidation, reduction of inflammatory cytokines, and suppression of apoptosis pathway.

Wenfei Buqi Tongluo Formula Against Bleomycin-Induced Pulmonary Fibrosis by Inhibiting TGF-β/Smad3 Pathway

Pulmonary fibrosis (PF) is the end stage of various chronic and progressive interstitial lung diseases. TGF-β, a profibrotic cytokine, can promote epithelial–mesenchymal transition (EMT), extracellular matrix (ECM) accumulation, and fibroblast proliferation, which contribute to progressive lung remodeling in PF. The Wenfei Buqi Tongluo (WBT) formula has been certified to be effective in the prevention and treatment of PF in clinical practice and has inhibitory effects on EMT, inflammation, and profibrotic factors. However, the pharmacological mechanisms of WBT against PF need to be further explored. In this study, we first analyzed the chemical components of the WBT formula using the UHPLC/Q-TOF-MS analysis. The potential targets of the identified compounds from WBT were predicted by the network pharmacology, which was confirmed by in vivo and in vitro study. After screening by the PubChem database, we first identified the 36 compounds of WBT and predicted the TGF-β signaling pathway, with ECM degradation as potential mechanism of WBT against PF by the network pharmacology. Furthermore, WBT treatment inhibited the levels of TGF-β and Smad3 phosphorylation and subsequently alleviated EMT and ECM accumulation in the bleomycin-induced mouse model and TGF-β1–induced cell model. These findings indicate that WBT can block the progressive process of PF by inhibiting EMT and promoting ECM degradation via the TGF-β/Smad3 pathway. This study may provide new insights into the molecular mechanism of WBT for the prevention and treatment of PF in the clinical application.

Baicalin protects against insulin resistance and metabolic dysfunction through activation of GALR2/GLUT4 signaling

BACKGROUND

Type 2 diabetes mellitus is a complex metabolic disorder associated with obesity, glucose intolerance and insulin resistance. Activation of GALR2 has been proposed as a therapeutic target for the treatment of insulin resistance. The previous studies showed that baicalin could mitigate insulin resistance, but the detailed mechanism of baicalin on insulin resistance has not been fully explored yet.

PURPOSE

In the present study, we evaluated whether baicalin mitigated insulin resistance via activation of GALR2 signaling pathway.

STUDY DESIGN/METHODS

Baicalin (25 mg/kg/d and 50 mg/kg/d) and/or GALR2 antagonist M871 (10 mg/kg/d) were injected individually or in combinations into obese mice once a day for three weeks, and normal and GALR2 knockdown myotubes were treated with baicalin (100 μM and 400 μM) or metformin (4 mM) in the absence or presence of M871 (800 nM) for 12 h, respectively. The molecular mechanism was explored in skeletal muscle and L6 myotubes.

RESULTS

The present findings showed that baicalin mitigated hyperglycemia and insulin resistance and elevated the levels of PGC-1α, GLUT4, p-p38MAPK, p-AKT and p-AS160 in skeletal muscle of obese mice. Strikingly, the baicalin-induced beneficial effects were abolished by GALR2 antagonist M871 in obese mice. In vitro, baicalin dramatically augmented glucose consumption and the activity of PGC1α-GLUT4 axis in myotubes through activation of p38MAPK and AKT pathways. Moreover, baicalin-induced elevations in glucose consumption related genes were abolished by GALR2 antagonist M871 or silencing of GALR2 in myotubes.

CONCLUSIONS

The present study for the first time demonstrated that baicalin protected against insulin resistance and metabolic dysfunction mainly through activation of GALR2-GLUT4 signal pathway. Our findings identified that activation of GALR2-GLUT4 signal pathway by baicalin could be a new therapeutic approach to treat insulin resistance and T2DM in clinic.

An overview of pharmacological activities of baicalin and its aglycone baicalein: New insights into molecular mechanisms and signaling pathways

The flavonoids, baicalin, and its aglycone baicalein possess multi-fold therapeutic properties and are mainly found in the roots of Oroxylum indicum (L.) Kurz and Scutellaria baicalensis Georgi. These flavonoids have been reported to possess various pharmacological properties, including antibacterial, antiviral, anticancer, anticonvulsant, anti-oxidant, hepatoprotective, and neuroprotective effects. The pharmacological properties of baicalin and baicalein are due to their abilities to scavenge reactive oxygen species (ROS) and interaction with various signaling molecules associated with apoptosis, inflammation, autophagy, cell cycle, mitochondrial dynamics, and cytoprotection. In this review, we summarized the molecular mechanisms underlying the chemopreventive and chemotherapeutic applications of baicalin and baicalein in the treatment of cancer and inflammatory diseases. In addition, the preventive effects of baicalin and baicalein on mitochondrial dynamics and functions were highlighted with a particular emphasis on their anti-oxidative and cytoprotective properties. The current review highlights could be useful for future prospective studies to further improve the pharmacological applications of baicalein and baicalin. These studies should define the threshold for optimal drug exposure, dose optimization and focus on therapeutic drug monitoring, objective disease markers, and baicalin/baicalein drug levels.

Anti-Inflammatory Effects and Mechanisms of Pudilan Antiphlogistic Oral Liquid

Pudilan antiphlogistic oral liquid (PDL) is a commercial traditional Chinese medicine widely used in the treatment of a variety of inflammatory diseases. However, the specific mechanisms of PDL's anti-inflammatory effects have not been fully understood. In this research, five classic inflammatory models and a network pharmacology-based strategy were utilized to evaluate its anti-inflammatory efficacy and elucidate its multicomponent and multitarget mode of the anti-inflammatory mechanism. A systems pharmacology approach was carried out via a holistic process of active compound screening, target acquisition, network construction, and further analysis. The potential component-target-associated anti-inflammatory mechanisms of PDL were further verified both in vivo and in vitro. The results showed that PDL exhibited a proven anti-inflammatory effect on multiple types of inflammatory models, including β-hemolytic streptococcus-induced acute pharyngitis, LPS-induced acute lung injury, xylene-induced ear swelling, carrageenan-induced paw edema, and acetic acid-induced capillary permeability-increasing models. Systems pharmacology analysis predicted 45 ingredients of PDL that interact with 185 targets, of which 38 overlapped with the inflammation-related targets. Furthermore, KEGG pathway analysis showed that the predicted targets were mainly involved in hypoxia-inducible factor (HIF)-1, tumor necrosis factor (TNF), nuclear factor kappa-B (NF-κB), and NOD-like receptor (NLR) pathways. Both in vivo and in vitro experiments clarified that PDL has anti-inflammatory potency by inhibiting PI3K and p38 phosphorylation and activating the NLRP3 inflammasome. Our results suggested that PDL has an efficient and extensive anti-inflammatory effect, and its anti-inflammatory mechanisms may involve multiple inflammatory-associated signaling pathways, including HIF-1- and TNF-mediated pathways and NLRP3 inflammasome activation.

A metabolomic approach to elucidate the inhibitory effects of baicalin in pulmonary fibrosis

CONTEXT

Baicalin, a major flavonoid extracted from Scutellaria baicalensis Georgi (Lamiaceae), has been shown to exert therapeutic effects on pulmonary fibrosis (PF).

OBJECTIVE

To use serum metabolomics combined with biochemical and histopathological analyses to clarify anti-PF mechanisms of baicalin on metabolic pathways and the levels of potential biomarkers.

MATERIALS AND METHODS

Forty male Sprague-Dawley rats were randomly divided into the control, PF model, prednisolone acetate-treated (4.2 mg/kg/day) and baicalin-treated (25 and 100 mg/kg/day) groups. A rat model of PF was established using a tracheal injection of bleomycin, and the respective drugs were administered intragastrically for 4 weeks. Histomorphology of lung tissue was examined after H&E and Masson's trichrome staining. Biochemical indicators including SOD, MDA and HYP were measured. Serum-metabonomic analysis based on UPLC-Q-TOF/MS was used to clarify the changes in potential biomarkers among different groups of PF rats.

RESULTS

Both doses of baicalin effectively alleviated bleomycin-induced pathological changes, and increased the levels of SOD (from 69.48 to 99.50 and 112.30, respectively), reduced the levels of MDA (from 10.91 to 5.0 and 7.53, respectively) and HYP (from 0.63 to 0.41 and 0.49, respectively). Forty-eight potential biomarkers associated with PF were identified. Meanwhile, the metabolic profiles and fluctuating metabolite levels were normalized or partially reversed after baicalin treatment. Furthermore, baicalin was found to improve PF potentially by the regulation of four key biomarkers involving taurine and hypotaurine metabolism, glutathione metabolism, and glycerophospholipid metabolism.

CONCLUSIONS

These findings revealed the anti-fibrotic mechanisms of baicalin and it may be considered as an effective therapy for PF.

A novel definition and treatment of hyperinflammation in COVID-19 based on purinergic signalling

Hyperinflammation plays an important role in severe and critical COVID-19. Using inconsistent criteria, many researchers define hyperinflammation as a form of very severe inflammation with cytokine storm. Therefore, COVID-19 patients are treated with anti-inflammatory drugs. These drugs appear to be less efficacious than expected and are sometimes accompanied by serious adverse effects. SARS-CoV-2 promotes cellular ATP release. Increased levels of extracellular ATP activate the purinergic receptors of the immune cells initiating the physiologic pro-inflammatory immune response. Persisting viral infection drives the ATP release even further leading to the activation of the P2X7 purinergic receptors (P2X7Rs) and a severe yet physiologic inflammation. Disease progression promotes prolonged vigorous activation of the P2X7R causing cell death and uncontrolled ATP release leading to cytokine storm and desensitisation of all other purinergic receptors of the immune cells. This results in immune paralysis with co-infections or secondary infections. We refer to this pathologic condition as hyperinflammation. The readily available and affordable P2X7R antagonist lidocaine can abrogate hyperinflammation and restore the normal immune function. The issue is that the half-maximal effective concentration for P2X7R inhibition of lidocaine is much higher than the maximal tolerable plasma concentration where adverse effects start to develop. To overcome this, we selectively inhibit the P2X7Rs of the immune cells of the lymphatic system inducing clonal expansion of Tregs in local lymph nodes. Subsequently, these Tregs migrate throughout the body exerting anti-inflammatory activities suppressing systemic and (distant) local hyperinflammation. We illustrate this with six critically ill COVID-19 patients treated with lidocaine.

Adenosine A2A receptor antagonism protects against hyperoxia-induced retinal vascular loss via cellular proliferation

Retinopathy of prematurity (ROP) remains one of the major causes of blindness in children worldwide. While current ROP treatments are mostly disruptive to reduce proliferative neovascularization by targeting the hypoxic phase, protection against early hyperoxia-induced retinal vascular loss represents an effective therapeutic window, but no such therapeutic strategy is available. Built upon our recent demonstration that the protection against oxygen-induced retinopathy by adenosine A_2A receptor (A_2A R) antagonists is most effective when administered at the hyperoxia (not hypoxic) phase, we here uncovered the cellular mechanism underlying the A_2A R-mediated protection against early hyperoxia-induced retinal vascular loss by reversing the inhibition of cellular proliferation via possibly multiple signaling pathways. Specifically, we revealed two distinct stages of the hyperoxia phase with greater cellular proliferation and apoptosis activities and upregulation of adenosine signaling at postnatal 9 day (P9) but reduced cellular activities and adenosine-A_2A R signaling at P12. Importantly, the A_2A R-mediated protection at P9 was associated with the reversal of hyperoxia-induced inhibition of progenitor cells at the peripheral retina at P9 and of retinal endothelial proliferation at P9 and P12. The critical role of cellular proliferation in the hyperoxia-induced retinal vascular loss was validated by the increased avascular areas by siRNA knockdown of the multiple signaling molecules involved in modulation of cellular proliferation, including activin receptor-like kinase 1, DNA-binding protein inhibitor 1, and vascular endothelial growth factor-A.

Baicalin Promotes Mammary Gland Development via Steroid-Like Activities

Baicalin, the main flavonoid component extracted from Scutellaria roots, has a variety of biological activities and is therefore used in the treatment of many kinds of diseases. However, whether baicalin affects the normal development of tissues and organs is still unclear. Here, using a mouse mammary gland model, we investigated the effects of baicalin on the expansion of mammary stem cells (MaSCs) and mammary development, as well as breast cancer progression. Interestingly, we found that baicalin administration significantly accelerates duct elongation at puberty, and promotes alveolar development and facilitates milk secretion during pregnancy. Furthermore, self-renewal of MaSCs was significantly promoted in the presence of baicalin. Moreover, in a tumor xenograft model, baicalin promoted tumor growth of the MDA-MB-231 cell line, but suppressed tumor growth of the ZR-751 cell line. Mechanistically, baicalin can induce expression of the protein C receptor, while inhibiting the expression of the estrogen receptor. Transcriptome analysis revealed that baicalin is involved in signaling pathways related to mammary gland development, immune response, and cell cycle control. Taken together, our results from comprehensive investigation of the biological activity of baicalin provide a theoretical basis for its rational clinical application.

The role of natural products in the prevention and treatment of pulmonary fibrosis: a review

Pulmonary fibrosis is an incurable end-stage lung disease and remains a global public health problem. Although there have been some breakthroughs in understanding the pathogenesis of pulmonary fibrosis, effective intervention methods are still limited. Natural products have the advantages of multiple biological activities and high levels of safety, which are important factors for preventing and treating pulmonary fibrosis. In this review, we summarized the mechanisms and health benefits of natural products against pulmonary fibrosis. These natural products target oxidative stress, inflammatory injury, epithelial-mesenchymal transition (EMT), fibroblast activation, extracellular matrix accumulation and metabolic regulation, and the mechanisms involve the NF-κB, TGF-β1/Smad, PI3K/Akt, p38 MAPK, Nrf2-Nox4, and AMPK signaling pathways. We hope to provide new ideas for pulmonary fibrosis prevention and treatment strategies.

Active Components from Traditional Herbal Medicine for the Potential Therapeutics of Idiopathic Pulmonary Fibrosis: A Systemic Review

Idiopathic pulmonary fibrosis (IPF), a tumor-like disease, is a serious and fatal pulmonary inflammatory condition usually characterized by irreversible destruction of the lung parenchyma, excessive matrix accumulation, and decline in lung function. IPF still remains a great burden to the universe. At the moment, the available therapeutic regimens utilized for IPF such as non-pharmacological therapies (lung transplantation) and pharmacological therapies (drugs, nintedanib, pirfenidone, etc.) are normally accompanied by significant limitations, such as adverse reactions, low bioavailability, poor selectivity, low-tissue distribution, in vivo instability, systemic toxicity, inconveniency and unsafe usage. There is a need for the exploration and discovery of new novel remedies by researchers and scientists globally. Recent numerous preliminary studies have laid significant emphasis and demonstrated the antifibrotic importance, good curative actions (little or no adverse reactions), and multiple target sites of the active components from traditional herbal medicine (THM) against IPF, which could serve as a modern, alternative and potential therapeutics or drug candidates in treating IPF. This paper extensively summarizes the pharmacological actions and signaling pathways or mechanisms of active components obtained from THM for treating IPF. Moreover, the sources and modernization, markets, relevant FDA and CFDA studies (the USA and China), preclinical analysis, and various compositions of THM currently under clinical trials are also highlighted. Additionally, this present analytical data would be instrumental towards further drug progression or advancement of active components from THM for the potential therapeutics of IPF in the future.

Investigation on the function tropism of Tiaoqin and Kuqin (different specification of Scutellaria baicalensis) by comparing their curative effect on different febrile disease model

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellaria baicalensis (S. baicalensis) is the root of S. baicalensis Georgi. In traditional Chinese medicine it is divided into Tiaoqin (TQ, 1-3 years old) and Kuqin (KQ, more than 3 years old). However, the differences in TQ and KQ efficacy and their exact mechanisms are still unclear.

AIM OF THE STUDY

This study aimed to clarify the difference in the efficacy of TQ and KQ in relation to different fever types (damp heat and hyperpyrexia) by using rat models, as well as to determine the primary molecular mechanism.

MATERIALS AND METHODS

This study compared the compositional content of TQ and KQ by UPLC-MS/MS. Then, rat models of hyperpyrexia (HP, LPS) and damp heat (DH, high-fat and high-sugar diet feeding + fumigation in artificial climate chamber + E. coli injection) were established and their clinical symptoms, blood biochemistry, histopathological sections, cell cytokines and protein expression were compared following treatment with TQ or KQ. Finally, the mechanisms underpinning the differences observed for TQ and KQ were determined by measuring the components of these treatments in different target organs.

RESULTS

This study identified 31 compounds in the water extracts of both TQ and KQ, which differed significantly in their relative content. TQ and KQ showed different functional tropism in HP and DH model rats. Baicalin, wogonoside, oroxin A, baicalein, wogonin and oroxylin A appeared to be the basic functional components responsible for the functional tropism hypothesis, while the remaining compounds appeared to be the efficacy-oriented components. In addition, the difference in pharmacodynamics between TQ and KQ may be related to their absorption in vivo, which was consistent with the hypothesis of functional tropism proposed in this work.

CONCLUSION

In this study we adopted TQ and KQ-different specifications of Scutellaria baicalensis with similar chemical components-as a case study to systematically reveal the functional tropism of Chinese herbal medicine (CHM). The results showed that TQ and KQ contain the basic functional components to enable the basic function of 'clearing heat', while the variation in compositional content may result in their different therapeutic effects. A greater understanding and utilisation of the functional tropism of CHM would enormously improve the accuracy and scientific basis for the application of CHM medication, as well as in promoting the multi-function mechanism of CHM and guiding new drug development of CHM.

Pharmacological effects of indole alkaloids from Alstonia scholaris (L.) R. Br. on pulmonary fibrosis in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Alstonia scholaris (L.) R. Br. (Apocynaceae) is a Dai folk medicine for the treatment of lung diseases in China.

AIM OF THE STUDY

The present study investigated the anti-pulmonary fibrosis effects of total alkaloids (TA) and the potential active ingredients and its possible mechanism.

MATERIALS AND METHODS

After intratracheal instillation of bleomycin (BLM, 5 mg/kg), mice were divided into ten groups, and orally treated with the corresponding samples once daily for 28 days. The effect of indole alkaloids was determined through analysis of cytokines, as well as histopathological examinations and gene expressions.

RESULTS

Severe lung fibrosis was observed in the BLM-treated mice on day 28. However, the administration of TA significantly ameliorated the pathological changes in the lungs, decreased the content of Krebs von den Lungen-6, lactate dehydrogenase, transforming growth factor-β (TGF-β), hydroxyproline, type I collagen, and malonaldehyde, and enhanced the activity of superoxide dismutase in the serum and lung tissues. In addition, the enhanced TGF-β and matrix metalloproteinase-1 (MMP-1) expressions in BLM-induced mice were obviously weakened by indole alkaloids, as well as the ratio of matrix metalloproteinase-1 to tissue inhibitor of metalloproteinase-1 was decreased. Moreover, picrinine and scholaricine yielded markedly better values in the aforementioned indices than those in other samples, indicating that they may be the active ingredients of alkaloids.

CONCLUSIONS

TA exerted protective effects against BLM-induced pulmonary fibrosis by reducing collagen deposition through TGF-β/MMP-1 pathway.

Traditional Chinese medicine combined with pulmonary drug delivery system and idiopathic pulmonary fibrosis: Rationale and therapeutic potential

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Pathogenesis and characteristics of idiopathic pulmonary fibrosis (IPF) are presented.

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The history and current situation of traditional Chinese medicine (TCM) in treating lung diseases are introduced.

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Therapeutic mechanisms of different TCM to treat IPF are summarized.

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Advantages and types of pulmonary drug delivery systems (PDDS) are emphasized.

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Combining TCM with PDDS is a potential strategy to treat IPF.

Idiopathic pulmonary fibrosis (IPF) is a progressive pulmonary interstitial inflammatory disease of unknown etiology, and is also a sequela in severe patients with the Coronavirus Disease 2019 (COVID-19). Nintedanib and pirfenidone are the only two known drugs which are conditionally recommended for the treatment of IPF by the FDA. However, these drugs pose some adverse side effects such as nausea and diarrhoea during clinical applications. Therefore, it is of great value and significance to identify effective and safe therapeutic drugs to solve the clinical problems associated with intake of western medicine. As a unique medical treatment, Traditional Chinese Medicine (TCM) has gradually exerted its advantages in the treatment of IPF worldwide through a multi-level and multi-target approach. Further, to overcome the current clinical problems of oral and injectable intakes of TCM, pulmonary drug delivery system (PDDS) could be designed to reduce the systemic metabolism and adverse reactions of the drug and to improve the bioavailability of drugs. Through PubMed, Google Scholar, Web of Science, and CNKI, we retrieved articles published in related fields in recent years, and this paper has summarized twenty-seven Chinese compound prescriptions, ten single TCM, and ten active ingredients for effective prevention and treatment of IPF. We also introduce three kinds of inhaling PDDS, which supports further research of TCM combined with PDDS to treat IPF.

Inhibiting TGF-[Formula: see text] 1-Mediated Cellular Processes as an Effective Strategy for the Treatment of Pulmonary Fibrosis with Chinese Herbal Medicines

Pulmonary fibrosis (PF) is a chronic and irreversible interstitial lung disease that even threatens the lives of some patients infected with COVID-19. PF is a multicellular pathological process, including the initial injuries of epithelial cells, recruitment of inflammatory cells, epithelial-mesenchymal transition, activation and differentiation of fibroblasts, etc. TGF-[Formula: see text]1 acts as a key effect factor that participates in these cellular processes of PF. Recently, much attention was paid to inhibiting TGF-[Formula: see text]1 mediated cell processes in the treatment of PF with Chinese herbal medicines (CHM), an important part of traditional Chinese medicine. Here, this review first summarized the effects of TGF-[Formula: see text]1 in different cellular processes of PF. Then, this review summarized the recent research on CHM (compounds, multi-components, single medicines and prescriptions) to directly and/or indirectly inhibit TGF-[Formula: see text]1 signaling (TLRs, PPARs, micrRNA, etc.) in PF. Most of the research focused on CHM natural compounds, including but not limited to alkaloids, flavonoids, phenols and terpenes. After review, the research perspectives of CHM on TGF-[Formula: see text]1 inhibition in PF were further discussed. This review hopes that revealing the inhibiting effects of CHM on TGF-[Formula: see text]1-mediated cellular processes of PF can promote CHM to be better understood and utilized, thus transforming the therapeutic activities of CHM into practice.

The effects of polydeoxyribonucleotide on wound healing and tissue regeneration: a systematic review of the literature

Aim: The present study evaluated the effects of polydeoxyribonucleotide (PDRN) on tissue regeneration, paying special attention to the molecular mechanisms that underlie its tissue remodeling actions to better identify its effective therapeutic potential in wound healing. Materials & methods: Strategic searches were conducted through MEDLINE/PubMed, Google Scholar, Scopus, Web of Science and the Cochrane Central Register of Controlled Trials, from their earliest available dates to March 2020. The studies were included with the following eligibility criteria: studies evaluating tissue regeneration, and being an in vitro, in vivo and clinical study. Results: Out of more than 90 articles, 34 fulfilled the eligibility criteria. All data obtained proved the ability of PDRN in promoting a physiological tissue repair through salvage pathway and adenosine A2A receptor activation. Conclusion: Up to date PDRN has proved promising results in term of wound regeneration, healing time and absence of side effects.

Yu Gan Long Ameliorates Hepatic Fibrosis by Inhibiting PI3K/AKT, Ras/ERK and JAK1/STAT3 Signaling Pathways in CCl4-induced Liver Fibrosis Rats

Yu Gan Long (YGL) is a Chinese traditional herbal formula which has been reported to attenuate liver fibrosis for many years and we have explored its anti-fibrotic mechanism through blocking transforming growth factor (TGF-β) in the previous study. But the mechanisms associated with platelet-derived growth factor (PDGF)-BB remain obscure. In this study, we further investigated the mechanism of YGL reducing carbon tetrachloride (CCl₄)-induced liver fibrosis in rats. Our results showed that YGL suppressed CCl₄-induced upregulation of collagen IV (Col IV), type HI precollagen (PCHI), hyaluronuc acid (HA) and laminin (LN), which are implicated in liver fibrosis. Also, YGL reduced the α-smooth muscle actin (α-SMA) expression, which acts as the indicator of liver fibrosis. Furthermore, YGL decreased the serum levels of hepatic stellate cell (HSC) mitogen PDGF-BB and inflammation cytokines, including TNF-α, IL-1β, IL-6. Markers involved in liver fibrosis, such as Ras, p-Raf-1, p-ERK1/2, p-JNK, p-P38, p-PI3K, p-AKT, p-JAKl, p-STAT3 were downregulated significantly after treatment with YGL. Our results indicated that YGL ameliorated CCl₄-induced liver fibrosis by reducing inflammation cytokines production, and suppressing Ras/ERK, PI3K/AKT, and JAK1/STAT3 signaling pathways, which provided further evidence towards elucidation of the anti-fibrotic mechanism of YGL.

Baicalein Alleviates Erectile Dysfunction Associated With Streptozotocin-Induced Type I Diabetes by Ameliorating Endothelial Nitric Oxide Synthase Dysfunction, Inhibiting Oxidative Stress and Fibrosis

BACKGROUND

Management of diabetes mellitus induced-erectile dysfunction (DMED) is challenging because of its poor responses to phosphodiesterase type 5 inhibitors. Increasingly important roles of 12-lipoxygenase (12-LOX) have been proven in diabetes mellitus.

AIM

To investigate 12-LOX activity and therapeutic effect of its inhibitor, baicalein (BE), on DMED.

METHODS

Intraperitoneal streptozotocin injection was used to induce type I DM, and an apomorphine test was used to evaluate erectile function. In experiment A, we assessed 12-LOX expression alteration in the corpus cavernosum (CC) of rats with DMED of different levels of severity. In experiment B, rats with DMED were intraperitoneally injected with BE for 4 weeks, and control rats were injected with vehicles. The erectile function was tested by cavernous nerve stimulation before penile tissue was harvested. We performed Western blot, immunohistochemistry, immunofluorescence, Masson trichrome staining, and enzyme-linked immunosorbent assays to measure related proteins in CC.

MAIN OUTCOME MEASURE

The main outcome measures included rectile response, histologic examination, and expression alteration of related proteins.

RESULTS

12-LOX upregulation was associated with the progression of type I DMED. After 4 weeks treatment, compared with the DMED group, the DMED + BE group showed better erectile responses to cavernous nerve stimulation. In the DMED + BE group, significantly enhanced endothelial nitric oxide synthase/nitric oxide/cyclic guanosine monophosphate pathway, reduced 12-LOX expression, and inhibited p38 mitogen-activated protein kinase/arginase II/L-arginine pathway were showed in CC relative to the DMED group. In addition, overactivated oxidative stress and fibrosis in the DMED group were both partially ameliorated in the DMED + BE group.

CLINICAL IMPLICATIONS

BE may be considered as an effective therapy for DMED, but needs to be verified in future human investigations.

STRENGTHS & LIMITATIONS

The role of 12-LOX and its inhibitor, BE, is firstly demonstrated in rats with type I DMED. However, the experimental data are derived from animal models with without evidences from cellular-based experiments.

CONCLUSION

12-LOX might serve as an important factor in the pathogenesis of type I DMED. BE alleviated erectile dysfunction in rats with type I DMED probably by inhibiting 12-LOX expression, ameliorating endothelial nitric oxide synthase dysfunction, as well as suppressing oxidative stress and fibrosis. Chen Y, Zhou B, Yu Z, et al. Baicalein Alleviates Erectile Dysfunction Associated With Streptozotocin-Induced Type I Diabetes by Ameliorating Endothelial Nitric Oxide Synthase Dysfunction, Inhibiting Oxidative Stress and Fibrosis. J Sex Med 2020;17:1434-1447.

Asiaticoside might attenuate bleomycin-induced pulmonary fibrosis by activating cAMP and Rap1 signalling pathway assisted by A2AR

Asiaticoside (AS) has been reported to have protective effect on pulmonary fibrosis (PF). In this study, we aimed to explore the potential mechanism of the therapeutic role of AS and its relationship with A2AR in PF. Adenosine 2A receptor gene knockout (A2AR^−/−) mice and wild‐type (WT) mice were used to establish bleomycin (BLM)‐induced PF models and were then treated with AS (50 mg/kg/d). Pulmonary inflammation and fibrosis were observed in the PF model with much higher severity in A2AR^−/−mice than that in WT mice and AS significantly alleviated lung inflammation and fibrosis; however, it was less effective in A2AR^−/− mice than in WT mice via histopathological analysis. Using RNA sequencing analysis, we found up‐regulated differentially expressed genes (DEGs) in BLM group were enriched in immune and inflammation‐associated pathways compared with control group. There were 242 common DEGs between down‐regulated in BLM vs control group and up‐regulated in BLM + AS vs BLM group, which were enriched in cAMP and Rap1 signalling pathways. Furthermore, the expression of five key factors of these two pathways including adenylate cyclase (ADCY1, ADCY5, ADCY8, cAMP and Rap1) were confirmed up‐regulated by AS with the presence of A2AR. Therefore, AS might attenuate BLM‐induced PF by activating cAMP and Rap1 signalling pathways which is assisted by A2AR, making it a promising therapeutic optional for PF.

Asiaticoside attenuates bleomycin-induced pulmonary fibrosis in A2aR-/- mice by promoting the BMP7/Smad1/5 signaling pathway

Idiopathic Pulmonary fibrosis(PF)is a chronic progressive disease, which is a lack of effective treatment,and the pathogenesis of IPF is not fully elucidated. Asiaticoside(AS) is isolated from Centella asiatica and has the effect of promoting scar healing and reducing scar formation. However,its possible role in idiopathic pulmonary fibrosis remains unclear. Adenosine A2A receptor (A2AR) is reported a protective factor in pulmonary fibrosis, and the bone morphogenetic protein 7 (BMP7) signaling pathway plays a crucial role in fibrosis in multiple organs. But the impact of A2AR on the BMP7 pathway has not yet been reported. Therefore, we hypothesized AS may promote the expression of A2AR, and then influence the BMP7/Smad1/5 pathway to alleviate pulmonary fibrosis. A2AR^-/- mice and wild-type (WT) mice were administered bleomycin (BLM) by intratracheal injection. AS (50 mg/kg/d) was given daily for 28 days. AS reduced collagen deposition in lung tissue, interstitial lung inflammation. Furthermore, AS promoted A2AR expression and BMP7 pathway. Collectively, AS may attenuate BLM-induced pulmonary fibrosis by upregulating the BMP7 signaling pathway through A2AR.

Baicalin attenuates fibrogenic process in human renal proximal tubular cells (HK-2) exposed to diabetic milieu

AIMS

Baicalin, a flavonoid glycoside substance extracted from Scutellaria baicalensis Georgi, has been shown to exhibit multiple therapeutic properties owing to its anti-inflammatory effect. Diabetes is characterized by chronic hyperglycemia, inflammation and oxidative stress, which promote renal fibrosis and kidney failure. Although anti-fibrogenic effects of baicalin in lung and liver have been reported previously, no study has investigated its roles in renal fibrosis. Here, we demonstrated protective effects of baicalin against fibrogenic process in human kidney proximal tubular epithelial cells (HK-2) exposed to diabetic milieu.

MAIN METHODS

To investigate the effects of baicalin on oxidative stress- and inflammation-induced fibrosis in HK-2 cells, protein and gene expressions of NF-κB- and STAT3-associated inflammatory molecules and TGFβ-associated extracellular matrix proteins were examined by western blotting, immunocytochemistry and qRT-PCR. To determine physiological changes of HK-2 exposed to diabetic milieu in response to baicalin, production of cAMP and cGMP and Ca2+ influx were measured.

KEY FINDINGS

Baicalin attenuated oxidative stress- and inflammation-inudced IκB and JAK2 phosphorylations and, subsequent, NF-κB nuclear translocation and STAT3 phosphorylation. Consequently, it markedly reduced transactivation of NF-κB- and STAT3-associated inflammatory genes such as ICAM1, VCAM1, TGFβ, IL1β and MCP1, and protein expression of TGFβ-associated extracellular matrix proteins, such as fibronectin and collagen IV. These effects are, partially, attributed to its regulatory function of intracellular concentration of Ca2+ via interaction with type A γ-aminobutyric acid receptor.

SIGNIFICANCE

This is the first study which investigated anti-fibrogenic effect of baicalin in human kidney cells, and our results highlight a potential therapeutic application of baicalin for diabetic nephropathy.

Baicalin alleviates bleomycin‑induced pulmonary fibrosis and fibroblast proliferation in rats via the PI3K/AKT signaling pathway

Baicalin is an important flavonoid compound THAT is isolated from the Scutellaria baicalensis Georgi Chinese herb and plays a critical role in anti‑oxidative, anti‑inflammatory, anti‑infection and anti‑tumor functions. Although baicalin can suppress the proliferation of tumor cells, the underlying mechanisms of baicalin in bleomycin (BLM)‑induced pulmonary fibrosis remain to be elucidated. Thus, the aim of the present study was to determine the role of baicalin in pulmonary fibrosis and fibroblast proliferation in rats. Hematoxylin and eosin (H&E) and Masson staining were used to measure the morphology of pulmonary fibrosis, ELIASA kits were used to test the ROS and inflammation, and western blotting and TUNEL were performed to study the apoptosis proteins. In vitro, MTT assay, flow cytometry, western blotting and immunofluorescence were performed to investigate the effects of baicalin on proliferation of fibroblasts. The most significantly fibrotic changes were identified in the lungs of model rats at day 28. Baicalin (50 mg/kg) attenuated the degree of pulmonary fibrosis, and the hydroxyproline content of the lung tissues was decreased in the baicalin group, compared with the BLM group. Further investigation revealed that baicalin significantly increased glutathione peroxidase (GSH‑px), total‑superoxide dismutase (T‑SOD) and glutathione (GSH) levels, whilst decreasing that of serum malondialdehyde (MDA). TUNEL‑positive cells were significantly decreased in rats treated with baicalin group, compared with the model group. Furthermore, it was found that BLM promoted fibroblasts viability in a dose‑dependent manner in vivo, which was restricted following treatment with different concentrations of baicalin. Moreover, BLM promoted the expression levels of cyclin A, D and E, proliferating cell nuclear antigen, phosphorylated (p)‑AKT and p‑calcium/calmodulin‑dependent protein kinase type. BLM also promoted the transition of cells from the G0/G1 phase to the G2/M and S phases, and increased the intracellular Ca2+ concentration, which was subsequently suppressed by baicalin. Collectively, the results of the present study suggested that baicalin exerted a suppressive effect on BLM‑induced pulmonary fibrosis and fibroblast proliferation.

Low-molecular-weight fucoidan attenuates bleomycin-induced pulmonary fibrosis: possible role in inhibiting TGF-β1-induced epithelial-mesenchymal transition through ERK pathway

The therapeutic options for pulmonary fibrosis (PF), a progressive interstitial disease of the lung, are extremely limited. Studies have shown that transforming growth factor-β1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) functions as a central mediating process that contributes to PF. Also, low-molecular-weight fucoidan (LMWF), a sulfated polysaccharide extracted from brown seaweed, has been reported to have antifibrotic characteristics that can help to alleviate kidney fibrosis by inhibiting TGF-β1-mediated EMT. Thus we hypothesized that LMWF might be an attractive candidate for alleviating PF. Eighty C57BL/6 mice and A549 cells were respectively involved in our vivo and vitro experiments. The lung fibrosis was primarily assessed by hematoxylin and eosin (H&E), Masson's trichrome stain, lung wet-to-dry weight ratio and hydroxyproline content. TGF-β1 levels were determined by enzyme-linked immunosorbent assay (ELISA) and immunofluorescence, and the expression of EMT markers and extracellular signal-regulated kinase (ERK) signaling were mainly based on immunostaining, real-time PCR and Western blot. As expected, our vivo models showed that LMWF was associated with improved lung fibrotic histopathology and significantly reduced lung hydroxyproline content. Levels of TGF-β1 expression in bronchoalveolar lavage fluid (BALF) and lung tissue decreased than it had been before treatment. Immunostaining, real-time PCR, and Western blot demonstrated that the lung EMT phenotype was attenuated and ERK signaling downregulated after LMWF administration. The vitro experiments resulted in a similar pharmacologic inhibitory effect of TGF-β1-induced EMT with downregulated ERK signaling. Collectively, our results preliminary suggested that LMWF could attenuate bleomycin-induced PF by inhibiting TGF-β1-induced EMT through ERK signaling.

Spironolactone inhibits endothelial-mesenchymal transition via the adenosine A2A receptor to reduce cardiorenal fibrosis in rats

AIMS

The mechanisms underlying cardiorenal syndromes are complex and not fully understood; Fibrosis seems to be a primary driver of the diseases' pathophysiology. Spironolactone can reduce cardiac or renal fibrosis by inhibiting endothelial-mesenchymal transition (EndMT). Spironolactone protection may rely on activation of adenosine receptors, but the role of the adenosine A2A receptor (A2AR) is unclear. We hypothesize that spironolactone may modulate A2AR to suppress EndMT and reduce cardiorenal remodeling.

MAIN METHODS

A model of renal injury followed by heart failure was established by subcutaneous administration of isoprenaline (Iso) to rats. Assessment of cardiac and renal function, fibrosis, EndMT markers, adenosine and A2AR expression was performed. TGF-β was used to induce EndMT in primary human umbilical vein endothelial cells (HUVECs). Rats or cells were divided into four groups: those that treated with spironolactone alone or in combination with A2AR antagonist ZM241385 or neither, and compared to normal controls.

KEY FINDINGS

Isoprenaline-treated rats exhibited cardiac and renal fibrosis, impaired cardiac and renal function, enhanced EndMT, and lower A2AR expression. Spironolactone significantly up-regulated A2AR expression and inhibited EndMT in vivo and in vitro. Moreover, spironolactone improved cardiorenal remodeling and reduced dysfunction. These changes were exacerbated by administration of ZM241385. Together, these findings show that spironolactone up-regulated A2AR to reduce EndMT and ameliorate cardiorenal fibrosis.

SIGNIFICANCE

The anti-fibrotic effects of spironolactone may partly depend on the up-regulation of A2AR, and that A2AR might be a potential therapeutic target for the treatment of cardiorenal syndrome.

YaTCM: Yet another Traditional Chinese Medicine Database for Drug Discovery

Traditional Chinese Medicine (TCM) has a long history of widespread clinical applications, especially in East Asia, and is becoming frequently used in Western countries. However, owing to extreme complicacy in both chemical ingredients and mechanism of action, a deep understanding of TCM is still difficult. To accelerate the modernization and popularization of TCM, a single comprehensive database is required, containing a wealth of TCM-related information and equipped with complete analytical tools. Here we present YaTCM (Yet another Traditional Chinese Medicine database), a free web-based toolkit, which provides comprehensive TCM information and is furnished with analysis tools. YaTCM allows a user to (1) identify the potential ingredients that are crucial to TCM herbs through similarity search and substructure search, (2) investigate the mechanism of action for TCM or prescription through pathway analysis and network pharmacology analysis, (3) predict potential targets for TCM molecules by multi-voting chemical similarity ensemble approach, and (4) explore functionally similar herb pairs. All these functions can lead to one systematic network for visualization of TCM recipes, herbs, ingredients, definite or putative protein targets, pathways, and diseases. This web service would help in uncovering the mechanism of action of TCM, revealing the essence of TCM theory and then promoting the drug discovery process. YaTCM is freely available at http://cadd.pharmacy.nankai.edu.cn/yatcm/home.