Baicalin Magnesium Salt Attenuates Lipopolysaccharide-Induced Acute Lung Injury via Inhibiting of TLR4/NF-κB Signaling Pathway

Preparation and characterisation of baicalin magnesium and its protective effect in ulcerative colitis via gut microbiota-bile acid axis modulation

BACKGROUND

Scutellaria baicalensis Georgi is a well-known herb in traditional Chinese medicine that is frequently prescribed for various gastrointestinal conditions, including ulcerative colitis (UC). Its primary active constituent, baicalin, has poorly water solubility that reduces its efficacy.

PURPOSE

To enhance the aqueous solubility of baicalin by optimising its extraction process. We compared the modulatory effects of isolated water-soluble baicalin and water-insoluble baicalin on UC, and delved deeper into the potential mechanisms of water-soluble baicalin.

METHODS

We successfully extracted a more hydrophilic baicalin directly from an aqueous S. baicalensis Georgi extract through the process of recrystallisation following alcoholic precipitation of the aqueous extract obtained from S. baicalensis Georgi, eliminating the need for acid additives. This specific form of baicalin was conclusively identified by UV, IR, atomic absorption spectroscopy, elemental analysis, 1H NMR, 13C NMR, and ESI-HRMS. We subsequently compared the regulatory effects of baicalin on UC before and after optimisation, employing 16S rDNA sequencing, bile acid-targeted metabolomics, and transcriptome analysis to elucidate the potential mechanism of water-soluble baicalin; and the key genes and proteins implicated in this mechanism were verified through RT-PCR and western blotting.

RESULTS

A new form of baicalin present in the aqueous solution of S. baicalensis Georgi was isolated, and its structural characterisation showed that it was bound to magnesium ions (baicalin magnesium) and exhibited favorable water solubility. Baicalin magnesium offers enhanced therapeutic benefits over baicalin for UC treatment, which alleviated the inflammatory response and oxidative stress levels while improving intestinal mucosal damage. Further investigation of the mechanism revealed that baicalin magnesium could effectively regulate bile acid metabolism and maintain intestinal microecological balance in UC mice, and suppress the activation of the nuclear factor-kappa B and peroxisome proliferator-activated receptor α signalling pathways, thereby playing a therapeutic role.

CONCLUSIONS

Baicalin magnesium has good water solubility, which solves the bottleneck problem of water insolubility in the practical applications of baicalin. Moreover, baicalin magnesium exhibits therapeutic potential for UC significantly better than baicalin.

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.

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.

Protective effecs of baicalin magnesium on non-alcoholic steatohepatitis rats are based on inhibiting NLRP3/Caspase-1/IL-1β signaling pathway

Baicalin magnesium is a water-soluble compound isolated from the aqueous solution by Scutellaria baicalensis Georgi. Preliminary experiments have demonstrated that baicalin magnesium can exert protective effects against acute liver injury in rats induced by carbon tetrachloride or lipopolysaccharide combined with d-galactose by regulating lipid peroxidation and oxidative stress. The aim of this study was to investigate the protective effect of baicalin magnesium on non-alcoholic steatohepatitis (NASH) in rats and to elucidate the underlying mechanisms. NASH was induced through a high-fat diet (HFD) for 8 weeks, and Sprague-Dawley rats were intravenously injected with baicalin magnesium, baicalin, and magnesium sulfate for 2 weeks, respectively. Serum was obtained for biochemical analyses and the determination of oxidative stress indicators. Liver tissues were collected for use in liver index assessment, histopathological examination, inflammatory factor analysis, and protein and gene expression analysis. The results revealed that baicalin magnesium markedly improved HFD-induced lipid deposition, inflammatory response, oxidative stress, and histopathological impairments. And baicalin magnesium may exert a protective effect on NASH rats by inhibiting the NLR family pyrin domain involving the 3 (NLRP3)/caspase-1/interleukin (IL)-1β inflammatory pathway. Additionally, the effect of baicalin magnesium was remarkably superior to that of equimolar baicalin and magnesium sulfate in regard to ameliorating NASH symptoms. In conclusion, the findings suggested that baicalin magnesium may represent a potential drug for the treatment of NASH.

Protective effects of baicalin against L-glutamate-induced oxidative damage in HT-22 cells by inhibiting NLRP3 inflammasome activation via Nrf2/HO-1 signaling

Objectives

To explore the ability and underlying molecular mechanisms involved in the protective effects of Baicalin (BA) against L-Glutamate-induced mouse hippocampal neuron cell line HT-22.

Materials and Methods

The cell injury model of HT-22 cells was induced by L-glutamate, and cell viability and damage were detected by CCK-8 and LDH assays. Generation of intracellular reactive oxygen species (ROS) was measured by DCFH-DA in situ fluorescence method. The SOD activity and MDA concentration in the supernatants were determined by WST-8 and colorimetric method, respectively. Furthermore, Western blot and real-time qPCR analysis were utilized to detect the expression levels of the Nrf2/HO-1 signaling pathway and NLRP3 inflammasome proteins and genes.

Results

L-Glutamate exposure induced cell injuries in HT-22 cells, and the concentration of 5 mM L-Glutamate was chosen to be the modeling condition. Co-treatment with BA significantly promoted cell viability and reduced LDH release in a dose-dependent manner. In addition, BA attenuated the L-Glutamate-induced injuries by decreasing the ROS production and MDA concentration, while increasing the SOD activity. Moreover, we also found that BA treatment up-regulated the gene and protein expression of Nrf2 and HO-1, and then inhibited the expression of NLRP3.

Conclusion

Our study found that BA could relieve oxidative stress damage of HT-22 cells induced by L-Glutamate, and the mechanism might be related to the activation of Nrf2/HO-1 and inhibition of NLRP3 inflammasome.

Total glycosides of Rhodiola rosea L. attenuate LPS-induced acute lung injury by inhibiting TLR4/NF-κB pathway

Acute lung injury (ALI) is a common respiratory disease in clinics, which is characterized by alveolar-capillary membrane loss, plasma protein leakage, pulmonary edema, massive neutrophil infiltration, and the release of proinflammatory cytokines and mediators. Rhodiola rosea L. an adaptogenic plant rich in phenylethanoloids, phenylpropanoids, monoterpenes, has anti-inflammatory and antioxidant effects. We hope to verify the relieving effect of total glycosides of Rhodiola rosea L. (RTG) on ALI in mice and clarify its mechanism through this study. In this study, we identified the effect and mechanism of RTG on ALI through LPS-induced ALI mice. After RTG treatment, the pathological structure of lung tissue in ALI mice induced by LPS was significantly improved, and the infiltration of inflammatory cells was reduced. In addition, RTG reduced the production of IL-6, IL-1β, and TNF-α in the serum of ALI mice and reduced the content or activity of MPO, T-SOD, GSH, and MDA in lung tissue. RNAseq analysis showed that RTG ameliorated LPS-induced ALI through anti-inflammatory, reduced immune response, and anti-apoptotic activities. The western blotting analysis confirmed that RTG could down-regulate the expression levels of TLR4, MyD88, NF-κB p65, and p-IκBα/IκBα. These results suggest that RTG can attenuate LPS-induced ALI through antioxidants and inhibition of the TLR4/NF-κB pathway.

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.

NF-κB and AMPK-Nrf2 pathways support the protective effect of polysaccharides from Polygonatum cyrtonema Hua in lipopolysaccharide-induced acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

The raw and honey-processed P. cyrtonema recorded in ancient classics of Chinese medicine as having the effect of moisturizing the lungs and relieving coughs, and it has also been proved to have therapeutic effects on lung diseases in modern research. Polysaccharides are the main components with biological activities in raw and honey-processed P. cyrtonema, but there is no research for their lung-protective effect.

AIM OF STUDY

This study aimed to investigate the protective effect and the possible mechanism of polysaccharides from raw and honey-processed P. cyrtonema in LPS-induced acute lung injury in mice.

MATERIALS AND METHODS

Polysaccharides, PCP and HPCP, were respectively separated and extracted from raw and honey-processed P. cyrtonema, and the molecular weight, monosaccharide composition and other basic chemical characteristics were analyzed by HPGCP, HPLC, FI-IR, and NMR. The model of ALI mice was established by intratracheal instillation of LPS. Moreover, the protective effects of PCP and HPCP for ALI mice were evaluated by detecting the wet-to-dry ratio and histopathology in the lungs, the content of inflammatory factors TNF-α, IL-6, IL-1β in BLAF, and the content of MPO and SOD in lung tissue. In addition, the lung-protective mechanism of PCP and HPCP was explored by detecting the levels of some proteins and mRNA related to inflammation and oxidative stress pathways.

RESULTS

PCP and HPCP with molecular weights of 8.842 × 10³ and 5.521 × 10³Da were mainly composed of three monosaccharides. Moreover, it is found that fructose and galactose were mainly β-D, and glucose was α-D. Both PCP and HPCP could significantly improve lung injury, reduce the level of inflammatory factors in BALF and the level of MPO in lung tissue, and increase the level of SOD. In addition, PCR and WB indicated that PCP and HPCP at least inhibited pulmonary inflammation through the NF-κB pathway, and reduced the occurrence of pulmonary oxidative stress through the AMPK-Nrf2 pathway.

CONCLUSIONS

Polysaccharides from raw and honey-processed P. cyrtonema had a protective effect in LPS-induced lung injury in mice. This effect may be related to the antioxidant and anti-inflammatory activities of PCP and HPCP in the lungs through the NF-κB pathway and AMPK-Nrf2 pathway. And HPCP seems to perform more than PCP.

Periostin regulates LPS-induced apoptosis via Nrf2/HO-1 pathway in periodontal ligament fibroblasts

OBJECTIVE

Periostin is important for the maintenance of periodontal tissue, but its role in periodontitis is controversial. This research investigated the effect of periostin in periodontitis and the underlying mechanism.

DESIGN

Mouse periodontitis models in vivo and inflammation model in vitro which were induced by Porphyromonas gingivalis lipopolysaccharide were established to evaluate periostin expression. Human periodontal ligament fibroblasts (PDLFs) were treated with lipopolysaccharide and N-acetylcysteine, fluorescence staining, flow cytometry, western blot, and qRT-PCR were used to detect reactive oxygen species (ROS), periostin expression, and apoptosis-related makers. The periostin gene was successfully transfected into PDLFs to verify the effect of periostin on apoptosis. Then, the Nrf2 inhibitor was added to clarify the mechanism.

RESULTS

Periostin expression decreased in the periodontal ligaments of mouse periodontitis models and lipopolysaccharide-induced PDLFs. Lipopolysaccharide promoted the activation of ROS and apoptosis in PDLFs, whereas N-acetylcysteine reversed this condition. Overexpression of periostin suppressed apoptosis of PDLFs and reversed the inhibitory effect of lipopolysaccharide on nuclear Nrf2 expression. Moreover, the Nrf2 inhibitor attenuated the protective effect of periostin on lipopolysaccharide-induced apoptosis.

CONCLUSIONS

Lipopolysaccharide induced apoptosis in PDLFs by inhibiting periostin expression and thus Nrf2/HO-1 pathway, indicating that periostin could be a potential therapeutic target for periodontitis.