Baicalin-treated Group Research Articles

Baicalin enhances antioxidant, inflammatory defense, and microbial diversity of yellow catfish (Pelteobagrus fulvidraco) infected with Aeromonas hydrophila.

The aim of this research was to clarify the mechanism through which baicalin exerts its inhibitory effects on Aeromonas hydrophila infection. The antibacterial efficacy of baicalin was assessed by determining its minimum inhibitory concentration (MIC) against A. hydrophila. Various parameters, including the growth curve, cell wall integrity, biofilm formation, AKP content, and morphological alterations of A. hydrophila, were analyzed. In vivo experiments involved the administration of A. hydrophila 4 h postintraperitoneal injection of varying doses of baicalin to induce infection, with subsequent monitoring of mortality rates. After a 3 d period, liver, spleen, and intestinal tissues were harvested to evaluate organ indices, antioxidant and immune parameters, as well as intestinal microbial composition. The findings indicated that baicalin treatment resulted in the disruption of the cell wall of A. hydrophila, leading to the loss of its normal structural integrity. Furthermore, baicalin significantly inhibited biofilm formation and facilitated the release of intracellular proteins (P < 0.05). In vivo, baicalin enhanced the survival rates of yellow catfish infected with A. hydrophila. Compared to the control group, the liver index of yellow catfish was elevated, while the spleen and intestinal indices were reduced in the baicalin-treated group (P < 0.05). Additionally, baicalin at an appropriate dosage was found to increase levels of SOD, GSH, CAT, ACP, and AKP in yellow catfish (P < 0.05), while simultaneously decreasing MDA accumulation and the mRNA expression of inflammatory markers such as Keap1, IL1, IFN-γ, and TNF-α, (P < 0.05). Moreover, baicalin significantly enhanced the operational taxonomic unit (OTU) count in A. hydrophila-infected yellow catfish (P < 0.05), restoring the abundance of Barnesiellaceae, Enterobacteriaceae, Plesiomonas, and UBA1819 (P < 0.05). In summary, baicalin demonstrates the potential to improve the survival rate of yellow catfish subjected to A. hydrophila infection, augment antioxidant and immune responses, mitigate inflammation, and enhance intestinal microbial diversity.

Baicalin ameliorates the gut barrier function and intestinal microbiota of broiler chickens.

The deoxynivalenol (DON)-contaminated feeds can impair chicken gut barrier function, disturb the balance of the intestinal microbiota, decrease chicken growth performance and cause major economic loss. With the aim of investigating the ameliorating effects of baicalin on broiler intestinal barrier damage and gut microbiota dysbiosis induced by DON, a total of 150 Arbor Acres broilers are used in the present study. The morphological damage to the duodenum, jejunum, and ileum caused by DON is reversed by treatment with different doses of baicalin, and the expression of tight junction proteins (ZO-1, claudin-1, and occludin) is also significantly increased in the baicalin-treated groups. Moreover, the disturbance of the intestinal microbiota caused by DON-contaminated feed is altered by baicalin treatment. In particular, compared with those in the DON group, the relative abundances of Lactobacillus, Lachnoclostridium, Ruminiclostridium and other beneficial microbes in the baicalin-treated groups are significantly greater. However, the percentage of unclassified_f__Lachnospiraceae in the baicalin-treated groups is significantly decreased in the DON group. Overall, the current results demonstrate that different doses of baicalin can improve broiler intestinal barrier function and the ameliorating effects on broiler intestinal barrier damage may be related to modulations of the intestinal microbiota.

PSVIII-26 Baicalin Alleviates Lincomycin-Induced Intestinal Injury By Regulating Gut Microbiota in Weaned Pigs

Abstract Lincomycin and related antibiotics are widely used in swine clinics, but its side effects including diarrhea and inflammatory bowel disease are difficult to detect and controlled. The purpose of this study was to investigate the effect and mechanism of baicalin, a flavonoid extracted from scutellaria baicalensis, on alleviating lincomycin-related intestinal injury. Forty-eight 21-day-old weaned pigs were selected and randomly divided into three groups: control group, lincomycin group (LC), and baicalin treatment group (LC + BL). Pigs in the LC and LC + BL groups were administered with 1 g/kg lincomycin in feed for 1 week. In the second week, pigs in the LC + BL group were administered 500 mg/kg baicalin in feed. After 2 weeks, 6 piglets in each group were selected to obtain intestinal samples for subsequent analysis, and the body weight of the remaining piglets was recorded on day 28. The results showed that lincomycin significantly reduced the body weight of the pigs on day 28 (P &amp;lt; 0.05), but baicalin treatment restored the body weight of piglets on day 28 to the control level. As for intestinal morphology, lincomycin damaged intestinal morphology and reduced villus height in the jejunum of piglets, but these indexes recovered to the control level after baicalin treatment (P &amp;lt; 0.05). In addition, lincomycin decreased claudin-1, TNF-α, and IL-1β mRNA expression in the jejunum (P &amp;lt; 0.05), but these indexes recovered to the control level after baicalin treatment. Then 16S rDNA sequencing was used to examine the microbial composition in the jejunum. Lincomycin significantly increased the abundance of Proteobacteria, Chloroflexi, and Deinococcota (P &amp;lt; 0.05), but baicalin decreased the abundance of Chloroflexi, Acidobacteriota, Patescibacteria, Myxococcota, and Gemmatimonadota in phylum level (P &amp;lt; 0.05). At genus level, lincomycin significantly increased the abundance of Citrobacter, Corynebacterium, Delftia, Agathobacter, Trichococcus, Tissierellales, Enterococcus, Paracoccus, Shewanella, unclassified_c__Clostridia, Alistipes, Sphingomonas, and Massilia, etc (P &amp;lt; 0.05). However, these results were not observed in the LC + BL group, and baicalin treatment increased the abundance of beneficial bacteria such as norank_f__Muribaculaceae (P &amp;lt; 0.05). Fecal microbiota transplantation was employed to further investigate whether these results were relevant to gut microbes. The body weight, villus height, and crypt depth of mice receiving LC group microbiota were significantly lessthan that of the control group, while the body weight of mice receiving LC + BL group microbiota was not significantly different from that of the control group. Overall, these results suggest that baicalin may alleviate lincomycin-induced intestinal damage and inflammation by inhibiting the growth of harmful bacteria. Our findings expand our knowledge of antibiotic-induced injury and provide new avenues for identifying potential therapeutic targets for the treatment of antibiotic-induced injury and its complications.

The Protective Effect and Mechanism of Baicalin on Postoperative Cognitive Function and Nerves in Aged Rats

To explore the effect of baicalin on cognitive function and nerves after splenectomy in aged rats is the main objective of the study. Aged rats were randomly divided into a sham operation group, a model group (to construct a splenectomy surgical model) and a baicalin treatment group (baicalin was given after the model was constructed). The pathological conditions like interleukin-6, tumor necrosis factor alpha, interleukin-1 beta content; brain detection by terminal deoxynucleotidyl transferase dUTP nick end labeling method apoptosis of tissue cell; western blot method was used to detect the expression of related proteins and real-time fluorescence quantitative polymerase chain reaction method was used to detect the messenger ribonucleic acid levels of related genes. Compared with the control group, the brain tissue cell apoptosis increased and the expression of inflammatory factors increased in the model group; compared with the model group, the brain tissue apoptosis of the baicalin treatment group decreased, the expression of Ki67 positive cells increased and the inflammation-related factor interleukin-6, tumor necrosis factor alpha, interleukin-1 beta levels were significantly decreased, N-methyl D-aspartate receptor subtype 2B, phosphorylated-extracellular signal-regulated kinase, phosphorylated-cAMP response element-binding protein expressions were significantly increased. Baicalin can improve postoperative cognitive dysfunction and nerve injury in aged rats after splenectomy by improving the pathological state of brain tissue, attenuating the inflammatory response and promoting apoptosis of brain tissue.

Effect of Baicalin on Wound Healing in a Mouse Model of Pressure Ulcers

One of the most frequent comorbidities that develop in chronically ill or immobilized patients is pressure ulcers, also known as bed sores. Despite ischemia-reperfusion (I/R)-induced skin lesion having been identified as a primary cause of pressure ulcers, wound management efforts have so far failed to significantly improve outcomes. Baicalin, or 5,6,7-trihydroxyflavone, is a type of flavonoid which has been shown to possess a variety of biological characteristics, including antioxidative and anti-inflammatory effects and protection of I/R injury. In vitro wound scratch assay was first used to assess the function of baicalin in wound healing. We established a mouse model of advanced stage pressure ulcers with repeated cycles of I/R pressure load. In this model, topically applied baicalin (100 mg/mL) induced a significant increase in the wound healing process measured by wound area. Histological examination of the pressure ulcer mouse model showed faster granulation tissue formation and re-epithelization in the baicalin-treated group. Next, baicalin downregulated pro-inflammatory cytokines (IL-6 and IL-1β), while upregulating the anti-inflammatory IL-10. Additionally, baicalin induced an increase in several growth factors (VEGF, FGF-2, PDGF-β, and CTGF), promoting the wound healing process. Our results suggest that baicalin could serve as a promising agent for the treatment of pressures ulcers.

Baicalin improves podocyte injury in rats with diabetic nephropathy by inhibiting PI3K/Akt/mTOR signaling pathway.

ObjectiveTo investigate the effect of baicalin on diabetic nephropathy (DN) rats and podocytes and its mechanism.MethodsThe rat models with DN were established by high-fat and high-sugar diet and intraperitoneal injection of streptozotocin. The fasting blood glucose (FBG) and weight of rats in each group were measured at 0, 1, 2, 3, and 4 weeks. Their biochemical indicators, expression of inflammatory, and antioxidant factors were measured using an automatic biochemical analyzer together with ELISA. Hematoxylin–eosin staining and periodic acid-schiff staining were used to observe the morphological changes in the kidneys of rats in each group. Finally, the expressions of related molecules and PI3K/Akt/mTOR signaling pathway proteins in renal tissues and podocytes were examined by qRT-PCR and Western blot.ResultsCompared with the DN group, the FBG and weight, serum creatinine, blood urea nitrogen, total cholesterol, triacylglycerol, microalbumin, and albumin/creatinine ratio were all significantly decreased in the Baicalin treatment groups in a concentration-dependent manner. The levels of inflammatory factors in kidney tissue and podocytes were decreased. In addition, the activities of lactate dehydrogenase and malondialdehyde in tissue were decreased, while the superoxide dismutase was increased. The pathological sections showed that glomerular atrophy and glomerular basement membrane thickening caused by hyperglycemia were improved in the Baicalin treatment groups. Meanwhile, baicalin inhibited the downregulation of Nephrin and Podocin expressions and upregulation of Desmin expression caused by DN, and inhibited the expressions of p-PI3K, p-Akt, and p-mTOR proteins.ConclusionBaicalin slows down podocyte injury caused by DN by inhibiting the activity of PI3K/Akt/mTOR signaling pathway.

Protective effect of baicalin against pulmonary arterial hypertension vascular remodeling through regulation of TNF-α signaling pathway.

Pulmonary arterial hypertension (PAH) is a progressive cardiovascular disease with high mortality. However, there were no efficient medical drugs for PAH to enormously improve the survival and quality of life measures. The present study aimed to explore the protective effect of baicalin against experimental PAH in vivo and vitro. All the experimental rats received intraperitoneal injection of monocrotaline (MCT) to induce PAH model. Baicalin was given by intragastric administration from 2 days after MCT injection. Forty animals were randomly divided into four groups: Control, MCT, saline‐, and baicalin‐treated groups (n = 10 in each). Post‐operation, hemodynamic data, and index of right ventricular hypertrophy (RVHI) were recorded to evaluate the inhibition of baicalin on MCT‐induced PAH. Furthermore, pulmonary artery smooth muscle cells (PASMCs) model induced by tumor necrosis factor‐α (TNF‐α) was used to observe the inhibition of vascular cells proliferation in vitro. The results demonstrated that baicalin significantly attenuated MCT‐induced right ventricular systolic pressure (RVSP), the index of right ventricular hypertrophy, and vessel wall thickness; inhibit inflammatory and cell proliferation induced by MCT or TNF‐α, respectively. In addition, we found that baicalin might protect against experimental PAH via regulating the TNF‐α/BMPR2 signaling pathway.

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.

Baicalin Protects Against Acute Pancreatitis Involving JNK Signaling Pathway via Regulating miR-15a.

Acute pancreatitis (AP) is a kind of reversible inflammatory process of the exocrine pancreas. During the process, systemic inflammatory syndromes are involved, which relates closely to inflammatory mediators. Baicalin is a type of flavone compound extracted from Scutellaria baicalensis Georgi and exhibits anti-inflammation effect in several cancers. In this study, baicalin displayed a suppressing role on IL-1[Formula: see text], TNF[Formula: see text] and IL-6 in both cell and mice models. Necrosis was decreased in the baicalin treatment group and got a markedly lower pathological score. In this study, miR-15a is the core intermediate in baicalin regulation, which increased through baicalin treatment and protected pancreas cells and tissues, inhibiting the JNK signaling pathway by targeting MAP2K4. The long non-coding RNA MALAT1 is also a direct target of miR-15a and forms a competitive endogenous RNA (ceRNA) network with MAP2K4, which can be regulated by baicalin. In addition, upstream genes, including CDC42 and MAP3K1, were also regulated by baicalin, of which CDC42 was confirmed to form the second ceRNA network with MALAT1 and miR-15a. In conclusion, baicalin exhibits therapeutic activity towards AP by pumping up miR-15a level and inhibiting CDC42/MAP3K1, which affects AP as a brake by targeting MAP2K4 and inhibiting the JNK signaling pathway.

Baicalin inhibits inflammation caused by coinfection of Mycoplasma gallisepticum and Escherichia coli involving IL-17 signaling pathway

Coinfection of Mycoplasma gallisepticum (MG) and Escherichia coli (E. coli) is frequently reported in poultry farms. Baicalin possess various pharmacological properties such as anti-inflammatory, anticancer, and antioxidant, etc. However, the protective effects of baicalin against coinfection of MG and E. coli are still elusive. In this study, baicalin (450 mg/kg) treatment was started on day 13 after infection and continued for 5 d. Histopathological examination, qRT-PCR, ELISA, and molecular docking technique were used to evaluate the effects of baicalin on MG and E. coli coinfection in chicken lung and trachea. The results showed that coinfection caused severe lesions in the lung and tracheal tissues. However, baicalin treatment partially alleviated these lesions in coinfection group. Histopathological examination showed the alveolar spaces and mucosal layer thickening was restored and cilia gradually recovered with baicalin treatment compared in coinfection group and MG-infection group. Meanwhile, IL-17 singling pathway–related genes were significantly reduced (P < 0.05) in baicalin treatment group in lung, including IL-17C, TRAF6, NF-κB, CXCL1, CXCL2, MMP1, GM-CSF, and MUC5AC. The activities of cytokines and chemokines (CXCL1, CXCL2, MMP1, GMCSF, and MUC5AC) were decreased significantly (P < 0.05) in baicalin-treated group. The molecular docking of baicalin and NF-κB showed the highest fitness score and interaction. From these results, it has been suggested that baicalin proved effective against coinfection of MG and E. coli in chicken and provided scientific basis for further dose–response and drug–target interaction studies.

Baicalin inhibits root resorption during tooth movement in a rodent model

ObjectiveBaicalin mediates bone metabolism and has shown protective activity against periodontal tissue damage in a rat model of periodontitis. Therefore, we hypothesized that baicalin may inhibit the root resorption that occurs during orthodontic tooth movement and examined its effect on the histological changes in periodontal tissue that occur during tooth movement. MethodsFirst molars of rats were subjected to traction using excessive orthodontic force to produce a root resorption model. Rats in the baicalin group received baicalin for 3 weeks during tooth movement, and the amount of first molar movement on day 21 after the initiation of traction was measured by three-dimensional micro-computed tomography analysis. After tooth movement, tissue samples from the mesial and tension sides were collected, and successive horizontal sections were prepared and examined using hematoxylin–eosin and tartrate-resistant acid phosphatase (TRAP) staining and immunohistochemical staining for the receptor activator of NF-kB ligand (RANKL) and osteoprotegerin (OPG). The severity of root resorption was also determined by histological analysis. ResultsThere was no significant intergroup difference in tooth movement during the experimental exaggerated tooth movement. In comparison with the control group, the baicalin-treated group showed increased OPG expression, suppressed RANKL expression, and significantly fewer TRAP-positive cells in the first molars. The root resorption area was significantly smaller in the baicalin group. ConclusionsTreatment with baicalin prevented root resorption without preventing tooth movement. Baicalin may be useful for the management of root resorption during orthodontic treatment.

Protective effect of baicalin on the regulation of Treg/Th17 balance, gut microbiota and short-chain fatty acids in rats with ulcerative colitis.

Baicalin is reported as an effective drug for ulcerative colitis (UC). However, its effect on gut microbiota and short-chain fatty acids (SCFAs) remains unknown. In this study, we investigated the role of baicalin on Th17/Treg balance, gut microbiota community, and SCFAs levels in trinitrobenzene sulphonic acid (TNBS)-induced UC rat model. We found the DAI scores were significantly increased in the TNBS-treated rats, while reduced in the baicalin-treated group in a dose-dependent manner, accompanied with the alleviation of mucosal injury, the reduction of ZO-1, Occludin, and MUC2 expression. At the meanwhile, baicalin repressed the increased levels of reactive oxygen species (ROS) and MDA, while deceased the GSH and SOD levels in colon tissue of rats treated with TNBS. On the other hand, administration of baicalin attenuated the TNBS-induced upregulations of Th17/Treg ratio, indicating a strong amelioration in the colorectal inflammation. More importantly, pyrosequencing of the V4 regions of 16S rRNA genes in rat feces revealed a deviation of the gut microbiota in response to baicalin treatment. In particular, the decreased Firmicutes-to-Bacteroidetes ratios and endotoxin-bearing Proteobacteria levels indicated that baicalin reversed TNBS-induced gut dysbiosis OTUs. In addition, we further investigated the fecal levels of major SCFAs in rats and found that baicalin significantly resorted the fecal butyrate levels in rats treated with TNBS. The increased butyrate levels were in consistent with the higher abundance of butyrate-producing species such as Butyricimonas spp., Roseburia spp., Subdoligranulum spp., and Eubacteriu spp. in baicalin-treated group. In conclusion, our findings suggest that baicalin possibly protected rats against ulcerative colitis by regulation of Th17/Treg balance, and modulation of both gut microbiota and SCFAs. Baicalin may be used as a prebiotic agent to treat ulcerative colitis-associated inflammation and gut dysbiosis.

Baicalin attenuates lipopolysaccharide-induced renal tubular epithelial cell injury by inhibiting the TXNIP/NLRP3 signalling pathway via increasing miR-223-3p expression.

Baicalin has been used in China to treat inflammation-related diseases, such as inflammation-induced acute kidney injury (AKI). However, the specific mechanism of baicalin remains unclear. To observe the protective effects of baicalin on lipopolysaccharide (LPS)-induced inflammatory injury of renal tubular epithelial cells (HK-2 cells) and to explore its protective mechanism. LPS (1 mg/L) was used to induce an HK-2 cell inflammatory injury model in vitro. The cells were divided into seven groups: the normal control group, LPS-induced group, LPS plus 5 μmol/L baicalin treatment group, LPS plus 15 μmol/L baicalin treatment group, LPS plus 25 μmol/L baicalin treatment group, LPS plus 50 μmol/L baicalin treatment group, and LPS plus 75 μmol/L baicalin treatment group. 3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2-H-tetrazolium bromide (MTT) assay was employed for detecting the relative survival rate of HK-2 cells. Enzyme-linked immunosorbent assay was used for detecting the levels of inflammatory factors, including interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α). Moreover, the expression of inducible nitric oxide synthase (iNOS); cyclooxygenase-2 (COX-2); nuclear factor kB65 (NF-κB65); phosphorylated NF-κB inhibitory protein-α (p-IκB-α); NF-κB inhibitory protein (IκB); human thioredoxin interacting protein (TXNIP); and human NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) were determined by Western blot analysis. The expression levels of NLRP3 and TXNIP mRNA and miR-223-3p were determined by RT-PCR. Results found that the relative survival rate of HK-2 cells treated with different baicalin concentrations was significantly increased (P<0.05) and the levels of the inflammatory factors IL-6, IL-1β, and TNF-α were significantly decreased (P<0.05) compared with those of the LPS-induced group. The expression levels of the inflammatory proteins inducible nitric oxide synthase and cyclooxygenase-2 and the genes expressions of TXNIP and NLRP3 were significantly decreased in the cells (P<0.05), while the expression level of miR-223- 3p was significantly increased (P<0.05). These changes were induced in a dose-dependent manner. The results suggest that baicalin significantly inhibited the expression of inflammation-related proteins and alleviated LPS-induced inflammatory injury in HK-2 cells. The mechanism may be associated with the inhibition of activation of the TXNIP/NLRP3 inflammatory pathway, which might be mediated by increased expression of miR-223-3p. Thus, NLRP3 is a regulatory target of miR-223-3p.

Baicalin Attenuates Mycoplasma gallisepticum-Induced Inflammation via Inhibition of the TLR2-NF-κB Pathway in Chicken and DF-1 Cells.

BackgroundPrevious reports demonstrated that baicalin possesses potential anti-inflammatory properties. The present study was conducted to determine the effects of baicalin against inflammatory responses in chicken and DF-1 cells infected with Mycoplasma gallisepticum (MG).MethodsAn MG infection model was developed in chickens to study the anti-inflammatory mechanism of baicalin. Baicalin was mixed in water at a dose of 450 mg/kg per day, and the treatment is continued for 7 consecutive days. Samples were taken at 1, 4, and 7 days post treatment.ResultsBy using transmission electron microscopy, ultrastructure of lung and tracheal cells has been examined. It can be seen that the cilia cells in the MG-infected group have pyknosis, degeneration, and necrosis. In the lung tissues, alveolar type-I epithelial cells were severely damaged. In the baicalin-treated group, cilia were swollen, mushroom-shaped edema bubbles formed on the apex, and fused together. Alveolar type I epithelial cells injury was significantly reduced. Compared to MG-infection group, the levels of proinflammatory cytokines IL-1β and TNF-α were significantly decreased (P < 0.01). The corresponding proteins TLR2 and P-p65 decreased in the baicalin-treated group after 1 (p > 0.05), 4 (p < 0.05), and 7 days (p < 0.05), respectively.ConclusionThe results showed that baicalin can interfere with inflammatory injury by suppressing the release of inflammatory cytokines IL-1β and TNF-α during MG infection both in vivo and in vitro. Meanwhile, baicalin suppressed TLR2-NFκB signaling pathway by inhibiting the phosphorylation of p65 and IκB, thereby affecting the expression of inflammatory factors. The results suggested that baicalin acts as a potential anti-inflammatory agent against MG infection in chicken and DF-1 cells.

Baicalin mitigated Mycoplasma gallisepticum-induced structural damage and attenuated oxidative stress and apoptosis in chicken thymus through the Nrf2/HO-1 defence pathway

The thymus is a primary lymphoid organ and plays a critical role in the immune response against infectious agents. Baicalin is a naturally derived flavonoid famous for its pharmacological properties, but the preventive effects of baicalin against immune impairment remain unclear. We examined this effect in the context of Mycoplasma gallisepticum (MG) infection-induced structural damage in the chicken thymus. Histopathological examination showed that the compact arrangement of cells in the thymus was lost in the MG-infected group. Inflammatory cell infiltration and nuclear debris accumulated, and the boundary between the cortex and medulla was not clearly visible. The mRNA and protein expression of apoptosis-related genes were significantly increased in the MG-infected group compared to the control group and the baicalin group. The number of positively stained nuclei in the terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay were increased in the MG-infected group. In addition, electron microscopic examination showed chromatin condensation, mitochondrial swelling and apoptotic vesicles in the MG-infected group. However, baicalin treatment significantly alleviated the oxidative stress and apoptosis induced by MG infection. Importantly, the abnormal morphology was partially ameliorated by baicalin treatment. Compared to the MG-infected group, the baicalin-treated group showed significantly reduced expression of apoptosis-related genes at both the mRNA and protein levels. Meanwhile, the nuclear factor erythroid 2-related factor 2 (Nrf2) signalling pathway and downstream genes were significantly upregulated by baicalin to counteract MG-induced oxidative stress and apoptosis in the thymocytes of chickens. In summary, these findings suggest that baicalin treatment efficiently attenuated oxidative stress and apoptosis by activating the Nrf2 signalling pathway and could protect the thymus from MG infection-mediated structural and functional damage.

Baicalin improves the in vitro developmental capacity of pig embryos by inhibiting apoptosis, regulating mitochondrial activity and activating sonic hedgehog signaling.

Baicalin, a traditional Chinese medicinal monomer whose chemical structure is known, can be used to treat female infertility. However, the effect of baicalin on embryonic development is unknown. This study investigated the effects of baicalin on in vitro development of parthenogenetically activated (PA) and in vitro fertilized (IVF) pig embryos and the underlying mechanisms involved. Treatment with 0.1μg/ml baicalin significantly improved (P < 0.05) the in vitro developmental capacity of PA pig embryos by reducing the reactive oxygen species (ROS) levels and apoptosis and increasing the mitochondrial membrane potential (ΔΨm) and ATP level. mRNA and protein expression of sonic hedgehog (SHH) and GLI1, which are related to the SHH signaling pathway, in PA pig embryos at the 2-cell stage, were significantly higher in the baicalin-treated group than in the control group. To confirm that the SHH signaling pathway is involved in the mechanism by which baicalin improves embryonic development, we treated embryos with baicalin in the absence or presence of cyclopamine (Cy), an inhibitor of this pathway. Cy abolished the effects of baicalin on in vitro embryonic development. In conclusion, baicalin improves the in vitro developmental capacity of PA and IVF pig embryos by inhibiting ROS production and apoptosis, regulating mitochondrial activity and activating SHH signaling.

Baicalin protects mouse testis from injury induced by heat stress.

Heat stress has been documented to reduce reproductive performance of female animals through injury to germ cells, with few studies available in male animals. The objectives of this study were to evaluate protective effects of baicalin on testicular tissue damage of mice subjected to heat stress and its related mechanisms. In this experiment, A total of forty mice were divided into four groups, including control group (C), baicalin group (B), heat stressed group (H) and heat stress with baicalin treatment (H+B) group. Morphological changes, activities of antioxidant enzymes and apoptosis-related parameters in the mice testes tissue were monitored. The results showed that the process of spermatogenesis in mice testis was impaired and the cellular apoptosis increased due to acute heat stress at 41°C. Interestingly, the tissue damage was alleviated with the significant (P < 0.05) increase in the activities of SOD, CAT and GSH-Px enzymes, decrease (P<0.05) in MDA content and number of cellular apoptosis recorded in mice of H+B group compared with those in mice from H group. In addition, the Fas, FasL and P-JNK protein expressions were significantly (P<0.05) increased; and apaf-1, caspase-3, -9 were slightly expressed in the H group, while there was no difference in Bcl-2 expression, compared with C, B and H+B groups. The above results clearly indicate that heat stress induces macroscopic/apoptotic and oxidative changes in the testicular tissue of mice; these changes are alleviated by Baicalin through increasing anti-oxidative enzyme activities and possibly through blocking Fas/FasL pathway.

Baicalin inhibits IgG production by regulating Treg/Th17 axis in a mouse model of red blood cell transfusion

This study was conducted to evaluate whether baicalin inhibits red blood cell (RBC) immunization and elucidate the underlying mechanism. We used human RBCs with adjuvant lipopolysaccharide (LPS) and transfused mice to induce antibodies as an experimental system for studying the effect of baicalin on RBC immunization. Mice were divided into a human RBC transfused positive control group administered with human RBC and LPS intravenously once or weekly for 4 weeks, control group administered dexamethasone (DEX) intraperitoneally daily for 4 weeks, and treatment group administered baicalin intraperitoneally daily for 4 weeks. Assessment of human RBC immunization was performed by measuring serum immunoglobulin G (IgG) and immunoglobulin M (IgM) against human RBC weekly. Lymphocyte changes in spleen were monitored by flow cytometry. We found that baicalin treatment significantly decreased serum IgG but not IgM production in a time and does dependent manner, with a concomitant reduction in Th17 cells and increase in CD4 regulatory T cells in the spleen. The percentage of CD4-positive cells in the spleen was not decreased in the baicalin-treated group but was decreased in the dexamethasone-treated group. In conclusion, baicalin inhibited RBC immunization, particularly IgG production by regulating the Treg/Th17 axis without damaging spleen function.

Deciphering the potential of baicalin as an antiviral agent for Chikungunya virus infection

The past decade has seen the re-emergence of Chikungunya virus (CHIKV) as a major global health threat, affecting millions around the world. Although fatal infections are rare among infected patients, the occurrence of long-lasting polyarthralgia has a significant impact on patients' quality of lives and ability to work. These issues were the stimuli for this study to determine the potential of baicalin, a bioflavonoid, as the novel antiviral compound against CHIKV. It was found that baicalin was well tolerated by Vero, BHK-21 and HEK 293T cells with maximal nontoxic doses >600 μM, ≈ 350 μM and ≈110 μM, respectively. Antiviral assays indicated that baicalin was the most effective inhibitor when tested for its direct virucidal activity with EC50 ≈ 7 μM, followed by inhibition of virus entry into the host cell, attachment of virus particle to cellular receptors and finally intracellular replication of viral RNA genome. In silico analysis using molecular docking demonstrated close interactions between baicalin and CHIKV envelope protein with considerably strong binding affinity of −9.7 kcal/mol. qRT-PCR analysis revealed that baicalin had the greatest effect on the synthesis of viral negative stand RNA with EC50 ≈ 0.4 μM followed by the inhibition of synthesis of positive-strand genomic (EC50 ≈ 13 μM) and subgenomic RNAs (EC50 ≈ 14 μM). These readings indicate that the compound efficiently inhibits replicase complexes formation but is a less potent inhibitor of existing replicase complexes. Coherent with this hypothesis, the use of recombinant CHIKV replicons harboring Renilla luciferase marker showed that replication of corresponding replicon RNAs was only slightly downregulated at higher doses of baicalin, with EC50 > 100 μM. Immunofluorescence and western blotting experiments demonstrated dose-dependent inhibition of expression of different viral proteins. It was also observed that levels of important protein markers for cellular autophagy (LC3) and apoptosis (Bax) were reduced in baicalin treatment groups as compared with untreated virus infected controls. In summary, given its low toxicity and high efficacy against CHIKV, baicalin has great potential to be developed as the novel antiviral compound for CHIKV. In vivo studies to evaluate its activity in a more complexed system represent a necessary step for future analysis.

Effects of baicalin on the changes in hemorheology of acute respiratory distress syndrome in rats

Objective: To investigate the effect of baicalin on the changes in hemorheology and its mechanism during the development of Acute Respiratory Distress Syndrome(ARDS) induced by oleic acid (OA) in rats. Methods: Rats were randomized into 3 groups: control, ARDS (OA induction, 0.12 mg/kg) and ba-icalin-treated group (300 mg/kg). The blood samples were collected at 30 min, 1, 2, 3, 6, 12 and 6 h after OA injection. The whole blood viscosity, plasma viscosity, Maximum erythrocyte deformability index (DImax) were detected. Meanwhile, blood gas analysis and Routine blood test were also performed. Results: The level of arte-rial oxygen partial pressure and oxygenation index decreased (P<0.01 vs. control) and oxygenation index (178 mm Hg, 1 mm Hg=0.133 kPa) reached the diagnostic standard of ARDS at 2 h in ARDS group. In baicalin-treated group, the level of arterial oxygen partial pressure and oxygenation index increased versus the ARDS group. The platelet count (PLT) decreased in baicalin-treated and ARDS groups. Compared with the ARDS group, the level of PLT increased significantly in baicalin-treated group at 30min, 1, 2, and 3 h. Hematocrit (HCT) increased in baicalin-treated and ARDS groups. Compared with the ARDS group, the level of HCT de-creased significantly in baicalin-treated group at 2, 3, 6 and 12 h. Meanwhile, all the index of hemorheology improved in baicalin-treated group. Conclusion: Baicalin may improve hypoxemia of ARDS induced by OA in rats. It may be due to the Improvement of microcirculation of lung.