Naringin attenuates Actinobacillus pleuropneumoniae-induced acute lung injury via MAPK/NF-κB and Keap1/Nrf2/HO-1 pathway.

Actinobacillus pleuropneumoniae (APP) causes porcine pleuropneumonia (PCP), which is clinically characterized by acute hemorrhagic, necrotizing pneumonia, and chronic fibrinous pneumonia. Although many measures have been taken to prevent the disease, prevention and control of the disease are becoming increasingly difficult due to the abundance of APP sera, weak vaccine cross-protection, and increasing antibiotic resistance in APP. Therefore, there is an urgent need to develop novel drugs against APP infection to prevent the spread of APP. Naringin (NAR) has been reported to have an excellent therapeutic effect on pulmonary diseases, but its therapeutic effect on lung injury caused by APP is not apparent. Our research has shown that NAR was able to alleviate APP-induced weight loss and quantity of food taken and reduce the number of WBCs and NEs in peripheral blood in mice; pathological tissue sections showed that NAR was able to prevent and control APP-induced pathological lung injury effectively; based on the establishment of an in vivo/in vitro model of APP inflammation, it was found that NAR was able to play an anti-inflammatory role through inhibiting the MAPK/NF-κB signaling pathway and exerting anti-inflammatory effects; additionally, NAR activating the Nrf2 signalling pathway, increasing the secretion of antioxidant enzymes Nqo1, CAT, and SOD1, inhibiting the secretion of oxidative damage factors NOS2 and COX2, and enhancing the antioxidant stress ability, thus playing an antioxidant role. In summary, NAR can relieve severe lung injury caused by APP by reducing excessive inflammatory response and improving antioxidant capacity.

Naringin's Alleviation of the Inflammatory Response Caused by Actinobacillus pleuropneumoniae by Downregulating the NF-κB/NLRP3 Signalling Pathway.

Actinobacillus pleuropneumoniae (APP) is responsible for causing Porcine pleuropneumonia (PCP) in pigs. However, using vaccines and antibiotics to prevent and control this disease has become more difficult due to increased bacterial resistance and weak cross-immunity between different APP types. Naringin (NAR), a dihydroflavonoid found in citrus fruit peels, has been recognized as having significant therapeutic effects on inflammatory diseases of the respiratory system. In this study, we investigated the effects of NAR on the inflammatory response caused by APP through both in vivo and in vitro models. The results showed that NAR reduced the number of neutrophils (NEs) in the bronchoalveolar lavage fluid (BALF), and decreased lung injury and the expression of proteins related to the NLRP3 inflammasome after exposure to APP. In addition, NAR inhibited the nuclear translocation of nuclear factor kappa-B (NF-κB) P65 in porcine alveolar macrophage (PAMs), reduced protein expression of NLRP3 and Caspase-1, and reduced the secretion of pro-inflammatory cytokines induced by APP. Furthermore, NAR prevented the assembly of the NLRP3 inflammasome complex by reducing protein interaction between NLRP3, Caspase-1, and ASC. NAR also inhibited the potassium (K+) efflux induced by APP. Overall, these findings suggest that NAR can effectively reduce the lung inflammation caused by APP by inhibiting the over-activated NF-κB/NLRP3 signalling pathway, providing a basis for further exploration of NAR as a potential natural product for preventing and treating APP.

Naringin alleviates pneumonia caused by Klebsiella pneumoniae infection by suppressing NLRP3 inflammasome.

Klebsiella pneumoniae (Kpn) is an important pathogen of hospital-acquired pneumonia, which can lead to sepsis and death in severe cases. In this study, we simulated pneumonia induced by Kpn infection in mice to investigate the therapeutic effect of naringin (NAR) on bacterial-induced lung inflammation. Mice infected with Kpn exhibited increases in white blood cells (WBC) and neutrophils in the peripheral blood and pathological severe injury of the lungs. This injury was manifested by increased expression of the inflammatory cytokines interleukin (IL)- 18, IL-1ß, tumor necrosis factor-α (TNF-α) and IL-6, and elevated the expression of NLRP3 protein. NAR treatment could decrease the protein expression of NLRP3, alleviate lung inflammation, and reduce lung injury in mice caused by Kpn. Meanwhile, molecular docking results suggest NAR could bind to NLRP3 and Surface Plasmon Resonance (SPR) analyses also confirm this result. In vitro trials, we found that pretreated with NAR not only inhibited nuclear translocation of nuclear factor (NF)-κB protein P65 but also attenuated the protein interaction of NLRP3, caspase-1 and ASC and inhibited the assembly of NLRP3 inflammasome in mice AMs. Additionally, NAR could reduce intracellular potassium (K+) efflux, inhibiting NLRP3 inflammasome activation. These results indicated that NAR could protect against Kpn-induced pneumonia by inhibiting the overactivation of the NLRP3 inflammasome signaling pathway. The results of this study confirm the efficacy of NAR in treating bacterial pneumonia, refine the mechanism of action of NAR, and provide a theoretical basis for the research and development of NAR as an anti-inflammatory adjuvant.

Therapeutic Effect and Safety Evaluation of Naringin on Klebsiella pneumoniae in Mice.

Critically ill patients with Corona Virus Disease 2019 (COVID-19) often develop secondary bacterial infections that pose a significant threat to patient life safety, making the development of drugs to prevent bacterial infections in the lungs critical to clinical care. Naringin (NAR) is one of the significant natural flavonoids rich in Pummelo Peel (Hua Ju Hong), with anti-inflammatory, antimicrobial, and antioxidant activities, and is commonly used in treating respiratory tract infectious diseases. In this study, the in vitro and in vivo findings revealed that, after Klebsiella pneumoniae (Kpn) infection, NAR inhibited overactivation of the nuclear factor kappa-B(NF-κB) signaling pathway in alveolar macrophages of mice, reduced neutrophil (NEs) recruitment, and lowered the induced production of proinflammatory markers, such as Interleukin-6(IL-6) and tumor necrosis factor α(TNF-α). Thus, it suppressed excessive immune responses in the lungs, as well as attenuated the induced pulmonary fibrosis and inflammatory infiltrates. These results suggest that NAR has a preventive effect against Kpn in mice. In addition, the study evaluated NAR's potential toxicity, demonstrating that NAR is safe at effective doses. These results suggested that NAR effectively reduces excessive inflammatory damage in the lungs induced by Kpn and enhances the body's ability to clear bacteria. Therefore, NAR may be an effective and safe healthcare drug for preventing and caring for bacterial pneumonia.

Asiatic acid and andrographolide reduce hippocampal injury through suppressing neuroinflammation caused by Salmonella typhimurium infection.

Damage caused by Salmonella is not only limited to the gastrointestinal tract, but also occurs in the central nervous system (CNS). The aim of this study was to explore the protective effects of asiatic acid (AA) and andrographolide (AD) on the CNS through simulating common infection in mice by oral administration of Salmonella typhimurium (S. typhimurium). The results showed that the neurons in the hippocampus of mice were damaged after S. typhimurium invaded CNS in mice, and the inflammation was increased, which was manifested by the increased expression of inflammatory factors interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, IL-6, interferon (IFN)-γ and IL-12b and the activation of NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasomes. The damage and inflammatory response of mouse hippocampal neurons were effectively reduced by AA or AD pretreatment. Furthermore, we observed the significant activation of microglia after S. typhimurium infection. AA and AD attenuated S. typhimurium -induced hippocampal injury by reducing the inflammatory response on microglia. The findings suggest that the AA and AD protect CNS from injury caused by S. typhimurium infection through inhibiting over expression of multiple neuroinflammatory mediators and NLRP3 inflammasome in mice.

Asiatic Acid Attenuates Inflammation Induced by Salmonella via Upregulating LncRNA TVX1 in Microglia.

Salmonella typhimurium (S.T) induces damage to the central nervous system; however, the role of Asiatic acid (AA) in this is still unknown. Microglia play a role as macrophages to recognize the invaded pathogenic microbes in the brain. The aim of this study was to investigate the protective effect and mechanism of AA on the central nervous system through an in vitro model of S.T infection in microglia. We pre-treated microglia with AA before S.T infection and explored the anti-infection mechanism of AA by sequencing, quantitative reverse transcription PCR (RT-qPCR), and Western blotting. Long non-coding RNA (lncRNA) sequencing demonstrated that inflammation is a major factor in S.T infection of microglia. RT-qPCR data demonstrated that AA inhibited S.T-induced increases in the mRNA levels of the pro-inflammatory factors interleukin (IL)-1ß, IL-6, and IL-18. Western blotting demonstrated that AA inhibited S.T-induced activation of the nuclear factor (NF)-κB pathway and activation of the NLR family, pyrin domain-containing 3 (NLRP3) inflammasome. Expression of the lncRNA TVX1 in microglia was decreased by S.T infection and increased by pretreatment with AA. Inhibition of TVX1 expression reversed the anti-inflammatory effect of AA, and overexpression of TVX1 in microglia suppressed S.T-induced inflammation. In conclusion, AA attenuated S.T-induced microglial inflammation by upregulating the expression of the lncRNA TVX1.

Screening of essential oils with acaricidal activity against Haemaphysalis longicornis (Acari: Ixodidae) and analysis of active components.

Haemaphysalis longicornis (Acari: Ixodidae) is an important vector of numerous pathogens and poses a great threat to veterinary and public health. Commercially available tick repellents are extensively used and primarily comprise synthetic molecules; however, there are concerns over their safety and environmental impacts. Biologically based acaricides, particularly the plant-derived essential oils (EOs), may constitute an appealing alternative. We screened 20 different EOs by packet tests of unfed H. longicornis nymphs, and found that EOs of cinnamon, clove and chamomile were the most toxic (mortality > 80 %). Cinnamon EO had the most competitive acaricidal activity, with lethal concentration 50 (LC50) rates of 0.4530 %, 0.2316 % and 0.0342 % (v/v) for unfed adults, nymphs and larvae, respectively. Furthermore, 5.00 % (v/v) cinnamon EO showed reproductive inhibition against H. longicornis, with significantly higher rates of oviposition reduction (53.19 %) and hatching reduction (46.21 %) compared with the negative control group. Composition analysis of cinnamon EO by gas chromatography-mass spectrometry (GC-MS) revealed that the major chemical compounds were trans-cinnamaldehyde (72.21 %) and cinnamic acid (19.45 %), with the former showing similar levels of acaricidal activity and oviposition inhibition as cinnamon EO. This study has demonstrated the potential of cinnamon EO and trans-cinnamaldehyde as natural acaricides against H. longicornis, and is the first to characterize their oviposition inhibition activity.

Genetic and environmental factors in Alzheimer's and Parkinson's diseases and promising therapeutic intervention via fecal microbiota transplantation.

Neurodegenerative diseases are characterized by neuronal impairment and loss of function, and with the major shared histopathological hallmarks of misfolding and aggregation of specific proteins inside or outside cells. Some genetic and environmental factors contribute to the promotion of the development and progression of neurodegenerative diseases. Currently, there are no effective treatments for neurodegenerative diseases. It has been revealed that bidirectional communication exists between the brain and the gut. The gut microbiota is a changeable and experience-dependent ecosystem and can be modified by genetic and environmental factors. The gut microbiota provides potential therapeutic targets that can be regulated as new interventions for neurodegenerative diseases. In this review, we discuss genetic and environmental risk factors for neurodegenerative diseases, summarize the communication among the components of the microbiota-gut-brain axis, and discuss the treatment strategy of fecal microbiota transplantation (FMT). FMT is a promising treatment for neurodegenerative diseases, and restoration of the gut microbiota to a premorbid state is a novel goal for prevention and treatment strategies.

Combined Effect of Shegandilong Granule and Doxycycline on Immune Responses and Protection Against Avian Infectious Bronchitis Virus in Broilers.

Infectious bronchitis (IB) causes significant economic losses to commercial chicken farms due to the failures of vaccine immunization or incomplete protection. In this study, we evaluated the combination effect of Shegandilong (SGDL) granule (a traditional Chinese veterinary medicine) and doxycycline on the prevention of IBV infection and injury in the respiratory tract in broilers. A total of 126, 7-day-old broilers were randomly divided into four groups after vaccination. Group I served as a control. Broilers in Group II were given doxycycline, and Group III was given SGDL granule through drinking water. Broilers in Group IV were given SGDL granule and doxycycline by drinking water. Broilers in all groups were challenged with IBV through intraocular and intranasal routes at day 28. Results showed that the anti-IBV antibody level was higher in group IV compared with the level in other groups. Immunohistochemistry and ELISA results showed that an increase of immunoglobulin A (IgA) was observed in the trachea with the maximum level observed at day 14. In addition, SGDL granule + doxycycline effectively inhibited IBV replication and stopped IBV propagation from the trachea to the lung; modulated the mRNA expressions of IL-1ß, IL-6, TNF-α, and IFN-γ; and extenuated the histopathology lesions in trachea and lung. These data imply that a combination of SGDL granule and doxycycline is effective in preventing IBV infection and respiratory tract injury in broilers.

The gut microbiota attenuate neuroinflammation in manganese exposure by inhibiting cerebral NLRP3 inflammasome.

Manganese (Mn) exposure has been reported to cause neurodegenerative disorders. ß-Amyloid (Aß) induced Tau pathology in an NLRP3-dependent manner is at the heart of Alzheimer's and Parkinson's diseases. The gut microbiota plays a crucial role in the bidirectional gut-brain axis that integrates the gut and central nervous system (CNS) activities. In this study, we found that Mn exposure increases Aß1-40 and Tau production in brain, and causes hippocampal degeneration and necrosis. Meanwhile, Mn exposure can stimulate neurotoxicity by increasing inflammation either in peripheral blood and CNS. Importantly, we found that transplantation of gut microbiota from normal rats into Mn exposure rats reduced Aß and Tau expression, and the cerebral expression of NLRP3 was downregulated, and the expression of neuroinflammatory factors was also downregulated. Therefore, improving the composition of gut microbiota in Mn exposure rats can attenuate neuroinflammation, which is considered as a novel therapeutic strategy for Mn exposure by remodelling the gut microbiota.

The gut microbiota confers protection in the CNS against neurodegeneration induced by manganism.

Among all types of pollution, heavy metals are considered the greatest threat to human health, and heavy metals are associated with an increased risk of cardiovascular disease, coronary heart disease and neurodegenerative disorders. Manganese (Mn) exposure is well reported to exert neurotoxicity and various neurodegenerative disorders, but the mechanisms are not clear. The gut microbiota plays a crucial role in the bidirectional gut-brain axis that integrates the gut and central nervous system (CNS) activities. The changes in chemical signaling, metabolism and gut microbiota associated with Mn exposure have provided deeper insight into the neurotoxic mechanism of Mn. We observed that Mn exposure increases host manganic bioaccumulation, and ß-amyloid (Aß), receptor-interacting protein kinase 3 (RIP3) and caspase-3 production in the brain, and causes hippocampal degeneration and necrosis. Mn exposure led to decreased gut bacterial richness, especially for Prevotellaceae, Fusobacteriaceae and Lactobacillaceae. In addition, Mn exposure altered the metabolism of tryptamine, taurodeoxycholic acid, ß-hydroxypyruvic acid and urocanic acid. Meanwhile, we found correlations between the abundance of certain bacterial species and the level of tryptamine, taurodeoxycholic acid, ß-hydroxypyruvic acid and urocanic acid. Fecal microbiome transplantation from normal rats could alleviate the neurotoxicity of Mn exposure by shaping the gut microbiota. Our findings highlight the role of gut dysbiosis-promoted neurotoxicity in Mn exposure and suggest a novel therapeutic strategy of remodeling the gut microbiota.

Design and content determination of Genhuang dispersible tablet herbal formulation.

The aim of the present study was to optimize the shaping technology of the traditional herbal formula Genhuang dispersible tablets, and also establish a method for content determination. The optimal formulation of Genhuang dispersible tablets was determined based on the results of single factor test and orthogonal design test. The disintegration was used as the main study indicator. The proportion of each adjuvant in the optimal formulation consisted of 40% MCC as bulking agent, 15% PVPP and 7% L-HPC as disintegrant, ethanol as adhesive, CSD as lubricant, preparing the dispersible tablets with wet granulation. The content of baicalin in Genhuang dispersible tablets was determined by RP-HPLC method, the C18 column (150×4.6 mm, 10µm) was used, the mobile phase was methanol-water-phosphoric acid (47: 53: 0.2) with the flow rate of 1mL/min, the detection wavelength was at 280 nm and the column temperature was 30oC. The prepared dispersible tablets could be totally disintegrated within three minutes and in accordance with the standard of the Chinese pharmacopoeia. In conclusion, the formulation was suitable for Genhuang dispersible tablets, and the determination method was simple, sensitive and accurate. Therefore, the Genhuang dispersible tablets can be used for industrial production and effectively controlled.

EVALUATION OF THE ACUTE AND SUBCHRONIC TOXICITY OF Aster tataricus L. F.

BACKGROUND: Aster tataricus L. f. is used as a traditional Chinese drug to relieve cough and asthma symptoms and to eliminate phlegm. However, Aster tataricus L. f. possesses toxicity, and little systematic research has been conducted on its toxic effects in the laboratory. METHODS AND MATERIALS: The acute group was administered 75% alcohol extract of Aster tataricus L. f. in a single dose. A subchronic toxicity study was performed via daily oral administration of Aster tataricus L. f. at a dose of 0.34 g/kg body weight in SD rats. The rats were divided into six groups: a petroleum ether extract (PEA) group, an ethyl acetate extract (EEA) group, an n-butyl alcohol extract (NEA) group, a remaining lower aqueous phases (REA) group, a 75% alcohol extract (AEA) group and a control group. Quantitative measurements of cytokines were obtained by fluorescence with a laser scanner using a Cy3 equivalent dye. RESULTS: The LD50 of the 75% alcohol extract of Aster tataricus L. f. was 15.74 g/kg bw. In the subchronic toxicity study, no significant differences were observed among groups in relative organ weights, urine traits, liver antioxidase levels, or cytokine levels. However, significant sporadic differences were observed in body weight gains, haematology indices, biochemistry values, and histopathology features in PEA, EEA group. In addition, sporadic changes in other groups in measures such as WBC, MCHC, CK, ALP, AST, ALT, LDH, T-BIL, LDL-C, HDL-C, and TC were observed. CONCLUSION: The toxicity study showed that Aster tataricus L. f. can produce toxic effects, mainly on the liver; much less on the heart. The LD50 was 15.74 g/kg BW in mice, and the subchronic toxicity study, used a dosage of 0.34 g/kg/d.BW, showed that the toxic components of Aster tataricus L. f. were mainly concentrated in the petroleum ether fraction, followed by the ethyl acetate fraction, the n-butyl alcohol fraction, the lower aqueous phase and the 75% ethanol extracts. Abbreviations: PEA, petroleum ether extract of Aster tataricus L. f.; EEA, ethyl acetate extract of Aster tataricus L. f.; NEA: n-butyl alcohol extract of Aster tataricus L. f.; REA: lower aqueous phases of Aster tataricus L. f.; AEA, 75% alcohol extract of Aster tataricus L. f.; WBC, white blood cell; RBC, red blood cell, PLT, platelet; HCT, haematocrit; MCV, mean corpuscular volume; HGB, haemoglobin; MCH, mean corpuscular haemoglobin; MCHC, mean corpuscular haemoglobin concentration; CREA, creatinine; LDH, lactate dehydrogenase; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; T-BIL, total bilirubin; ALT, alanine aminotransferase; ALP, alkaline phosphatase; AST, aspartate aminotransferase; TP, total protein; ALB, albumin; Glu, glucose; TC, total cholesterol; TG, triglycerides; CK, creatine kinase; GSH, Glutathione; MDA, malondialdehyde; T-SOD, total superoxide dismutase; TNF, tumour necrosis factor; IFN, interferon; MCP, monocyte chemotactic protein C.

Differential cardiovascular effects of synthetic peptides derived from endomorphin-1 in anesthetized rats.

Previously, five synthetic peptides derived from endomorphin-1 (Tyr1-Pro2-Trp3-Phe4-NH2, EM-1), including Tyr-D-Ala-Trp-p-Cl-Phe-NH2 (HDAPC), Tyr-D-Ala-Trp-Phe-NH2 (HDADC), Nalpha-amidino-Tyr-D-Ala-Trp-p-Cl-Phe-NH2 (GDAPC), Nalpha-amidino-Tyr-D-Ala-Trp-Phe-NH2 (GDADC) and Nalpha-amidino-Tyr-D-Pro-Gly-Trp-p-Cl-Phe-NH2 (GBDPC), were described to elicit analgesia by subcutaneous administration with enhanced metabolic stabilities. To further our knowledge of the influences of particular modification on the pharmacological activities of EM-1, the present study was undertaken to investigate cardiovascular effects of these peptides in anesthetized rats by intravenous injection. Our results showed that the four D-Ala-containing peptides decreased the systemic arterial pressure (SAP) and heart rate (HR) through a naloxone-sensitive mechanism. Different patterns, potencies and durations of cardiovascular effects were observed among these peptides. When compared to EM-1, the hemodynamic responses to these four tetrapeptides were significantly lower in magnitude but much longer in duration. Surprisingly, intravenous administration of the only pentapeptide GBDPC produced fairly prolonged hypertensive and tachycardiac effects, which was naloxone-insensitive, thus providing evidence that changes in the primary structure of a peptide can profoundly affect its pharmacological activity. Comparisons of the cardiovascular effects between these peptides showed that each modification introduced into EM-1, including N-amidination, chloro-halogenation and unnatural amino acid substitution, played a role in the influence on the cardiovascular regulation of these peptides.