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.

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.

Phillygenin activates PKR/eIF2α pathway and induces stress granule to exert anti-avian infectious bronchitis virus.

The prevalence of avian infectious bronchitis virus (IBV) is still one of causes inducing severe losses of production in the poultry industry worldwide. Vaccination does not completely prevent IBV infection and spread due to immune failure and viral mutations. ForsythiaeFructus and its compounds have been widely used in a lot of prescriptions of the traditional Chinese medicine for a long history, and it is well-known as safety and efficiency in heat-clearing and detoxifying. This study aims to investigate the anti-IBV activity and mechanism of phillygenin. The results showed that phillygenin inhibited IBV replication by disturbing multiple stages of the virus life cycle, including viral adsorption, invasion, internalization, and release in Vero cells. After being treated with 100, 125 and 150 µg/mL phillygenin, the expression of G3BP1 was significantly increased and the phosphorylation of PKR/eIF2α was activated, which increased stress granule, thereby triggering the antiviral response in Vero cells. The anti-virus activity of PHI was decreased when G3BP1 was interfered by si-RNA, and G3BP1 was down-regulated when PKR/eIF2α was interfered by si-RNA. In conclusion, our findings indicate that phillygenin activates PKR/eIF2α pathway and induces stress granule formation to exert anti-IBV, which holds promise to develop into a novel anti-IBV drug. Further study in vivo is needed to explore phillygenin as a potential and effective drug to prevent IB in poultry.

Huang Bai Jian Pi decoction alleviates diarrhea and represses inflammatory injury via PI3K/Akt/NF-κB pathway: In vivo and in vitro studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Huang Bai Jian Pi (HBJP) decoction, a Chinese herbal formula based on the Pulsatilla decoction (PD) and Si Junzi decoction, is efficacy to treat clinical diarrhea in calves. AIM OF THE STUDY: The mechanism of HBJP decoction to treat calf diarrhea remains unclear. This study was to investigate the therapeutic effect and anti-inflammatory mechanism of HBJP decoction on diarrhea in rats. MATERIALS AND METHODS: Thirty-six Sprague Dawley rats were randomly divided into control group, model group, PD group and three treated groups with HBJP decoction. The diarrheal model in rats was established by multiple factors including high-sugar and fat diet, high temperature and dampness environment, biological pathogenic factors. The diarrheal animals were treated with HBJP decoction or PD for 5 days. The inflammatory model of the intestinal epithelioid cell line 6 (IEC-6) was induced by TNF-α. The clinical symptoms, blood routine and biochemistry parameters, histopathology of main organs were detected. The proteins associated with PI3K/Akt/NF-κB pathway and the expression levels of cytokines associated with inflammation were detected in vivo and in vitro by Western blot and ELISA. RESULTS: The model rats showed obvious diarrheal symptoms, and the obvious systemic inflammatory response accompanied with abnormal change in blood routine, biochemistry parameters and histopathology. HBJP decoction alleviated obviously the clinical symptoms, and pathological changes of the liver, colon and lung, and abnormal blood routine and biochemistry indexes in rats. The expression of P-PI3K, P-Akt, P-NF-κB, IL-1ß, IL-6 was significantly increased, and the expression of IL-10 was markedly decreased in diarrheal rats and IEC-6 with inflammation. HBJP decoction significantly inhibited the PI3K/AKT/NF-κB signal pathway and adjusted the expression of these inflammatory cytokines. CONCLUSIONS: The finding suggested that HBJP decoction alleviate the inflammation in diarrhea through inhibiting the PI3K/Akt/NF-κB signal pathway, which provides scientific evidences for the clinical application of HBJP decoction in diarrhea.

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.