Standardized myrtol attenuates lipopolysaccharide induced acute lung injury in mice.

CONTEXT: Standardized myrtol, an essential oil containing primarily cineole, limonene and α-pinene, has been used for treating nasosinusitis, bronchitis and chronic obstructive pulmonary disease (COPD). OBJECTIVE: To investigate the effects of standardized myrtol in a model of acute lung injury (ALI) induced by lipopolysaccharides (LPS). MATERIALS AND METHODS: Male BALB/c mice were treated with standardized myrtol for 1.5 h prior to exposure of atomized LPS. Six hours after LPS challenge, lung injury was determined by the neutrophil recruitment, cytokine levels and total protein concentration in the bronchoalveolar lavage fluid (BALF) and myeloperoxidase (MPO) activity in the lung tissue. Additionally, pathological changes and NF-κB activation in the lung were examined by haematoxylin and eosin staining and western blot, respectively. RESULTS: In LPS-challenged mice, standardized myrtol at a dose of 1200 mg/kg significantly inhibited the neutrophile counts (from 820.97 ± 142.44 to 280.42 ± 65.45, 103/mL), protein concentration (from 0.331 ± 0.02 to 0.183 ± 0.01, mg/mL) and inflammatory cytokines level (TNF-α: from 6072.70 ± 748.40 to 2317.70 ± 500.14, ng/mL; IL-6: from 1184.85 ± 143.58 to 509.57 ± 133.03, ng/mL) in BALF. Standardized myrtol also attenuated LPS-induced MPO activity (from 0.82 ± 0.04 to 0.48 ± 0.06, U/g) and pathological changes (lung injury score: from 11.67 ± 0.33 to 7.83 ± 0.79) in the lung. Further study demonstrated that standardized myrtol prevented LPS-induced NF-κB activation in lung tissues. DISCUSSION AND CONCLUSION: Together, these data suggest that standardized myrtol has the potential to protect against LPS-induced airway inflammation in a model of ALI.

[Cigarette smoke exposure induced pulmonary artery pressure increase through inhibiting Kv1.5 and Kv2.1 mRNA expression in rat pulmonary artery smooth muscles].

OBJECTIVE: To investigate the effect of cigarette smoke exposure on Kv1.5 and Kv2.1 mRNA expression in rat pulmonary arterial smooth muscle cells (PASMCs), and further to clarify the possible mechanism of cigarette smoking induced pulmonary arterial hypertension. METHODS: Primary cell culture and animal experiments were used in this study. Rat distal PASMCs were isolated and cultured by collagenase digestion. PASMCs were treated by nicotine 100 nmol/L. After 48 h, Kv1.5 and Kv2.1 mRNA expression were detected by real-time quantitative PCR and compared with the control group. Rat model of chronic exposure to cigarette smoke was established. Thirty-six male SD rats were randomly divided equally into 6 groups: (1) 1 month control group; (2) 1 month cigarette exposure group; (3) 3 month control group; (4) 3 month cigarette exposure group; (5) 6 month control group; (6) 6 month cigarette exposure group. Direct right heart manometry, HE staining and real-time quantitative PCR were used to detect the effect of smoke exposure on rat right ventricular systolic pressure (RVSP), mean pressure (mPAP), right ventricular hypertrophy index [RV/(LV + S)] as well as Kv1.5 and Kv2.1 mRNA expression on pulmonary artery smooth muscle at different time points (1 month, 3 months and 6 months). RESULTS: The mPAP and RVSP in cigarette smoke exposure 6 month group were (13.08 ± 0.64) mm Hg and (29.73 ± 0.83) mm Hg, slightly higher than those in the control 6 month group [(10.16 ± 0.44) mm Hg and (22.56 ± 0.64) mm Hg] (P < 0.01). The ratio of Kv1.5 mRNA expression in distal pulmonary arteries in 1 month, 3 month, 6 month cigarette exposure group to that in control groups was (52 ± 11)%, (64 ± 19)% and (75 ± 11)% (P < 0.05). The ratio of Kv2.1 mRNA expression in distal pulmonary arteries in 1 month, 3 month, 6 month cigarette exposure groups to that in control groups was (51.0 ± 18.6)%, (78.7 ± 10.1)% and (71.4 ± 2.3)% (P < 0.01); Chronic exposure to cigarette smoke significantly decreased Kv1.5 and Kv2.1 mRNA expression in rat pulmonary arterial smooth muscle at each time point. The ratio of Kv1.5 and Kv2.1 mRNA expression in rat distal PASMCs treated with nicotine (100 nmol/L, 48 h) to control group were (62 ± 14)% (P < 0.05) and (72 ± 15)% (P < 0.01), respectively. Nicotine inhibited Kv1.5 and Kv2.1 mRNA expression in rat distal PASMCs. CONCLUSION: Cigarette smoke exposure may be involved in pulmonary hypertension by downregulating potassium channels Kv1.5 and Kv2.1 mRNA expression in rat pulmonary artery smooth muscles.

Preventive and therapeutic effects of Danhong injection on lipopolysaccharide induced acute lung injury in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Danhong injection (DHI), a Chinese Materia Medica standardized product extracted from Radix et Rhizoma Salviae Miltiorrhizae (Salvia miltiorrhiza Bge., Labiatae, Danshen in Chinese) and Flos Carthami (Carthamus tinctorius L., Compositae, Honghua in Chinese), has been reported to have anti-inflammatory, anti-oxidative and anti-fibrinolytic properties, which is used extensively for the treatment of cardiovascular diseases in clinic. AIM OF THIS STUDY: The present study aimed to investigate the preventive and therapeutic effects of DHI on lipopolysaccharide (LPS) induced acute lung injury (ALI) in mice. MATERIALS AND METHODS: Lung injury was induced by intranasal instillation with 10 µg LPS. Mice were randomly divided into four groups: Control group; LPS group; LPS+5 ml/kg DHI group and LPS+10 ml/kg DHI group. The effects of DHI on LPS-induced neutrophils influx, inflammatory cytokines release, protein leakage, myeloperoxidase (MPO) and superoxide dismutase (SOD) activities, malondialdehyde (MDA) level were examined. In addition, the NF-κB activation in lung tissues was detected by Western blot. RESULTS: In LPS challenged mice, DHI significantly reduced the infiltration of activated neutrophils and decreased the levels of TNF-α and IL-6 in bronchoalveolar lavage fluid (BALF). DHI also inhibited protein extravasation in BALF, attenuated edema and the pathological changes in the lung. In addition, DHI markedly prevented LPS-induced elevation of MDA and MPO levels, as well as reduction of SOD activity. Further study demonstrated that DHI effectively inhibited the NF-κB activation in lung tissues. CONCLUSION: DHI has been demonstrated to protect mice from LPS induced acute lung injury by its anti-inflammatory and anti-oxidant activities.