Pharmacokinetic, tissue distribution and excretion of ginsenoside-Rd in rodents.

Ginsenoside-Rd (GS-Rd) is one of the major active components of Panax ginseng, and was shown to have the protective effects against several insults. However, we still lack some basic knowledge of GS-Rd, including its pharmacokinetic, tissue distribution and excretion in vivo in experimental animal, such as mice and rats. In this study, HPLC and radioactive tracer assays were performed to determine pharmacokinetic, tissue distribution and excretion of GS-Rd in rodents. After intravascular administration with 20, 50 or 150 mg/kg GS-Rd, the dynamic changes of GS-Rd concentrations in plasma were consistent with a two-compartment model while the concentration of ³H-labeled GS-Rd was rapidly reached the peak in plasma, and distributed to various tissues, among which the highest concentration was observed in the lung.

[Inhibitory effects of apigenin on the expression of GATA-3 and Th2 cytokines in asthmatic mice].

OBJECTIVE: To investigate the inhibitory effects and mechanism of apigenin (APG) on dominant response of Th2 cells in asthma model of mice. METHODS: Thirty-two 6-week-old healthy BALB/c mice, SPF grade, were randomly divided into four groups equally, the normal control group (A), the asthma model group (B), and the two APG groups (C and D) consisted of asthma model mice treated respectively with high-dose (20 mg/kg per day) and low-dose (2 mg/kg per day) APG given by dissolving in 1% dimethyl sulphoxide via intraperitoneal injection. The murine asthma model was established by ovalbumin (OVA) sensitization and provocation. Twenty-four hours after the last airway provocation, acetylcholine (Ach) was administered via caudalis vein for measuring airway resistance by pulmonary function detector; levels of IL- 4 and IL-13 in bronchoalveolar lavage fluid (BALF) and total IgE in serum were determined by enzyme-linked immunosorbent assay (ELISA); total and differential cell counts in BALF were measured by light microscopy; the airway inflammatory infiltration was detected by haematoxylin and eosin (HE) staining; and the signal transducer and activator of transcription 3 (GATA-3) in the lung tissue was determined by Western blot analysis. RESULTS: As compared with Group A, the airway hyper-reactivity, airway inflammation, cell count and eosinophil percentage in BALF, levels of total serum IgE and BALF IL-4 and IL-13, and GATA-3 protein expression in the lung tissue were significantly increased in Group B (P < 0.05). As compared with Group B, all the above-mentioned indices in Group C and D were lower, showing respective significant difference (P < 0.05), and significant difference was also shown between the two APG treated groups (P < 0.05). CONCLUSION: APG could reduce the airway inflammation and hyper-reactivity by down-regulating the expressions of pulmonary GATA-3 and Th, cytokines, which is a potential drug for asthma therapy.

[Effect of arsenic trioxide on apoptosis of pulmonary eosinophile in asthmatic guinea-pigs].

OBJECTIVE: To study the effect and mechanism of arsenic trioxide (As2O3) on apoptosis of pulmonary eosinophiles (PE) in asthmatic guinea-pigs. METHODS: Thirty guinea-pigs were divided into 3 groups at random, the control group, the asthmatic group and the As2O3 group. The dosage of As2O3 used was 2 mg/kg. The apoptotic PE were labelled by TdT-mediated dUTP nick end labelling technique, and the PE infiltration and apoptosis were detected quantitatively using computerized image analysis technique. RESULTS: In the control group, the amount of infiltrating PE was 4.4 +/- 2.5 cells/HP and the PE apoptotic index (AI) was 0.42 +/- 0.08%. In the asthmatic group, the amount increased (P < 0.01) and AI decreased significantly (P < 0.01). After the asthmatic animals had been treated with As2O3, the two parameters changed reversedly significantly (P < 0.01), and there was a significantly negative correlation between them (r = -0.949, P < 0.01). CONCLUSION: The PE apoptosis abnormality is one of the important mechanisms that cause bronchial asthma, As2O3 could alleviate the airway inflammation through promoting PE apoptosis and lower PE infiltration. Low dose of As2O3 is proved to be effective with relative safety, it also has potential value in treating asthma.