Morin alleviates LPS-induced mastitis by inhibiting the PI3K/AKT,MAPK, NF-κB and NLRP3 signaling pathway and protecting the integrity of blood-milk barrier

Mastitis is a common veterinary clinical disease that restricts the development of dairy farming around the world. Morin, extracted from Mulberry Tree and other herbs, has been reported to possess the function of anti-bacteria, anti-oxidant, and anti-inflammatory. However, whether morin could protect lipopolysaccharide (LPS)-induced mouse mastitis in vivo has not well known. This study firstly aims to evaluate the effects of morin on LPS-induced mouse mastitis in vivo, and then try to illustrate the mechanism involved in the process. Before injected with LPS, mice were intraperitoneally pre-injected with different concentrations of morin, and mice of the control and LPS group were injected with the same amount of saline. Pathologic changes of mammary gland were determined by histopathological examination. Myeloperoxidase (MPO) activities of mammary gland were determined by the MPO kits. The mRNA expressions of inflammatory cytokines including TNF-α, IL-1β and IL-6, and those of chemokine factors CCL2 and CXCL2, and those of tight junctions occludin claudin-3 were examined by qRT-PCR analysis. The activities of IκB, p65, ERK, P38, AKT, PI3K, NLPR3, claudin-1, claudin-3 and occludin were determined by western blotting. The results showed that morin alleviated LPS-induced edema, destructed structures and infiltrated inflammatory cells of mammary gland. Morin administration significantly decreased LPS-induced TNF-α, IL-1β, IL-6, CCL2 and CXCL2 mRNA expressions. Furthermore, western blot analysis also showed that morin significantly reduced LPS-induced phosphorylation of p65, IκB, p38 and ERK, and enhanced LPS-induced phosphorylation of AKT and PI3K. It was also found that LPS-decreased claudin-3 and occludin expressions were also inhibited by morin treatment. In summary, above results suggest that morin indeed protect LPS-induced mouse mastitis in vivo, and the mechanism was through inhibiting the PI3K/AKT, MAPK, NF-κB and NLRP3 signaling pathways and protecting the integrity of blood-milk barrier by regulating the tight junction proteins expressions.     

Protective effect of flavonoids against red blood cell hemolysis by free radicals

BACKGROUND:

Flavonoids are polyphenolic substances with antioxidant properties, and they are found in different vegetables and fruits. Epidemiological studies have shown that the consumption of flavonoids reduces the prevalence of cardiovascular diseases. The use of synthetic antioxidants, however, has been limited because of their toxicity. Therefore, medical researchers have intensified their quest to find natural antioxidants.

OBJECTIVES:

To investigate the effect of several pure flavonoids, such as kaempferol, quercetin, morin and rutin, on red blood cell hemolysis and evaluate their -SH capacity as an indicator of membrane protection.

METHODS:

The rate of hemolysis and cell membrane -SH capacity were determined by spectrophotometry. Red blood cell peroxidation was induced using 2,2′-azo-bis-(2-amidinopropane) dihydrochloride. The effect of each flavonoid on hemolysis was examined at three concentrations (0.5 μg/mL, 5 μg/mL and 10 μg/mL), however, only the greatest concentration (10 μg/mL) of each flavonoid was used to study the effect on -SH groups.

RESULTS:

In all cases, the antioxidant activity was dose-dependent. Rutin showed the highest inhibitory effect on hemolysis among flavonoids (42.5%). The protective effect of kaempferol, rutin and morin against -SH group oxidation measured 7.7%, 23.3% and 26.4%, respectively.

CONCLUSIONS:

Results showed that flavonoids and flavonoid-containing plants can be used as natural antioxidants for the treatment and prevention of disease conditions, the pathogenesis of which is mediated by lipid peroxidation.     

Effect of uremia on incorporation of acetate into rat plasma and tissue lipids

Experimental uremia was induced in rats by means of bilateral nephrectomy or bilateral ureteral ligation. Incorporation of acetate-1-¹⁴C into expired ¹⁴CO₂ and into plasma and tissue lipids was studied immediately after surgery and at 48 hr, when the rats were uremic. In rats studied immediately after surgery, bilateral nephrectomy, but not bilateral ureteral ligation, significantly decreased the conversion of acetate-1-¹⁴C metabolism to ¹⁴CO₂ was not significantly altered in either group. Plasma triglyceride concentrations and ¹⁴C-acetate incorporation into triglycerides were increased in the 48-hr uremic groups, but plasma and liver triglyceride specific radioactivities were not significantly altered. Plasma free fatty acid concentrations and incorporation of acetate into free fatty acids were lower in the 48-hr uremic groups than in controls. Plasma cholesterol concentrations and specific radioactivities were increased in these uremic groups, as were liver free cholesterol specific activities. These results suggest that increased triglyceride and cholesterol synthesis from acetate may contribute to the hypertriglyceridemia and hypercholesterolemia observed in uremic rats.     

居住区大气中铍的桑色素荧光分光光度法检验方法的改良

[目的]对居住区大气中铍的卫生检验标准方法-桑色素荧光分光光度法进行优化改良。[方法]按照国家环境污染物监测方法标准制修订技术导则,对我国现行的居住区大气中铍的卫生检验标准方法-桑色素荧光分光光度法进行了优化改良,并对改良后的方法进行方法学评价。[结果]方法的检出限为0.05ng/ml,测定下限为0.2ng/ml,测量范围为0.0002～0.005μg/ml,对空气中铍的测定范围为0.002～0.05μg/m3(采样体积为1m3)。相对标准偏差分别为2.5%～4.2%(n=6)。回收率为98.0～106.0%。[结论]改良后的方法比原标准方法更加简便易操作,提高了方法灵敏度、测定的精密度和准确度。     

Electrochemical study on the behavior of Morin and its interaction with DNA

Voltammetric behavior of Morin was studied in 0.1 M HAc–NaAc + 50 mM KCl (pH 3.4) solution at glassy carbon electrode (GCE) using cyclic voltammetry (CV). Morin showed an irreversible anodic peak at 0.720 V in CV which was involving two electrons and two protons. Also, the interaction of Morin with double-stranded calf thymus DNA (ctDNA) was studied by CV at GCE with an irreversible electrochemical equation. As a result of reaction with ctDNA, the voltammetric peak of Morin was a position shift and the peak current decreased. The diffusion coefficients of both free and binding Morin (D_f = 1.1086 × 10⁻⁷ cm² s⁻¹ and D_b = 8.2544 × 10⁻⁹ cm² s⁻¹), binding constant (K = 1.7765 × 10⁷ cm³ mol⁻¹), and binding site size (s = 0.8510) of the Morin–DNA complex were obtained simultaneously by non-linear fit analysis. The results demonstrate that Morin can bind to ctDNA in 0.1 M HAc–NaAc + 50 mM KCl (pH 3.4) solution and the ring B of Morin intercalates between the DNA base pairs.     

Upper extremity neuropathies following median sternotomy

The status of 958 patients who underwent median sternotomy between January, 1978, and May, 1981, was analyzed. Fifty-four patients had an upper extremity neuropathy. Among 38 patients who underwent further evaluation, motor and sensory nerve conduction studies localized the injury to the level of the elbow in 13, to the brachial plexus in 10, and to both locations in 6. Ninety-two percent of these 38 patients were asymptomatic 3 months after operation.     

Effect of Morin on pharmacokinetics of Piracetam in rats,in vitro enzyme kinetics and metabolic stability assay using rapid UPLC method

The aim of this study was to investigate the effect of Morin on the pharmacokinetics of Piracetam in rats, in vitro enzyme kinetics and metabolic stability (high throughput) studies using human liver microsomes in UPLC. For pharmacokinetics studies, male Wistar rats were pretreated with Morin (10 mg/kg) for one week and on the last day, a single dose of Piracetam (50 mg/kg) was given orally. In another group, both Morin and Piracetam were co‐administered to evaluate the acute effect of Morin on Piracetam. The control group received oral distilled water for one week and administered with Piracetam on the last day. As Morin is an inhibitor of P‐ Glycoprotein (P‐gp) and CYP 3A, it was anticipated to improve the bioavailability of Piracetam. Amazingly, relative to control, the areas under the concentration time curve and peak plasma concentration of Piracetam were 1.50‐ and 1.45‐fold, respectively, greater in the Morin‐pretreated group. However, co‐administration of Morin had no significant effect on these parameters. Apart from the aforementioned merits, the results of this study are further confirmed by clinical trials; Piracetam dosages should be adjusted to avoid potential drug interaction when Piracetam is used clinically in combination with Morin and Morin‐containing dietary supplements. The in vitro enzyme kinetics were performed to determined km, V_max & CL_ins. The in vitro metabolic stability executed for the estimation of metabolic rate constant and half‐life of Piracetam. These studies also extrapolate to in vivo intrinsic hepatic clearance (Cl_{int, in vivo}) from in vitro intrinsic hepatic clearance (CL_{int, in vitro})_. Copyright © 2012 John Wiley & Sons, Ltd.     

桑色素对迟发型超敏反应的作用研究

目的 桑色素(morin)对迟发型超敏反应的影响机制.方法 通过致敏剂DNFB诱发DTH模型,检测morin对模型小鼠耳廓重量变化及肿胀程度的影响,并将致敏侧耳组织做冷冻切片HE染色,使用光学显微镜观察炎性细胞浸润程度的变化;酶联免疫吸附法检测小鼠血清IFN-γ含量.结果 对各组小鼠耳廓组织进行称重及厚度测量,发现morin (50 mg/ml)处理组显著抑制DTH炎症反应,鼠耳重量减轻、厚度变薄,差异有统计学意义(P＜0.05);HE染色切片显示morin处理组鼠耳水肿减轻,淋巴细胞等浸润程度显著减少;morin处理组DTH小鼠血清中IFN--γ的水平下降明显.结论 morin可能通过抑制淋巴细胞分泌1FN-γ水平,使DTH小鼠耳廓水肿和淋巴细胞浸润程度减轻.     

Effects of morin pretreatment on the pharmacokinetics of diltiazem and its major metabolite, desacetyldiltiazem in rats

The purpose of this study was to investigate the effect of morin, a flavonoid, on the pharmacokinetics of diltiazem and one of its metabolites, desacetyldiltiazem in rats. Pharmacokinetic parameters of diltiazem and desacetyldiltiazem were determined after oral administration of diltiazem (15 mg/kg) in rats pretreated with morin (1.5, 7.5, and 15 mg/kg). Compared with the control group (given diltiazem alone), pretreatment of morin significantly increased the absorption rate constant (Ka) and peak concentration (Cmax) of diltiazem (p<0.05, p<0.01). Area under the plasma concentration-time curve (AUC) of diltiazem in rats pretreated with morin were significantly higher than that in the control group (p<0.05, p<0.01), hence the absolute bioavailability (AB%) of diltiazem was significantly higher than that of the control group (p<0.05, p<0.01). Relative bioavailability (RB%) of diltiazem in rats pretreated with morin was increased by 1.36- to 2.03-fold. The terminal half-life (t1/2) and time to reach the peak concentration (Tmax) of diltiazem were not altered significantly with morin pretreatment. AUC of desacetyldiltiazem was increased significantly (p<0.05) in rats pretreated with morin at doses of 7.5 and 15 mg/ kg, but metabolite-parent ratio (MR) of desacetyldiltiazem was decreased significantly (p<0.05), implying that pretreatment of morin could be effective to inhibit the CYP 3A4-mediated metabolism of diltiazem. There were no apparent changes of Tmax and t1/2 of desacetyldiltiazem with morin pretreatment. Collectively, the pretreatment of morin significantly altered pharmacokinetics of diltiazem, which can be attributed to increased intestinal absorption as well as reduced first-pass metabolism. Based on these results, dose modification should be taken into consideration when diltiazem is used concomitantly with morin or morin-containing dietary supplements in clinical setting.