Effect of tubeimoside I on the activity of cytochrome P450 enzymes in human liver microsomes.

This study assessed the effect of tubeimoside I on CYP1A2, 2A6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4 to reveal the potential of tubeimoside I to induce drug-drug interaction.The evaluation of cytochromes P450 enzyme (CYP) activity was performed in pooled human liver microsomes with probing substrates of CYP1A2, 2A6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4. Typical inhibitors were employed as positive controls and the effect of 0, 2.5, 5, 10, 25, 50, and 100 µM tubeimoside I was investigated.The activity of CYP2D6, 2E1, and 3A4 was significantly inhibited by tubeimoside I with the IC50 values of 10.34, 11.58, and 9.74 µM, respectively. The inhibition of CYP2D6 and 2E1 was competitive with the Ki value of 5.66 and 5.29 µM, respectively. While the inhibition of CYP3A4 was non-competitive with the Ki value of 4.87 µM. Moreover, the inhibition of CYP3A4 was time-dependent with the KI and Kinact values of 0.635 µM-1 and 0.0373 min-1, respectively.Tubeimoside I served as a competitive inhibitor of CYP2D6 and 2E1 exerting weak inhibition and a non-competitive inhibitor of CYP3A4 exerting moderate inhibition.

Human liver microsomes study on the inhibitory effect of plantainoside D on the activity of cytochrome P450 activity.

BACKGROUND: Plantainoside D is widely existed in the herbs and possesses various pharmacological activities, making it possible to co-administrate with other herbs. Its effect on cytochrome P450 enzymes (P450) is a risk factor for inducing adverse drug-drug interactions. To assess the effect of plantainoside D on the activity of major P450 isoenzymes in human liver microsomes. METHODS: The Cocktail method was conducted in human liver microsomes in the presence of probe substrates. The activity of P450 isoenzymes was evaluated by the production of corresponding metabolites. The concentration-dependent and time-dependent inhibition assays were performed in the presence of 0, 2.5, 5, 10, 25, 50, and 100 µM plantainoside D to characterize the inhibitory effect of plantainoside D. RESULTS: Significant inhibition was observed in the activity of CYP1A2, 2D6, and 3A, which was concentration-dependent with the IC50 values of 12.83, 8.39, and 14.66 µM, respectively. The non-competitive manner and competitive manner were observed in the CYP3A inhibition (Ki = 7.16 µM) and CYP1A2 (Ki = 6.26 µM) and 2D6 inhibition (Ki = 4.54 µM), respectively. Additionally, the inhibition of CYP3A was found to be time-dependent with the KI of 1.28 µM-1 and Kinact of 0.039 min-1. CONCLUSIONS: Weak inhibitory effects of plantainoside D on the activity of CYP1A2, 2D6, and 3A were revealed in vitro, implying its potential of inducing interactions with CYP1A2-, 2D6-, and 3A-metabolized drugs. Although further in vivo validations are needed, the feasibility of the Cocktail method in evaluating P450 activity has been verified.

Preventive Effects of Long-Term Intake of Plant Oils With Different Linoleic Acid/Alpha-Linolenic Acid Ratios on Acute Colitis Mouse Model.

Objective: To investigate the preventive effects of plant oils with different linoleic acid/alpha-linolenic acid (LA/ALA) ratios against colitis symptoms, and dysbiosis of gut microbiota in acute colitis mouse model. Methods: Sixty male C57BL/6 mice were assigned into six groups (n = 10): three groups were fed low-fat diets with low, medium, and high LA/ALA ratios; and three groups were fed with high-fat diets with low, medium, and high LA/ALA ratios. After 3 months of diet, the mice were exposed to dextran sodium sulfate solution to induce acute colitis. The severity of colitis was estimated by disease activity index (DAI) and histopathological examination. 16S rRNA gene sequencing was used for the analysis of gut microbiota. Results: Plant oils with a lower LA/ALA ratio showed higher alleviating effects on the symptoms of colitis, which were accompanied by the better prebiotic characteristics manifested as effectively inhibiting the abnormal expansion of phylum Proteobacteria and genus Escherichia-Shigella in the gut microbiota of colitis mouse models. Conclusion: A potential IBD prevention strategy of reducing the LA/ALA ratio in the daily consumed plant oils was proposed in this study. Furthermore, based on the optimized LA/ALA ratio, this preventive effect might not be weakened by the high intake of plant oils.

[Protective effect of qi dong yi xin on acute myocardial infarction in dogs].

OBJECTIVE: To observe the protective effects on acute myocardial infarction of QDYX in dog. METHOD: The corconary ciculation and cardial oxygen metabolism, the degree and range of myocardial ischemia, myocardial infarct size, and the changes of the enzymes in serum were determined by using the acute myocardial infarction model of ligation of LAD in the anaesthetized open-chest dogs. RESULT: The coronary resistance and cardial oxygen consumption were decreased and the myocardial blood flow was increased in dogs treated with QDYX of 1.0,2.0 mg.kg-1. The degree and range of myocardial ischemia, myocardial infarct size and the activity of serum CK, LDH were decreased in acute myocardial infarcion dogs treated with QDYX of 1.0,2.0 mg.kg-1. CONCLUSION: QDYX can decrease cardial oxygen consumption in dogs, thus having protective effect on myocardial ischemia.