Effects And Mechanism Of Atractylodes Macrocephala On The Pharmacokinetics Of Strychnos Nux Vomica

The efficacy of strychnos nux is to clear collaterals and relieve pain,disperse nodules and reduce swelling,etc.It has many pharmacological effects such as anti-inflammatory and analgesic,anti-tumor,regulating immunity,promoting nerve function recovery,promoting fracture healing,repairing cartilage damage,anti-bone hyperplasia,improving blood circulation,improving alcohol dependence,and regulating small intestine movement.But Strychnos nux has strong toxicity,resulting in a narrow therapeutic window,limiting clinical application.The effects of atractylodes are good for spleen and qi,dryness and dampness,antiperspirant,and birth control,pain stop.The compatibility of traditional Chinese medicine prescriptions is not only a major feature of traditional Chinese medicine treatment,but also one of the important ways to enhance efficacy and control drug toxicity.Doctors in the past dynasties believed that atractylodes combined with strychnine could be used in the treatment of bi syndrome,spleen and stomach pain and other diseases.Modern pharmacological studies have also shown that atractylodes can reduce the toxicity and enhance the efficacy of pomegranate,but the specific mechanism of action has not been fully understood.Previous research by this research group shows that atractylodes can inhibit the intestinal absorption of the active ingredient of strychni nux;the compatibility of atractylodes chinensis reduces the ability of drug metabolizing enzymes to clear the alkaloids of strychnos nux;the effective ingredient of atractylodes Ⅱ is inhibited by CYP450 enzyme thus inhibits the metabolism of alkaloids of strychnos nux and strychnine;the atractylodes partly induces the CYP3A4 enzyme activity;the active ingredient of the pteris is mainly metabolized by the CYP3A4 enzyme,but don’t impact the activity of CYP3A4 enzyme The compatibility of atractylodes inhibits intestinal absorption in the angle of absorption and inhibits metabolism in the perspective of metabolic.These two results will inevitably lead to the opposite blood concentration.In order to explore which link has the main pharmacodynamic effect on the body,the rat pharmacokinetic experiment of the combination of atractylodes with strychnos nux was conducted.Atractylolide I(AT-1)and Atractylolide II are generally considered to be the main active ingredients of anti-inflammatory and anti-cancer of atractylodes.In order to explore the effect mechanism of atractylodes on biopharmaceuticals.This research group has studied the interaction of Atractylodes and Atractylodes lipid Ⅱ on the content of strychnos nux enzymes from the perspective of metabolic enzymes.Therefore this study will further study the interaction between atractylodes I,another effective components of atractylodes,and strychnos nux metabolic enzyme.This experiment is conducive to the effective evaluation of the clinical safety medication of strychnos nux and atractylodes,and to explore the interaction between atractylenolide I and metabolic CYP450 enzymes,and to provide a basis for the clinical application of atractylodes combined with other drugs.The main work of this article includes the following four parts1.Determining the effect of atractylodes on the pharmacokinetics of strychnos nux LC-MS was used to detect blood drug concentrations at different time points in rats after a single administration,and DAS 3.0 software was used to calculate the pharmacokinetic parameters of the drug.SPSS Statistics 21 was used to analyze the main parameters of pharmacokinetics for the alkaloids of strychnos nux before and after the compatibility of atractylodes and strychnos nux.to study the effect of atractylodes on the pharmacokinetics of strychnos nux alkaloid and strychnine in strychnine nut.The results showed that the linear relationship was good and the methodology met the requirements when strychnos nux alkaloid was in the range of 0.16-44.8 ng·mL-1,and that of strychnine was in the range of 0.34-96.0 ng·mL-1.Within the pharmacopoeia dose range,the main pharmacokinetic parameters of Astragalus alkaloids in rat plasma were significantly increased after compatibility with Atractylodes,and the apparent distribution volume Vz/F,clearance The rate CLz/F decreases.This shows that Atractylodes can increase the blood concentration of ranch alkaloids in the body and reduce the elimination of ranch alkaloids in the body.Combined with the previous research of this research group,it is speculated that the metabolic link is the main link of increasing blood drug concentration Therefore,it is more convincing to explore the principle of increasing the effectiveness and reducing the toxicity of Atractylodes from the perspective of metabolism.Biopharmaceuticals are related to effects,and an increase in blood concentration will result in increased efficacy or increased toxicity.However,the dose used in the experiment is far below the poisoning dose,and the highest blood concentration is also below the poisoning blood concentration.Therefore,an increase in blood concentration may lead to an increase in efficacy without toxicity2.Metabolic kinetics of AT-I in liver microsomesIn this section,the incubation time,liver microsomal protein concentration,and substrate AT-I concentration are used as the research objects to optimize the incubation conditions of AT-I in human and rat liver microsomes.The substrate elimination method is used to calculate AT-I in metabolic dynamics in human and rat liver microsomes The results showed that AT-I metabolic parameters Vmax(maximum response rate),S50(constant),CLint(clearance),and n were 34.93± 2.009 and 1672 ± 433.6 pmol/min/mg in human and rat liver microsomes,respectively protein,0.2898±0.0192 and 0.6355±0.1886 μM,0.12±0.0007 and 2.63±0.0003 mL/min/mg protein;2.451 ± 0.2079 and 1.618 ± 0.161.The metabolic kinetic parameter S50 is the optimal metabolic dose for studying the metabolic pathway of AT-I.3.Metabolic phenotype of AT-I in liver microsomesIn this chapter,chemical inhibitors and recombinases are used to study the enzyme metabolic pathways of AT-I.The metabolism of AT-I under the action of CYP1A2,CYP2C19,CYP2C9,CYP2D6 and CYP3A4 specific chemical inhibitors in different concentrations,and the metabolism of AT-I in five recombinant enzymes were used to identify the CYP450 enzyme phenotypes involved in at-i metabolism.The metabolism of at-i was most inhibited by ketoconazole,followed by nootkatone,and the remaining three inhibitors were only partially or almost completely inhibited.The results showed that as the concentration of each inhibitor increased,the metabolism of AT-I was most significantly inhibited by ketoconazole,followed by nocardione,and the remaining three inhibitors were only few Partial or almost no inhibition.It shows that AT-I is mainly metabolized by CYP3A4 and CYP2C19 enzymes,while only a small part is metabolized by CYP1A2 and CYP2C9 enzymes.Contrast inhibition rate found that in rats,the CYP3A4 enzyme contributed more to AT-I metabolism than the CYP2C19 enzyme;in humans,the CYP2C19 enzyme contributed more to AT-I metabolism than the CYP3A4 enzyme The active ingredient of pomegranate is mainly metabolized by CYP3 A4 enzyme,but it has no significant effect on the activity of CYP3A4 enzyme,indicating that Atractylodes may reduce the metabolic amount of active ingredient of pomegranate by competing with CYP3A4 enzyme mechanism.4.Study on the effect of AT-I on CYP450 enzymeTo investigate the effect of AT-I on CYP450 enzyme subtype activity in clinical drug metabolism,and to incubate probe drug with different concentrations of AT-I to detect the metabolism of probe drug.Graphpad Prism 6.0 software was used to calculate the IC50 value of AT-I on CYP450 enzyme subtypes.The results showed that with the increase of AT-I concentration,the CYP enzyme activity gradually decreased.In human liver microsomes,AT-I showed a moderate inhibitory effect on CYP2C19,with an IC50 value of 49.25 μM,and a weak inhibitory effect on CYP1A2,CYP2C9,CYP2D6 and CYP3A4,with an IC50 value of 106.2,57.02,58.53 and 66.27μM.In mouse liver microsomes,AT-I showed moderate inhibitory effects on CYP2C19,CYP 2C9 and CYP2D6,and the inhibition types of AT-I on liver microsomes CYP450 were further investigated.The IC50 value was 47.08,22.93,30.37 μM,which showed a weak inhibitory effect on CYP1A2,and the IC50 value was 67.1μM.The IC50 value was 47.08,22.93,30.37 μM,which showed a weak inhibitory effect on CYP1A2,and the IC50 value was 67.1 μM.Combined with human liver and mouse liver microsomes,AT-I was found to have a moderate inhibitory effect on CYP2C19;however,AT-I has a weak inhibitory effect on CYP3A4 in human liver microsomes,and AT-I induces CYP3A4 in mouse liver microsomes effect.AT-I in human liver microsomes is a non-competitive inhibitor of CYP1A2 and CYP 2D6,with Ki valuesof 84.67,84.52 μM,and mixed inhibition of CYP2C19,CYP 2C9,and CYP 3A4,with Ki values of 74.64,38.70 and>200 μM.AT-I in rat liver microsomes is a non-competitive inhibition of CYP1A2 with a Ki value of 31.37 μM,a competitive inhibition of CYP2C9 with a Ki value of 94.23 μM,and a mixed model inhibition of CYP2C19 and CYP 2D6 with Ki values of 83.04,>200 μM The results of AT-I’s interaction with CYP450 enzyme can confirm that AT-I is not easy to interact with other drugs.After purifying the CYP3A4 enzyme,the weakly inhibiting CYP3A4 enzyme activity of AT-I in human liver may result in a decrease in the metabolism of the horse’s body,which will increase the blood concentration of the horse’s body alkaloid and increase the curative effect.In rat liver,AT-I can partially induce CYP3A4 enzyme activity.During the competition between Atractylodes and strychnos nux,the ability of Atractylodes and Enzyme to bind is stronger than that of strychnos nux,which increases the CYP3 A4 enzyme’s metabolism to Atractylodes and thus reduces that to strychnos nux.The metabolism of pomegranate leads to an increase in the blood concentration of pomegranate alkaloids in rats,which increases the efficacy.