Inhibitory Effects of Cajanonic Acid A on 5 Kinds of Common CYP 450 Enzyme in Human Liver Microsomes in vitro / 中国药房

OBJECTIVE：To study the inhibitor y effects of cajanonic acid A on 5 kinds of cytochrome P 450（CYP）enzyme，in human liver microsomes in vitro . METHODS ：By Cocktail probe substrate method ，50.0，15.0，5.0，1.5，0.5，0.15，0.05 μmol/L cajanonic acid A were added into liver microsomes ， and incubated with mixed probe substrates [including phenacetin ， dextromethorphan，omeprazole，testosterone and toluenesulfonbutylurea （probe substrates of CYP 1A2，CYP2D6，CYP2C19， CYP3A4，CYP2C9，respectively）]. On the basis of setting up blank group and positive control group [ α-naphthalene brass ， quinidine，（+）-N-3-benzyl vanillin ，ketoconazole and sulfabendazole （specific inhibitors of CYP 1A2，CYP2D6，CYP2C19， CYP3A4，CYP2C9，respectively）]，using puerarin as internal standard ，UPLC-MS/MS method was adopted to determine the contents of corresponding metabolites （acetaminophen， dextrophane， 5-hydroxy omeprazole ， 6 β-hydroxytestosterone， hydroxytolbutamide）. The determination was performed on ACQUITY UPLC ® BEH C 18 column，with mobile phase consisted of 0.01％ formic acid aqueous solution- 0.01％ acetonitrile formic acid （gradient elution ）at the flow rate of 0.4 mL/min. The column temperature was 40 ℃，and the sample size was 2 μL. An electrospray ionization source was used to conduct positive and negative ion scanning in the multiple reaction monitoring mode. The data acquisition range was m/z 100-1 200，the collision gas was argon ， the atomized gas was nitrogen ，the gas flow rate of the cone hole was 50 L/h，the desorption gas flow rate was 800 L/h，the capillary voltage under positive and negative mode was 2.0， 1.5 kV，and the ion source temperature was 120 ℃，110 ℃， respectively. The desolvent temperature were 400 ℃ and 450 ℃ ， respectively. Non linear regression analysis was performed by using Graphpad Prism 5.0 software and IC 50 wascalculated. RESULTS ：The linear ranges of above metabolifes were 0.26-8.35，0.36-34.56，0.10-3.09, 3.67-117.37，0.15-4.88 μmol/L（R2＞0.99）. The limits of quantitation were 0.26，0.36， 0.10，3.67，0.15 μmol/L，respectively. The IC 50 values of specific inhibitors in positive control group to CYP 1A2，CYP2D6， CYP2C19，CYP3A4 and CYP 2C9 in human liver microsomes were all within the acceptable range reported in the literature. The IC50 values of cajanonic acid A to CYP 1A2，CYP2D6 and CYP 3A4 in human liver microsomes were all more than 50 μmol/L，and the IC 50 values of CYP 2C9 and CYP 2C19 were 4.94 and 18.00 μmol/L，respectively. CONCLUSIONS ：Cajanonic acid A has no inhibitory effect on CYP 1A2，CYP2D6 and CYP 3A4，but has a certain inhibitory effect on CYP 2C9 and CYP 2C19.

Study on Metabolic Differences of Cajanonic Acid A in Different Species of Liver Microsomes by UPLC-MS/MS / 中国药房

OBJECTIVE： To establish a determination method for the concentration of cajanonic acid A （CAA） in liver microsome incubation system， and to compare the metabolism characteristics of it in different species of liver microsomes. METHODS： CAA was dissolved in liver microsome incubation system of rat， Beagle dog and human initiated by reduced nicotinamide adenine dinucleotide phosphate （NADPH）， and was incubated in water at 37 ℃. The reaction was terminated with acetonitrile at 0， 5， 10， 15， 30， 45 and 60 min， respectively. Using genistein as internal standard， the concentration of CAA in  different incubation systems was determined by UPLC-MS/MS. The determination was performed on Waters BEH C18 column with mobile phase consisted of water （containing 0.1％ formic acid）-acetonitrile （containing 0.1％ formic acid） （45 ∶ 55， V/V） at the flow rate of 0.25 mL/min. The column temperature was 30 ℃， and the sample size was 2 μL. The electrospray ionization source was used to the select reaction monitoring mode for negative ion scanning. The ion pairs for quantitative analysis were m/z 353.14→309.11 （CAA）， m/z 269.86→224.11 （internal standard） respectively. The residual percentage and enzymatic kinetic parameters of CAA in different incubation systems were calculated according to the mass concentration of CAA at 0 min. RESULTS： The linear range of CAA was 0.05-20 μg/mL； the limit of quanti- tation was 0.05 μg/mL， and the lowest detection limit was 0.01 μg/mL. RSDs of intra-day and inter-day were lower than 10％； relative errors ranged －4.83％-8.94％； extraction method and matrix effect did not affect the determination of the substance to be measured. At 60 min of incubation， residual percentages of CAA in rat， Beagle dog and human liver microsomes were（62.79±9.99）％，（64.07±11.59）％，（96.66±5.71）％， respectively. The half-life period （72.19， 68.61 min） of CAA in rat and Beagle dog liver microsomes were significantly shorter than human liver microsome （364.74 min）. The clearance rates [0.019 2， 0.020 2 mL/（min·mg）] were significantly higher than human liver microsome [0.003 8 mL/（min·mg）] （P＜0.05）. CONCLUSIONS： Established UPLC-MS/MS method is simple， rapid， specific and sensitive， and can be used for the determination of CAA concentration in liver microsome incubation system and the study of metabolism stability in vitro. The stability of CAA metabolism in rat and Beagle dog liver microsomes are poorer than human liver microsome.

Study on Plasma Protein Binding Rate of Cajanonic Acid A with Different Species of Plasma by Ultrafiltration Combined with UPLC-MS/MS / 中国药房

OBJECTIVE： To compare plasma protein binding rate of cajanonic acid A with different species of plasma. METHODS：Using UPLC-MS/MS as the detection means. Plasma protein binding rate of low， medium and high concentrations of cajanonic acid A （2.5， 5， 20 μg/mL） with rats， rabbits and human plasma were determined by ultrafiltration method. The chromatographic conditions included that Waters BEH C18 as chromatographic column， WatersVanGuard BEH C18 as guard column， mobile phase consisted of ultrapure water solution containing 0.01％ formic acid （solvent A） and acetonitrile solution of 0.01％ formic acid （solvent B） gradient elution， at the flow rate of 0.15 mL/min， column temperature of 30 ℃， sample size of 2 μL. Mass spectrum condition included that ESI， negative ion mode acquisition， capillary voltage of 1.5 kV， cone voltage of 30 V， ion source temperature of 100 ℃， desolvent gas temperature of 400 ℃， cone gas flow of 50 L/h， desolvent gas flow of 800 L/h， scanning range of m/z 50→1 200. RESULTS： At the concentration of 2.5， 5 and 20 μg/mL， the plasma protein binding rates of cajanonic acid A were （75.63±0.90）％， （98.30±0.03）％ and （99.42±0.01）％ in the rats plasma； （79.61±1.08）％， （98.48±0.10）％ and （99.42±0.03）％ in rabbits plasma （n＝3）； （76.74±1.22）％， （97.99±0.11）％ and （99.37±0.01）％ in human plasma （n＝3）. At the concentration of 2.5 μg/mL， plasma protein binding rates of cajanonic acid A in plasma of rats and human were significantly lower than that in plasma of rabbits （P＜0.05）. CONCLUSIONS： The plasma protein binding rate of 5，20 μg/mL cajanonic acid A with rats， rabbits and human plasma are higher than that of 2.5 μg/mL cajanonic acid A. There is significant difference in plasma protein binding rate of 2.5 μg/mL cajanonic acid A with different species of plasma，and there is no significant difference in plasma protein binding rate of 5， 20 μg/mL cajanonic acid A with different species of plasma.

Transport Characteristics of Cajanonic Acid A across Caco-2 Cell Monolayer Model / 中国药学杂志

OBJECTIVE: To study the absorption characteristics of cajanonic acid A using in vitro Caco-2 cell model. METHODS: The toxicity of cajanonic acid A on Caco-2 cells was investigated by MTS, the bi-directional transport of cajanonic acid A from AP→BL and BL→AP was investigated, the cumulative transport and apparent permeability(Papp) were calculated,and the relationships between the transport amount and concentration, time, and the P-glycoprotein inhibitor verapamil were further studied. RESULTS: The transport amount of cajanonic acid A increased with time and concentration, the Papp from apical(AP) side to basolateral(BL) side was 2.01×10-6-3.95×10-6 cms-1, and the Papp from basolateral(BL) side to apical(AP) side was 2.51×10-6-6.03×10-6 cms-1. CONCLUSION: The current data suggests that the absorption of cajanonic acid A in the Caco-2 cell model is not a simple passive diffusion, the efflux ratio indicates that the efflux protein of P-gp may be involved, and the Papp suggests that the oral absorption is medium.

Inhibitory effect of cajanonic acid A on lipogenesis and lipolysis in 3 T3-L1 adipocytes / 中国药理学通报

Aim To investigate the effects of cajanonic acid A (CAA) on lipid metabolism in murine 3T3-L1 adipocytes. Methods 3T3-L1 cells induced to differ-entiated into mature adipocytes were treated with CAA in different dosages for 48 h, then total lipids as well as triglyceride, free fatty acid and glycerol were meas-ured. The expression levels of genes related to lipid metabolism were quantitatively analyzed by real-time fluorescent quantitative polymearase chain reaction ( RTFQ-PCR) . Results Total lipids and triglyceride in 3T3-L1 adipocytes were markedly reduced by CAA. The release of free fatty acid and glycerol was lower than that of control. This coincided with decreased mRNA levels of the key enzymes involved in de novo lipogenesis ( acetyl CoA carboxylase and fatty acid syn-thase) , fatty acid uptake ( lipoprotein lipase) , and li-polysis ( hormone sensitive lipase and adipose triglycer-ide lipase ) . While the expression of fatty acid oxida-tive genes including acyl CoA oxidase and carnitine palmitoyl transferase1 was increased after CAA treat-ment. Conclusion CAA may inhibit lipogenesis and lipolysis,reduce circulating free fatty acid and improve the lipid metabolism in adipocytes by regulating gene expressions.