Effect of vanillin and ethyl vanillin on cytochrome P450 activity in vitro and in vivo

Investigation of the drug-drug interaction and incompatibility mechanism between Aconitum carmichaelii Debx and Pinellia ternata (Thunb.) Breit

ETHNOPHARMACOLOGICAL RELEVANCE

The combination of Aconitum carmichaelii Debx (Chuanwu, CW) and Pinellia ternata (Thunb.) Breit (Banxia, BX) forms an herbal pair within the eighteen incompatible medicaments (EIM), indicating that BX and CW are incompatible. However, the scientific understanding of this incompatibility mechanism, especially the corresponding drug-drug interaction (DDI), remains complex and unclear.

AIM OF THE STUDY

This study aims to explain the DDI and potential incompatibility mechanism between CW and BX based on pharmacokinetics and cocktail approach.

MATERIALS AND METHODS

Ultraperformance liquid chromatography-tandem mass spectrometry methods were established for pharmacokinetics and cocktail studies. To explore the DDI between BX and CW, in the pharmacokinetics study, 10 compounds were determined in rat plasma after administering CW and BX-CW herbal pair extracts. In the cocktail assay, the pharmacokinetic parameters of five probe substrates were utilized to assess the influence of BX on cytochrome P450 (CYP) isoenzyme (dapsone for CYP3A4, phenacetin for CYP1A2, dextromethorphan for CYP2D6, tolbutamide for CYP2C9, and omeprazole for CYP2C19). Finally, the DDI and incompatibility mechanism of CW and BX were integrated to explain the rationality of EIM theory.

RESULTS

BX not only enhances the absorption of aconitine and benzoylaconine but also accelerates the metabolism of mesaconitine, benzoylmesaconine, songorine, and fuziline. Moreover, BX affects the activity of CYP enzymes, which regulate the metabolism of toxic compounds.

CONCLUSIONS

BX altered the activity of CYP enzymes, consequently affecting the metabolism of toxic compounds from CW. This incompatibility mechanism may be related to the increased absorption of these toxic compounds in vivo.

Advances in the study of liver microsomes in the in vitro metabolism and toxicity evaluation of foodborne contaminants

Foodborne contaminants are closely related to anthropologic activities and represent an important food safety hazard. The study of metabolic transformation and toxic side effects of foodborne contaminants in the body is important for their safety assessment. Liver microsomes contain a variety of enzymes related to substance metabolism and biotransformation. An in vitro model simulating liver metabolic transformation is associated with a significant advantage in the study of the metabolic transformation mechanisms of contaminants. This review summarizes the recent progress in the application of liver microsomes in metabolic transformation and toxicity evaluation of various foodborne pollutants based on metabolic kinetics, molecular docking and enzyme inhibition studies. The purpose of this review is to distinguish the existing studies involving liver microsomes and provide strategies for their application in the future. Finally, the prospects and challenges of the liver microsomal model are discussed.

Metabolite-based cell sorting workflow for identifying microbes producing carbonyls in tobacco leaves

Carbonyl compounds represented by aldehydes and ketones make an important contribution to the flavor of tobacco. Since most carbonyl compounds are produced by microbes during tobacco fermentation, identifying their producers is important to improve the quality of tobacco. Here, we created an efficient workflow that combines metabolite labeling with fluorescence-activated cell sorting (ML-FACS), 16S rRNA gene sequencing, and microbial culture to identify the microbes that produce aldehydes or ketones in fermented cigar tobacco leaves (FCTL). Microbes were labeled with a specific fluorescent dye (cyanine5 hydrazide) and separated by flow cytometry. Subsequently, the sorted microbes were identified and cultured under laboratory conditions. Four genera, Acinetobacter, Sphingomonas, Solibacillus, and Lysinibacillus, were identified as the main carbonyl compound-producing microbes in FCTL. In addition, these microorganisms could produce flavor-related aldehydes and ketones in a simple synthetic medium, such as benzaldehyde, phenylacetaldehyde, 4-hydroxy-3-ethoxy-benzaldehyde, and 3,5,5-trimethyl-2-cyclohexene-1-one. On the whole, this research has developed a new method to quickly isolate and identify microorganisms that produce aldehydes or ketones from complex microbial communities. ML-FACS would also be used to identify other compound-producing microorganisms in other systems. KEY POINTS: • An approach was developed to identify target microbes in complex communities. • Microbes that produce aldehyde/ketone flavor compounds in fermented cigar tobacco leaves were identified. • Functional microbes that produce aldehyde/ketone flavor compounds from the native environment were captured in pure cultures.

E-liquids and vanillin flavoring disrupts retinoic acid signaling and causes craniofacial defects in Xenopus embryos

Environmental teratogens such as smoking are known risk factors for developmental disorders such as cleft palate. While smoking rates have declined, a new type of smoking, called vaping is on the rise. Vaping is the use of e-cigarettes to vaporize and inhale an e-liquid containing nicotine and food-like flavors. There is the potential that, like smoking, vaping could also pose a danger to the developing human. Rather than waiting for epidemiological and mammalian studies, we have turned to an aquatic developmental model, Xenopus laevis, to more quickly assess whether e-liquids contain teratogens that could lead to craniofacial malformations. Xenopus, like zebrafish, has the benefit of being a well-established developmental model and has also been effective in predicting whether a chemical could be a teratogen. We have determined that embryonic exposure to dessert flavored e-liquids can cause craniofacial abnormalities, including an orofacial cleft in Xenopus. To better understand the underlying mechanisms contributing to these defects, transcriptomic analysis of the facial tissues of embryos exposed to a representative dessert flavored e-liquid vapor extract was performed. Analysis of differentially expressed genes in these embryos revealed several genes associated with retinoic acid metabolism or the signaling pathway. Consistently, retinoic acid receptor inhibition phenocopied the craniofacial defects as those embryos exposed to the vapor extract of the e-liquid. Such malformations also correlated with a group of common differentially expressed genes, two of which are associated with midface birth defects in humans. Further, e-liquid exposure sensitized embryos to forming craniofacial malformations when they already had depressed retinoic acid signaling. Moreover, 13-cis-retinoic acid treatment could significantly reduce the e-liquid induced malformation in the midface. Such results suggest the possibility of an interaction between retinoic acid signaling and e-liquid exposure. One of the most popular and concentrated flavoring chemicals in dessert flavored e-liquids is vanillin. Xenopus embryos exposed to this chemical closely resembled embryos exposed to dessert-like e-liquids and a retinoic acid receptor antagonist. In summary, we determined that e-liquid chemicals, in particular vanillin, can cause craniofacial defects potentially by dysregulating retinoic acid signaling. This work warrants the evaluation of vanillin and other such flavoring additives in e-liquids on mammalian development.

pH responsive release of paclitaxel by self-assembling Chitosan-ethyl vanillin@GNRs nanocomposites

Carboxylation chitosan achieved by alkalization linked with ethyl vanillin to obtain Chitosan-ethyl vanillin (EV-CMCS) compound through Schiff base reaction and confirmed by FT-IR, UV, XRD, TG and NMR. EV-CMCS refluxed with GNRs for acquisition of EV-CMCS@GNRs nanocomposites for PTX Loading and release. Results demonstrated that both EV-CMCS and EV-CMCS@GNRs are nanoscale composites with excellent solubilization due to their micelle structure taking CMC values of 0.06683 mg/mL and 0.06537 mg/mL. It was found that the loading and encapsulation rate of EV-CMCS and EV-CMCS@GNRs for PTX are 19.59~37.64% and 60.36~80.79% as well as 20.99~37.02% and 58.78~79.77%. Compared with only the delayed release of EV-CMCS that it have 11.5% and 18.7% accumulative release amount for 24 h and 14.9% and 23.7% for 48 h under both pH 6.8 and 7.4, the EV-CMCS@GNRs represent sudden release that it have an accumulative release amount of 90.2% for 24 h and 96.0% for 48 h at pH 6.8. It deduced that the broken Schiff base under acidic condition can increase CMC of EV-CMCS@GNRs, which offered an alternative way for paclitaxel delivery for tumor therapy.

Ethyl Vanillin Protects against Kidney Injury in Diabetic Nephropathy by Inhibiting Oxidative Stress and Apoptosis

Diabetes-induced oxidative stress and apoptosis is regarded as a critical role in the pathogenesis of diabetic nephropathy (DN). Treating diabetes-induced kidney damage and renal dysfunction has been thought a promising therapeutic option to attenuate the development and progression of DN. In this study, we investigated the renoprotective effect of ethyl vanillin (EVA), an active analogue of vanillin isolated from vanilla beans, on streptozotocin- (STZ-) induced rat renal injury model and high glucose-induced NRK-52E cell model. The EVA treatment could strongly improve the deterioration of renal function and kidney cell apoptosis in vivo and in vitro. Moreover, treating with EVA significantly decreased the level of MDA and reactive oxygen species (ROS) and stabilized antioxidant enzyme system in response to oxidative stress by enhancing the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in vivo and in vitro. Furthermore, EVA also markedly suppressed cleaved caspase-3, Bax, and nuclear transcription factor erythroid 2-related factor (Nrf2) expression in STZ-induced rats. Therefore, these results of our investigation provided that EVA might protect against kidney injury in DN by inhibiting oxidative stress and cell apoptosis.

Protective effect of ethyl vanillin against Aβ-induced neurotoxicity in PC12 cells via the reduction of oxidative stress and apoptosis

Increased aggregation of β-amyloid (Aβ) peptides induces oxidative stress, which is considered a major contributor in the development of Alzheimer's disease (AD). Prevention of Aβ-induced neurotoxicity is proposed as a possible modality for treatment of AD. The present study aimed to elucidate possible effects of ethyl vanillin (EVA), an analog of vanillin isolated from vanilla beans, on the Aβ_1-42-induced oxidative injury in PC12 cells. EVA restrained the decrease in PC12 cell viability and apoptosis induction caused by treatment with Aβ_1-42. In addition, EVA markedly alleviated intracellular lipid peroxidation as demonstrated by malondialdehyde levels and reactive oxygen species production in Aβ_1-42-treated PC12 cells. In addition, the reduction in the activity levels of the antioxidative enzymes superoxide dismutase, catalase and glutathione peroxidase was detected in Aβ_1-42-treated PC12 cells. This effect was partially reversed by treatment with EVA. Furthermore, the results indicated that EVA attenuated Aβ_1-42-induced caspase-3 activation and the increase noted in the apoptosis regulator Bcl-2/apoptosis regulator Bax ratio of PC12 cells. These results indicated that EVA could be used as an efficient and novel agent for the prevention of neurodegenerative diseases via inhibition of oxidative stress and cell apoptosis.

In vitro metabolism of 4, 5-dimethoxycanthin-6-one by human liver microsomes and its inhibition on human CYP1A2

AIMS

P. quassioides is a traditional Chinese medicine used for the treatment of gastroenteritis, snakebite, infection and hypertension in China. 4, 5-dimethoxycanthin-6-one is one of the main active canthinone alkaloid isolated from P. quassioides. The aim of this work was to identify the cytochrome P (CYP) 450 enzymes responsible for the metabolism of 4, 5-dimethoxycanthin-6-one (DCO) and to evaluate the inhibitory effect of DCO on CYP activity in human liver microsomes (HLM) in vitro.

MATERIALS AND METHODS

the CYP isoforms responsible for DCO metabolism and the inhibitory effects of DCO on CYP activity was studied in HLM.

KEY FINDINGS

The in vitro metabolic enzyme of DCO was CYP3A4 (mediated the formation of metabolites M1-M5), CYP2C9 (mediated the formation of metabolites M1-M3, M6 and M8) and CYP2D6 (mediated the formation of metabolite M3) in HLM. Furthermore, the present work found that DCO uncompetitively inhibited CYP1A2-mediated phenacetin O-deethylation with an IC₅₀ value of 1.7μM and a Ki value of 2.6μM.

SIGNIFICANCE

The results suggested that the metabolic interaction should be existed when the substrate drugs of CYP1A2 were co-administered with DCO or traditional Chinese medicine containing it, such as the extract of P. quassioides and Kumu injection.

Influences of Re Du Ning Injection, a traditional Chinese medicine injection, on the CYP450 activities in rats using a cocktail method

ETHNOPHARMACOLOGICAL RELEVANCE

Re Du Ning Injection (RDN), a traditional Chinese medicine injection, is made from the extracts of Lonicerae japonicae flos (LJF), Artemisiae annuae herba (AAH) and Gardeniae fructus (GF). Since last decade, RDN has been widely used in China for the treatment of fever, inflammation, allergy and viral infection.

AIM OF THE STUDY

To elucidate the potential influences of RDN on the activities of four cytochrome P450 (CYP) isozymes in rats (CYP1A2, CYP2C11, CYP2D1 and CYP3A1/2) by "cocktail method".

MATERIALS AND METHODS

A sensitive and specific LC-MS method capable of simultaneous quantification of four substrates and their metabolites in rat plasma was developed and validated. Relative activity estimation of four isozymes was carried out by comparing plasma pharmacokinetics of substrates and their metabolites (phenacetin/ paracetamol for CYP1A2, tolbutamide/4-hydroxytolbutamide for CYP2C11, dextromethorphan/ dextrorphan for CYP2D1 and dapsone/N-acetyl dapsone for CYP3A1/2) between control and RDN treatment groups.

RESULTS

Compared with control group, RDN at different levels could increase the total amount of tolbutamide, dextromethorphan and dapsone absorbed into blood, while decrease the total amount of phenacetin absorbed into blood at low and medium dosage and increase it at high dosage.

CONCLUSIONS

RDN could inhibit the activities of CYP2C11, CYP2D1 and CYP3A1/2, induce the activity of CYP1A2 at low and medium dosage but inhibit it at high dosage. The results indicated that drug co-administrated with RDN may need dose adjustment.

Pinelliae rhizoma, a toxic chinese herb, can significantly inhibit CYP3A activity in rats

Raw Pinelliae Rhizoma (RPR) is a representative toxic herb that is widely used for eliminating phlegm or treating cough and vomiting. Given its irritant toxicity, its processed products, including Pinelliae Rhizoma Praeparatum (PRP) and Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine (PRPZA), are more commonly applied and administered concomitantly with other chemical drugs, such as cough medications. This study aimed to investigate the effects of RPR, PRP, and PRPZA on CYP3A activity. Testosterone (Tes) and buspirone (BP) were used as specific probe substrates ex vivo and in vivo, respectively. CYP3A activity was determined by the metabolite formation ratios from the substrates. Ex vivo results show that the metabolite formation ratios from Tes significantly decreased, indicating that RPR, PRP, and PRPZA could inhibit CYP3A activity in rats. CYP3A protein and mRNA levels were determined to explore the underlying mechanism. These levels showed marked and consistent down-regulation with CYP3A activity. A significant decrease in metabolite formation ratios from BP was also found in PRPZA group in vivo, implying that PRPZA could inhibit CYP3A activity. Conclusively, co-administration of PR with other CYP3A-metabolizing drugs may cause drug–drug interactions. Clinical use of PR-related formulae should be monitored carefully to avoid adverse interactions.

Coadministration of Pinellia ternata Can Significantly Reduce Aconitum carmichaelii to Inhibit CYP3A Activity in Rats

Chuanwu (CW), the mother root of Aconitum carmichaelii Debx., is a traditional Chinese medicine (TCM) for treating traumatic injuries, rheumatoid arthritis, and tumors. CW coadministered with banxia (BX), the root of Pinellia ternata, is also widely prescribed in clinical practice. However, the mechanism of this combination is yet deciphered. Current study aimed to investigate the effects of CW, including raw chuanwu (RCW) and processed chuanwu (PCW) alone, as well as CW coadministered with BX on CYP3A activity. Buspirone (BP) and testosterone (Tes) were used as specific probe substrates in vivo and ex vivo, respectively. CYP3A activity was determined by the metabolites formation ratios from the substrates. Compared with those in the control group, the metabolites formation ratios significantly decreased in the RCW and PCW alone groups, accompanied by a marked decrease in CYP3A protein and mRNA levels. However, there was a significant increase in those ratios in the RCW-BX and PCW-BX groups compared to the RCW and PCW alone groups. The results indicated that both RCW and PCW can inhibit CYP3A activity in rats because of downregulation of CYP3A protein and mRNA levels. Decreases in CYP3A activity can be reversed by coadministration with BX.

Phenolic compounds in particles of mainstream waterpipe smoke

INTRODUCTION

Waterpipe tobacco smoking has in recent years become a popular international phenomenon, particularly among youth. While it has been shown to deliver significant quantities of several carcinogenic and toxic substances, phenols, an important class of chemical compounds thought to promote DNA mutation and cardiovascular diseases, however, has not been studied. Due to the relatively low temperature characteristic of waterpipe tobacco during smoking (i.e., <450 °C), it was hypothesized that phenolic compounds, which form at approximately 300 °C, will be found in abundance in waterpipe smoke.

METHODS

In this study, phenolic compounds in the particle phase of waterpipe mainstream smoke were quantified. Waterpipe and cigarette mainstream smoke generated using standard methods were collected on glass fiber pads and analyzed using gas chromatography/mass spectroscopy selected ion current profile chromatogram method for quantification.

RESULTS

We found that relative to a single cigarette, a waterpipe delivers at least 3 times greater quantities of the 7 analyzed phenols (phenol, o-cresol, m-cresol, p-cresol, catechol, resorcinol, and hydroquinone). Moreover, phenol derivatives such as methylcatechol, and flavorings such as vanillin, ethyl vanillin, and benzyl alcohol were found in quantities up to 1,000 times greater than the amount measured in the smoke of a single cigarette.

CONCLUSION

The large quantities of phenols and phenol derivatives in waterpipe smoke add to the growing evidence that habitual waterpipe use may increase the risk of cancer and cardiovascular diseases.