04novembre

CYP3A4, genetics, scopoletin

Facteurs génétiques du paludisme

CYP3A4, genetics and scopoletin. In a pionneering study in 2010, the University of Louvain had studied the anti-inflammatory effect and modulation of cytochrome P450 activities by Artemisia annua tea infusions in human intestinal Caco-2 cells Melillo de Magalhães, Yves-Jacques Schneider. Anti-inflammatory effect and modulation of cytochrome P450 activities by Artemisia annua tea infusions in human intestinal Caco-2 cell Food Chemistry 134(2):864-71 · September 2012 These assays were done on aqueous infusionsof Artemisia annua samples from 7 different origins. For all samples there was a significant reduction in the CYP3A4 activity with the highest reduction down to 37% of the control value for the sample from Luxembourg (registration number MNHNL17732 at the herbarium of Luxembourg). Ketoconazole, a well-known specific and potent CYP3A4 inhibitor used for comparison at 50 µM, completely inhibited the CYP3A4 activity. Artemisinin, rosmarinic and chlorogenic acids tested at plausible intestinal concentrations had no effect on the CYP3A4 activity. More recently similar assays were run at the Vrije Universiteit Brussel. They used ethanolic extracts 32 gr dried leaves of Artemisia plant material extracted by Soxhlet in 1 litre ethanol. They worked with Artemisia plants from different origins, including the species Artemisia abrotanum, Artemisia apiacea, Artemisia pontica, Artemisia herba alba, Artemisia absintium, Artemisia afra. The CYP3A4 inhibition was surprisingly high for all Artemisia samples, up to 6 times higher the for ketoconazol (0.11 µg/mL) or for diluted grapefruit juice. This is surprising because grapefruit juice has the reputation to be the strongest CYP3A4 inhibitor from plant origin. Surprising is also the fact that all Artemisia samples show this strong CYP3A4 inhibition without a particular strength for one of these 7 species. Lazaridi Kristina. Invloed van de chemische samenstelling van Artemisia annua op CYP3A4-activiteit en antioxidant vermogen. Masterproef VUB, 2014 This is confirmed by a recent study from Egypt on the extracts of 57 medicinal plants. Generally Aqueous extracts have a stronger effect than ehanolic extracts. Among all these plants, for a concentration of 100 µg/ml, Artemisia annua and Artemisia capillaris are ranking at the top with a few others with an inhibition of 83.96 and 82,36 % respectively. No difference thus between the two species, indicating that artemisinin plays no role. ML Ashour, F Youssef, H Gad, M Wink, Inhibition of CYP3A4 activity by extracts from 57 plants used in TCM. Pharmacognosy Magazine, 2017, 13 :300-8 Cytochrome P450 3A4 (abreviated CYP3A4), is an important enzyme in the body, mainly found in the liver and in the intestine. Its purpose is to oxidize small foreign organic molecules (xenobiotics), such as toxins or drugs, so that they can be removed from the body. It is responsible for the metabolism of more than half of ingested drugs, including artemisinin and its derivatives Svensson US, Mäki-Jouppila M, Hoffmann KJ, Ashton M. Characterisation of the human liver in vitro metabolic pattern of artemisinin and auto-induction in the rat by use of nonlinear mixed effects modelling. Biopharm Drug Dispos. 2003 Mar;24(2):71-85. Gupta S, Svensson US, Ashton M. In vitro evidence for auto-induction of artemisinin metabolism in the rat. Eur J Drug Metab Pharmacokinet. 2001 Jul-Sep;26(3):173-8. Giao PT, de Vries PJ. Pharmacokinetic interactions of antimalarial agents. Clin Pharmacokinet. 2001; 40(5):343-73. CYP 3A4 enzymes pose a problem in drug development and clinical use of drugs because of interactions with drug disposition and/or drug-drug interactions. A high level of enzyme activity toward a drug causes a decrease in that drugs bioavailability. Conversely, drugs, or compounds that inhibit this enzyme can reduce the normal metabolism of another drug, causing elevated levels and potential toxic side effects The inhibitory effect on CYP3A4 is generally measured by the biotransformation and hydroxylation of the drug Midazolam. The University of Otoga in New Zealand evaluated the inhibition of CYP3A4 by a full range of flavonoids, coumarins and some 20 related compounds. The strongest inhibition is caused by bergapten from grapefruit juice, followed in decreasing order by chrysin, quercetin, naringenin, scopoletin, psoralen, hesperitin, kaempferol Ping-Chuen Ho, Dorothy J. Saville. Inhibition of human CYP3A4 activity by grapefruit flavonoids, furanocoumarins and related compounds J Pharm Pharmaceut Sci 4(3):217-227, 2001 Chrysoplenetin a flavonoid present in Artemisia annua inhibits CYP3A4 and increases the AUC of artemisinin. Shijie Wei, Hongyan Ji, Bei Yang, Liping Ma, Zhuchun Bei Impact of chrysosplenetin on the pharmacokinetics and anti-malarial efficacy of artemisinin against Plasmodium berghei as well as in vitro CYP450 enzymatic activities in rat liver microsome. Malar J. 2015; 14: 432. The activity of quercetin (absent in Artemisia annua) is controversial. Some authors even find that it activates CYP3A4. Chae YJ, Cho KH, Yoon IS, Noh CK, Lee HJ, Park 2, Ji E, Seo MD, Maeng HJ. Vitamin D Receptor-Mediated Upregulation of CYP3A4 and MDR1 by Quercetin in Caco-2 cells. Planta Med. 2016 Jan;82(1-2):121-30. doi: 10.1055/s-0035-1557898. The action depends on the number of OH groups attached to the flavonoid. Biochem Pharmacol. 2008 Mar 15;75(6):1426-37. doi: 10.1016/j.bcp.2007.11.012. Quintieri L, Palatini P, Nassi A, Ruzza P, Floreani M. Flavonoids diosmetin and luteolin inhibit midazolam metabolism by human liver microsomes and recombinant CYP 3A4 and CYP3A5 enzymes. Hanqing Dong, Wenwei Lin, Jing Wu, and Taosheng Chen Flavonoids activate pregnane × receptor-mediated CYP3A4 gene expression by inhibiting cyclin-dependent kinases in HepG2 liver carcinoma cells BMC Biochem. 2010; 11: 23. doi: 10.1186/1471-2091-11-23 But these effects have all been studied in vitro. The in vivo administration of purified forms of these compounds failed to show an effect. Kaempferol administered to rats did not inhibit CYP3A4. Li P, Callery PS, Gan LS, Balani SK. Esterase inhibition by grapefruit juice flavonoids leading to a new drug interaction. Drug Metab Dispos. 2007 Jul;35(7):1203-8. Epub 2007 Apr 23. The in vitro inhibitors naringin and quercetin do not contribute to the in vivo inhibition of CYP3A4 either. Rashid J, McKinstry C, Renwick AG, Dirnhuber M, Waller DG, George CF. Quercetin, an in vitro inhibitor of CYP3A, does not contribute to the interaction between nifedipine and grapefruit juice. Br J Clin Pharmacol. 1993 Nov;36(5):460-3. The inhibition of CYP 3A4 by essential oils of several plants had already been studied in 2004 . At a concentration of 100 µg/ml grapefruit oil inhibited 75%, eucalyptol 52 % and menthol 5%. Striking in this study is the fact that the inhibition by grapefruit oil is by far stronger than the inhibition by grapefruit juice. The effect of spice constituents on the CYP3A4 was studied in Australia, Unger, M., Arzneimittelinteraktionen durch Phytopharmaka und Lebensmittel. Phytotherapie 2005; 5:22-27. Wenxia Zhang, Lee-Yong Lim. Effects of spice constituents on P-glycoprotein-mediated transport and CYP3A4-mediated metabolism in vitro. Drug Metabolism and Disposition: the Biological Fate of Chemicals 2008, 36 (7): 1283-90 Piperine was already known as a bioavailability enhancer. The following spices were found to inhibit CYP3A4 approximately in this ranking order for a 50% reduction in activity : curcumin (40 µM), 6-gingerol (100 µM), citral (250 µM), d-limonene (400 µM), β-caryophyllene (500 µM), 1,8-cineole (1mM), myrcene (1mM). This study has thus shown that spices have a modulation effect, although modest, on CYP3A4. It may even be prudent to advise against the coadministration of potent drugs together with curcumin. The inhibitory effect of saturated and polyunsaturated fatty acids on CYP3A4 was studied in Thailand. V Hirunpanich. Inhibitory Effect of Docosahexaenoic Acid (DHA) on the Intestinal Metabolism of Midazolam: In Vitro and in Vivo Studies in Rats. Int J Pharm 351 (1-2), 133-143. 2007 Oct 05. Saturated fatty acids (SFA) like palmitic or stearic acid have no effect. Polyunsaturated fatty acids (PUFA), like linoleic, linolenic, docosahexaeonic acid however have a strong inhibitory effect. This deserves more research as fish oils and omega oils are sold on a large scale as food complements. Plants of the Artemisia family also contain unsaturated fatty acids ranging from 0,3 to 1.7 %. The acids with 18 carbon atoms are more abundant than those with 20 carbons. The predominant acid in all Artemisia species are linoleic and linolenic acid. CYP3A4 enzymes metabolize arachidonic acid and linoleic to several biologically active acids like hydroxyeicosatetraenoic acids (HETEs) Bylund J, Kunz T, Valmsen K, Oliw EH Cytochromes P450 with bisallylic hydroxylation activity on arachidonic and linoleic acids studied with human recombinant enzymes and with human and rat liver microsomes. J Pharmacol Exp Ther. 1998 Jan;284(1):51-60. The interaction PUFA-CYP3A4 is thus very complex and deserves further study. In vitro studies performed in human cell cultures and animal models suggest that vitamin E might increase the hepatic production of cytochrome CYP3A4; this could potentially lower the efficacy of any drug metabolized by CYP3A4. Clarke MW, Burnett JR, Croft KD. Vitamin E in human health and disease. Crit Rev Clin Lab Sci 2008;45:417-50. Back to cited text no. 26 The inhibition of CYP3A4 by grapefruits is mainly related to furanocoumarins (bergamottin, psoralens). Their inhibition potential is equal or stronger than ketoconazole the protypical CYP3A4 inhibitor. Fukuda K, Ohta T, Oshima Y, Ohashi N, Yoshikawa M, Yamazoe Y. Specific CYP3A4 inhibitors in grapefruit juice: furocoumarin dimers as components of drug interaction. Pharmacogenetics. 1997 Oct; 7(5):391-6. When furanocoumarins have been removed from grapefruit juice the in vivo inhibition of CYP3A4 becomes insignificant. Paine MF, Widmer WW, Hart HL, Pusek SN, Thomas BF, Watkins PB. A furanocoumarin-free grapefruit juice establishes furanocoumarins as the mediators of the grapefruit juice-felodipine interaction. Am J Clin Nutr. 2006 May;83(5):1097-105. Furthermore, the inhibition occurs exclusively in the small intestine. The lack of effect of furanocoumarins in hepatic CYP3A4 is exemplified by the lack of effect of intravenous administration. Grapefruit juice consumption leads to excretions of a fluorescent material identified as conjugated scopoletin. The precursor of scopoletin is widely present at different concentrations in commercially available grapefruit juices. Runkel M, Tegtmeier M, Legrum W. Metabolic and analytical interactions of grapefruit juice and 1,2-benzopyrone (coumarin) in man. Eur J Clin Pharmacol. 1996;50(3):225-30. It is thus of interest to investigate which other plants are rich in coumarins, particularlyscopoletin. There are not many plants where scopoletin has been found and analyzed, with the exception of a few medicinal plants like Morinda citrifolia (Noni), Melia azedirach, Tilia cordata. One of the first plants where scopoletin was detected hundred years ago is Artemisia afra. Goodson JA. The Constituents of the Flowering Tops of Artemisia afra, Jacq. Biochem J. 1922;16(4):489-93. Coumarins, particularly scopoletin, strongly inhibit iNOS. Tien-Ning Chang, Jeng-Shyan Deng, Yi-Chih Chang, Chao-Ying Lee, Liao Jung-Chun, Ameliorative Effects of Scopoletin from Crossostephium chinensis against Inflammation Pain and Its Mechanisms in Mice. Evid Based Complement Alternat Med. 2012; 2012: 595603. doi: 10.1155/2012/595603 Quercetin is a NO inhibitor too, but scopoletin is ten times stronger. Aneta Janecki, Beitrag zur Kenntnis der Inhaltsstoffe und der Wirkung des Pelargonium sidoides Spezialextraktes. Thesis, 2012, Freie Universität Berlin Scopoletin is well present in most species of the Artemisia family. The NO inhibitory effect by scopoletin was demonstrated in Artemisia feddei Kang TH, Pae HO, Jeong SJ, Yoo JC, Higuchi R, Kim YC.Scopoletin: an inducible nitric oxide synthesis inhibitory active constituent from Artemisia feddei. Planta Med. 1999 Jun;65(5):400-3. Scopoletin has anti-inflammatory effects which are mainly related to inhibitory activities on PGE₂ and TNF-α overproduction, particlarly in gout X Yao, Z Ding, Y Xia, Y Dai. Inhibition of monosodium urate crystal-induced inflammation by scopoletin. Internat Immunopharmacology, 2012, 14, 454-462 Z Ding, Yue Dai, Z Wang. Anti-inflammatory effects of scopoletin and underlying mechanisms. Pharmac Biol. 2008, 46-12. TN Chang, J Deng, Y Chang, G Huang. Ameliorative effects of scopoletin against inflammation pain. Evidence-Based Complementary and Alternative Medicine, 2012, article ID 595603 It was even patented for Artemisia annua (US 6337095, 2002). The authors find higher concentrations of scopoletin in the stems than in the leaves (0.3 vs 0.2%). Very important in this context appears the fact that Artemisia annua from Luxembourg genotype only contains 0.02 % of scopoletin versus 0.2 % for Artemisia annua of the high artemisinin hybrid Rosine Chougouo, Thesis, Université des Montagnes, Cameroon, 2011 and Laboratory Celabor (personal communication). Scopoletin exhibits an immediate and dose-dependent hypouricemic effect after intraperitoneal administration (50, 100, 200 mg/kg) in hyperuricemic mice Ding Z, Dai Y, Wang Z. Hypouricemic action of scopoletin arising from xanthine oxidase inhibition and uricosuric activity. DOI: 10.1055/s-2005-837789 Scopoletin is a dye that can be used to detect the release of reactive oxygen species during the oxidative burst or measure the concentration of hydrogen peroxide in solution. Scopoletin can markedly affect the pharmacokinetics of artemisinin and increase the plasma concentration, more than other molecules present in Artemisia like arteannuin-B, artemisinic acid, casticin, chrysoplenol Chao Zhang, Mu-Xin Gong, Feng Qiu, Jing Li, Man-Yuan Wang. Effects of arteannuin B, arteannuic acid and scopoletin on pharmacokinetics of artemisinin in mice. Asian Pacific J of Trop Med. June 2016.05.04 Scopoletin in vivo even displays an antimalarial activity which had never been detected in vitro The distribution of scopoletin in murine tissues after oral administration was studied in China. Yu-feng Xia, Yue Dai, Qing-yu Meng, Qiang Wang, Ling-ling Qiu. Studies on absorption kinetics of scopoletin in rat stomachs and intestines. Zhongguo Zhong Yao Za Zhi 2008 Aug;33(15):1890-4 The highest concentrations are found in liver, kidney, stomach and small intestine. Between patients there is a wide variability in the extent of interaction of inhibitors with CYP3A4. Genetic polymorphisms and allele frequencies contribute to four clinical predominant phenotypes: poor, intermediate, extensive and ultra-rapid metabolizers. Ripudaman K. Bains. African variation at Cytochrome P450 genes, Evolutionary aspects and the implications for the treatment of infectious diseases. Evol Med Public Health. 2013; 2013(1): 118–134. doi: 10.1093/emph/eot010 The CYP3A4*3 allele for example has a lower frequency in Africa. Frequencies of xenobiotic-metabolizing polymorphisms had already been found in the Philippines between Filipino, Chinese, Korean, Japanese, Malaysian, Indian and Caucasian populations. Roldan M. De Guia, Ariana Anne P. Baluyot , Marice R. Ralph Rayman. Frequencies of Xenobiotic-Metabolizing Enzyme Gene Polymorphisms CYP3A4, GSTM1 and GSTT1 in a Filipino Population. Current Pharmacogenomics and Personalized Medicine, 2014, 12, 51-55 51. Modiano D, Petrarca V, Sirima BS, Nebié I, Diallo D, Esposito F, Coluzzi M. Different response to Plasmodium falciparum malaria in west African sympatric ethnic groups. Proc Natl Acad Sci U S A. 1996 Nov 12;93(23):13206-11 Bereczky S, Dolo A, Maiga B, Färnert A. Spleen enlargement and genetic diversity of Plasmodium falciparum infection in two ethnic groups with different malaria susceptibility in Mali, West Africa. Trans R Soc Trop Med Hyg. 2006 Mar; 100(3):248-57 This may of course have an impact on the treatment of malaria and the asymptomatic load of parasites. It may also have an impact on molecular markers linked to resistance in Plasmodium falciparum as studied in Madrid on blood samples imported over a period of 8 years from 17 African countries. Aranzazu Amor, Pedro Berzosa, Molecular markers in P falciparum linked to resistance to anti-malarial drugs in samples imported from Africa over an eight-year period (2002-2010): impact of the introduction of artemisinin combination therapy. Malaria Journal 2012 11:100.. PM Lelliot, BJ McMorran, S Foote, G Burgio. The influence of host genetics on erythrocytes and malaria infection : is there therapeutic potential. Malaria Journal, 2015 14 :289 Immunoglobulin also play an underappreciated role in protection from malaria and host genetics may influence the antigen specificity of IgM and IgG responses to infection. They are significantly higher in the malaria-resistant Fulani versus the malaria-susceptible Dogon. C Arama, J Skinner, D Doumtabe, P Crompton. Genetic resistance to malaria is associated with greater enhancement of IgM than IgG to a broad array of Plasmodium falciparum antigens. OFID, DOI 10.1093/ofid/ofv118 A study in Mali showed that blood group 0 is associated with a 66% reduction in the odds of developing severe malaria compared with the non-0 groups. JA Rowe, IG Handel, JM Moulds, Blood group 0 protects against severe Plasmoidium falciparum malaria through the mechanism of reduced rosetting. PNAS, 2007. 104-44 17471-76

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