Beta-hematin inhibition a key weapon against malaria

Beta-hematin inhibition and antimalarial properties Recent results obtained at the AlQuds University in partnership with IFBV-BELHERB from Luxembourg show that freshly prepared infusion of Artemisia annua or Artemisia afra is stronger than chloroquine in the inhibition of beta-hematin (hemozoin) formation. In infected erythrocytes, the malaria parasite generates large quantities of toxic ferri-heme, the Achille’s heel of Plasmodium. With hydrogen peroxyde which is present in all living beings, heme forms aggressive radicals which kill the parasite, like artemisinin probably does. M J Davies. Detection of peroxyl and alkoxyl radicals produced by reaction of hydroperoxides with rat liver microsomal fractions Biochem. J. (1989) 257, 603-606 The parasite avoids these toxic effects by polymerizing these heme molecules within the food vacuole at pH 4.5–5.0, into a nontoxic, unreactive, insoluble crystalline compound called hemozoin or “malaria pigment” A synthetic analog to hemozoin called β-hematin is structurally and spectroscopically identical to purified hemozoin, making it an excellent target for biochemistry studies. The mechanism of quinine and all its derivates, chloroquine, amodiaquine operates by inhibiting this hemozoin crystallization. The scientific literature is poor in research work dealing with beta-hematin inhibition, except for the papers dealing with quinine and its derivatives chloroquine and amodiaquine. The biodegradation of hemoglobin by the parasite generates hydrogen peroxide which degrades heme. H₂O₂ is produced by the spontaneous dismutation of superoxide radicals generated during methemoglobin formation. Intact Plasmodium falciparum trophozoite-infected human red blood cells were shown to produce H₂O₂ and OH radicals about twice as much as normal erythrocytes. No increase in hydrogen peroxide production over that observed in uninfected erythrocytes could be detected at the ring stage when host cell digestion is absent. These results suggest that reactive oxygen species are produced in the parasite's food vacuole during the digestion of host cell cytosol, and are able to egress from the parasite to the host cell compartment. The hydrogen peroxide produced may kill the parasite but it also dismantles hemozoin. Atamna H, Ginsburg H. Origin of reactive oxygen species in erythrocytes infected with Plasmodium falciparum. Mol Biochem Parasitol. 1993 Oct;61(2):231-41. Chloroquine inhibits this peroxidative degradation. P Loria, S Miller, M Foley, and L Tilley. Inhibition of the peroxidative degradation of haem as the basis of action of chloroquine and other quinoline antimalarials. Biochem J. 1999 Apr 15; 339(Pt 2): 363–370. The Universidad de Antioquia in Colombia has shown that there is a good correlation between beta-hematin inhibition and parasite inhibition Katalina Muñoz, Javier Sierra, Geyson Fernandez , Fernando Alzate, Gabriel J. Arango , Cesar Segura , Karent E. Bravo . Inhibition of a specific antimalarial molecular target and correlation with the activity against Plasmodium falciparum as selection criteria of potential antimalarials from natural sources. Pharmacologyonline 3: 656-661 (2006) Weissbuch I, Leiserowitz L. Interplay between malaria, crystalline hemozoin formation, and antimalarial drug action and design. Chem Rev. 2008 Nov;108(11):4899-914. doi: 10.1021/cr078274t. Y Kurasawa, A Dorn, M Kitsuji-Shirane, Hematin plymerizationassay as a high-throughput screen for idenfification of new antimalarial pharmacophores. Antimicrob Ag and Chemotherapy, 2000, 44-10, 2638-44 Similar work was done in India Kumar S, Guha M, Choubey V, Maity P, Bandyopadhyay UAntimalarial drugs inhibiting hemozoin (beta-hematin) formation: a mechanistic update. Life Sci. 2007 Feb 6;80(9):813-28.. Soni Sanketkumar Chandrakant. Screening of medicinal plant extracts and isolated compounds against sensitive and resistant strains of Plasmodium falciparum for antimalarial activity. University of Baroda, PhD thesis 2012 Al Quds university in previous work has shown that extracts from Salvia officinalis also inhibit hemozoin formation. Mutaz Akkawi, Abd-Alkarem Sharif, Khaled Salem, Azzam Saleh and Qasem AbuRemeleh. Wild sage (Salvia officinalis) as a potential anti-malarial drug. Malaria Journal201211(Suppl 1):P3 DOI: 10.1186/1475-2875-11-S1-P3 British Journal of Pharmacology and Toxicology 5(5): 156-162, 2014 Extracts from Artemisia sieberi growing in Palestine were shown to have similar properties. More recently the strongest inhibitory effect was displayed by Artemisia annua infusions as used by thousands of people in China, Africa, South America. S. Jaber, S. Abu-Lafi, A. Asharif, M. Qutob, Q. Aburemeleh and M. Akkawi Potential Antimalarial Activity from Alcoholic Extracts of Wild Salvia palaestina Leaves. British Journal of Pharmacology and Toxicology. 4(5): 201-206.:201-206 · October 2013 Suhair Jaber, Saleh Abu-Lafi, Pierre Lutgen, Mutaz Qutob, Qassem Abu-Remeleh and Mutaz Akkawi. Bicarbonate In-Vitro Effect on Beta-Hematin Inhibition by Artemisia sieberi Aqueous Infusion. Journal of Pharmacy and Pharmacology 3 (2015) 63-72 doi: 10.17265/2328-2150/2015.02.003 Mutaz Akkawi, Suhair Jaber, Qassem Abu-Remeleh, Ogwang Patrick Engeu and Pierre Lutgen. Investigations of Artemisia Annua and Artemisia Sieberi Water Extracts Inhibitory Effects on Β-Hematin Formation Investigations of Artemisia Annua and Artemisia Sieberi Water Extracts Inhibitory Effects on Β-Hematin Formation. Medicinal and Aromatic Plants,2014. ISSN: 2167-0412 They also found that Inula viscosa, another Palaestinian medicinal plant inhibits beta-hematin: the first study showing this effect which was similar to that of chloroquine. M. Akkawi, I. Abbasi, S. Jaber, Q. Aburemeleh, A. Naseredin and Pierre Lutgen Investigation of Traditional Palestinian Medicinal Plant Inula viscosa as Potential Anti-malarial ISSN. British Journal of Pharmacology and Toxicology 5(5): 156-162, 2014 2044-2459; Not all Artemisia annua plants are giving the same beta-hematin inhibition, the plant from Cameroon being much stronger than the plant from Luxembourg. Mutaz Akkawi, Suhair Jaber, Saleh Abu-Lafi, Mutaz Qutob, Qassem Abu-Rmeleh, Pierre Lutgen. HPLC separation and in vitro antimalarial studies of Artemisia annua plants from two different origins: Cameroon versus Luxembourg. MalariaWorld Journal, 2014, 5:11. ISSN 2214-4374 In their research work it could also be demonstrated that it is essential to prepare fresh infusions rather than working with extracts. It was a surprising discovery by Al Quds University that lyophilized extracts even when kept in hermetic glassware lose their power over weeks. This has also been documented for other isolated molecules like artesunate. Sandrine Houzé, Aline Munier1, Xavier Paoletti, Halima Kaddouri, Pascal Ringwald and Jacques Le Bras. Shelf Life of Predosed Plates Containing Mefloquine, Artemisinin, Dihydroartemisinin, and Artesunate as Used for In Vitro Plasmodium falciparum Susceptibility Assessment. J Clin Microbiol. Aug 2007, 2734-2736) and may have an impact not only on in vivo treatment results but also on in vitro results obtained with aged extracts. The University of Al Quds also found that the addition of sodium chloride and sodium bicarbonate even more, enhanced the beta-hematin inhibition properties of Artemisia infusions. Suhair Jaber, Saleh Abu-Lafi, Pierre Lutgen, Mutaz Qutob, Qassem Abu-Remeleh and Mutaz Akkawi. Bicarbonate In-Vitro Effect on Beta-Hematin Inhibition by Artemisia sieberi Aqueous Infusion. Journal of Pharmacy and Pharmacology. 2015 Volume: 3 Pages: 63-72. M Akkawi, S Jaber, S Abu-Lafi, Q Abu-Remeleh and P. Lutgen. Bicarbonate in vitro effect on beta-hematin inhibition by a Artemisia sieberi aqueous infusion. 5th Inter Conf and Exhib Natural&Alternat Medicin Sept 05-07 Beijing China Normal serum bicarbonate concentration in serum is approximately 25 mM but may decrease to <10mM at sites of infection. Edeker BL, Rasmussen GT, Britigan BE. Bicarbonate and phosphate ions protect transferrin from myeloperoxidase-mediated damage. J Leukoc Biol. 1995 Jul;58(1):59-64 The extensive work of the University of Al Quds has been able to demonstrate (personal communication) that certain plants inhibit beta-hematin (Artemisia annua, Artemisia sieberi, Artemisia afra, Capparis spinosa, Origanum vulgare, Allium sativum, Inula viscosa, Cymbopogon citratus, Salvia officinalis, Thymus vulgaris, Punica granatum peel, Vitis vinifera seeds), others not like Moringa oleifera. The fact that Moringa oleifera has no antimalarial properties and even contains para-aminobenzoic which promotes malaria is an important issue. There are also differences between individual substances. Quercetin, ursolic acid and arginin, ellagic acid inhibit, others not: stevioside, camphor, piperazin, curcumin, cuminaldehyde, artemisinin, saccharin, vitamin C, thymol, mineral salts. The zinc-arginine complex inhibits but the individual zinc and arginine not. NO generated by arginine acts as an extremely strong ligand and its binding to the iron of heme groups has been shown to exert a large repulsive force, potentially disrupting the linkages within the crystal lattice of hemozoin, Melissa D Carter, Hemozoin : a pardigm for biomineralization in disease. Thesis, Vanderbilt University, Nashville, Tennessee. DT Uyen, NT Huy, DT Trang, K Kamei. Effects of amino-acids on malarial heme crystallization. Biol Pharm Bull, 2008, 31, 1484-88. Other substances even promote beta-hematin formation: ethanol, lipids, polyethylene glycol, para-aminobenzoic acid, lecithin, phospholipids. Huy NT, Maeda A, Uyen DT, Trang DT, Sasai M, Shiono T. Alcohols induce beta-hematin formation via the dissociation of aggregated heme and reduction in interfacial tension of the solution. Acta Trop. 2007,130-8. DT Xuan Trang, NT Huy, DT Uyen. Inhibition of beta-hematin formation initiated by lecithin for screening new antimalaria drugs. Analyt Biochem. 2006, 349, 292-296 MD Carter, VV Phelan, RD Sandlin, B Bachman, D Wright, Lipophilic mediated assays for beta-hematin inhibitors. Comb Chem High Throughput Screen, 2010, 13(3) 285-292. Alcohol water is even used as a medium for beta-hematin preparation Blauer G, Akkawi M. Alcohol-water as a novel medium for beta-hematin preparation. Arch Biochem Biophys, 2002, 1:398 (1):7-11. But all phospholipids do not act in the same way. Phosphatidylcholines (PC) induce beta-hematin in a dose dependent manner. Dimyristoylcholines (PE) have no effect NT Huy, Y Shima, A Maeda, K Kamel, Phospholipid membrane-mediated hemozoin formation: the effect of physical properties and evidence of membrane surrounding hemozoin, PLOS 2013, doi.org/10.1371/journal.pone.0070025