Ph.D. (University of Manitoba), Professor

Department of Animal Science

Faculty of Agricultural and Food Sciences, University of Manitoba

Department of Physiology and Pathophysiology

Faculty of Medicine, University of Manitoba

Principal Investigator
Integrative Biology Laboratory
Canadian Centre for Agri-Food Research in Health and Medicine,
St. Boniface Hospital Research Centre, 351 Tache Avenue,

Winnipeg, Manitoba, Canada R2H 2A6

Telephone: 1 (204) 235-3951
Email: karmino@sbrc.ca



Research Interest:

  • Impact of oxidative stress and antioxidants in health and disease progression;
  • Regulation of inflammatory response and lipid metabolism in metabolic disorders (fatty liver disease, hyperhomocysteinemia, diabetes, obesity) and cardiovascular disease;
  • Prevention and treatment of ischemia-reperfusion induced acute kidney injury (AKI) and chronic kidney disease (CKD);
  • Beneficial effect of folic acid supplementation, berberine, tyrosol and other compounds isolated from agricultural products and herbal medicine in health.

Selected peer-reviewed publications:

Wu N, Sarna LK, Hwang SY, Zhu Q, Wang P, Siow YL, O K. Activation of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase during high fat diet feeding. Biochim Biophys Acta - Molecular Basis of Disease. 2013;1832:1560-1568.

Wang P, Zhu Q, Wu N, Siow YL, Aukema H, O K. Tyrosol attenuates ischemia-reperfusion-induced kidney injury via inhibition of inducible nitric oxide synthase.J Agric Food Chem. 2013;61(15):3669-3675.

Hwang SY, Sarna LK, Siow YL, O K. High fat diet stimulates hepatic cystathionine β-synthase and cystathionine γ-lyase expression. Can J Physiol Pharmacol. 2013;91(11):913-919.

Zahradka P, Wright B, Weighell W, Blewett H, Baldwin A, O K, Guzman RP, Taylor CG. Daily non-soy legume consumption reverses vascular impairment due to peripheral artery disease. Atherosclerosis. 2013;230(2):310-314.

Isaak CK, Petkau JC, O K, Ominski K, Rodriguez-Lecompte JC, Siow YL. Seasonal variations in phenolic compounds and antioxidant capacity of Cornus stolonifera plant material: applications in agriculture. Can J Plant Sci 2013; 93: 725-734.

Munyaka PM, Tactacan G, Jing M, O K, House JD, St Paul M, Sharif S, Rodriguez-Lecompte JC. Response of older laying hens to an Escherichia coli lipopolysaccharide challenge when fed diets with or without supplemental folic acid. Poult Sci. 2013;92(1):105-113.

Lear S, Sarna LK, Siow TJ, Mancini J, Siow YL , O K. Oxidative stress is associated with visceral adipose tissue and sub-clinical atherosclerosis in a healthy multi-ethnic population. Appl Physiol Nutr Metab. 2012;37(6):1164-1170.

Sun L, Isaak CK, Zhou Y, Petkau JC, O K, Liu Y, Siow YL. Salidroside and tyrosol from Rhodiola protect H9c2 cells from ischemia/reperfusion-induced apoptosis. Life Sci. 2012;91(5-6):151-158.

Sarna LK, Wu N, Wang P, Hwang SY, Siow YL, O K. Folic acid supplementation attenuates high fat diet induced hepatic oxidative stress via regulation of NADPH oxidase. Can J Physiol Pharmacol. 2012; 90:155-165.

Munyaka PM, Tactacan G, Jing M, O K, House JD, Rodriguez Lecompte JC. Immunomodulation in young laying hens by dietary folic acid and acute immune responses after challenge with Escherichia coli lipopolysaccharide. Poult Sci. 2012;91(10):2454-63.

Tactacan GB, Rodriguez-Lecompte JC, O K, House JD. The adaptive transport of folic acid in the intestine of laying hens with increased supplementation of dietary folic acid. Poult Sci. 2012; 91:121-128.

Wu N, Sarna LK, Siow YL, O K. Regulation of hepatic cholesterol biosynthesis by berberine during hyperhomocysteinemia. Am J Physiol Regul Integr Comp Physiol. 2011;300:R635-43.

Hwang SY, Siow YL, Au-Yeung KK, House J, O K. Folic acid supplementation inhibits NADPH oxidase-mediated superoxide anion production in the kidney. Am J Physiol Renal Physiol. 2011 300:F189-198.

Siow YL, Petkau J, Sarna L, Enns J, O K. Berberine: biochemical analysis and cardiovascular benefits. In: Al-Mughrabi K (Ed) Plant science and biotechnology in North America: Focus on Canada. The Americas J Plant Sci Biotechnol 2011;5 (Special Issue 1): 121-126. (Review)

Siow YL, Sarna L, O K. Redox regulation in health and disease - therapeutic potential of berberine. Food Res Internat. 2011;44:2409-2417. (Review)

Wu N, Siow YL, O K. Ischemia/reperfusion reduces transcription factor Sp1-mediated cystathionine beta-synthase expression in the kidney. J Biol Chem. 2010;285:18225-18233.

Sarna LK, Wu N, Hwang SY, Siow YL and O K. Berberine Inhibits NADPH Oxidase Mediated Superoxide Anion Production in Macrophages. Can. J. Physiol Pharmacol 2010; 88: 369-378.

Wu N, Siow YL and O K. Induction of Hepatic Cyclooxygenase-2 by Hyperhomocysteinemia via Nuclear Factor kappa-B Activation. Am J Physiol Regul Integr Comp Physiol. 2009;297:R1086-1094.

Xu Z, Prathapasinghe GA, Wu N, Hwang SY, Siow YL and O K. Ischemia-reperfusion reduces cystathionine-beta-synthase mediated hydrogen sulfide generation in the kidney. Am J Physiol Renal Physiol. 2009; 297: F27- 35.

Prathapasinghe GA, Siow YL, Xu Z and O K. Inhibition of Cystathionine-beta-synthase activity during renal ischemia-reperfusion: Role of pH and Nitric Oxide. Am J Physiol Renal Physiol 2008; 295(4):F912-22.

Ganguly PK, Maddaford TG, Edel AL, O K, Smeda JS, Pierce GN. Increased homocysteine-induced release of excitatory amino acids in the striatum of spontaneously hypertensive stroke-prone rats. Brain Res. 2008;1226:192-198.

Cheung, YF, O K, Woo CWH, Armstrong S, Siow YL, Chow PC and Cheung EWY. Oxidative stress in children late after Kawasaki disease: relationship with carotid atherosclerosis and stiffness. BMC Pediatrics. 2008; 8:20, page 1-8; doi:10.1186/1471-2431-8-20.

Woo CWH, Siow YL and O K. Homocysteine induces monocyte chemoattractant protein-1 expression in hepatocytes mediated via AP-1 activation. J Biol Chem. 2008; 283: 1282-1292.

Cheung GTY, Siow YL and O K. Homocysteine stimulates monocyte chemoattractant protein-1 expression in mesangial cells via NF-kappa B &activation. Can. J. Physiol. Pharmacol. 2008;86:88-96.

Hwang SY, Woo CWH, Siow YL, Zhu TY and O K. Homocysteine stimulates monocyte chemoattractant protein-1 expression in the kidney via nuclear factor kappa B activation. Am J Physiol Renal Physiol 2008; 294:F236-244.

Edirimanne, VER, Woo, CWH, Siow YL, Pierce, GN, Xie JY and O K. Homocysteine stimulates NADPH oxidase-mediated superoxide production leading to endothelial dysfunction in hyperhomocysteinemic rats. Can. J. Physiol Pharmacol. 2007; 85: 1236-1247.

Prathapasinghe GA, Siow YL and O K. Detrimental role of homocysteine in renal ischemia/reperfusion injury. Am J Physiol Renal Physiol 2007;2925:F1354-63.

Au-Yeung KKW, O K., Choy PC, Zhu D and Siow YL. Magnesium tanshinoate B protects endothelial cells against oxidized lipoproteins-induced apoptosis. Can. J. Physiol Pharmacol. 2007; 85: 1053-1062.

Siow YL, Au-Yeung KKW, Woo CWH and O K. Homocysteine stimulates phosphorylation of NADPH oxidase p47phox and p67phox subunits in monocytes via protein kinase C-beta activation. Biochem J. 2006;398:73-82.

Woo CWH, Siow YL and O K. Activation of CREB by homocysteine in HepG2 is mediated via cAMP/PKA signaling pathway. Arterioscler Thromb Vasc Biol 2006;26:1043-1050.

Au-Yeung KK, Yip Johnny C.W. Siow YL and O K. Folic acid inhibits homocysteine-induced nuclear factor kappa B activation in macrophages. Can J Physiol Pharmacol 2006;84:141-147.

Woo CW, Prathapasinghe GA, Siow YL and O K. Hyperhomocysteinemia induces liver injury in rat: protective effect of folic acid supplementation. Biochim Biophys Acta Mol Basis of Disease 2006 Jul;1762(7):656-665.

Siow YL, Gong Y, Au-Yeung KK, Woo CW, Choy. PC and O K. Emerging issues in traditional Chinese medicine. Can. J. Physiol. Pharmacol 2005;83:321-334.

Woo CW, Siow YL, Pierce GN, Choy PC, Minuk GY, Mymin D and O K. Hyperhomocysteinemia induces hepatic cholesterol biosynthesis and lipid accumulation via activation of transcription factors. Am J Physiol Endocrinol Metab 2005; 288(5): E1002-1010.

Zhang F, Siow YL and O K. Hyperhomocysteinemia activates NF-kB and inducible nitric oxide synthase in the kidney. Kidney Int 2004;65:1327-1338.

Au-Yeung KKW, Woo CWH, Sung FL, Yip JCW, Siow YL and O K. Homocysteine stimulates nuclear factor kappa B activity through I?B kinase activating in vascular endothelial cells. Circ Res 2004;94:28-36.
Woo CWH, Cheung F, Chan, VWH, Siow YL and O K. Homocysteine stimulates iNOS expression in macrophages: Antagonizing effect of ginkgolides and bilobalide. Mol Cell Biochem 2003;243:37-47.

Wang G, Woo CWH, Sung FL, Siow YL and O K. Increased monocyte adhesion to aortic endothelium in rat with hyperhomocysteinemia: Role of chemokine and adhesion molecules. Arterioscler Thromb Vasc Biol 2002; 22:1777 - 1783.

Sung FL, Zhu TY, Au-Yeung KKW, Siow YL and O K. Enhanced MCP-1 expression during ischemia/reperfusion injury is mediated by oxidative stress and NF-kB. Kidney Int 2002; 62(4):1160-1170.

Zhu T, Au-Yeung KKW, Siow YL, Wang G and O K. Cyclosporine-A protects against apoptosis in ischaemic/reperfused rat kidneys. Clin Expt Pharmac Physiol 2002; 29(9):852-854.

Man RYK, Lynn EG, Cheung F, Tsang PSY and O K. Cholestin inhibits cholesterol synthesis and secretion in hepatic cells (HepG2). Mol Cell Biochem 2002; 233:153-158.

Tan, KCB, O K. Chow WS, Ai VHG, Siow YL, Lam KSL. Hyperhomocysteinemia and impaired vasomotor function in patients with type 2 diabetes mellitus. Eur J Clin Invest 2002; 32(5):328-334.

Lynn EG, Siow YL, Frohlich J, Cheung GTY and O K. Lipoprotein-X stimulates monocyte chemoattractant protein-1 expression in mesangial cells via nuclear factor-kB. Kidney Int 2001; 60:520-532.

Wang G and O K. Homocysteine stimulates the expression of monocyte chemoattractant protein-1 receptor CCR2 in human monocytes: possible involvement of oxygen free radicals. Biochem J 2001; 357:233-240.

Wang G, Siow YL and O K. Homocysteine-induced monocytes chemoattractant protein-1 expression in human monocytic cells is mediated by nuclear factor-kB activation. Am J Physiol 2001; 280:H2840-H2847.

Au-Yeung KKW, Zhu DY and O K. Siow YL. Inhibition of stress-activated protein kinase in the ischemic/reperfused heart: Role of magnesium tanshinoate B in preventing apoptosis. Biochem Pharmacol 2001; 62:483-93.

Cheung F, Siow YL and O K. Ginkgolides and bilobalide affect the production of nitric oxide in THP-1 macrophages but not in endothelial cells. Biochem Pharmacol 2001; 61:503-510.


Graduate students and fellows

Lindsei Sarna, PhD candidate (Department of Animal Science)
Peggy Wang, PhD candidate (Department of Animal Science)
Victoria Sid, PhD candidate (Department of Physiology and Pathophysiology)
Yvette Shang, PhD candidate (Department of Animal Science
Nan Wu, PhD (Department of Physiology and Pathophysiology, graduated in June 2014)Sun-Young Hwang, postdoctoral fellow (Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Research Centre)


  • ANSC 7390 Advanced Animal Science Seminar
  • ANSC 7510 Special Topics in Nutritional Biochemistry & Metabolism
  • ANSC 7540 / ANSC 4570 Advanced Applied Animal Nutrition
  • ANSC 2530 Nutritional Toxicology
  • IMED 7090 Cell Biology
  • PHGY 7030 Special Physiology(Part A, Part B)