Solomon Owumi, Ph.D.

Postdoctoral Research fellow

Research

HIV studies

Glucose transporter-1 (Glut-1), a receptor for human T-cell leukemia virus (HTLV). HTLV is similar to the human immunodeficiency virus-1 (HIV-1). We show that Glut-1 (an isotope of the glucose carrier) is up-regulated in PBMC treated with Tat and this is much so evident at 5% oxygen tension (physiologic oxygen) compared to 20% oxygen tension (normoxic conditions). Glut-1 induction may be a mechanism for viral entry into T-cells in HIV infection and disease pathogenesis.

CD3-expressing human null cells. We are currently phenotyping a previously unidentified subset of CD3+ve lymphocytes (null cells) that emerge from CD3-ve population when stimulated with Tat. Upon Tat treatment, these ''Null cells" tend to appear after 16-24 hours and disappear at 48hrs. 

Acetaminophen-APAP (Tylenol) studies

N-acetyl-p-amino-phenol (acetaminophen, APAP, Tylenol) overdose causes damage to the liver. We demonstrate that oral administration of equimolar APAP and N-acetylcysteine (NAC) formulation can mitigate toxicity up to 600mg/Kg body weight. The prospect of an APAP-NAC drug becoming available as an over the counter (OTC) may reduce the dangers associated with inadvertent APAP (Tylenol) overdose.

APAP, an OTC analgesic drug, is the most widely studied hepatotoxicant, though its regioisomer 3-amidophenol (AMAP) appears to be relatively safe. APAP overdose results in liver injury, acute liver failure and over 450 deaths yearly in the United State. Implicated in these series of adverse effect is N-acetyl-p-benzoquinone imine (NAPQI), a reactive metabolite from a fraction of APAP metabolism. Conjugation of NAPQI with glutathione (GSH) leads to its biliary excretion and GSH depletion. Accumulation of NAPQI and its binding to cellular macromolecules have been implicated in APAP toxicity. Consequently, Kupffer cells (KC) activation and neutrophil recruitment may exacerbate this situation. NAC from inception in the 1970 is an effective antidote to APAP toxicity, still finds relevance in the management of accidental or suicidal APAP overdose.

Publications

Toxicity associated with repeated administration of artemether-lumefantrine in rats. Michael. A. Gbadegesin, Solomon E. Owumi, Oyeronke A. Odunola, Ayodeji M. Adegoke and Anthony O. Uwaifo. Environ Toxicol. Accepted for publication.

Protective effect of Juglans nigra on sodium arsenite-induced toxicity in rats. Owumi SE, Odunola OA, Gbadegesin MA, Nulah KL. Pharmacognosy Res. 2013 Jul;5(3):183-8. PMID: 23901214.

Induction of micronuclei in bone marrow cells and hepatotoxicity of one of the most common over-the-counter pyrethriod insecticide products in Nigeria. Odunola, Oyeronke A.; Gbadegesin, Michael A.; Owumi, Solomon E.; Somade, Oluwatobi T. Toxicological and Environmental Chemistry, Volume 94, Number 9, 1 October 2012 , pp. 1822-1831(10

Depletion of Kupffer cells modulates ethanol-induced hepatocyte DNA synthesis in C57Bl/6 mice. Owumi SE, Corthals SM, Uwaifo AO, Kamendulis LM, Klaunig JE. Environ Toxicol. 2012 Sep 20. PMID: 22996800.

Co-administration of sodium arsenite and ethanol: Protection by aqueous extract of Aframomum longiscapum seeds. Owumi SE, Odunola OA, Aliyu M. Pharmacognosy Res. 2012 Jul;4(3):154-60. PMID: 22923953.

Aflatoxin B₁ and ethanol co-exposure induces hepatic oxidative damage in mice. Adedara IA, Owumi SE, Uwaifo AO, Farombi EO. Toxicol Ind Health. 2010 Nov;26(10):717-24. PMID: 20837563.

Petroleum Refining Chemicals enhances aflatoxin B1-induced Toxicities in Wistar Rats. Oyeronke A. Odunola, Michael A. Gbadegesin, Solomon E. Owumi and Anthony O. Uwaifo. Journal of Medical Sciences. 2007: 7(4):615-619.