Chukwuemeka R Nwokocha |
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PhD Medical Physiology, PhD En...
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15.06
Research experience
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Jan 2011–
presentTeaching: The University of the West Indies, Mona
The University of the West Indies, Mona · Department of Basic Medical SciencesJamaica · Kingston
Questions and Answers (1) View all
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Question asked in Interventional Cardiology1 What are the genes of interest for potassium and calcium ion channel function in vascular smooth muscle function and reactivity?For PCR and western blot determination of protein expressions.For PCR and western blot determination of protein expressions.By Chukwuemeka Nwokocha · The University of the West Indies at MonaFollowing
Publications (28) View all
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Article: Comparative study on the hepatoprotection to heavy metals of Zingiber officinale.
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ABSTRACT: Zingiber officinale (Zingiberaceae) is a herb used for culinary and therapeutic purposes due to its anti-inflammatory and antioxidant potentials. We examined its protective ability against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. MATERIALS #ENTITYSTARTX00026; Ground Zingiber officinale (7%, w/w of feed) was administered to rats either at the same time with the exposure ofheavy metals (group 2), a week after exposure to heavy metals (group 3) or given a week before heavy metal exposure (group 4) for six weeks. Animals were exposed to either of Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) in drinking water. The heavy metal accumulations in the liver were determined using AAS. Weight losses induced by these metals were not reversed by Zingiber officinale administration. There was a significant (P<0.01) increase in protection to Pb (97%) and Cd (63%) accumulation when compared to Hg (32%) at week 2. The protective ability was significantly (P<0.01) decreased at week 4 when compared to week 2 for Cd and Pb but not to Hg in groups 3 (50%) and 4 (52%). At week 6, hepatoprotection to Hg (44%) and Cd (85%) was significantly (P<0.01) different but not to Pb which was only significant (P<0.05) in week 2 of treatment for all groups. Zingiber officinale affected the bioavailability, elimination and uptake of these metals in a time-dependent way with highest beneficial reducing effect to Cd followed by Hg and least protection to Pb in the liver.Pharmacognosy research. 10/2012; 4(4):208-13. -
SourceAvailable from: Chukwuemeka R Nwokocha
Article: Comparative analysis on the effect of palm oil (Elaeis guineensis) in reducing cadmium and lead accumulation in liver of Wistar rats.
Chukwuemeka R Nwokocha, Magdalene I Nwokocha, Daniel U Owu, Joshua Obi, Bukola Olatunde, Chioma Ebe, Ozioma Nwangwu, Moses O Iwuala[show abstract] [hide abstract]
ABSTRACT: Palm oil from Elaeis guineensis is an edible nutrient substance with anti-inflammatory and antioxidant properties. We examined its protective effect against lead (Pb) and cadmium (Cd) accumulation in the liver. 12% w/w of palm oil (PO) in rat chow concentrate was fed to rats exposed to Cd (200ppm) and Pb (100ppm) in drinking water at different feeding regimens. PO was administered either at the same time with the metals (group 2), post-treatment after exposure (group 3) or pre-treatment before exposure (group 4) for six weeks. The heavy metal accumulations in the liver were determined using AAS. Weight losses induced by these metals were significantly (P<0.05) reversed by PO administration. Analysis among the groups showed that post-treatment group had a significant (P<0.05) higher percentage protection to Cd, but same time treatment for Pb (P<0.05) when compared with other groups. The protective ability to PO was only significantly (P<0.05) increased for Pb at week 2, but showed a time-dependent significant (P<0.05) increase for Cd across all treatment regimens. PO is beneficial in reducing metal accumulation in the liver and has a higher hepatoprotective effect to Cd compared to Pb at the selected doses by possibly affecting the processes of uptake, assimilation and elimination of these metals.Pharmacognosy research. 10/2012; 4(4):214-8. -
SourceAvailable from: Chukwuemeka R Nwokocha
Article: Possible mechanisms of action of the hypotensive effect of Annona muricata (soursop) in normotensive Sprague-Dawley rats.
Chukwuemeka R Nwokocha, Daniel U Owu, Angeline Gordon, Karen Thaxter, Garsha McCalla, Raymond I Ozolua, Lauriann Young[show abstract] [hide abstract]
ABSTRACT: Context: Annona muricata Linn (Annonaceae) (soursop) is a food plant reported to have antihypertensive properties. Objective: We investigated the blood pressure reducing effect of its aqueous leaf extract and the possible mechanisms that may be responsible. Methods: Intravenous administration of an aqueous leaf extract (9.17-48.5 mg/kg) of A. muricata on the mean arterial pressure and heart rate were recorded invasively on anaesthetized, normotensive Sprague-Dawley rats. Contractile responses of rat aortic rings to the extract (0.5-4.0 mg/mL) were studied using standard organ bath techniques. Results: A. muricata (9.17-48.5 mg/kg) caused significant (p < 0.05) dose-dependent reduction in blood pressure without affecting the heart rates. The hypotensive effects were unaffected by atropine (2 mg/kg), mepyramine (5 mg/kg), propranolol (1 mg/kg) and L-NAME (5 mg/kg). A. muricata leaf aqueous extract significantly (p < 0.05) relaxed phenylephrine (10(-9)-10(-4) M) and 80 mM KCl induced contractions in endothelium intact and denuded aortic rings; and caused a significant (p < 0.05) rightward shift of the Ca(2+) dose response curves in Ca(2+)-free Kreb's solution containing 0.1 mM EGTA. Conclusions: The hypotensive effects of A. muricata are not mediated through muscarinic, histaminergic, adrenergic and nitric oxide pathways, but through peripheral mechanisms involving antagonism of Ca(2+).Pharmaceutical Biology 09/2012; 50(11):1436-41. · 0.88 Impact Factor -
SourceAvailable from: Chukwuemeka R Nwokocha
Article: Possible mechanisms of action of the aqueous extract of Artocarpus altilis (breadfruit) leaves in producing hypotension in normotensive Sprague-Dawley rats.
Chukwuemeka R Nwokocha, Daniel U Owu, Michca McLaren, Jeann Murray, Rupika Delgoda, Karen Thaxter, Garsha McCalla, Lauriann Young[show abstract] [hide abstract]
ABSTRACT: Artocarpus altilis (Parkinson) Fosberg (Moraceae) (breadfruit) leaves are used as an antihypertensive remedy. We investigated the possible mechanisms of action of its aqueous extract and its effect on cytochromes P450 (CYP) enzyme activities. Intravenous administration of an aqueous leaf extract (20.88-146.18 mg/kg) of A. altilis on mean arterial pressure and heart rate were recorded via cannulation of the carotid artery on anaesthetized normotensive Sprague-Dawley rats. Recordings of the contractile activity of the aortic rings to the extract (0.71-4.26 mg/mL) were studied using standard organ bath techniques. Inhibitions of human CYP3A4 and CYP2D6 enzyme activities were evaluated by means of a fluorometric assay in 96 well plates using heterologously expressed microsomes. A. altilis caused significant (p < 0.05) hypotensive and bradycardiac responses unaffected by atropine (2 mg/kg) and mepyramine (5 mg/kg), but attenuated by propranolol (1 mg/kg) and N(G)-nitro-L-arginine methyl ester (5 mg/kg). The extract (0.71-4.26 mg/mL) significantly (p < 0.05) relaxed phenylephrine (10⁻⁹-10⁻⁴ M) and 80 mM KCl-induced contractions in endothelium intact and denuded aortic rings; and caused a significant (p < 0.05) rightward shift of the Ca²⁺ dose-response curves in Ca²⁺-free Kreb's solution. Moderate inhibitions of cytochrome P450s (CYP3A4 and CYP2D6) enzyme activities with IC₅₀ values of 0.695 ± 0.187 and 0.512 ± 0.131 mg/mL, respectively, were produced. A. altilis exhibits negative chronotropic and hypotensive effects through α-adrenoceptor and Ca²⁺ channel antagonism. Drug adversity effects are unlikely if the aqueous leaf extract is consumed with other medications reliant on CYP3A4 and CYP2D6 metabolism. This study thus provides scientific evidence for the use of the breadfruit in the treatment of hypertension.Pharmaceutical Biology 07/2012; 50(9):1096-102. · 0.88 Impact Factor -
SourceAvailable from: Chukwuemeka R Nwokocha
Article: Comparative analysis on the effect of Lycopersicon esculentum (tomato) in reducing cadmium, mercury and lead accumulation in liver.
Chukwuemeka R Nwokocha, Magdalene I Nwokocha, Imaria Aneto, Joshua Obi, Damian C Udekweleze, Bukola Olatunde, Daniel U Owu, Moses O Iwuala[show abstract] [hide abstract]
ABSTRACT: L. esculentum (tomato) contain compounds with anti-oxidant and anti-inflammatory properties, able to synthesize metal chelating proteins. We examined the ability of fruit extract to protect against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. Rats were fed on tomato mixed with rat chow (10% w/w), while Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) was given in drinking water. Tomato was administered together with the metals (group 2), a week after exposure (group 3) or a week before metal exposure (group 4) for a period of six weeks. The metal accumulations in the liver were determined using AAS. There was a significant (P<0.05) increase in protection by tomato to Cd and Hg accumulation but not to Pb (P<0.05) in weeks 2 and 4 for groups 2 and 3. The protective ability was significantly (P<0.05) increased for Pb in group 4, but was less comparable to Cd and Hg. Tomato reduces uptake while enhancing the elimination of these metals in a time dependent manner. The highest hepatoprotective effect was to Cd followed by Hg and least to Pb. Its administration is beneficial in reducing heavy metal accumulation in the liver.Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 04/2012; 50(6):2070-3. · 2.99 Impact Factor