Olamide O Crown | Federal University Of Technology Akure,Nigeria (original) (raw)

Papers by Olamide O Crown

Journal of Pharmacology and Toxicology, Jan 15, 2023

Atherosclerosis and its complications represent the major cause of death in developed countries. ... more Atherosclerosis and its complications represent the major cause of death in developed countries. Statins are inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A [HMGCoA] reductase and consequently inhibitors of cholesterol biosynthesis. Statins have been described as the most potent class of drugs to reduce serum cholesterol levels. In clinical trials, statins are beneficial in primary and secondary prevention of coronary heart disease. Statins, were initially designed as cholesterol-lowering drugs. However, these drugs, besides their lipid-lowering properties, exert a number of protective effects on the cardiovascular system that emerged over the past years. The benefits observed with statin treatment appear to be greater than that might be expected from reduction in lipid levels alone, suggesting effects beyond cholesterol lowering. These cholesterol-independent effects have been called "pleiotropic". The cholesterol-independent or "pleiotropic" effects of statins involve improvement of endothelial function, stability of atherosclerotic plaques, decrease of oxidative stress and inflammation, and inhibition of thrombogenic response. These pleiotropic effects of statins have been proposed as key properties of these drugs to reduce cardiovascular morbidity and mortality. The present review will emphasize the molecular mechanisms underlying the effects of statins on endothelial function and oxidative stress. In particular, inhibition of small GTP-binding proteins, Rho, Ras and Rac, which are regulated by isoprenoids [farnesyl pyrophosphate and geranylgeranyl pyrophosphate], seems to play an important role in mediating the pleiotropic effects of statins.

Circulation, 2001

Background Endothelial function is impaired in coronary artery disease and may contribute to its ... more Background Endothelial function is impaired in coronary artery disease and may contribute to its clinical manifestations. Increased oxidative stress has been linked to impaired endothelial function in atherosclerosis and may play a role in the pathogenesis of cardiovascular events. This study was designed to determine whether endothelial dysfunction and vascular oxidative stress have prognostic impact on cardiovascular event rates in patients with coronary artery disease. Methods and Results Endothelium-dependent and -independent vasodilation was determined in 281 patients with documented coronary artery disease by measuring forearm blood flow responses to acetylcholine and sodium nitroprusside using venous occlusion plethysmography. The effect of the coadministration of vitamin C (24 mg/min) was assessed in a subgroup of 179 patients. Cardiovascular events, including death from cardiovascular causes, myocardial infarction, ischemic stroke, coronary angioplasty, and coronary or peri...

NeuroToxicology, 2022

The neurobehavioral, brain redox-stabilizing and neurochemical modulatory properties of catechin ... more The neurobehavioral, brain redox-stabilizing and neurochemical modulatory properties of catechin and quercetin in rotenone-induced Parkinsonism, and the involvement of NF-κB-mediated inflammation, were investigated. Male Wistar rats subcutaneously administered with multiple doses of 1.5mg/kg rotenone were post-treated with 5-20mg/kg catechin or quercetin. This was followed by neurobehavioral evaluation, biochemical estimations, and assessment of neurotransmitter metabolism in the striatum. Expression of genes involved in the canonical pathway for the activation of NF-κB mediated inflammation (IL-1β, TNF-α, NF-κB, and IκKB) and the pro-apoptotic gene, p53, in the striatum was determined by RT-qPCR. Catechin and quercetin mitigated neurobehavioral deficits caused by rotenone. Both flavonoids attenuated striatal redox stress and neurochemical dysfunction, optimized disturbed dopamine metabolism, and improved depletion of neuron density caused by rotenone toxicity. While administration of catechin produced a more pronounced attenuating effect on IL-1β, TNF-α, and p53 genes, the attenuating effect of quercetin (20mg/kg) was more pronounced on NF-κB and IκKB gene expressions when compared to the group administered with rotenone only. Comparatively, quercetin demonstrated superior protection against rotenone neurotoxicity. It is concluded that catechin and quercetin have potential relevance in Parkinson's disease therapy through amelioration of redox stress, optimization of dopamine metabolism, and modulation of anti-inflammatory and anti-apoptotic pathways.

Nigerian journal of physiological sciences : official publication of the Physiological Society of Nigeria, 2019

Nephrotoxicity, with the attendant risk of progression to kidney failure, is a growing problem in... more Nephrotoxicity, with the attendant risk of progression to kidney failure, is a growing problem in many parts of the world. Current orthodox treatment options for nephrotoxicity and kidney failure are limited and there is need for alternative or complementary approaches. This study aimed at evaluating the effect of three structurally related flavonoids, catechin, quercetin and taxifolin on renal redox and metabolite biochemical disturbances in rotenone intoxicated animals. Male Wistar rats were administered 1.5 mg/kg rotenone (s.c.) for ten days followed by post-treatment with catechin (5, 10 or 20 mg/kg), quercetin (5, 10, or 20 mg/kg) and taxifolin (0.25, 0.5 or 1.0 mg/kg) (s.c.), for 3 days. Renal redox indices and levels of renal-related metabolites (creatinine, urea and uric acid) were assessed after sacrifice of animals. Catechin, quercetin and taxifolin significantly attenuated rotenone-induced effects on oxidative stress markers and metabolites linked to renal health. Querce...

Bioorganic & Medicinal Chemistry Letters, 2020

The number of reported cases of Human African Trypanosmiasis (HAT), caused by kinetoplastid proto... more The number of reported cases of Human African Trypanosmiasis (HAT), caused by kinetoplastid protozoan parasite Trypanosoma brucei, is declining in sub-Saharan Africa. Historically, such declines are generally followed by periods of higher incidence, and one of the lingering public health challenges of HAT is that its drug development pipeline is historically sparse. As a continuation of our work on new antitrypanosomal agents, we found that partially saturated quinoline-based vinyl sulfone compounds selectively inhibit the growth of T. brucei but displayed relatively weak inhibitory activity towards T. brucei's cysteine protease rhodesain. While two nitroaromatic analogues of the quinoline-based vinyl sulfone compounds displayed potent inhibition of T. brucei and rhodesain. The quinoline derivatives and the nitroaromatic-based compounds discovered in this work can serve as leads for ADME-based optimization and preclinical investigations.

European Journal of Medicinal Plants, 2018

Antiaris africana belongs to the family Moraceae, it is commonly called "False Iroko" tree and on... more Antiaris africana belongs to the family Moraceae, it is commonly called "False Iroko" tree and one of the medicinal plants used in treatment of mental and nervous disorders in Nigeria. We have previously established the neuroprotective properties of crude extract of A. africana. The present study was thus designed to investigate the neuroprotective effect of different solvent fractions of A. africana against cyanide neurotoxicity in vitro. Cyanide induced a significant (P<0.01) inhibition of NADH succinate dehydrogenase, a key enzyme in mitochondria function as well as significant increase in oxidative stress as observed in the high level of malonedialdehyde (MDA), protein carbonyl (PC) and activity of monoamine oxidase (MAO) and decreased concentration of reduced glutathione (GSH) as compared to the control. Co-administration with different solvent fractions of Original Research Article

African Journal of Urology, 2020

Background Moonseed vine (Triclisia gilletii Staner) in the family Menispermaceae is a robust cre... more Background Moonseed vine (Triclisia gilletii Staner) in the family Menispermaceae is a robust creeper of up to 10 cm diameter, of the lowland dense rain forest. In Ondo State, located in the South Western part of Nigeria, the plant which is usually called Peshe is used for the management of renal-related ailments. The present study was undertaken to explore the efficacy of Triclisia gilletii, a folkloric therapy in the management of renal-related ailment. Results Phenols, steroids, saponins, and flavonoids are present in the TGME with a total antioxidant capacity of (30.36 ± 1.90 (mg GAE/g extract), LD50 greater than 5000 mg/kg b.w., and in vitro anti-nucleation activity (iC50 = 7.09 mg/mL). Calcium oxalate stone formation as a result of oxalate from ethane-1,2-diol was evident by hypocalcemia, and further electrolyte imbalance and decreased glomerular filtration rate. The enhanced oxidative milieu in hyperoxaluria was evident by increased MDA and PC and decreased enzymatic and non-...

International Journal of Engineering Applied Sciences and Technology, 2019

Garcinia kola is called a wonder plant in forklore medicine because every part of the plant has t... more Garcinia kola is called a wonder plant in forklore medicine because every part of the plant has therapeutic value. This study aimed at investigating the hepatoprotective and antidyslipidemic activities of methanolic extract of Garcinia kola leaves in streptozotocin-induced diabetic rats. The animals were divided into seven groups of six animal each: vehicle; 100 mg/kg Garcinia kola leaf extract; 200 mg/kg Garcinia kola leaf extract; untreated diabetic group; treated diabetic group administered 100 mg/kg Garcinia kola leaf extract; treated diabetic group administered 200 mg/kg Garcinia kola leaf extract; and treated diabetic group administered glibenclaimide 0.5 mg/kg. Results for serum lipid profile showed a significant decrease in triglyceride, total cholesterol, very low density lipoprotein-cholesterol and low density lipoprotein-cholesterol as well as a significant increase in high density lipoprotein cholesterol in the extract treated diabetic groups compared to the untreated diabetic group. Similarly, a significant increase in the antioxidant activity of hepatic catalase as well as a significant decrease in lipid peroxidation were also observed in the extract treated diabetic rats compared to the untreated rats. Histopathological examination of the hepatic tissues of the extract treated diabetic rats showed active regeneration of the hepatocytes, well preserved architecture and the absence of lesions and necrosis compared to the untreated group which showed severe necrosis, inflammation and degeneration of hepatocytes. The extract showed better improvement in treating diabetes-induced dyslipidemia and liver damage compared with the standard antidiabetic drug, glibenclaimide. This study suggests that Garcinia kola leaves might be an effective phytotherapy for treating diabetes-induced complications.

Heliyon, 2019

Studies have shown that diesel exhaust particles (DEP) induced oxidative stress and inflammation.... more Studies have shown that diesel exhaust particles (DEP) induced oxidative stress and inflammation. This present study examined the molecular effects of aqueous rooibos extract (RE) on the cardiovascular toxic effect of methanol extract of DEP in exposed Wistar rats. The results showed that DEP caused significant (p < 0.001) increase in MDA and CDs levels in the aorta and heart but this increase was significantly (p < 0.001) attenuated by rooibos extract. DEP

African Journal of Biochemistry Research, May 31, 2014

The antidenaturation and antioxidant properties of Spondias mombin Linn (Anacardiaceae) methanol ... more The antidenaturation and antioxidant properties of Spondias mombin Linn (Anacardiaceae) methanol leaf extract (SMC) and fractions prepared from it were evaluated in this study. SMC and its fractions: ether (SME), saponin-rich (SMS) and flavonoid-rich (SMF) were phytochemically screened and evaluated for total antioxidant activity (TAA), ability to inhibit deoxyribose degradation (DEO), lipid peroxidation inhibitory activity (LPIA), 2,2-diphenyl-1-picryl hydrazyl scavenging activity, ability to chelate ferrous ions and protein denaturation inhibitory activity (PRO). The antioxidant and antidenaturation activities were in the order SME > SMF > SMC > SMS. TAA strongly correlated with DEO, LPIA and PRO. The results indicate that S. mombin contains a diverse array of phytochemicals with potent antioxidant and bio-preservative properties which can serve as candidates for food preservation and drug development.

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences, 2015

Abstract In the present study, toxicity of the alkaloid extract and crude methanol extract of Par... more Abstract In the present study, toxicity of the alkaloid extract and crude methanol extract of Parinari curatellifolia seeds and their anti-hyperlipidemic effect in Triton X-1339 intoxicated rats were investigated. Triton (200 mg/kg i.p)-induced hyperlipidemic rats were treated with nicotinic acid (500 mg/kg), alkaloid extract (15 mg/kg) or crude extract (150 mg/kg) by gavage for 10 days following which biochemical and histological analyses were carried out on heart, aorta and sera of the animals. Administration of triton led to increased levels of total cholesterol and triglycerides, low/very low density lipoproteins, and promoted cardiac oxidative stress. In addition, high density lipoprotein level was decreased while coronary and atherogenic risk indices were increased. The alkaloid extract (15 mg/kg) and crude methanol extract (150 mg/kg) significantly (P < 0.001) salvaged triton-induced effects on cardiac antioxidant status, total cholesterol (41 and 36 %), triglyceride (53 and 42 %), low density lipoprotein (80 and 79 %), very low density lipoprotein (53 and 41 %), high density lipoprotein (50 and 166 %), coronary risk index (97 and 86 %) and atherogenic risk index (90 and 94 %) as comparable to the reference compound, nicotinic acid. In addition, improved heart and aortic histological architecture were observed in rats treated with both extracts. The present results revealed the antihyperlipidemic, antiatherogenic and antioxidant effects of P. curatellifolia alkaloids in triton-induced hyperlipidemic rats and indicate their potential usefulness as a source of hypolipidemic and anti-atherogenic drugs.

Food Science and Human Wellness, 2015

The effects of ethylacetate extract of red onion (Allium cepa) tunic (ACTE) on some hemodynamic a... more The effects of ethylacetate extract of red onion (Allium cepa) tunic (ACTE) on some hemodynamic and biochemical parameters were evaluated in normotensive albino rats. Blood pressure parameters were determined in anaesthetized rats orally administered ACTE (10-, 20-, or 40 mg/kg) or ramipril (1 mg/kg) once daily for 14 days. Respectively, 10-, 20-, or 40 mg/kg ACTE produced significant (P < 0.01), dose-dependent fall in systolic blood pressure, SBP (21%, 27%, 33%), diastolic blood pressure, DBP (6%, 10%, 16%), pulse pressure, PP (42%, 49%, 56%), mean arterial blood pressure, MAPB (13%, 18%, 23%) and heart rate, HR (4%, 5%, 7%). The highest effective dose (40 mg/kg) compared well with ramipril (1 mg/kg) with regards to SBP (41%), DBP (19%), PP (70%), MABP (29%) and HR (10%). Similar trends (decreases) were recorded for 40 mg/kg ACTE and ramipril, respectively, as regards the activities of serum enzymes: creatine kinase (60% and 65%), ALT (18% and 14%) and ALP (28% and 16%). HPLC fingerprints of the flavonoid-rich ACTE revealed that flavonols: quercetin, quercitrin, isoquercitrin, rutin and kaempferol are the active flavonoids. The results demonstrate the hypotensive effect of A. cepa tunic flavonoids initiating further investigation of their individual or synergistic contribution(s) to the observed effects.

Asian Pacific Journal of Tropical Medicine, 2013

Human & Experimental Toxicology, 2013

Rutin and quercetin were investigated for their effects on blood pressure and antioxidant defense... more Rutin and quercetin were investigated for their effects on blood pressure and antioxidant defense system of rats fed with 8% sodium chloride-supplemented diet (high salt diet) for 6 weeks. Animals fed with high salt diet demonstrated an increase in systolic, diastolic, pulse, and mean arterial blood pressures ( p < 0.05) as well as lipid peroxidation but decreases in the activities of antioxidant enzymes compared with control group. Groups post-treated with rutin and quercetin for 2 weeks showed significant reversals in the values of these indices compared with the group fed with only the high salt diet but not post-treated. The high salt diet also led to significant increase in serum glucose, urea, creatinine, triglycerides, low-density-lipoprotein, and total cholesterol concentrations. Treatment with rutin and quercetin ameliorated the effects of high salt diet on these biochemical indices. The reference standard, nifedipin was less effective than rutin and quercetin. The resul...

Molecules, 2021

Malaria remains a significant cause of morbidity and mortality in Sub-Saharan Africa and South As... more Malaria remains a significant cause of morbidity and mortality in Sub-Saharan Africa and South Asia. While clinical antimalarials are efficacious when administered according to local guidelines, resistance to every class of antimalarials is a persistent problem. There is a constant need for new antimalarial therapeutics that complement parasite control strategies to combat malaria, especially in the tropics. In this work, nopol-based quinoline derivatives were investigated for their inhibitory activity against Plasmodium falciparum, one of the parasites that cause malaria. The nopyl-quinolin-8-yl amides (2–4) were moderately active against the asexual blood stage of chloroquine-sensitive strain Pf3D7 but inactive against chloroquine-resistant strains PfK1 and PfNF54. The nopyl-quinolin-4-yl amides and nopyl-quinolin-4-yl-acetates analogs were generally less active on all three strains. Interesting, the presence of a chloro substituent at C7 of the quinoline ring of amide 8 resulted ...

Asian Pacific Journal of Tropical Biomedicine

Abstract Objective To explore the possible inhibitory potentials and mechanism by Mobola plum (Pa... more Abstract Objective To explore the possible inhibitory potentials and mechanism by Mobola plum (Parinari curatellifolia) seeds crude methanol (CE) and flavonoid-rich (FE) extracts on angiotensin-1-converting enzyme (ACE Ⅰ). Methods The sensitivity and kinetic model of inhibition of CE and FE on ACE Ⅰ using N-[3-(2-furyl)-acryloyl]-Phe-Gly-Gly as enzyme substrate for ACE Ⅰ was evaluated by Michealis Menten approach. The inhibition mechanism was explored from Lineweaver–Burk model and IC50 was determined from Cheng–Prusoff empirical analysis. Results The IC50 of CE and FE were 13.54 and 39.38 μg/mL, respectively. Both extracts exhibited mixed type inhibition with the inhibitory constant (Ki) of CE was between 0.38 and 0.37 μg/mL while that of FE showed a two-fold increase (1.62 μg/mL and 0.28 μg/mL). FE on ACE Ⅰ demonstrated positive cooperativity with a Hill's coefficient of 1.89. Conclusions The study reveals the superior ACE Ⅰ inhibitory potential of CE over FE and suggest that mixed inhibition pattern of the enzyme might be the underlying mechanism of antihypertensive activity.

$Research paper thumbnail of Neuromodulatory effect of solvent fractions of Africa eggplant (Solanium dadyphyllum) against KCN-induced mitochondria damage, viz. NADH-succinate dehydrogenase, NADH- cytochrome c reductase, and succinate-cytochrome c reductase$

Background: In the past few years, there has been a tremendous increase in the number of plant-ba... more Background: In the past few years, there has been a tremendous increase in the number of plant-based health supplements with respect to their safety and efficacy in diseases treatment and prevention. Solanum dasyphyllum, also known as Africa eggplant is ethnomedicinally used as an antivenom, pain reliever and anticonvulsant in various part of Nigeria, however, there is no scientific data to support some of these claims. Methods: This study evaluated the protective effect of solvent fractions of Solanum dasyphyllum, hexane fraction of S. dasyphyllum (HFSD), dichloromethane fraction of S. dasyphyllum (DFSD), ethylacetate fraction of S. dasyphyllum (EAFSD), methanolic fraction of S. dasyphyllum (MFSD) and crude fraction of S. dasyphyllum (CFSD) on cyanideinduced oxidative stress and neurotoxicity in vitro in the cerebral cortex. Neuroprotective activities were evaluated by assaying for markers of oxidative stress, neurotoxicity and electron transport system enzymes via evaluating lipid peroxidation (LPO), protein carbonyl (PC), reduced glutathione (GSH), acetylcholinesterase (AChE), NADH-succinate dehydrogenase (NSD), NADH-cytochrome c reductase (NCR), and succinate-cytochrome c reductase (SCR) in the homogenate of cerebral cortex.

Nigerian Journal of Natural Products and Medicine

Comparative Clinical Pathology