Browsing by Author "Asare, G. A."
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Item African diet: A toxic/protective dilemma(Transworld Research Network, Kerala, India, 2009) Mossanda, K.S.; Asare, G. A.Food shortages and high prevalence of poverty-related chronic diseases including HIV/AIDS, malaria and tuberculosis have culminated in health crisis in African continent. The diet of the majority of African populations consists largely of maize and cassava flour. Apart from being deficient in essential amino-acids, important vitamins and micronutrients, maize and cassava flour are prone to fungal infestation and thus to contamination by mycotoxins which increases the risk of cancer development mostly in HIV/AIDS individuals. In addition, digestive cancers and especially squamous cell carcinoma of the oesophagus (SCCE) are become the most common cancers in Southern African black men (incidence: 14.5%). Among other factors including hepatitis B and C, excessive intake of dietary iron as a result of drinking homebrewed in iron pots constitutes one of the most important factors leading into hepatocellular carcinoma (HCC). Alcohol consumption has been also implicated in the aetiology of both SCCE associated with cigarette smoking, low intake of dietary antioxidants, consumption of compounds such as polycyclic hydrocarbons, nitrosamines, heterocyclic amines found in African diet and HCC associated with increased hepatic iron stores inducing successively fibrosis and cirrhosis which finally progress into liver cancer. Despite our progress in antioxidant, environmental, genetic and carcinogenic studies, the mechanism of induction of those two types of cancer is still not fully understood. Our histological findings and the immuno-histochemistry evidence of DNA damage by the presence in situ (biopsies) of 8-hydroxy-deoxyguanosine (8-OHdG) and that of lipid peroxidation by the presence in situ of 4-hydroxy-nonenal (4-HNE) increasing with the disease progression, have provided a consistent correlation between low intake of dietary antioxidant and the occurrence of carcinoma. In contrast to those toxicological aspects of African diet leading to the occurrence of digestive and liver cancers in African populations, an expanding body of evidence from epidemiological and laboratory studies demonstrated that edible plant as whole, or their ingredients have substantial protective effects on human carcinogenesis. We have recently demonstrated the anti-oxidative and anti-mutagenic properties of some African indigenous edible plants: Bambara groundnut (Vignea subterranean) and beverage: Rooi bos tea (Aspalathus linearis). Their chemo-preventive and antiinflammatory activities have been tested in cell culture using human breast epithelial (MCF-10A) cells and in animal model using mouse skin. Methanolic extracts of some other African plants (Sutherlandia fructescens and Harpagophytum procumbens) used as beverages showed inhibition of 12-O-tetradecanoyl-phorbol-13 acetate (TPA)- induced cyclo-oxygenase (COX-2) expression in mouse skin, which appears to be mediated through blocking of catalytic activity of extracellular signal-regulated protein kinase (ERK) and through inhibition of activator protein-1 (AP-1) and cylic AMP response element binding (CREB) protein activation, suggesting their chemopreventive and chemo-protective activities. Due to the fact that inhibition of COX-2 is now regarded as an effective and promising strategy for prevention of anti-inflammatory process precluding the initiation and tumor stage, more research on African food plants and beverages should be conducted using this strategy in order to understand the molecular mechanism underlying those specific activities. In the light of these data, the extensive use of African foodstuffs and beverage bearing preventive and protective factors should be recommend in the diet of African populations for reducing the incidence of digestive and liver cancers in those areas.Item Effect of hormonal contraceptives on lipid profile and the risk indices for cardiovascular disease in a Ghanaian community(University of Ghana, 2014-06) Asare, G. A.; Santa, S.; Ngala, R.A.; Asiedu, B.; Afriyie, D.; Amoah, A. AB.Background: Hormonal contraceptives (HCs) have been shown to alter lipid profile among various population groups with different patterns of dyslipidemia and cardiovascular (CV) risk. The study aimed at determining the lipid profile pattern and CV risk in a Ghanaian cohort. Methods: Purposive random sampling was done. Forty-seven and 19 cases were on oral contraceptives (OCs) and injectable contraceptives (ICs), respectively; five were on subdermal implant. Twenty-four non-users served as controls. Biodemographic and lipid profiles were determined. Total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), and very-low-density lipid lipoprotein cholesterol (VLDLC), were determined. Castelli index I and II were calculated. Results: The mean age difference between the HC and control groups was insignificant. However, diastolic blood pressure (BP) differences were significant (P=0.006). The body mass index (BMI) of the OC and IC groups were significantly different from the control group (P=0.003 and P=0.008, respectively). TC levels for the control and case groups were 3.35±0.62 mmol/L and 4.07±0.91 mmol/L, respectively (P=0.002). LDLC levels for the control and case groups were 1.74±0.57 mmol/L and 2.38±0.84 mmol/L, respectively (P=0.003). Castelli index I (TC/HDLC) and II (LDLC/HDLC) were significantly different between the control and OC groups (P=0.026 and P=0.014, respectively). Spearman’s rho correlation showed significant influence of HC use on TG (P=0.026), TC (P=0.000), LDLC (P=0.004), and VLDLC (P=0.026) over time. Conclusion: HC use is associated with significant increases in BMI, diastolic BP, TC, LDLC, and Castelli index I and II. These changes carry a potential risk in the development of CV disease.Item Effects of exogenous antioxidants on dietary iron overload.(The Society for Free Radical Research, Japan, 2009) Asare, G. A.; Kew, M.C.; Mossanda, K.S.; Paterson, A.C.; Siziba, K.; Kahler-Venter, C.P.In dietary iron overload, excess hepatic iron promotes liver damage. The aim was to attenuate free radical-induced liver damage using vitamins. Four groups of 60 Wistar rats were studied: group 1 (control) was fed normal diet, group 2 (Fe) 2.5% pentacarbonyl iron (CI) followed by 0.5% Ferrocene, group 3 (Fe + V gp) CI, Ferrocene, plus vitamins A and E (42x and 10x RDA, respectively), group 4 (Fe - V gp) CI, Ferrocene diet, minus vitamins A and E. At 20 months, glutathione peroxidase (GPx), superoxide dismutase (SOD), Oxygen Radical Absorbance Capacity (ORAC), Ames mutagenicity test, AST, ALT and 4-hydroxynonenal (4-HNE) immunohistochemistry were measured. 8OHdG levels of the Fe + V and Fe - V groups were 346 +/- 117 and 455 +/- 151, ng/g w.wt, respectively. Fe + V and Fe - V differences were significant (p<0.005). A positive correlation between DNA damage and mutagenesis existed (p<0.005) within the iron-fed gps. AST levels for Fe + V and Fe - V groups were 134.6 +/- 48.6 IU and 202.2 +/- 50.5 IU, respectively. Similarly, ALT levels were 234.6 +/- 48.3 IU and 329.0 +/- 48.6 IU, respectively. However, Fe - V and Fe + V groups transaminases were statistically insignificant. 4-HNE was detected in Fe + V and Fe - V gp livers. Vitamins A and E could not prevent hepatic damage.Item Possible adverse effect of high delta-alpha-tocopherol intake on hepatic iron overload: enhanced production of vitamin C and the genotoxin, 8-hydroxy-2'- deoxyguanosine.(Informa healthcare, UK, 2010-04) Asare, G. A.; Ntombini, B.; Kew, M.C.; Kahler-Venter, C.P.; Nortey, E.N.Excess hepatic iron generates reactive oxygen species that result in oxidative stress and oxidative damage to the liver. Vitamins have hitherto been considered to be a possible remedy. The aim of this study was to determine if high doses of delta-alpha-tocopherol supplementation in iron overload would ameliorate the oxidative stress. Four groups of 20 male Wistar albino rats were studied: group 1 (control) was fed normal diet, group 2 (Fe) 0.75% Ferrocene iron, group 3 (FV gp) 0.75% Ferrocene/delta-alpha-tocopherol (10x RDA), group 4 (V gp) normal diet/delta-alpha-tocopherol. After 12 months, serum iron, reduced glutathione, catalase, vitamin C, Oxygen Radical Absorbance Capacity, lipid peroxidation, 8-hydroxy-2'-deoxyguanosine (8-OHdG), aspartate transaminase (AST), and alanine transaminase (ALT) were measured. Vitamin C levels were: F gp = 5.04 +/- 0.09; FV gp = 5.85 +/- 0.13 (micromol/l) (p < 0.05). 8-hydroxy-2'-deoxyguanosine levels were: F gp = 143.6 +/- 6.4; FV gp = 179.2 +/- 18.2 (ng/ml) (p < 0.05). Oxidative liver damage, as determined by serum AST and ALT levels, was not attenuated by alpha-tocopherol. A positive correlation existed between vitamin C and 8-OHdG, suggesting possible delta-alpha-tocopherol toxicity.Item Serum levels of Cu, Se, and Zn in adult rural/urban residents in Ghana: paradigm shift?(Human Press, 2010-11) Asare, G. A.; Nani, A.Deficiencies in Cu, Se, and Zn impair one or more biochemical functions, and excess are associated with toxicity. Baseline studies on the Ghanaian population are scanty. The study was undertaken to determine whether significant rural/urban differences in the serum levels of Cu, Se, and Zn did exist. Forty males/60 females from rural and 50 males/50 females from urban Ghanaian communities were sampled. Serum Cu, Se, and Zn were determined using flame atomic absorption spectrometry. Cu level for rural and urban subjects was 997 +/- 333 and 979 +/- 290 microg/L, respectively (p = 0.68). However, Cu levels were significantly higher in the rural females (1,063 +/- 367 microg/L) than the rural males (898 +/- 249 microg/L; p = 0.0085). Se levels for rural/urban subjects were 97 +/- 36 and 87 +/- 31 microg/L, respectively (p = 0.03). Zn levels in the rural/urban subjects were 312 +/- 218 and 150 +/- 102 microg/L, respectively (p = 0.002). Additionally, Zn was significantly higher in rural females (428 +/- 204 microg/L) than the urban females (166 +/- 103 microg/L; p = 0.0002). Finally, Zn was significantly higher in rural females (428 +/- 204 microg/L) than males (172 +/- 116 microg/L; p = 0.0028). In conclusion, Cu, Se, and Zn were higher in the rural group compared to the urban group, and the generally low Zn levels were confirmed in another cohort follow-up study.