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Articles by L. Shackelford
Total Records ( 16 ) for L. Shackelford
  J. Boateng , M. Verghese , L.T. Walker , L. Shackelford and C.B. Chawan
  The aim of this study was to examine antitumor effects of Kidney Beans (KB) on Azoxymethane (AOM) induced colon cancer and the cytotoxic effects of KB extracts on colon cancer cell lines (CaCO2). For ACF study, 12 Fisher 344 male rats were fed AIN-93G control diet (C) (n = 6) and 20% KB (n = 6), for 13 week. In the EPTM two groups of rats (n = 14) were fed AIN-93G control diet (C) and 20% KB. All rats received two s/c injections of AOM at 7 and 8 week of age at the rate of 16 mg kg-1 body weight in saline. At 17 week (ACF) and 45 week of age (End-point) all rats were killed by CO2 asphyxiation. For lactate dehydrogenase (LDH) assay, cells were incubated (24 and 48 h) with selected concentrations (0.5-25 mg/100 mL) of KB extract. Total number of ACF was 158 and 72 for groups fed C and 20% KB. Tumor size (mm) and TBR for C and 20% KB were 6.50; 1.16 and 3.8; 1.44, respectively. LDH release (%) in CaCO2 cells after 24 and 48 h incubation with KB extracts ranged from 13.8 to 62.8 and 23.5 to 84.1, respectively. Feeding KB significantly (p<0.05) reduced the incidence of AOM induced colon tumorigenesis and KB extracts demonstrated cytotoxic effects on colon cancer cell lines (CaCO2).
  M. Guyton , M. Verghese , L. T. Walker , C. B. Chawan , L. Shackelford , J. Jones and J. Khatiwada
  The aim of this study was to explicate the effect of feeding peanuts at 3 levels (10, 15 and 20 g 100-1 g of feed) on azoxymethane (AOM)-induced Aberrant Crypt Foci (ACF) in Fisher 344 male rats. Four groups of rats were fed AIN93-G control diet (n = 8) and 3 experimental diets containing 10, 15 and 20% peanuts (n = 8) for 13 weeks. All rats received 16 mg kg-1 body weight of AOM at 7 and 8 week of age. The rats continued to receive the assigned diets until euthanized by CO2 at 17 weeks of age. The percent reductions in ACF in the groups consuming diets containing 10, 15 and 20% peanuts were 31.9, 48.7 and 61%, respectively. GST activity (μmol mg-1) in the rats fed control diet was significantly (p<0.05) lower compared to the rats fed peanuts. Present results indicate that feeding peanuts significantly reduced AOM-induced ACF in Fisher 344 male rats. The phytochemicals present in peanuts may have antitumor properties and could possibly reduce colon cancer.
  V. Panala , M. Verghese , J. Boateng , R. Field , L. Shackelford and L.T. Walker
  The objective of this study was to compare the inhibitory effects of Rice bran oil (RBO), Corn oil (CO) and Soybean oil (SBO) at 7% (normal fat level) and 14% (high fat level) on Azoxymethane (AOM) induced Aberrant Crypt Foci (ACF). The long term effect (End Point Tumor (EPT) study) of dietary fat from the above sources on colon cancer in Fisher 344 male rats was determined. In the ACF study 2 groups of F344 rats (4 weeks old) (n = 6) received AIN-93G Control (C) diet containing 7 and 14% Soybean oil (SBO). The remaining groups were assigned treatment diets consisting of 7 and 14% RBO and CO. The rats remained on their respective diets for 13 weeks. Rats in the EPT study were fed a control (AIN-93G) diet with 7% SBO, while the treatment groups were fed diets containing 7% RBO and CO, respectively. At 20 week of age rats in the EPT study were switched to AIN-93Maintenance (M) diets. All rats received 2 s/c injections of AOM at 7 and 8 week of age @ 16 mg kg-1 body weight in saline. At 17 and 45 week of age all rats were killed by CO2 asphyxiation. Total colonic ACF in the rats fed SBO, RBO and CO at 7 and 14% levels ranged from 101-189. In the EPT study, all the rats fed 7% SBO and CO developed tumors (100% tumor incidence) while tumor incidence in the groups fed RBO, was 54% while tumor size (mm) and tumor/Tumor Bearing Rat ratio (TBR) in the rats fed SBO, RBO and CO ranged from 1.3-6.86 and 1.83-5.86, respectively. Present results indicate that the type and constituents (such as n-3 PUFA, vitamin E, phytosterols) of dietary fat plays a significant role in the formation of AOM induced colonic ACF and tumors in Fisher 344 rats.
  D. Gajula , M. Verghese , J. Boateng , L.T. Walker , L. Shackelford , S.R. Mentreddy and S. Cedric
  Basil (Ocimum basilicum L. and Ocimum tenuiflorum L.) contains important phytochemicals that have been reported to afford protection against several chronic diseases due to their anti-inflammatory and antioxidant activities. The purpose of this study was to determine the effects of three accessions of Ocimum tenuiflorum (Holy Basil) Denmark (HBD), Cuba (HBC), India (HBI)) and one accession of Ocimum basilicum (Culinary Basil) (CB) at 1 and 2% levels on azoxymethane (AOM) induced Aberrant Crypt Foci (ACF) in Fisher 344 male rats and to determine the effect of oven drying on total phenolics, flavonoids and anthocyanins of Basil and antioxidative activity. Fifty four rats were divided into 9 groups (n = 6) after a 1 week period of acclimatization. Group 1 was fed a control (C) diet (AIN-93 G) and remaining groups were fed C+1 or 2% CB, HBD, HBC and HBI. All rats received s/c injections of AOM in saline at 16 mg kg-1 b.wt. at 7 and 8 week of age. Rats were killed by CO2 asphyxiation at 17 week of age. The ACF in rats fed C (158.1) was higher than in rats fed C+1% CB, HBD, HBC, HBI (77, 86, 76, 73) and C+2% CB, HBD, HBC, HBI (65, 78, 61, 67). The GST and CAT activities (╬╝mol mg-1) in rats fed C+1 and 2% CB, HBD, HBC and HBI were significantly (p<0.05) higher compared to C. Results showed that feeding culinary and Holy Basil leaves reduced the number of AOM-induced ACF and therefore may have implications in the food industry as a potential chemopreventive agent.
  J. Boateng , M. Verghese , V. Panala , L.T. Walker and L. Shackelford
  In this study we examined the preventive properties of Rice Bran (RB) and germ on the incidence of azoxymethane induced colon tumorigenesis in Fisher 344 male rats. We also examined the cytotoxic and apoptotic properties of RB using an in vivo model. Tumor incidence (%) in C and RB 5% and RB 10% were 100, 55 and 64, respectively. Tumors/tumor Bearing Rats (TBR) were 3.8, 2 and 1.56 for C, RB 5% and RB 10%, respectively. Tumor size (mm) was larger in control (6.50) than in rats fed RB 5% and RB 10% (1.33 and 0.64). After 12, 24 and 48 h of incubation with RB extracts, LDH (%) release ranged from 2.25-46.79. Present results suggest that feeding RB at 5 and 10% levels significantly (p<0.05) reduced the incidence of AOM induced colon tumors in Fisher 344 male rats. We conclude that the protective effects of RB against colon tumorigenesis may possibly be attributed to the synergistic/additive actions of phytochemicals contained in RB.
  R. Sunkara , M. Verghese , L. Shackelford , L.T. Walker and E. Cebert
  The objective of this study was to determine the effects of dietary administration of sorrel calyx and sorrel juice on the induction and development of azoxymethane (AOM) induced Aberrant Crypt Foci (ACF) in Fisher 344 rats. Thirty male F344 rats were randomly divided into 5 groups and fed AIN 93-G diet as control, AIN 93-G+sorrel meal (5 and 10%) or juice (2.5 and 5%). Rats were given subcutaneous injections of AOM (16 mg kg-1 b.wt.) once a week for 2 weeks and were killed after administering sorrel for 13 weeks. The effect of sorrel on detoxification (phase I and II) and antioxidant enzymes (catalase (CAT) and superoxide dismutase (SOD)) was also determined. Treatment with dietary sorrel meal and juice significantly (p<0.05) decreased total number of ACF and the total number of aberrant crypts compared to the control fed rats. Feeding sorrel meal at 10% level significantly (p<0.05) reduced the percentage of ACF by 70% compared to the control. Administration of sorrel to rats significantly (p<0.05) increased hepatic Glutathione-S-Transferase (GST), CAT and SOD activities by 3.3-6.5 fold compared to the control fed rats. However, no effect on CYP2E1 activity was observed among the treatment groups. Present results demonstrate the chemopreventive potential of sorrel either as meal or juice on AOM induced ACF as well as its ability to modulate detoxification and antioxidant enzymes.
  A.A. Miller , M. Verghese , J. Boateng , L. Shackelford and L.T. Walker
  The aim of the study was to test the chemopreventive potential of almonds and pecans on (AOM) induced aberrant crypt foci (ACF). Following a 1 week period of acclimatization, 30 Fisher 344 male rats were randomly divided into 5 groups. One group was fed AIN93G (growth) diet as Control(C) and the other groups were fed almonds (A) and pecans (P) at 5% (5 g/100 g level) and 10% (10 g/100 g level). At 7 and 8 weeks of age rats received subcutaneous injections of Azoxymethane (AOM) at 16 mg kg-1 body weight and were killed by CO2 asphyxiation at 17 weeks of age. Selected enzyme activities such as, glutathione-s-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) were determined. ACF incidence in rats fed Pecans and Almonds at 5 and 10% dose levels were significantly (p<0.05) lower than rats fed control. ACF was reduced by 46-61% in the treatment groups compared to the control. GST and CAT activities (μmol g-1) in rats fed Pecan and Almonds at 5 and 10% dose levels were significantly higher (p<0.05) compared to control fed rats and ranged from 22.03 to 26.44 and 2.38 to 2.98, respectively. We also noted a significant increase in SOD activity (μmol g-1) in rats fed the treatment diets compared to those fed control. Present data indicate that feeding almonds and pecans significantly (p<0.05) reduced incidence of AOM induced ACF which are precancerous lesions.
  D. Asiamah , M. Verghese , J. Boateng , B. Kanda , L. Shackelford and L.T. Walker
  Bitter Melon, (BM) Momordica charantia is known in Asia for regulation of blood glucose levels and as a treatment for Diabetes mellitus. However, studies on its effect in preventing cancer are scarce. This study was conducted to investigate the chemopreventive properties of bitter melon on azoxymethane (AOM)-induced Aberrant Crypt Foci (ACF) in Fisher 344 male rats and determine its effects on selected hepatic detoxification and antioxidant enzymes. Rats were fed AIN93G as control (C) and treatment diets containing 2 and 4% BM. At 7 and 8 weeks of age, ACF was induced by administering 2 s/c injections of AOM at 16 mg kg-1 b.wt. and killed by CO2 asphyxiation at 17 weeks of age. Total ACF in proximal and distal colons were 35, 26 and 21; 116, 54 and 38 in rats fed C, 2% BM and 4% BM, respectively. Catalase and SOD activities (μmol mg-1) were higher in rats fed treatment diets (0.293 and 0.03; 1.82 and 0.27 for rats fed 2 and 4% BM, respectively) compared to control (0.04). Glutathione-S-Transferase (GST) (μmol mg-1) activity and Glutathione (GSH) levels were higher in treatment groups compared to control. Physicochemical analysis was conducted on bitter melon fruit (total phenolics, free radical scavenging activity (DPPH) and Ferric Reducing Antioxidant Power (FRAP)). Total phenolic content was 34.31 mg/GAE/g fresh fruit, DPPH activity was 2.99% and FRAP was 0.652 μmol Fe2+/g/mL. Results indicate bitter melon reduced incidence of AOM induced ACF. Thus inclusion of BM in diets may have possible implications in reducing the risk of colon cancer.
  B. Kanda , J. Boateng , L. Shackelford , S. Appiah , K. Campbell L. T. Walker and M. Verghese
  Peach is an important fruit consumed worldwide. This study was conducted to investigate the effects of processed peaches (dried, frozen and juice) on Azoxymethane-induced (AOM) Aberrant Crypt Foci (ACF) in Fisher 344 male rats, their effect on selected hepatic enzyme activities and to determine the effect of processing (Blanching+Freezing, Blanching+Freeze drying) on total phenolic content and antioxidant potential (DPPH and FRAP). Rats were fed AIN93G as control (CON), treatment diets containing 2 and 4% peaches, and pasteurized juice (PJ) (2 and 4%). Rats received AOM injections s/c at 16 mg kg-1 b wt. during the 7th and 8th wk of age and killed by CO2 asphyxiation at 17 weeks of age. ACF incidence was higher in rats fed CON compared to treatment diets. Rats fed PJ had the lowest ACF (100 and 59 for 2 and 4%) compared to the treatment groups. Blanching (STB+BWB) influenced the incidence of ACF with STB having lower ACF numbers compared to BWB. GST, SOD and CAT (mmol/mg) activities, (9.56-1.43, 1.98-0.49 and 0.53-0.33), respectively were higher in rats fed treatment diets, compared to CON. Total phenolics, ranged from 98.09-120.38, 111.05-120.19, 104.76-122.09 (mg/GAE/g fwb) in FU, FRB and FDB peaches, respectively. FRAP (μg g-1) in FU, FRB and FDB peaches ranged from 0.028-0.042 while (%) DPPH (T30) ranged from 21.588-73.449. Results indicate processing of fruits may impact its role in chemoprevention, total phenolics and antioxidant activity, since fruits are highly perishable; optimum technique is required to minimize losses during and after processing.
  R.L. Miller-Cebert , J. Boateng , L. Shackelford , E. Cebert , L.T. Walker and M. Verghese
  Cruciferous vegetables contain naturally occurring substances that are beneficial to health. The purpose of this study was to investigate the effects of selected cruciferous vegetables (Collard Green (CG), cabbage (CB), turnip green (TG) and canola green (CN) on Azoxymethane (AOM)-induced Aberrant Crypt Foci (ACF) on Fisher 344 male rats. Thirty-six rats were randomly assigned to 9 groups (n = 4). The control group was fed AIN-93G diet and the other eight groups were fed AIN-93G along with the selected vegetables at 5 and 10%. The rats were administered subcutaneous injections of AOM at 7 and 8 weeks of age at 16 mg kg-1 body weight. At 17 weeks of age, rats were killed by CO2 asphyxiation. Total ACF numbers in rats fed CB, TG, CG and CN at 5% were 55, 41, 47 and 59, while at the 10% level, ACF numbers were 54, 63, 54 and 46, respectively. Total ACF in rats fed 5 and 10% cruciferous vegetables were significantly (p<0.05) lower (41-63) than rats fed the control diet (151). Findings indicate that cruciferous vegetables, including canola reduced the incidence of ACF and could potentially be used as a dietary chemopreventive agent against colon cancer.
  J. Jones , M. Verghese , L.T. Walker , L. Shackelford and C.B. Chawan
  Inhibitory potential of grape products on Azoxymethane (AOM) induced Aberrant Crypt Foci (ACF) were investigated in Fisher 344 male rats. Bioactive components present in the grapes have shown anticarcinogenic properties in in vitro and epidemiological studies. Following an acclimatization period of one week, 24 male weanling rats were fed control and experimental diets consisted of either grape Juice (50%) or Raisins (10%). All rats received 16 mg kg-1 b.wt. of AOM at 7 and 8 week of age. Rats were euthanized by CO2 at 17 week of age. Number of ACF was enumerated in colon and Glutathione S-transferase (GST) activity was analyzed in liver of rats. No significant differences were observed in the weight gain of rats among the groups. Highest (73%) reduction in ACF was found in rats fed with Grape juice followed by rats fed with raisins (66%). The total number of crypts were significantly lower in treatment group rats (Juice-93.62±4.3; raisins-116.66±5.3) compared to the control group (358±13.3). Glutathione S-transferase enzyme activity was increased by 2-3 fold in the treatment groups. This study indicates that administering grape juice at 50% and raisins at 10% in diet of rats significantly reduced the ACF in Fisher 344 male rats and may offer protection against colon cancer development.
  K. Busambwa , R.L. Miller-Cebert , L. Aboagye , L. Dalrymple , J. Boateng , L. Shackelford , L.T. Walker and M. Verghese
  Peas (yellow and green) and lentils contain bioactive compounds with protective properties. Sprouting of grains has shown to improve nutritional value due to activation of hydrolytic enzymes. The aim of this study was to determine anticarcinogenic potential of sprouted and non-sprouted green-split and yellow peas and lentils at 5 and 10% on Azoxymethane (AOM)-induced Aberrant Crypt Foci (ACF) in Fisher 344 male rats. Seventy-eight rats were randomly assigned to 13 groups: Control (C) received AIN-93G diet; treatment diets included Lentils sprouted and non-sprouted (LS, LNS), Green peas sprouted and non-sprouted (GS, GNS), Yellow peas sprouted and non-sprouted (YS, YNS) at 5 and 10% levels in an AIN 93 based diet. At 7 and 8 week, rats received 2 subcutaneous injections of AOM at 16 mg kg-1 b.wt. Rats were euthanized at 17 week by CO2 Asphyxiation. Total ACF ranged from 88 to 181.33 in rats fed C, LS and LNS, GS and GNS, YS and YNS. ACF reductions (%) compared to C were 68.56; 63.25 and 51.46 in rats fed LS at 10%, LNS at 10% and YNS at 10%, respectively. Glutathione content, Glutathione-S-transferase and Catalase activities were significantly higher (p<0.05) in rats fed treatment diets compared to C. Findings from this study indicate that sprouted and non sprouted green split and yellow peas and lentils reduced AOM-induced aberrant crypt foci in F344 male rats with the greatest reduction in rats fed Lentil sprouted (10%). Selected legumes appear to have beneficial potential in reducing colon cancer.
  J. Boateng , R. Miller-Cebert , L. Shackelford and M. Verghese
  Background and Objectives: There is limited information on the effect of pistachio nuts in cancer prevention. Since pistachios contain several protective compounds with antioxidants properties, the aim of this study is to determine if pistachios can reduce precancerous colon cancer lesions in rats by affecting several biomarkers of oxidative stress including induction of endogenous antioxidant enzymes. Methodology: Thirty Fisher 344 male rats were randomly assigned to 5 groups. Rats in groups 1 and 2 were fed AIN-93G as positive (CON+) and negative control (CON-), while rats in groups 3-5 were assigned AIN-93G with 5, 10 and 15% pistachio meal (PM). Rats (except group 2), received AOM injections at 7 and 8 weeks of age and killed at 17 weeks of age by CO2 asphyxiation. Results: Total ACF and crypt multiplicity, antioxidant enzymes: Glutathione-s-transferase (GST), glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), glutathione reductase (GR) and superoxide dismutase (SOD) were determined. Total serum cholesterol (TC) and triglycerides (TG) were also assessed. Results showed significant (p<0.05) reductions in ACF in all treatment groups compared to the rats fed CON+(158). The ACF ranged from 72-119 in rats fed 5, 10 and 15% PM. Rats in group 2 developed no ACF. Significant (p<0.05) increase in antioxidant enzyme activities (protein μmol mg–1) was observed compared to CON+. The GST (5.86-10.84), GR (4.91-7.21), CAT (1.66-3.38), GPx (4.25-7.61) and SOD (protein U mg–1) (1.02-1.73). The TC and TG were significantly (p<0.05) decreased in the treatment groups compared to CON+. Data indicated PM reduced ACF by enhancing phase II and antioxidant enzyme activities and reducing serum lipids. Conclusion: The PM could be investigated as putative dietary chemoprevention in colon cancer therapy.
  A. Clisby , M. Verghese , E. Cebert , L.T. Walker , R. Field , L. Shackelford , J. Boateng and C.B. Chawan
  The aim of the current study was to determine the efficacy of selected canola or mustard seeds (S) and canola sprouts (SP) cultivars (5 and 10% levels) on azoxymethane (AOM) induced Aberrant Crypt Foci (ACF) in Fisher 344 male rats. Following a one week period of acclimatization Fisher 344 male rats were randomly assigned to groups (n = 6). At seven and eight weeks of age rats received two successive s/c injections of AOM in saline at 16 mg kg-1 body weight. Rats were killed by CO2 asphyxiation at 17 weeks of age. The number of ACF in the proximal and distal colon in the treatment groups ranged from 6.33 (5% Pacific gold) to 15.55 (5% Jetton) and 21.33 (10% Pacific gold) to 52.0 (5% Idagold). Glutathione-S-transferase activity (μmol mg-1) was significantly (p<0.05) higher in the groups fed canola or mustard seeds compared to the control. Among the treatment groups the highest GST activity (μmol mg-1) was observed in the rats fed 10% Pacific gold group (32.50). The results from this study show that canola or mustard sprouts and seeds reduced the incidence of AOM-induced ACF and may possibly prevent the incidence of colon cancer.
  K. Busambwa , M. Verghse , R.M. Cebert , L. Dalrymple , J. Allen , J. Boateng , L. Shackelford and L.T. Walker
  Lentils, green and yellow split-peas have been reported to provide health benefits against colon cancer due to the amount of nutrients and non-nutrient phytochemical compounds present. The aim of this study was to investigate and compare the chemopreventive potential of sprouted and non-sprouted lentils (LS, LNS), green (GS, GNS) and yellow split-peas (YS, YNS) on azoxymethane (AOM)-induced colon cancer. Following a 1 week acclimatization period, 42 Fisher-344 male rats were randomly assigned to 6 groups (n = 6). Five groups were fed treatment diets consisting of the selected legumes (Sprouted and non-sprouted), while the control group (C) was fed AIN-93 growth and maintenance of diet. Colon tumors were induced by administration of AOM at 7 and 8 weeks of age. Rats were killed by CO2 asphyxiation at age 46 weeks. Results showed lower tumor incidence in treatment groups at 66.7% in GS compared to 100% in LNS and the control. Rats fed control diet had higher Tumors/Tumor Bearing Rat (TBR) ratio (4.33) compared to those in treatment groups (1.2-2). Cecal pH was significantly higher in control (7.81) compared to the treatment diets. Glutathione-S-Transferase (GST) activity was significantly higher in sprouted legumes (8.55-14.04 μM min–1 mL–1) compared to non-sprouted legumes (4.53-5.67 μM min–1 mL–1). Glutathione concentration (GSH) ranged from a low of 636.34 μM in rats fed GNS to a high of 791.07 μM in rats fed YNS. Selected legumes were effective in reducing incidence of AOM-induced colon tumors in Fisher-344 male rats (2.1-4.3 times) and may be promoted for consumption as part of healthy eating habits to prevent chronic diseases such as cancer.
  S. Willis , J. Boateng , K. Busambwa , L. Shackelford and M. Verghese
  Background and Objective: Demand for plant preparations is on the rise urging the need to investigate their potential for toxicity. The aim of this study was to evaluate the effect of oral supplementation of bitter melon (BMLT) and blueberry leaf teas (BLUT) on redox and drug metabolizing enzymes: Glutathione (GSH) levels, Glutathione-S-Transferase (GST), superoxide dismutase (SOD), catalase (CAT) activities were determined. Methodology: Rats (n = 5) were administered once daily by gavages 0, 1000, 2000 and 4000 mg kg–1 b.wt., of BMLT, BLUT for 28 days. Day 29, rats were killed by CO2 asphyxiation and tissue and blood samples were collected for analysis. Results: Results also showed GST, CAT and SOD (μmol mg–1 protein) activities in experimental groups ranged from 0.89-2.14, 0.93-1.38 and 0.35-0.55, respectively. There were no significant differences in GSH (μmol/mg protein) levels between the control and treatment groups. Conclusion: Results indicated BMLT and BLUT prevented oxidative stress by improving the activity of antioxidant enzymes. Results also showed no apparent toxicity in rats administered LHT.
 
 
 
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