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Antioxidant and Apoptotic Activity of Papaya Peel Extracts in HepG2 Cells

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Food and Nutrition Sciences 2016年第6期7卷 485-494页

作者： Swetha Salla Rajitha Sunkara lloyd t. walker Martha Verghese Nutritional Biochemistry and Food toxicology Laboratory Department of Food Science Alabama A & M University Normal AL USA Food Chemistry Laboratory Department of Food Science Alabama A & M University Normal AL USA

Papaya peels (PP) are discarded after consuming the fruit. However, they contain antioxidants. Oxidative damage caused by free radicals has major implications in many chronic diseases. the objective of this study was to determine in-vitro antioxidant and apoptotic activity of PP extracts. Modulation of endogenous glutathione (GSH), superoxide dismutase (SOD), catalase (CAt), glutathione peroxidase (GPx), glutathione reductase (GR), cyclo-oxygenase-2 (COX-2), caspase-3 activities and DNA fragmentation by PP extracts in HepG2 cells were evaluated. Gallic acid (18.06 μg/g), caffeic acid (29.28 μg/g), p-coumaric acid (38.16 μg/g), ferulic acid (95.46 μg/g) and quercetin (3.17 μg/g) were the major polyphenols quantified in PP extracts. In-vitro antioxidant capacity of PP was determined by ferric reducing antioxidant potential (31.86 μM Fe+2/g), trolox equivalent antioxidant capacity (14.56 mM trolox equivalents (tE)/g), oxygen radical scavenging activity (30.88 mM tE/g) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability (IC50-8.33 mg/ml). Induction of oxidative stress significantly (p ≤ 0.05) lowered SOD, CAt, GPx, GR activities and GSH levels by 3.1, 1.46, 2.87, 1.34 and 1.32 folds compared to control respectively. However, treating cells with PP extracts significantly (p ≤ 0.05) enhanced SOD, CAt, GPx, GR activities and GSH compared to oxidative stress induced cells. treating cells with PP extracts significantly (p ≤ 0.05) lowered COX-2 activity, enhanced caspase-3 activity and induced DNA fragmentation, indicating that PP extracts caused cell death by apoptosis. In conclusion, anti-cancer properties of PP extracts may be due to the synergistic effect of free radical scavenging ability, induction antioxidant enzymes and by inducing apoptosis.

关键词： Papaya Peel Cancer Polyphenols Antioxidants

Effect of Drying techniques on Antioxidant Capacity of Guava Fruit

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Food and Nutrition Sciences 2016年第7期7卷 544-554页

作者： Priyanka Patel Rajitha Sunkara lloyd t. walker Martha Verghese Nutritional Biochemistry Laboratory Normal AL USA

Frequent consumption of fruits and vegetables has been associated with low risk of chronic diseases. Guava (Psidium guajava Linn.) is a tropical, seasonal fruit rich in antioxidants, vitamin C and polyphenol compounds. Drying is one of the common methods to preserve and extend the shelf life of guava. the objective of this study was to determine the effect of drying techniques on the antioxidant activity of guava fruit. Guava was air dried in air dryer (45°C), freeze dryer and by osmatic drying techniques. Fresh guava extracts (FGE), freeze dried guava extracts (FDGE), oven dried guava extracts (ODGE) and osmotic-dehydrated guava extracts (OSGE) guava extracts were prepared and analyzed for total polyphenols (tP), flavonoids, antioxidant potential by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (tEAC), total antioxidant capacity (tAC) and nitric oxide radical scavenging activity (NORS). Inhibitory potential of guava extracts on enzymes α-glucosidase, α-amylase and lipase was also determined. tP in FG, FD, OD, and OS were 415.69 ± 56.95, 295.30 ± 4.11, 303.57 ± 1.41, and 182.93 ± 6.48 mg gallic acid equivalent (GAE)/100g, respectively. Flavonoids in Fresh, FD, OD, and OS were 202.01 ± 0.16, 96.93 ± 1.73, 105.07 ± 0.58, and 76.13 ± 2.74 mg catechin equivalent (CE)/100 g, respectively. FD extracts were the most effective in scavenging DPPH radical. Whereas FRAP, tEAC and tAC activities were found to be higher in FG followed by OD and FD. However, NORS activity of FD was significantly (p ≤ 0.05) lower compared to other treatments. Inhibition of α-glycosidase, α-amylase and lipase enzymes was (19% - 90%) observed at 0.4, 0.8, and 0.8 mg/ml, respectively. In conclusion, considering this in-vitro study, drying could be effectively utilized to preserve guava fruit with minimum effect on health benefits.

关键词： Guava Antioxidant Drying Methods Enzymes

Phytochemical Content, Radical Scavenging Ability &Enzyme Inhibiting Activities of Selected Spices (Cinnamon, Cardamom and Cloves)

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Food and Nutrition Sciences 2019年第3期10卷 266-275页

作者： Nigel Chimbetete Martha Verghese Rajitha Sunkara lloyd t. walker Food and Animal Science Department Alabama A & M University Normal AL USA

Cinnamon, cardamom and cloves have been widely used for medicinal purposes as well as essential cooking ingredients for flavor. the objective of the research was to investigate the antioxidant content, antioxidant capacity, and inhibition of lipid and carbohydrate metabolizing enzyme activities of selected spices (cinnamon, cardamom & cloves) methanol (ME) and water extracts (WE). the phytochemical content was determined by total phenolic and total flavanoid content. the antioxidant potential was determined by measuring 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and Ferric Reducing Antioxidant Power (FRAP) in spice’s (ME) and (WE) extracts. total phenolic (GAE mg/100g dry weight) and flavonoid (mg CE/100g dry weight) content were the highest in Cloves (ME) 174.4 and 101.06. the lowest values for phenolic content were seen in ME and WE of Cardamom at 31.24 and 7.55. the DPPH IC50 values ranged from 0.22mg/mL (Cloves ME) to 0.60mg/mL (Cardamom ME). FRAP (μmol Fe2+/100g dry weight) for Cinnamon, Cardamom (ME) was 2438.5 and 325. Clove (ME) had a significantly higher reducing potential of 6888.5 which might have been attributed by the high amounts of phenolics and flavonoids in the spice. FRAP in spice extracts (WE) was lower with values of 2296.5 and 218.5 and 2310.5, respectively. the highest inhibition of the α-glucosidase was observed by Clove (ME) 86.5%, which also had the highest amylase enzyme inhibition at 71%. However, inhibition of the lipase enzyme was highest by the Cinnamon (WE) extracts 44.3%. the potential of phytochemicals in spices was studied and if consumed in high amounts could offer antioxidative properties and regulate key digestive enzymes which may lead to prevention or decreased progression of diseases such as Cancer, Diabetes and Cardiovascular diseases.

关键词： Phytochemicals Cardamom Cinnamon Cloves Carbohydrate Metabolizing Enzymes

Chemopreventive Potential of Probiotics and Prebiotics

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Food and Nutrition Sciences 2014年第18期5卷 1800-1809页

作者： Rajitha Sunkata Josh Herring lloyd t. walker Martha Verghese Alabama A & M University USA

Utilization of probiotics and prebiotics in food products and in the diet supplemental form continues to gain interest because of their health benefits. Cancer is the leading cause of death and strategies for chemoprevention are important to reduce mortality and morbidity. Probiotics are gaining attention to use as preventive agents. Efficacy of their use as chemopreventive agents was established through research. this review focused on the mechanisms of prebiotics and probiotics action against cancer. Benefits of probiotics against cancer are attributed to competitive exclusion of pathogenic bacteria, direct physical binding to carcinogens, altering intestinal environment to modulate the production enzymes, antioxidant activity and immune modulation. Prebiotics are indigestible food components that could promote the growth of probiotics. Chemopreventive properties of prebiotics are due to their production of short chain fatty acids and enhancing the immunity of the host. Anticarcinogenic properties of pre- and probiotics result from a combination of events rather from a single event.

关键词： Prebiotics Probiotics Cancer Microbiota Oligosaccharides

A Comparison of the Antioxidative and Anti-Diabetic Potential of thermally treated Garlic, turmeric, and Ginger

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Food and Nutrition Sciences 2019年第2期10卷 207-219页

作者： Fredreana Hester Martha Verghese Rajitha Sunkara Shantrell Willis lloyd t. walker Food and Animal Sciences Department Alabama A & M University Normal AL USA

Spices have been used for centuries for food preservation, flavors, and medicinal properties. Research suggests that garlic, turmeric, and ginger contain potent antioxidants that may prevent and/or delay chronic diseases such as cancer, diabetes, and heart disease. Heat treatment of spices may potentially increase antioxidative activity by modifying the inherent chemical structure of potent antioxidative compounds within spices. the purpose of this study was to determine the impact of thermal treatment of garlic, ginger, and turmeric on total phenolic content (tPC), total flavonoid content (tFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing antioxidant potential (FRAP), trolox activity (tEAC), lipase, a-amylase, and a-glucosidase inhibition. Conventional stovetop heating of selected spices was performed followed by methanolic and aqueous extractions (1 - 5 minutes;70°C - 130°C). Overall methanolic extracts had higher phytochemical, antioxidative, and anti-diabetic potential. However, aqueous garlic extracts exhibited higher phytochemical and antioxidative potential over methanolic garlic extracts. the highest tPC for aqueous garlic extracts was observed at 1 minute (14.11 mg GAE/g) while methanolic garlic extracts at 1 minute were significantly lower (1.72 mg GAE/g). Methanolic turmeric extracts had highest tPC at 5 minutes (28.55 mg GAE/g). time and temperature influenced antioxidant activity in the spices. turmeric and ginger (methanolic extracts) resulted in higher percent inhibition of DPPH radical with an increase in time (5 minute) turmeric (86.9%) and ginger (79.09%) at 7.9 mg/mL concentration. the results of this study revealed both solvent and time for thermal treatment of spices influenced antioxidative potential as determined using DPPH and FRAP assays. therefore, the use of thermal application on spices presents promise in potentiating the antioxidant content and thereby their potential health promoting properties. Spices are

关键词： turmeric Garlic Ginger thermal treatment Antioxidant

Feeding Walnuts and Peanuts Reduced Development of Azoxymethane-Induced Precancerous Lesions

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Food and Nutrition Sciences 2016年第6期7卷 440-446页

作者： Hadyn Mathew Reid Rajitha Sunkara Louis Shackelford lloyd t. walker Martha Verghese Nutritional Biochemistry Laboratory Department of Food and Animal Sciences Alabama A&M University Normal Alabama USA

Walnuts and peanuts contain phytochemicals that exhibit properties that may prevent colon cancer development. the objective was to determine the potential of walnuts and peanuts on Azoxymethane (AOM) induced Aberrant Crypt Foci (ACF) and the activity of detoxification enzymes: Glutathione S-transferase (GSt), Catalase (CAt), and Superoxide Dismutase (SOD) in Fisher 344 male rats. After 1 week acclimatization period, 20 rats were randomly divided into 5 groups. One was fed AIN93G Control (C) diet, 4 groups were fed walnuts (W) and peanuts (P) at 5% and 10%. At 7 - 8 weeks, rats received AOM injections at 16 mg/kg body weight (subcutaneously). Rats were killed by CO2 asphyxiation at 17 weeks. Enzyme activities GSt, CAt and SOD were determined. ACF incidence in rats fed W (5% and 10%) was 131 and 95, and in those fed P (5% and 10%) was 110 and 56. Rats fed W and P had a significant (p t reduction (17.92% - 65.09%) in total ACF compared to C (159). Liver GSt activity (μmol/mg) in rats fed W (5% and 10%) was 3.64 and 3.98, and in those fed P (5% and 10%) was 3.84 and 3.30, compared to rats fed C (0.26). CAt activity (μmol/mg) in rats fed W (5% and 10%) was 0.57 and 0.65 and in those fed P (5% and 10%), was 0.76 and 1.26, compared to rats fed C (0.14). SOD activity (U/mg) in rats fed W (5% and 10%) was 529.38 and 576.57 and in those fed P (5% and 10%), was 293.50 and 466.95, compared to rats fed C (82.42). Feeding walnuts and peanuts, especially at 10%, significantly (p the incidence of AOM induced ACF, likely due to the phytochemicals present in nuts.

关键词： Aberrant Crypt Foci (ACF) Azoxymethane (AOM) Chemoprevention Fisher 344 Rats Nuts

Nestedness in insular floras:spatiotemporal variation and underlying mechanisms

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Journal of Plant Ecology 2013年第6期6卷 480-488页

作者： lloyd W.Morrison Department of Biology Missouri State University901 S.National AvenueSpringfieldMO 65897USA

Aims Nestedness is a characteristic of insular metacommunity *** few studies,however,have attempted to evaluate temporal changes in nestedness,or elucidate the mechanisms underlying nestedness.I evaluated both spatial and temporal patterns of nestedness in the insular floras of four archipelagoes of small islands in the Bahamas and the potential underlying environmental *** the NODF(a nestedness metric based on overlap and decreasing fill)and the matrix temperature measure,t,were used to quantify nestedness in insular floras on small islands near Abaco,Andros,Great Exuma and the Exuma Cays,*** different null models were employed for each nestedness *** environmental variables were evaluated in relation to nestedness by ordering islands according to gradients and recalculating NODF *** Findings All archipelagoes were significantly *** among sites contributed more to overall nestedness than did nestedness among *** scores varied among archipelagoes,but were surprisingly constant over *** islands by vegetated area yielded the highest nestedness scores for three archipelagoes;ordering islands by protection from exposure yielded the highest nestedness score for one *** scores varied little over time even though species compositions changed,indicating that extinctions occurred in a deterministic *** relative importance of area suggests extinction is an important mechanism in producing *** to determine the relative importance of immigrations or extinctions requires some assumptions,however,and both processes are likely cumulative in most cases.

关键词： Bahamas environmental gradient insular floras nestedness NODF metric

Chemopreventive and Anti-Inflammatory Potential of Select Herbal teas and Cinnamon in an <i>In-Vitro</i>Cell Model

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Food and Nutrition Sciences 2019年第9期10卷 1142-1156页

作者： Shantrell Willis Rajitha Sunkara Fredreana Hester Louis Shackelford lloyd t. walker Martha Verghese Department of Food and Animal Sciences Alabama Agricultural and Mechanical University Normal AL USA

Colon cancer is the third leading cause of death in the US. Herbal teas and spices may reduce the incidence of chronic diseases, including colon cancer. the objectives of this study were to determine the chemopreventive effects of herbal teas and cinnamon in an in-vitro cell model and to evaluate the inhibitory effects of selected extracts on enzymes associated with inflammatory disease. Effects of raspberry leaf (0.5 - 2.0 mg/mL), strawberry leaf (0.4 - 1.0 mg/mL), hibiscus flower (4.0 - 10.0 mg/mL) and cinnamon (400 - 1500 μg/mL) were evaluated for cytotoxicity, induction of caspase and DNA fragmentation in colon cancer (Caco-2) cells to determine possible chemopreventive effects. Effects of extracts on inhibition of cyclooxygenase-2 (COX-2) were also measured to determine possible anti-inflammatory potential. Caco-2 cells were obtained from American type Culture Collection (AtCC) and maintained in Dulbecco’s Modified Eagle’s Medium with 10% fetal bovine serum. As concentrations of tea increased, LDH release from Caco-2 cells increased, with cytotoxicity ranging from 1% - 80% (hibiscus flower 1.0 mg/mL and strawberry leaf (1.0 mg/mL) for teas. All extract concentrations of herbal teas and cinnamon were able to enhance caspase-3 activity with lowest activity (4.4 mmol/ min/mL) observed in the lowest concentration of cinnamon (400 μg/mL) and highest activity (6.0 mmol/min/mL) seen in the highest concentration of raspberry leaf (2 mg/mL). tea and spice extracts were able to induce apoptosis in Caco-2 cells exhibited by increased DNA fragmentation (expressed as enrichment factor). Enrichment factor ranged from 1.0 - 1.5 (raspberry leaf 1.0 mg/mL and hibiscus 10.0 mg/mL). teas and cinnamon exhibited anti-inflammatory potential by inhibiting COX-2 by 0.6% - 8.0% (raspberry leaf 1.0 mg/mL and strawberry leaf 0.8 mg/mL). the results suggest that herbal teas and cinnamon may have significant benefits in chemoprevention.

关键词： Colon Cancer Inflammation Herbal tea Cell Culture

<i>In Vitro</i>Analysis of the Antioxidant Effect of Allspice

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Food and Nutrition Sciences 2017年第7期8卷 778-792页

作者： Ebube N. Onwasigwe Martha Verghese Rajitha Sunkara Louis Shackelford lloyd t. walker Nutritional Biochemistry Laboratory Department of Food and Animal Sciences Alabama A and M University Normal AL USA

Antioxidants are free radical scavengers found in spices which may play a significant role in preventing cell death. Allspice is a dried unripe berry obtained from the Pimento dioica plant that may have antioxidant potential. the objective of this study was to determine the total phenolic, flavonoid content and antioxidant capacity of allspice using selected assays such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Potential (FRAP) and trolox Equivalent Antioxidant Capacity (tEAC), Nitric Oxide (NO) and Oxygen Reducing Antioxidant Capacity (ORAC). total phenolic and flavonoid contents of allspice were determined using both water and methanol extraction. A comparison of antioxidant activity of water and methanol extracts of allspice was conducted using the different assays (DPPH, tEAC, NO, ORAC and FRAP). the total phenolic content (6.9%), NO scavenging (38.8%) and ORAC (35.1%) activity were higher in methanol compared to water extracts of allspice while flavonoids (57%), FRAP (11.2%), and tEAC (1.82%) were higher in water extracts compared to methanol extracts of allspice. the total phenolic and flavonoid content were higher in methanol extracts compared to water extracts of allspice. the IC50 (DPPH), FRAP and tEAC, NO scavenging and ORAC activity were higher in methanol extracts compared to water extracts of allspice. total flavonoid content, FRAP and tEAC, NO scavenging and ORAC were significantly higher (p ≤ 0.5) in methanol extracts compared to water extracts of allspice. this shows that allspice has antioxidant potential and that the method of extraction can play a crucial role on the number of phytochemicals extracted from the plant. Utilization of allspice in food products may provide additional functional properties.

关键词： Allspice Extract (AAE) Pimenta dioica 1 1-Diphenylpicrylhydrazyl (DPPH) Ferric Reducing Antioxidant Potential (FRAP) Phenolics Flavonoids Reactive Oxygen Species Antioxidants