B.S. Jena

Antioxidant and antimutagenic activities of pomegranate peel extracts

Abstract Dried pomegranate peels were powdered and extracted in a Soxhlet extractor with ethyl acetate (EtOAc), acetone, methanol and water for 4 h each. The dried extracts were used to determine their antioxidant capacity by the formation of phosphomolybdenum complex and antimutagenicity against the mutagenicity of sodium azide by the Ames test. All the peel extracts exhibited marked antioxidant capacity, but the water extract was the lowest. The order of antioxidant capacity varied because of differential responses at four concentrations (25, 50, 75 and 100 μg/ml) in each solvent. All the extracts decreased sodium azide mutagenicity in Salmonella typhimurium strains (TA100 and TA1535), either weakly or strongly. At 2500 μg/plate all the extracts showed strong antimutagenicity. The antimutagenicity of the water extract was followed by acetone, EtOAc and methanol extracts. The overall results showed that the pomegranate peel extracts have both antioxidant and antimutagenic properties and may be exploited as biopreservatives in food applications and neutraceuticals.

Evaluation of Antioxidant Activities and Antimutagenicity of Turmeric Oil: A Byproduct from Curcumin Production

Curcumin removed turmeric oleoresin (CRTO) was extracted with hexane and concentrated to get turmeric oil, and that was fractionated using silica gel column chromatography to obtain three fractions. These fractions were analyzed by GC and GC-MS. Turmeric oil contained aromatic turmerone (31.32%), turmerone (15.08%) and curlone (9.7%), whereas fractions III has aromatic turmerone (44.5%), curlone (19.22%) and turmerone (10.88%) as major compounds. Also, oxygenated compounds (5,6,8-10) were enriched in fraction III. Turmeric oil and its fractions were tested for antioxidant activity using the β-carotene-linoleate model system and the phosphomolybdenum method. The fraction III showed maximum antioxidant capacity. These fractions were also used to determine their protective effect against the mutagenicity of sodium azide by means of the Ames test. All the fractions and turmeric oil exhibited a markedly antimutagenicity but fraction III was the most effective. The antioxidant effects of turmeric oil and its fractions may provide an explanation for their antimutagenic action.

Ageing in Fishes

Fishes show three types of senescence. Lampreys, eels and pacific salmon exhibit rapid senescence and sudden death at first spawning. The guppy, red panchax, medaka, platyfish, Indian murrel and many other teleosts undergo gradual senescence, as observed in most of the vertebrates. A number of fishes (e.g. sturgeons, paddlefish, female plaice, flatfish, rockfish) show indeterminate growth, the occurrence of senescence in them is supposed to be very slow or negligible. Neuroendocrine mechanisms are involved in rapid senescence. Most of the evidences in favour of the occurrence of senescence in fishes have been derived from studies in species showing gradual senescence. Age-related increases in mortality rate, accumulation of lipofuscin, lipid peroxidation, collagen cross-linking and decreases in growth rate, reproductive capacity and protein utilisation are clearly marked in such species. Anatomical changes in various organs during ageing also confirm increases in degenerative changes and pathological symptoms. Dietary restriction and lower environmental temperature retard the ageing processes in a few species showing gradual senescence. These results tentatively support the contention of commonality in mechanism of ageing processes in vertebrates. At present, anatomical, cellular, biochemical and genetic evidences in support or against the occurrence of slow senescence or negligible senescence in long-lived fish species are almost nonexistent. Extensive studies on ageing in fishes are needed to explain the multiple mechanisms which are not unexpected considering the number and variety of the existing species.

Microencapsulation of Garcinia Cowa Fruit Extract and Effect of its use on Pasta Process and Quality

Microencapsulation is employed to protect bioactive ingredients in foods and is also used for their controlled release at targeted sites. Hydroxycitric acid ((-)-HCA) is present in the fruits of certain species of Garcinia and it has been studied extensively for its unique regulatory effect on fatty acid synthesis, lipogenesis, appetite, and weight loss. Since hydroxycitric acid is hygroscopic in nature, it is very difficult to convert liquid extract from the fruits of Garcinia into dried powder. Hence, microencapsulation of Garcinia cowa fruit extract was performed in a pilot-scale co-current spray dryer with whey protein isolate as a wall material. In this study, two different wall-to-core ratios (1:1 and 1.5:1) and dryer outlet temperatures (90 and 105°C) were used for assessing the encapsulation efficiency. The results in this study showed that the microencapsulation efficiency (based on HPLC analysis) and antioxidant properties (based on 2,2-diphenyl-1-picrylhydrazyl assay) were higher at 90°C outlet temperature of the spray dryer using 1.5:1 wall-to-core ratio feed. Further, the spray-dried powders were incorporated into pasta processing and evaluated its quality characteristics. The results of this study demonstrated that incorporation of powder spray-dried at 90°C outlet temperature with 1.5:1 wall-to-core pasta exhibited higher antioxidant activity as well as better cooking and sensory characteristics.

Microencapsulation of Garcinia fruit extract by spray drying and its effect on bread quality.

BACKGROUND (-)-Hydroxycitric acid (HCA) is the major acid present in the fruit rinds of certain species of Garcinia. HCA has been reported to have several health benefits. As HCA is highly hygroscopic in nature and thermally sensitive, it is difficult to incorporate in foodstuffs. Hence, Garcinia cowa fruit extract was microencapsulated using three different wall materials such as whey protein isolate (WPI), maltodextrin (MD) and a combination of whey protein isolate and maltodextrin (WPI + MD) by spray drying. Further, these microencapsulated powders were evaluated for their impact on bread quality and HCA retention. RESULTS Maltodextrin (MD) encapsulates had higher free (86%) and net HCA (90%) recovery. Microencapsulates incorporated breads had enhanced qualitative characteristics and higher HCA content than water extract incorporated bread due to efficient encapsulation during bread baking. Comparatively, bread with MD encapsulates showed softer crumb texture, desirable sensory attributes with considerable volume and higher HCA content. CONCLUSION The higher HCA contents of encapsulate incorporated breads were sufficient to claim for functionality of HCA in bread. Comparatively, MD had efficiently encapsulated Garcinia fruit extract during spray drying and bread baking. Spray drying proved to be an excellent encapsulation technique for incorporation into the food system.

Evaluation of Antioxidant and Antimutagenic Activities of the Extracts from the Fruit Rinds of Garcinia cowa

Recent studies have reported the biological activities of the crude extracts/purified compounds from various parts of Garcinia cowa. In the present study, the dried fruit rinds of G. cowa were extracted with hexane and chloroform and the extracts were used to evaluate their antioxidant and antimutagenic activities. Using β-carotene-linoleate-model system, at 200 ppm concentration, hexane, chloroform extracts and butylated hydroxyanisole (BHA) showed 91.7, 93.7, and 98.0% antioxidant activity, respectively, whereas, at 50 ppm concentration the radical scavenging activity was 83.3, 86.3, and 88.5%, respectively, through DPPH method. At a concentration of 5000 μg/plate, hexane extract exhibited strong antimutagenicity against the mutagenicity of sodium azide in both the tester strains of Salmonella typhimurium (TA-100 and TA-1535). Chloroform extract showed strong antimutagenicity in both the tester strains at a concentration of 2500 μg/plate and above. However, the chloroform extract exhibited higher antioxidant and antimutagenic activities than that of hexane extract. This study showed that both the extracts from the fruit rinds of G. cowa possess antioxidant and antimutagenic properties.

Effects of age and manganese (II) chloride on peroxidase activity of brain and liver of the teleost, Channa punctatus.

Fish provide enormous spectrum of longevity and thus present the possibility of multiple mechanisms of senescence. Oxidative stress as a causative agent of senescence and the protective role of antioxidant enzymes were tested in the teleost, Channa punctatus taking peroxidase (POD) (EC 1.1 1.1.7) as the representative enzyme. The activity of POD in brain and liver declined during maturation phase (young vs middle-aged). During senescence phase (middle-aged to old) the enzyme activity increased in liver but remained stabilized in brain. The degree of increase in peroxidase activity following in vitro MnCl2 treatment was always higher in liver than in brain. The rate of MnCl2 induced increase in POD activity of both tissues showed an increasing trend with age. However statistical significance was observed only in brain during senescence phase. No significant loss of enzyme activity in both the tissues and greater degree of increase by MnCl2 in brain suggest that antioxidant capacity is not impaired in old murrels.

Age-related changes in catalase activity and its inhibition by manganese (II) chloride in the brain of two species of poikilothermic vertebrates

Two species of poikilothermic vertebrates, a teleost fish (Channa punctatus) and the garden lizard (Calotes versicolor) were used to study the effect of age on brain catalase (CT) activity and its inhibition by manganese (II) chloride (MnCl(2)). While in fish the CT activity of brain remained unchanged throughout the lifespan, the enzyme activity decreased during maturation and then showed an increase during aging in the garden lizard. MnCl(2) at a concentration of 333 muM in incubating medium significantly inhibited the CT activity of the brain of both fishes and lizards of all the three age groups (young, middle-aged and old), the degree of inhibition showing a trend of increase with advancing age. However, statistical significance was observed when fishes of the young age group were compared either with those of middle-aged or old counterparts, and between young versus old and middle-aged versus old lizards. Increased susceptibility to Mn(2+) during aging suggests changes in regulation of CT.

Effect of age on lipid peroxides, lipofuscin and ascorbic acid contents of the lungs of male garden lizard

Oxidative damage was assessed through the estimation of lipid peroxides (LP) in the lungs of an ageing short-lived species of reptile, Calotes versicolor, commonly known as the garden lizard. Attempts were also made to trace its relationship with the age pigment, lipofuscin and the antioxidant ascorbic acid. While LP increased with advancing age the contents of both lipofuscin and ascorbic acid did not show appreciable change during maturation ( < 1-1 year old) but declined during senescence phase (1 to 2-4 year old). While the pattern of age associated changes in LP and ascorbic acid indicate similarity with the pattern observed in most of the mammals, the reduction of lipofuscin in older lizards is a significant departure from the common trend.

Lanthanum induced B-to-Z transition in self-assembled Y-shaped branched DNA structure.

Controlled conversion of right-handed B-DNA to left-handed Z-DNA is one of the greatest conformational transitions in biology. Recently, the B-Z transition has been explored from nanotechnological points of view and used as the driving machinery of many nanomechanical devices. Using a combination of CD spectroscopy, fluorescence spectroscopy, and PAGE, we demonstrate that low concentration of lanthanum chloride can mediate B-to-Z transition in self-assembled Y-shaped branched DNA (bDNA) structure. The transition is sensitive to the sequence and structure of the bDNA. Thermal melting and competitive dye binding experiments suggest that La3+ ions are loaded to the major and minor grooves of DNA and stabilize the Z-conformation. Our studies also show that EDTA and EtBr play an active role in reversing the transition from Z-to-B DNA.