Charles Olaiya

Dietary consumption of monosodium L-glutamate induces adaptive response and reduction in the life span of Drosophila melanogaster

Adaptive response is the ability of an organism to better counterattack stress‐induced damage in response to a number of different cytotoxic agents. Monosodium L‐glutamate (MSG), the sodium salt of amino acid glutamate, is commonly used as a food additive. We investigated the effects of MSG on the life span and antioxidant response in Drosophila melanogaster (D. melanogaster). Both genders (1 to 3 days old) of flies were fed with diet containing MSG (0.1, 0.5, and 2.5‐g/kg diet) for 5 days to assess selected antioxidant and oxidative stress markers, while flies for longevity were fed for lifetime. Thereafter, the longevity assay, hydrogen peroxide (H2O2), and reactive oxygen and nitrogen species levels were determined. Also, catalase, glutathione S‐transferase and acetylcholinesterase activities, and total thiol content were evaluated in the flies. We found that MSG reduced the life span of the flies by up to 23% after continuous exposure. Also, MSG increased reactive oxygen and nitrogen species and H2O2 generations and total thiol content as well as the activities of catalase and glutathione S‐transferase in D. melanogaster (P < .05). In conclusion, consumption of MSG for 5 days by D. melanogaster induced adaptive response, but long‐term exposure reduced life span of flies. This study may therefore have public health significance in humans, and thus, moderate consumption of MSG is advocated by the authors.

Bioregulators Favourably Affect the Levels of Vitamins and Sugars in Tomato Fruit Tissues

Bioregulators Favourably Affect the Levels of Vitamins and Sugars in Tomato Fruit Tissues This study aimed to examine the influence of exogenous application of the bioregulators indole acetic acid (IAA), indole butyric acid (IBA) and naphthalene acetic acid (NAA) on the vitamin and sugar content of tomatoes. Harvested fruits of the treated tomato genotypes, namely NHLy 11, NHLy 12, NHLy 13, NHLy 15 and NHLy 16, were analysed for these parameters. Spectrophotometric analysis results showed that IAA significantly increased (p<0.05) the concentrations of β-carotene, vitamin A and ascorbate in all the tested genotypes, with the highest values of 707.84 μg·100 g-1 fwb, 118.21 μg·100 g-1 RE and 20.36 μg·100 g-1 fwb, respectively, in the NHLy16 genotype. The total sugar content was not significantly affected by the treatments. It is proposed that exogenous application of these bioregulators to plant foods such as tomatoes can improve their phytonutrient concentrations, promoting better public health. Korzystny Wpływ Bioregulatorów na Zawartość Witamin i Cukrów w Tkankach Owoców Pomidora Celem badań było określenie wpływu egzogennego stosowania bioregulatorów takich jak kwas: indolilooctowy (IAA), kwas indolilomasłowy (IBA) i kwas naftalenooctowy (NAA) na zawartość witamin i cukrów w pomidorach. Zebrane owoce traktowanych genotypów pomidora: NHLy 11, NHLy 12, NHLy 13, NHLy 15 i NHLy 16, analizowano pod względem zawartości tych składników. Wyniki analizy spektrofotometrycznej wykazały, że IAA istotnie zwiększał (p<0,05) stężenie β-karotenu, witaminy A oraz askorbinianu we wszystkich badanych genotypach, przy czym najwyższe wartości uzyskano dla genotypu NHLy 16, odpowiednio 707,84 μg·100 g-1 św. m., 118,21 μg·100 g-1 RE i 20,36 μg·100 g-1 św. m. Zastosowane traktowania nie wpłynęły istotnie na całkowitą zawartość cukrów. Egzogenne traktowanie bioregulatorami produktów roślinnych, takich jak pomidory, może poprawić w nich stężenia fitosubstancji odżywczych, wpływając w ten sposób korzystnie na zdrowie konsumenta.

Influence of auxin bioregulators on physiological changes and shelf-life of tomatoes.

Influence of Auxin Bioregulators on Physiological Changes and Shelf-Life of Tomatoes Tomato (Solanum lycopersicon) is one of the most popular and extensively consumed vegetable crops worldwide. Their highly perishable nature poses great limitation to their marketability over long distances. We have earlier demonstrated that the 100 mg·L-1 concentration of the bioregulators Indoleacetic acid (IAA), indole butyric acid (IBA) and naphthalene acetic acid (NAA) is suitable for tomato growth under field conditions. We have also reported the effects of these bioregulators on tomato fruit yield and postharvest quality. In this study, the shelf - life and associated physiological changes of fruits of five bioregulator - treated tomato genotypes in practical conditions of storage time and temperature were investigated. Seeds of the tomato genotypes namely NHLy 11, NHLy 12, NHLy 13, NHLy 15 and NHLy 16 were subjected to treatments with 100 mg·L-1 concentrations of the bioregulators IAA, IBA, NAA and distilled water (control) before planting. The fruits were harvested at the orange - red ripe stage. Sensory and visual fruit changes were determined and deterioration level measured during storage trials for up to ten days in order to evaluate their quality. The results revealed that the bioregulator - treated tomato genotypes generally exhibited better storage features than those of controls, with the NAA - treated NHLy 12 genotype having the highest storability index of 6.00 after ten days of storage. The present findings show that treating tomatoes with bioregulators, especially the ones used in this work improves their storage at ambient conditions. Wpływ Bioregulatorów Auksynowych na Zmiany Fizjologiczne i Trwałość Przechowalniczą Pomidorów Pomidor (Solanum lycopersicon) jest jednym z najbardziej popularnych warzyw spożywanych na dużą skalę na całym świecie. Owoce pomidora szybko ulegają zepsuciu, co stanowi bardzo duże ograniczenie ich atrakcyjności rynkowej po długim okresie transportu. Wykazaliśmy wcześniej, że stężenie 100 mg·L-1 bioregulatorów: IAA - kwas indolilooctowy, IBA - kwas indolilomasłowy, oraz NAA - kwas naftylooctowy, jest odpowiednie dla uprawy pomidora w warunkach polowych. Opisaliśmy również wpływ tych bioregulatorów na plon owoców pomidora i jakość pozbiorczą. W niniejszej pracy badano trwałość przechowalniczą i związane z tym zmiany fizjologiczne owoców pięciu genotypów pomidora traktowanych bioregulatorami w praktycznych warunkach. Nasiona genotypów NHLy 11, NHLy 12, NHLy 13, NHLy 15 i NHLy 16 poddano traktowaniu bioregulatorami IAA, IBA, NAA w stężeniu 100 mg·L-1 oraz wodą destylowaną (kontrola) przed wysiewem. Owoce zbierano w pomarańczowo-czerwonej fazie dojrzałości. Określano zmiany sensoryczne i wizualne oraz mierzono poziom zepsucia i ich jakość podczas 10 dni przechowywania. Otrzymane wyniki wykazały, że genotypy pomidora traktowane bioregulatorami odznaczały się lepszą trwałością przechowalniczą niż genotypy kontrolne (nietraktowane), przy czym genotyp NHLy 12 traktowany bioregulatorem NAA miał najwyższy wskaźnik trwałości przechowalniczej (6,00) po 10 dniach składowania. Uzyskane obecnie dane pokazują, że traktowanie pomidorów bioregulatorami, szczególnie tymi wykorzystanymi w niniejszych badaniach, poprawia ich trwałość przechowalniczą w warunkach otoczenia.

Antioxidant activities of methanol extracts of Curculigo pilosa rhizome and Gladilous psittascinus corm against lipid peroxidation in rat’s liver and heart

ABSTRACT Antioxidant activities of methanol extracts of the rhizome of Curculigo pilosa (CP) and corm of Gladiolus psittacinus (GP) were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effect, reducing power, total antioxidant capacity (TAC), total phenolics content (TPC), and total flavonoid content (TFC). Lipid peroxidation was induced by sodium nitroprusside (SNP) in the liver and heart of healthy Wistar albino rats (in vitro) and peroxidation was monitored by malondialdehyde (MDA) content. Phytochemical screening showed the presence of tannins, steroids, and flavonoids in CP rhizomes and saponins and cardiac glycosides in GP corms. The results showed that CP possessed higher TPC, TFC, and TAC than GP and higher DPPH scavenging and reducing power activities. CP and GP inhibited the production of MDA in SNP-incubated heart and liver homogenates in a dose-dependent manner. However, the methanol extracts of the CP rhizomes showed higher reduction in MDA content than the corms of GP.

Antioxidant and Antibacterial Activities of the Essential Oils of Cymbopogon citratus and Citrus sinensis

Aims: The use of essential oils from plants as natural antioxidant and antimicrobial is a field of growing interest. The aim of this study was to investigate the antioxidant and antibacterial properties of the essential oils of Cymbopogon citratus L. (lemongrass) and Citrus sinensis (orange peels) independently. Methodology: Essential oils extracted by hydrodistillation from Cymbopogon citratus and Citrus sinensis were individually assayed for 1,1 –diphenyl2 picrylhydrazyl (DPPH) radical scavenging activity, hydrogen peroxide scavenging, reducing power and metal chelating activity in relation to the total phenolic and total flavonoid content of each essential oil. Antimicrobial analyses were carried out using pour plate method for the determination of the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the oils on pathogenic bacteria Staphylococcus epidermidis and Staphylococcus aureus and non-pathogenic bacteria Lactobacillus casei and Lactobacillus brevis. Short Research Article Olaiya et al.; EJMP, 16(1): 1-10, 2016; Article no.EJMP.28176 2 Results: The two essential oils possessed antioxidant and antibacterial activities. However, the essential oil of C. citratus showed a higher level of total phenolic (372.81±1.36 μg/ml) and total flavonoid (377.88±1.52 μg/ml) content when compared to the essential oil of C. sinensis which showed a lower total phenolic (262.81±2.66 μg/ml) and flavonoid (79.65±1.44 μg/ml) contents. These resulted in a higher level of DPPH radical scavenging and metal chelating activity of C. citratus compared to C. sinensis. MIC of 212.5 mg/ml oil concentration was obtained for C. citratus against S. epidermidis and less than 106.25 mg/ml against S. aureus while 210 mg/ml oil concentration was obtained for C. sinensis against S. aureus and 850 mg/ml oil concentration against S. epidermidis. MBC was observed for C. citratus at 425 mg/ml while C. sinensis showed MBC at 840 mg/ml oil concentration. None of the oils showed a significant inhibition against the non-pathogenic bacteria compared to the (Gentamycin) negative control. Conclusion: The essential oils of C. citratus and C. sinensis have potential for use as natural antioxidants and antibacterial agents.