CHANGES IN CARBOHYDRATES ASSOCIATED WITH SENESCENCE OF CUT GLADIOLUS SPIKES UNDER PULSING AND WET COLD STORAGE DURATIONS

Several biochemical and metabolic changes are associated with senescence of cut gladioli, particularly in relation to quality characteristics, including dynamism of carbohydrates. The objective of this study was to evaluate the effect of pulsing and wet cold storage on the starch and sugar biomarkers on cut Gladiolus ( Gladiolus grandiflorus L. cv. Fado) vase quality. Pulsing treatments of 600-ppm 8-hydroxyquinoline sulphate, plus 5% sucrose solution, versus distilled water, were administered prior to wet cold storage durations of 0 - 5 days, on the cut Gladiolus grown from corms. This was done in the open field at the Horticulture Research and Teaching Field, Egerton University in Kenya, during two successive seasons. There was a significant difference (P <0.01) in total soluble sugars (TSS) and total starch of spikes pulsed with 600 ppm 8 - HQS + 5% sucrose, compared with the control, during the third day in the vase life of the cut flowers. Prolonged vase life of cut spikes was associated with a decrease in total soluble sugars and increase in total starch, as influenced by pulsing and wet storage duration up to 4 days.Plusieurs changements biochimiques et m\ue9taboliques sont associ\ue9s \ue0 la s\ue9nescence des gla\uefeuls coup\ue9s, en particulier en relation avec les caract\ue9ristiques de qualit\ue9, y compris le dynamisme des glucides. L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer l\u2019effet du stockage au froid puls\ue9 et humide sur les biomarqueurs de l\u2019amidon et du sucre sur la qualit\ue9 des vases de gla\uefeul coup\ue9 ( Gladiolus grandiflorus L. cv. Fado). Des traitements puls\ue9s de sulfate de 8-hydroxyquinol\ue9ine \ue0 600 ppm, plus une solution de saccharose \ue0 5%, contre de l\u2019eau distill\ue9e, ont \ue9t\ue9 administr\ue9s avant des dur\ue9es de stockage au froid humide de 0 \ue0 5 jours, sur le gla\uefeul coup\ue9 \ue0 partir de bulbes. Cela a \ue9t\ue9 faite dans le champ de Horticulture Research and Teaching Field, Egerton University au Kenya, pendant deux saisons successives. Il y avait une diff\ue9rence significative (P <0,01) dans les sucres solubles totaux (TSS) et l\u2019amidon total des \ue9pis puls\ue9s avec 600 ppm 8 - HQS + 5% de saccharose, par rapport au t\ue9moin, au cours du troisi\ue8me jour de la vie en vase de la coupe fleurs. La dur\ue9e de vie prolong\ue9e en vase des \ue9pis coup\ue9s a \ue9t\ue9 associ\ue9e \ue0 une diminution du des sucres solubles totaux et \ue0 une augmentation de l\u2019amidon total, sous l\u2019influence de la dur\ue9e de stockage puls\ue9 et humide jusqu\u2019\ue0 4 jours

ANTIOXIDANT, ANTIMICROBIAL AND SYNERGISTIC ACTIVITIES OF TEA POLYPHENOLS

Microbial resistance to antibiotics has become an increasing global problem and there is a need to find out novel potent antimicrobial agents with alternative modes of action as accessories to antibiotic therapy. This study investigated the antioxidant, antimicrobial and synergistic properties of tea polyphenols. The tea germplasm from Kenya, China and Japan that are grown in Kenya were characterised for their biochemical profiles. The total phenolic content, theaflavins and thearubigins content of different tea products used in this study were determined spectrophotometrically according to Folin-Ciocalteus and flavognost methods, respectively. The individual catechin contents were characterised by high performance liquid chromatography (HPLC) and identified according to their HPLC retention times, elution order and comparison with authentic standards. The antioxidant activity of tea polyphenols was determined spectrophotometrically on its ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. The agar disc diffusion method was used to screen for antimicrobial and synergistic activities of the tea liquors. Black, green, purple coloured leaf and white (silvery tips) tea products differed significantly in the levels of total polyphenols, total catechins, catechins fractions, theaflavins and thearubigins (P<0.05). Green, purple coloured leaf (aerated) and black tea from terminal buds and white tea products analysed in this study exhibited slightly higher antioxidant activity than black tea. The different types of tea products exhibited significant influence on the inhibition zone diameters against bacteria and fungi exposed to the tea extracts. Methicillin and penicillinase resistant S. aureus ATCC 25923, C. albicans ATCC 90028 and a clinical isolate of C. neoformans were more susceptible to all tea extracts than E. coli and S. typhi . There was synergism between most tea extracts and penicillin G against methicillin and penicillinase resistant S. aureus ATTC 25923.La r\ue9sistance microbienne aux antibiotiques est devenue un probl\ue8me \ue9pineux au niveau global et il est n\ue9cessaire d\u2019identifier d\u2019autres agents antimicrobiens efficaces avec des modes alternatifs d\u2019action pour appuyer la th\ue9rapie antibiotique. Cette \ue9tude \ue9tait men\ue9e sur les antioxydants et les propri\ue9t\ue9s antimicrobiennes et synerg\ue9tiques des polyph\ue9nols du th\ue9. Les germoplasmes de th\ue9 en provenance du Kenya, de la Chine et du Japon cultiv\ue9s au Kenya ont fait l\u2019objet d\u2019une caract\ue9risation de leurs profiles biochimiques. La teneur ph\ue9nolique totale ainsi que les th\ue9aflavines et les th\ue9arubigines dans les diff\ue9rents produits de th\ue9 utilis\ue9s dans cette \ue9tude \ue9taient d\ue9termin\ue9e par spectrophotom\ue9trie respectivement sur base des m\ue9thodes dites de Folin-Ciocalteus et flavognost. Les teneurs individuelles en cat\ue9chine \ue9taient caract\ue9ris\ue9es par chromatographie liquide \ue0 haute performance (HPLC) et identifi\ue9es sur base de leurs temps de r\ue9tention de HPLC, de l\u2019ordre d\u2019\ue9lution en comparaison avec les standards normaux. L\u2019activit\ue9 antioxydante des polyph\ue9nols de th\ue9 \ue9tait d\ue9termin\ue9e par spectrophotom\ue9trie sur base de sa capacit\ue9 \ue0 capter le radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). La m\ue9thode de diffusion sur disque d\u2019agar \ue9tait utilis\ue9e pour tester les activit\ue9s microbiennes et synerg\ue9tiques des extraits du th\ue9. Les feuilles de th\ue9 de couleurs noir, verte, pourpre et les extraits du th\ue9 blanc diff\ue9raient significativement du point de vue niveaux de polyph\ue9nols totaux, des cat\ue9chines totales, des fractions de cat\ue9chines, des th\ue9aflavines et des th\ue9arubigines (P<0.05). Les feuilles de couleurs verte et pourpre ainsi que les th\ue9s noirs issues des bourgeons terminaux et extraits du th\ue9 blanc analys\ue9s dans cette \ue9tude ont montr\ue9 une activit\ue9 antioxydante l\ue9g\ue8rement sup\ue9rieure \ue0 celle du th\ue9 noir. Les diff\ue9rents types d\u2019extraits de th\ue9 ont montr\ue9 une influence significative sur les diam\ue8tres des zones de contamination une fois expos\ue9s \ue0 des bact\ue9ries ou des champignons. Staphylococcus aureus ATCC 25923, C. albicans ATCC 90028 et un isolant clinique de C. neoformans r\ue9sistants \ue0 la m\ue9thicilline et \ue0 la p\ue9nicillinase \ue9taient les plus susceptibles \ue0 tous les extraits de th\ue9 en comparaison avec E. coli et S. typhi . Il y avait un synergisme entre la plupart d\u2019extraits de th\ue9 et la p\ue9nicilline G contre S. aureus ATTC 25923 r\ue9sistant \ue0 la m\ue9thicilline et \ue0 la p\ue9nicillinase

Endotoxin-like effects in acute phase response to Trypanosoma brucei brucei infection are not due to gastrointestinal leakage

Trypanosomosis is mainly an immunological and inflammatory response mediated by increased levels of proinflammatory cytokines. Evidence suggests that pathological changes produced during infection with trypanosomes could be initiated by nonspecific endotoxin-like substances in trypanosomes and/or Gram-negative secondary bacterial infection. Studies in trypanosome-infected rats indicate damage to the gastrointestinal tract (GIT) accompanied by increased leakage of the GIT mucosa. The current Study was carried out to determine the in vivo response to endotoxin-like Substances of Trypanosoma brucei brucei. To this purpose we neutralized the entrance of endotoxin through the GIT using polymyxin-B treatment and monitored the plasma concentration of the acute phase proteins SAP and Hp. The results in this study, where infection was performed in the presence of oral antibiotic that is not absorbed from GIT and which binds to and inactivates endotoxin, show that the elevated plasma levels of endotoxin-like activity and the resulting acute phase response indicated by an increase in levels of Hp and SAP, are due to trypanosome infection. Results obtained in the present Study indicate that GIT is not the major source of elevated plasma endotoxin-like activity levels and the observed acute phase response was due to an increase in the levels of acute phase proteins SAP and haptoglobin. Therefore trypanosomes are responsible for the elevated plasma endotoxin-like activity levels and the subsequent systemic acute phase response in the host