The antibacterial activity of plant extracts containing polyphenols against Streptococcus mutans.

The minimum inhibitory concentrations (MIC) of commercially available and 70% aqueous propanone (P70) extracts from plants chosen for polyphenol content on Streptococcus mutans and other bacteria were determined using a standard susceptibility agar dilution technique to investigate their potential use as anticariogenic agents. The effects on adhesion of S. mutans to glass were also studied. The lowest MICs were for the P70 extracts of red grape skin (0.5 mg ml(-1)) and green tea and sloe berry skin (2 mg ml(-1)). The commercial extracts generally had a lower activity with a minimum MIC of 2 mg ml(-1) for tea extracts, grape seed extracts and Pynogenol (extract of maritime pine). All other extracts had MICs of > or = 4 mg ml(-1). Unfermented cocoa had greater antimicrobial activity than fermented cocoa and the activity of the fractionated extract increased with the extent of epicatechin polymerization. Epicatechin polymer had an MIC of 1 mg ml(-1) and an MBC of 64 mg ml(-1). Selected extracts were tested against other oral bacteria and showed activity against gram-positive organisms. P70 extracts of unfermented cocoa, epicatechin polymer fraction, green tea and red grape seed were bacteriostatic and prevented acid production when added at the MIC to cultures of S. mutans grown in a chemically defined medium supplemented with either glucose or sucrose. There was a reduction in viability which was greater when added to washed cells, but there were some viable cells after 24 h. The extracts also reduced adherence of S. mutans to glass.

The comparative gastrointestinal responses of children and adults following consumption of sweets formulated with sucrose, isomalt and lycasin HBC.

OBJECTIVES: To determine the gastrointestinal responses of children and adults following consumption of sucrose, isomalt and lycasin HBC and to compare these at two different dose levels in adults. DESIGN: Both studies were randomised, double-blind, cross-over designs. SUBJECTS: Fifty-one children aged 6-9 y were recruited from primary schools in the Salford area of Greater Manchester. Forty-eight children completed the study. Fifty healthy adult volunteers aged 18-24 y were recruited from the student population of the University of Salford. All subjects completed the study. INTERVENTIONS: Children consumed either 25 g of sucrose, isomalt or lycasin HBC and adults 25 and 40 g in hard boiled sweets per day for two consecutive test days. Test periods of 2 days were separated by 7 day washout periods. Children consumed sweets throughout test days and adults in no less than 30 min but no more than 90 min. Subjects reported the prevalence and magnitude of flatulence, borborygmi, bloating, colic, bowel movements and watery faeces. RESULTS: Consumption of 25 g isomalt provoked a mild laxative effect in children but not in adults. Consumption of 25 g isomalt significantly increased the prevalence and magnitude of gastrointestinal responses in both children and adults. Consumption of 25 g lycasin HBC significantly increased borborygml in children and adults but no other gastrointestinal responses. Consumption of 40 g lycasin HBC or isomalt by adults significantly increased the mean frequency of bowel movements and the number of subjects passing watery faeces. In adults, 40 g isomalt and lycasin HBC provoked significantly more gastrointestinal responses compared to 25 g of either product. CONCLUSIONS: Consumption of 25 g lycasin HBC does not provoke an unacceptable laxative effect or gastrointestinal response in children or adults compared to 25 g isomalt, which is associated with a mild laxative effect and increase in gastrointestinal responses. In adults gastrointestinal responses following consumption of products were found to be dose dependent.

Polyols in confectionery: the route to sugar-free, reduced sugar and reduced calorie confectionery.

Polyol-containing confectionery offers considerable advantages over traditional sucrose-based confectionery in terms of reduced energy content and reduced cariogenicity. However, over-consumption of polyol confectionery may lead to gastrointestinal symptoms in some individuals. Rather than consider this as a distinct disadvantage to the consumer, this article discusses how careful consideration of the physico-chemical properties of polyols and advances in product development and formulation can provide suitable polyol-based products for the consumer. Furthermore. food legislation and ingredient pricing issues are just some of the factors that must be taken into account when designing new polyol-containing products if their functional benefits and good product quality are to be delivered to the consumer.

Tolerance and breath hydrogen excretion following ingestion of maltitol incorporated at two levels into milk chocolate consumed by healthy young adults with and without fasting.

Little is known about the gastrointestinal effects of ingesting maltitol in chocolate. This study was designed to determine whether it leads to increased gastrointestinal symptomatology and if that symptomatology is dose related. It was also designed to discover whether breath hydrogen excretion in response to maltitol is dose related. In a double-blind, crossover study, 20 healthy volunteers aged 18-24 y ingested 100 g chocolate containing 40 g sucrose, 10 g sucrose plus 30 g maltitol or 40 g maltitol after fasting (abstinence from food and liquids from 2200 h on the night before chocolate consumption) and not fasting. There was no difference in symptomatology between fasting and nonfasting periods, and consumption order had no effect on symptomatology. Relative to ingestion of sucrose, 30 g maltitol caused no significant difference in symptoms, but 40 g resulted in more mild borborygmi (P < 0.05) and mild flatulence (P < 0.01) but not moderate or severe symptoms. Neither 30 nor 40 g maltitol caused significantly greater laxation than sucrose ingestion (P > 0.05). In a separate study, 10 healthy volunteers aged 18-24 y ate the same test products before breath H2 testing; 40 g maltitol in chocolate caused a greater total breath H2 excretion compared with 30 g maltitol (P < 0.05) or sucrose (P < 0.01). Total breath hydrogen excretion was also greater with 30 g maltitol compared with sucrose (P < 0.05). This dose-related response was consistent with the lower symptomatology after ingestion of 30 vs. 40 g maltitol. We have shown that 30 g maltitol in chocolate causes no significant symptomatology in young adults; however, 40 g caused mild borborygmi and flatus but no increased laxation. An increased breath H2 response indicates colonic fermentation of this polyol.

Dose-related gastrointestinal response to the ingestion of either isomalt, lactitol or maltitol in milk chocolate.

OBJECTIVES: To determine whether there were differences between different polyols (sugar alcohols) in terms of their ability to stimulate intolerance symptoms when consumed in milk chocolate. Also to discover whether symptomatology can be related to the dose of polyol ingested. DESIGN: The study was of a randomised double-blind cross-over design. SUBJECTS: 59 healthy volunteers aged 18-24 years were recruited from the student population of the University of Salford. All subjects successfully completed the trial. INTERVENTIONS: Subjects ingested 100 g milk chocolate containing 40 g bulk sweetner as either sucrose, isomalt, lactitol or maltitol or a mixture (10:30 w/w) of sucrose and isomalt, sucrose and lactitol or sucrose and maltitol. Each bar was taken as breakfast on one day with following products consumed at 1-week intervals. Subjects reported the incidence and severity of the symptoms of flatulence, borborygms, colic, motion frequency and loose stools. RESULTS: The ingestion of 30 g or 40 g lactitol resulted in a significant increase in the incidence and severity of all symptoms examined compared to reactions after the consumption of standard sucrose-containing chocolate (P <0.01). Similarly, 40 g isomalt led to an increased incidence of all symptoms, including mild laxation (P <0.01), but unlike lactitol none was rated as being severe. A reduction in isomalt to 30 g was marked by increased tolerance with evidence of only mild borborygms (P <0.01), mild flatulence, colic, and laxation (P <0.05), with no increase in motion frequency (P <0.35). Ingestion of 40 g maltitol caused less intolerance than 40 g isomalt, with evidence of only flatulence, borborygms and colic (P <0.01), symptoms being rated as only mild. A reduction to 30 g led to a decrease in all symptoms except mild flatulence. Maltitol did not have any laxative effect when ingested at either 30 g (P = 0.32) or 40 g (P = 0.13) per day. CONCLUSIONS: This work has shown that there are significant differences in the reporting of gastrointestinal symptomatology following the consumption of isomalt, lactitol and maltitol incorporated into milk chocolate. However, with all three polyols the incidence and severity of symptomatology was dose dependent.

Breath hydrogen after ingestion of the bulk sweeteners sorbitol, isomalt and sucrose in chocolate.

The effect of eating chocolate containing sugar alcohols as sweetening agents on colonic fermentation has been investigated by monitoring breath H2 levels. Levels were compared with those occurring after the consumption of normal, sugar-containing chocolate. Ten healthy volunteers aged 19 to 21 years ingested equal amounts of either sorbitol, isomalt or sucrose incorporated into standard chocolate bars. Breath H2 levels after consumption of chocolate containing either sorbitol or isomalt were significantly higher than those after consumption of chocolate containing sucrose (P < 0.001). After consumption of chocolate containing sorbitol, double the mean estimated volume of breath H2 was produced over 6 h compared with that produced after eating chocolate containing isomalt. Taken together with results relating to the incidence of intolerance symptoms, these findings demonstrate that sorbitol is associated with greater colonic fermentation compared with isomalt.

Comparative studies of gastrointestinal tolerance and acceptability of milk chocolate containing either sucrose, isomalt or sorbitol in healthy consumers and type II diabetics.

The objective was to compare reaction of adult consumers of confectionery to milk chocolate made with either isomalt, sucrose or sorbitol. Test chocolate was eaten by subjects at home during 7 days in amounts chosen by them up to a maximum of 100 g per day. In a double-blind crossover trial isomalt chocolate was associated in healthy consumers (n = 58) with increased motion frequency, wind and flatulence compared with sucrose chocolate. However, the intensity of these gastrointestinal effects was predominantly slight and insufficient to affect acceptability. In separate crossover trials, reactions of Type II diabetic consumers to eating isomalt chocolate (n = 53) or sorbitol chocolate (n = 51) were compared to reactions when eating no chocolate. Both isomalt and sorbitol chocolate were associated with higher incidence of wind and flatulence than for no chocolate, but only sorbitol chocolate increased motion frequency. Again intensity of gastrointestinal effects was slight. It is concluded that isomalt has potential use in both regular and diabetic chocolate.

Effects of conventional sucrose-based, fructose-based and isomalt-based chocolates on postprandial metabolism in non-insulin-dependent diabetics.

Milk chocolate is rich in both sucrose and fat, and is therefore considered unsuitable for diabetics. Nevertheless there is little information on the metabolic effects of conventional chocolate or specialized formulations with reduced sucrose content. In the present study six male non-insulin-dependent diabetes mellitus patients (age range 35-60 years; body-mass index less than 28) consumed test meals of chocolate (75 g) on three separate occasions. The control chocolate contained sucrose (45.5% w/w); the test chocolates contained either fructose (45.5% w/w) or isomalt (45.1% w/w). The latter is a sweet disaccharide alcohol which has no glycaemic effect when consumed as a pure compound. Venous blood samples were obtained at 30 min intervals for 5 h, and analysed for glucose, insulin, lactate and triglycerides. All three chocolates provoked a sustained rise in blood glucose, which reached a maximum at 90 min after ingestion and returned to baseline values by 5 h. The highest blood glucose levels occurred after conventional chocolate, and differences were statistically significant at 60 and 90 min (P less than 0.05). The area under the glycaemic curve for isomalt chocolate was 36% smaller than that for conventional chocolate (P less than 0.05), and there were differences in insulin and lactate levels, consistent with the lower glycaemic effect. The glycaemic response to the fructose-based chocolate was also lower than that to control chocolate but the difference was not significant. All three chocolates led to a similar sustained rise in serum triglyceride levels. Isomalt appears to be a palatable alternative sweetener capable of reducing the glycaemic effect of diabetic confectionary.

Association of a Mr 50,000 cap-binding protein with the cytoskeleton in baby hamster kidney cells.

A monoclonal antibody directed against eukaryotic mRNA 5'-cap-binding protein (anti-CBP antibody) was used to localize cap-binding protein (CBP) in BHK-21 baby hamster kidney cells by immunofluorescence microscopy. It was found that the antibody reacts with a fibrous network extending through the cytoplasm in a radial arrangement. The network behaves like intermediate filaments in colchicine-treated cells, suggesting a direct or indirect linkage of CBP with intermediate filaments. The association of CBP with a cytoskeletal element was further confirmed by isolation of proteins from Triton X-100-extracted cells and identification of CBP in the cytoskeletal fraction with anti-CBP antibody. The major polypeptide reacting with anti-CBP antibody is a Mr 50,000 component. Tryptic peptide mapping showed that this polypeptide is related to a Mr 24,000 polypeptide identified as CBP in earlier experiments [Sonenberg, N., Morgan, M. A., Testa, D., Colonna, R. J. & Shatkin, A. J. (1978) Proc. Natl. Acad. Sci. USA 75, 4843-4847].

Association of an Mr 50,000 cap binding protein with the cytoskeleton in BHK cells.

A monoclonal antibody (anti-CBP antibody) is shown to be directed against cap binding protein(s) (CBP) by virtue of its ability to inhibit the translation of capped reovirus mRNA in a cell-free system derived from L-cells and inhibit the specific (cap analogue-inhibited) cross-linking of proteins to the oxidized 5' terminal cap structure of reovirus mRNA. Anti-CBP antibody reacts with an Mr 50,000 polypeptide in rabbit reticulocyte polysomes and this polypeptide appears to be associated with the 5' cap structure of mRNA. In BHK-21 cells immunofluorescence microscopy reveals that the antibody reacts with a fibrous network extending through the cytoplasm in a radial arrangement. The network behaves like intermediate filaments in colchicine-treated cells suggesting a direct or indirect linkage of CBP with intermediate filaments. The association of CBP with a cytoskeletal element is further confirmed by isolation of proteins from Triton X-100-extracted cells and identification of CBP in the cytoskeletal fraction with anti-CBP antibody. The major polypeptide reacting with anti-CBP antibody is an Mr 50,000 component. Tryptic peptide mapping shows that this polypeptide is related to an Mr 24,000 polypeptide identified as cap binding protein in earlier experiments [Sonenberg, Morgan, Merrick & Shatkin (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 4843-4847].

Microtubule-disrupting agents affect two different events regulating the initiation of DNA synthesis in Swiss 3T3 cells.

The stimulatory effect of epidermal growth factor, alone or with insulin, on the rate of initiation of DNA synthesis in Swiss 3T3 cells can be synergistically enhanced by the addition of either Colcemid or colchicine at 1 microM. However, both Colcemid and colchicine can exert the synergistic effect only when added earlier than 8 hr of the prereplicative period (lag phase). Removal of Colcemid (which allows for rapid reassembly of microtubules) earlier than 10 hr of the lag phase results in a loss of the synergistic effect. This suggests that microtubules must remain disrupted for longer times to accomplish some putative event(s) necessary for increasing the rate of initiation of DNA synthesis. Preincubation of quiescent cells with either Colcemid or colchicine for 8 hr prior to adding epidermal growth factor, alone or with insulin, shortens the lag phase by about 4 hr, irrespective of the resulting rate of initiation of DNA synthesis. These results suggest that the state of microtubules is affecting independently at least two different events involved in regulating time initiation of DNA synthesis.

Cytoskeleton-disrupting drugs enhance effect of growth factors and hormones on initiation of DNA synthesis.

Addition of growth factors, such as prostaglandin F2 alpha or fibroblastic growth factor, to quiescent Swiss mouse 3T3 cells resulted in an abrupt increase in the rate of initiation of DNA synthesis after a lag phase of 13-15 hr. This increase could be quantified by a rate constant k. Addition of colchicine, Colcemid, or vinblastine had a synergistic effect on the initiation of DNA synthesis triggered by PGF2 alpha or FGF by increasing the value of k. These drugs alone had no effect. Colchicine had a synergistic effect only if added within 8 hr of the PGF2 alpha or FGF addition. Also, colchicine exerted its full effect when it was present only for the first 5 hr with either growth factor. These results suggest that an intact cytoskeleton is not required for the initiation of DNA synthesis. Furthermore, cytoskeleton-disrupting drugs enhance the stimulatory effect of the growth factors.