Biomedical subjects

Marco Di Buono

Publications and source records attributed to Marco Di Buono.

3 recordsLinked to original sources

PubMed2006

Korean red ginseng (Panax ginseng) improves glucose and insulin regulation in well-controlled, type 2 diabetes: results of a randomized, double-blind, placebo-controlled study of efficacy and safety.

BACKGROUND AND AIM: To address the paucity of randomized clinical studies assessing ginseng on long-term outcomes in type 2 diabetes, we assessed the clinical antidiabetic efficacy and safety of 12 weeks of supplementation with a Korean red ginseng (KRG) preparation, dose, and mode of administration, selected from an acute, clinical, screening model. METHODS AND RESULTS: Nineteen participants with well-controlled type 2 diabetes (sex: 11 M:8 F, age: 64+/-2 years, BMI: 28.9+/-1.4 kg/m(2), HbA(1c): 6.5%) completed the study. Using a double-blind, randomized, crossover design, each participant received the selected KRG preparation (rootlets) and placebo at the selected dose (2 g/meal=6 g/day) and mode of administration (preprandial oral agent [-40 min]) for 12 weeks as an adjunct to their usual anti-diabetic therapy (diet and/or medications). Outcomes included measures of efficacy (HbA1c and fasting- and 75-g oral glucose tolerance test [OGTT]-plasma glucose [PG], plasma insulin [PI], and insulin sensitivity index [ISI] indices); safety (liver, kidney, haemostatic, and blood-pressure function); and compliance (returned capsules, diet-records, and body-weight). There was no change in the primary endpoint, HbA(1c). The participants, however, remained well-controlled (HbA1c=6.5%) throughout. The selected KRG treatment also decreased 75 g-OGTT-PG indices by 8-11% and fasting-PI and 75 g-OGTT-PI indices by 33-38% and increased fasting-ISI (homeostasis model assessment [HOMA]) and 75 g-OGTT-ISI by 33%, compared with placebo (P<0.05). Safety and compliance outcomes remained unchanged. CONCLUSIONS: Although clinical efficacy, as assessed by HbA1c, was not demonstrated, 12 weeks of supplementation with the selected KRG treatment maintained good glycemic control and improved PG and PI regulation safely beyond usual therapy in people with well-controlled type 2 diabetes. Further investigation with similarly selected KRG treatments may yield clinical efficacy.

Administration, Oral↗

PubMed2006

Korean red ginseng rootlets decrease acute postprandial glycemia: results from sequential preparation- and dose-finding studies.

BACKGROUND: Fractionation of a ginseng source to produce differences in the ginsenoside profile might influence its effect on postprandial glycemia. To explore this possibility and identify an efficacious ginseng for a longterm study, we conducted a preparation-finding study of different Korean red ginseng (KRG) root fractions followed by a dose-finding study of the most efficacious fraction. METHODS: A double-blind, randomized, within-subject design was used in both studies. In the preparation-finding study, 7 healthy subjects (sex: 3m:4f, age: 32 +/- 4 y, BMI: 24 +/- 2 kg/m2) received 6 g placebo and KRG-rootlets, -body, and -H2O extract 40 min before a 50 g-OGTT with finger-prick blood samples at -40-, 0-, 15-, 30-, 45-, 60-, 90-, 120-min. In the dose-finding study, 12 healthy subjects (sex: 9M,3F, age: 29 +/- 3 y, BMI: 22.5 +/- 1 kg/m2) received 0 g (placebo), 2 g, 4 g, and 6 g of the most efficacious root fraction following the same protocol. Ginsenosides were analyzed using HPLC-UV. RESULTS: In the preparation-finding study, a wide variation in the ginsenoside profiles was achieved across the 3 KRG fractions. This variation coincided with differential effects. The main effects of KRG-rootlets (p = 0.050) and time (p < 0.001) and their interaction (p < 0.1) were significant. This was reflected in a 29% reduction in area under the curve (AUC) by KRG-rootlets compared with placebo (p = 0.052). Conversely, neither KRG-H2O extract nor KRG-body affected glycemia. Stepwise-multiple regression models identified Rg1 as the sole predictor of mean- and AUC postprandial blood glucose. In the dose-finding study, KRG-rootlets were tested as the most efficacious fraction. A significant effect of KRG-rootlets treatment (mean of 3 doses) but not dose was found. The mean of 3 doses decreased AUC by 17% compared with placebo (p = 0.057). CONCLUSIONS: Together the studies indicate 2 g KRG-rootlets is sufficient to achieve reproducible reductions in postprandial glycemia. But the longterm sustainability of KRG selected using this approach remains to be tested.

Adult↗

PubMed2003

Regulation of sulfur amino acid metabolism in men in response to changes in sulfur amino acid intakes.

We showed previously that 64% of the total dietary sulfur amino acid (SAA) requirement could be supported by dietary cysteine (Cys). However, the observation of such a sparing effect may be affected by the dietary intakes of SAA provided. The aim of this study was to compare methionine (Met) metabolism and transsulfuration (TS) in five healthy men fed three different diets (in random order) for 3 d each, with varying combinations of Met and Cys: 24 mg Met/(kg. d) and no Cys (diet A); 13 mg Met/(kg. d) and 11 mg Cys/(kg. d) (diet B); and 5 mg Met/(kg. d) and 19 mg Cys/(kg. d) (diet C). On d 3, Met kinetics and TS were assessed using orally administered L-[1-(13)C, methyl-(2)H(3)]methionine. Met demethylation (transmethylation, TM) significantly decreased as the dietary Met to Cys ratio decreased. Met TS was significantly lower during diets B [2.8 +/- 0.4 micro mol/(kg. h)] and C [1.5 +/- 0.5 micro mol/(kg. h)] than during diet A [7.8 +/- 2.9 micro mol/(kg. h)] (P < 0.05). The results of the present study indicate that when the ratio of Met to Cys fed is typical of that found in major food proteins and total SAA are sufficient to meet requirements, TS is significantly reduced compared with the case in which SAA needs are supplied by Met alone. We conclude that Cys sparing occurs through an increase in the fraction of the homocysteine pool destined for RM relative to TS (RM:TS).

Adult↗