Effects of a novel rice-based diabetes-specific formula on postprandial glucose and gastrointestinal hormones: a double-blinded multi-arm randomized crossover trial.

Introduction: We developed a novel rice-based medical food for diabetes (MFDM) powder formula, using locally available ingredients in Thailand, which can potentially improve patient access to diabetes-specific formula (DSF) by reducing cost and improving availability. Purpose: The goals of our studies were to 1) measure the glycemic index (GI) and glycemic load (GL) of the MFDM powder formula in healthy individuals, and 2) assess postprandial glucose, insulin, satiety, hunger, and gastrointestinal (GI) hormone responses in adults with prediabetes or early type 2 diabetes after consuming MFDM in comparison with a commercially available standard formula (SF) and a DSF. Methods: In Study 1, glycemic responses were assessed using the area under the curve (AUC), which was used to calculate GI and GL. Study 2 was a double-blinded multi-arm randomized crossover trial enrolling participants with either prediabetes or type 2 diabetes of ≤6 years. At each study visit, participants consumed either MFDM, SF, or DSF which contained 25 g of carbohydrates. Hunger and satiety were assessed using a visual analog scale (VAS). Glucose, insulin, and GI hormones were assessed using AUC. Results: All participants tolerated the MFDM well with no adverse events. In Study 1, the measured GI was 39 ± 6 (low GI) and GL was 11 ± 2 (medium GL). In Study 2, glucose and insulin responses were significantly lower after MFDM compared with SF (p-value<0.01 for both), however, those responses were similar between MFDM and DSF. MFDM suppressed hunger, promoted satiety, stimulated active GLP-1, GIP, and PYY, and suppressed active ghrelin although these changes were similar to SF and DSF. Conclusions: MFDM had a low GI and a low-to-medium GL. In people with prediabetes or early type 2 diabetes, MFDM elicited reduced glucose and insulin responses when compared with SF. Rice-based MFDM may be an option for patients who are at risk for postprandial hyperglycemia. Clinical Trial Registration: https://www.thaiclinicaltrials.org/show/TCTR20210731001, identifier TCTR20210731001; https://www.thaiclinicaltrials.org/show/TCTR20210730007, identifier TCTR20210730007.

Production and antimicrobial activity of trans-resveratrol, trans-arachidin-1 and trans-arachidin-3 from elicited peanut hairy root cultures in shake flasks compared with bioreactors.

Obtaining large-scale hairy root cultures is a major challenge to increasing root biomass and secondary metabolite production. Enhanced production of stilbene compounds such as trans-resveratrol, trans-arachidin-1 and trans-arachidin-3 was achieved using an elicitor treatment procedure. Two different hairy root inoculum densities were investigated and compared between shake flask and bioreactor cultures. The lowest growth index was observed using a 20 g/L inoculum size in the bioreactor, which differed significantly from bioreactor of 5 g/L. Increasing the hairy root inoculum size from 5 g/L to 20 g/L in both the shake flask and bioreactor significantly improve antioxidant activity, phenolic content and stilbene compound levels. The highest ABTS and FRAP antioxidant activity, and levels of total phenolic compounds, trans-arachidin-1 and trans-arachidin-3 in the crude extract were demonstrated in shake flask cultures with a 20 g/L inoculum after elicitation for 72 h. The minimum inhibitory concentrations (MICs) of the crude extract to inhibit growth of foodborne microbes, S. aureus, S. typhimurium and E. coli, were 187.5, 250 and 500 µg/mL, respectively. This was due to the ability of the crude extract to disrupt the cell membrane, as observed by scanning electron microscopy (SEM) showing ruptured pores on the S. aureus and S. typhimurium cell surfaces. Moreover, the E. coli cell division process could be inhibited by the crude extract, which promoted an increase in cell size. A DNA nicking assay indicated that a 50 µg/mL concentration of the crude extract caused plasmid DNA damage that might be due to a genotoxic effect of the pro-oxidant activity of the crude extract.

Effect of light and mechanical stress in combination with chemical elicitors on the production of stilbene compounds and defensive responses in peanut hairy root culture.

Plants encounter diverse stressors simultaneously with changing environmental factors. The combined effect of different types of stresses can have a wide range of effects on plants. The present study demonstrated that various stress factors such as the combination of chemical elicitors, namely paraquat (PQ), methyl jasmonate (MeJA) and methyl-ß-cyclodextrin (CD), light exposure versus darkness, and mechanical shearing stress affected the defence response in peanut hairy root culture. The antioxidant activities were dramatically increased at all time points after hairy roots were subjected to elicitation with PQ + MeJA + CD under root cutting in both light and dark conditions. The stilbene compounds were highly increased in the culture medium after elicitor treatment of uncut hairy roots under dark conditions. In contrast to the high stilbene contents detected in culture medium under dark conditions, the transcription of the stilbene biosynthesis genes PAL, RS and RS3 was enhanced by the effect of light in uncut hairy root tissues. The antioxidant enzyme genes APX, GPX and CuZn-SOD of uncut and cut hairy roots were more highly expressed in light conditions than in dark conditions. The pathogenesis-related protein (PR)-encoding genes chitinase, PR4A, PR5 and PR10 of uncut hairy roots were highly expressed in response to light conditions compared to dark conditions at all time points. Recent evidence of the production of antioxidant stilbene compounds and defence response genes has implicated plant protective functions through defence responses under different stress challenges. Plant responses might therefore be regulated by the coordination of different signal responses through dynamic pathways.

LC-MS/MS profiles and interrelationships between the anti-inflammatory activity, total phenolic content and antioxidant potential of Kalasin 2 cultivar peanut sprout crude extract.

Peanut is a potent natural source of phytochemical compounds and is associated with human health. In the present study, we determined the biological activity and chemical constituents of peanuts germinated for 0-9days. The ungerminated seed coat exhibited the highest antioxidant potential, phenolic compound content and anti-inflammatory activity. During the germination process, on the first germination day, root extract showed the highest antioxidant potential, phenolic compound content and anti-inflammatory activity. The kernel exhibited a low phenolic compound content and antioxidant activity at the early stage of germination and significantly increased after 9days of germination. Resveratrol increased to 7.19±0.07µg/g dry weight on the second day of germination. LC-MS/MS showed a variety of phenolic compounds and stilbene derivatives in different parts of germinated peanut. These results suggest that the peanut sprout exerts high anti-inflammatory effects that may be related to the polyphenolic content and antioxidant properties.