Some bee-pollinated plants provide nutritionally incomplete pollen amino acid resources to their pollinators.

For pollinators such as bees, nectar mainly provides carbohydrates and pollen provides proteins, amino acids, and lipids to cover their nutritional needs. Here, to examine differences in pollinator resources, we compared the amino acid profiles and total amino acid contents of pollen from 32 common entomophilous plants in seven families. Our results showed that the amino acid profiles and contents in pollen samples differed according to the plant family and the chromatography method used, i.e., high-performance liquid chromatography (HPLC) versus ion exchange chromatography (IEX). Pollen from Boraginaceae species had the highest total amino acid contents (361.2-504 µg/mg) whereas pollen from the Malvaceae family had the lowest total amino acid contents (136-243.1 µg/mg). Calculating an amino acid score (AAS) that reflects pollen nutritional quality showed that slightly less than half of the species (19 out of 32) had the maximum nutritional score (AAS = 1) and offered high nutritional quality pollen amino acids for bee pollinators. Though they had high total amino acid contents, the amino acid composition of the studied Boraginaceae species and several members of the Fabaceae was not optimal, as their pollen was deficient in some essential amino acids, resulting in suboptimal amino acid scores (AAS < 0.7). Except for cysteine, the measured amino acid contents were higher using IEX chromatography than using HPLC. IEX chromatography is more robust and is to be preferred over HPLC in future amino acid analyses. Moreover, our observations show that some bee-pollinated species fail to provide complete amino acid resources for their pollinators. Although the implications for pollinator behavior remain to be studied, these deficiencies may force pollinators to forage from different species to obtain all nutritionial requirements.

Comparative Analysis of the Bioactive Compounds in Chicken Cartilage: Protective Effects of Chondroitin Sulfate and Type II Collagen Peptides Against Osteoarthritis Involve Gut Microbiota.

This study was designed to explore osteoarthritis (OA) treatment from bioactive compounds of chicken cartilage food supplements. The OA rat model induced by sodium iodoacetate was used to evaluate the treatment effect in vivo. In this study, we used animal experiments to show that oral chondroitin sulfate (CS), cartilage powder, and type II collagen peptides could increase the athletic ability of rats and reduce inflammatory cytokine levels in serum or synovial fluid, including prostaglandin E2, tumor necrosis factor-α, interleukin (IL) 1ß, IL-6, and IL-17. CS displayed the best treatment effect against OA. The morphological structure of articular cartilage indicated that CS could significantly improve cartilage tissue morphology and reduce OA score. Oral CS slowed down the development of OA by modulating gut microbiota. These results provided a useful scientific basis for the high-value utilization of chicken cartilage.

Modulation of gut microbiota by chondroitin sulfate calcium complex during alleviation of osteoporosis in ovariectomized rats.

Although chondroitin sulfate calcium complex (CSCa) was claimed to have the bioactivity for bone care in vitro, its anti-osteoporosis bioactivity was little reported in vivo. Here, the effects of CSCa on osteoporosis rats were investigated. Results showed that, compared with the osteoporosis rats, CSCa could improve the bone mineral density and microstructure of femur, and change the bone turnover markers level in serum. 16S rRNA sequencing and metabolomics analysis indicated CSCa intervention altered the composition of gut microbiota along with metabolite profiles in ovariectomized rat faeces. The correlation analysis showed some gut microbiota taxa were significantly correlated with osteoporosis phenotypes and the enriched metabolites. Taken together, dietary CSCa intervention has the potential to alleviate the osteoporosis and related symptoms probably involving gut microbiota or the metabolite profiles as demonstrated in rats. This study provides some scientific evidence for the potential effects of CSCa as the food supplement on the osteoporosis.

Fabrication of chondroitin sulfate calcium complex and its chondrocyte proliferation in vitro.

Chondroitin sulfate (CS)-calcium complex (CSCa) was fabricated, and the structural characteristics of CSCa and its proliferative bioactivity to the chondrocyte were investigated in vitro. Results suggested calcium ions could bind CS chains forming polysaccharide-metal complex, and the maximum calcium holding capacity of CSCa reached 4.23 %. Characterization of CSCa was performed by EDS, AFM, FTIR, UV, XRD and 1H-NMR. It was found that calcium ions were integrated with CS by binding the sulfate or carboxyl groups. The thermal properties analysis indicated CSCa had a good thermal stability by TGA and DSC. CSCa could interact the calcium-sensing receptor increasing the intracellular calcium ions and influence the cell cycle. The TGF-ß1 secretion induced by CSCa could activate the TGF-ß/Smads pathway and change the genes associated proliferation expression ultimately leading to the chondrocyte proliferation. This research probably has an important implication for understanding the effect of CSCa on bone care as food supplements.

Lignocellulosic fibres surface interactions in enzymatic reaction using data-mining.

Lignocellulosic fibres modification focused so far essentially on the resulting material properties to create functional fibres instead of determining the reaction influencing parameters. Using a data-mining algorithm, surface chemical composition of the fibres after modifications was compared to multiple signals. A 24 h reaction at either 25 °C or 60 °C, pH5 was conducted in presence of trans-ferulic acid, laccase, and lignocellulosic fibres (flax, hemp, or cellulose) having different chemical surface composition. Dimers and trimers were detected in variable concentrations in the reaction filtrate and extractive. At 25 °C, crystalline cellulose, amorphous cellulose, xylans, mannans, and lignins were well correlated to specific reaction products while at 60 °C, only lignins and xylan were found correlated to reaction products. Fibres surface composition affected the extractive profile. Lignocellulosic surface composition influence on the product formed was unveiled using a data mining approach. This study presents a way to unveil non-evident chemical interface interaction in reactions.

Effect of extraction procedures on the chemical structure, antitumor and anticoagulant properties of ulvan from Ulva lactuca of Tunisia coast.

The effect of extraction procedures on chemical composition, structural, antitumor and anticoagulant properties of the sulphated polysaccharide 'ulvan' from the green seaweed Ulva lactuca were investigated. The structural features of ulvans were carried out by FTIR and by one- and two- dimensional 1H and 13C NMR spectroscopic. The ulvans were mainly composed of rhamnose, xylose, and uronic acid. Chemical and spectroscopic analyses demonstrated that ulvans were constituted of (1→4)-ß-glucuronic acid, (1→3,4)-α-L-rhamnose-3-sulphate and (1→4)-α-xylose. The extraction procedures effect were observed in chemical structure, Mw and biological activities. Cytotoxic activity of enzymatic-chemical extract on cervical cancer cells (HeLa) (IC50 = 1000 µg/mL) was higher than on normal peripheral blood lymphocytes cells (PBL). Acid extracts promoted to reduce HeLa cells and to grow PBL cells. At high concentrations, acid extracts showed the highest APTT and TT clotting time. Antitumoral and anticoagulant activities of ulvans from Ulva lactuca promote their use as effective therapeutic agent.

Novel dipeptidyl peptidase-IV and angiotensin-I-converting enzyme inhibitory peptides released from quinoa protein by in silico proteolysis.

Quinoa protein has been paid more and more attention because of its nutritional properties and beneficial effects. With the development of bioinformatics, bioactive peptide database and computer-assisted simulation provide an efficient and time-saving method for the theoretical estimation of potential bioactivities of protein. Therefore, the potential of quinoa protein sequences for releasing bioactive peptides was evaluated using the BIOPEP database, which revealed that quinoa protein, especially globulin, is a potential source of peptides with dipeptidyl peptidase-IV (DPP-IV) and angiotensin-I-converting enzyme (ACE) inhibitory activities. Three plant proteases, namely papain, ficin, and stem bromelain, were employed for the in silico proteolysis of quinoa protein. Furthermore, four tripeptides (MAF, NMF, HPF, and MCG) were screened as novel promising bioactive peptides by PeptideRanker. The bioactivities of selected peptides were confirmed using chemical synthesis and in vitro assay. The present work suggests that quinoa protein can serve as a good source of bioactive peptides, and in silico approach can provide theoretical assistance for investigation and production of functional peptides.

Anti-obesity effects of α-amylase inhibitor enriched-extract from white common beans (Phaseolus vulgaris L.) associated with the modulation of gut microbiota composition in high-fat diet-induced obese rats.

α-Amylase inhibitors (α-AI) have great potential to treat obesity. In this study, an α-AI enriched extract (α-AIE) with a specific activity of 1027.1 ± 154.2 (U per mg protein) was prepared from white common bean (Phaseolus vulgaris L.) seeds. Its anti-obesity effect and gut microbiota modulation properties were verified in high-fat diet-induced obese rats. The intake of the α-AIE significantly reduced body weight gain and improved serum lipid levels (p < 0.05). In addition, rats fed the α-AIE diet exhibited higher total short-chain fatty-acid (SCFA) concentrations (p < 0.05) in their colonic contents. ß-Diversity analysis, principal component analysis and a Venn diagram showed that α-AIE administration changed the gut microbiota composition. At the phylum level, the relative abundances of Firmicutes and Proteobacteria decreased and the relative abundances of Bacteroidetes and Akkermansia increased. In addition, 89 operational taxonomic units (OTUs) significantly responding to the high-fat diet and 30 OTUs significantly responding to the α-AIE were identified. The OTUs enriched by the α-AIE were mainly assigned to putative SCFA-producing bacteria, including Bacteroides, Butyricoccus, Blautia and Eubacterium. Twenty-two OTUs were found to be significantly correlated with obesity indexes. Taken together, the present results suggest that the intake of the α-AIE attenuated obesity and modulated gut microbiota.

Fermentation capacities of fructan- and pectin-rich by-products and purified fractions via an in vitro piglet faecal model.

BACKGROUND: Dietary strategies such as the inclusion of prebiotics have been suggested for modulating intestinal microbiota. In piglets, this strategy could result in a reduction of post-weaning-associated disorders and the use of antibiotics. To date, mainly purified fractions have been tested for their prebiotic effects at weaning while trials of potential health-promoting effects of products and corresponding by-products remain rare. In this study, fructan- and pectin-based ingredients have been tested in a two-step in vitro model for their fermentation kinetics as well as for their short-chain fatty acid production and microbiota profiles in fermentation broth as indicators for their prebiotic activity. RESULTS: Chicory root, in contrast to chicory pulp, exhibited an extensive and rapid fermentation similar to inulin and oligofructose, although butyrate levels of root and pulp did not reach those of the purified fractions. Chicory pulp showed higher relative levels of Lactobacillus spp., Bifidobacterium spp., Clostridium cluster IV and butyryl-CoA:acetate-CoA transferase gene abundance compared to chicory root. Sugar beet pulp, orange and citrus by-products displayed extensive gas fermentation patterns, equivalent to those of purified pectin, and revealed an elevated butyrate production compared to purified pectin. Moreover, several orange and citrus by-products displayed significantly higher relative levels of Bifidobacterium spp. in comparison to purified pectin. CONCLUSIONS: Chicory root and pulp as well as orange and citrus by-products appear to be promising ingredients for piglet diets for modulating intestinal fermentation for health purposes. © 2019 Society of Chemical Industry.

Is non-host pollen suitable for generalist bumblebees?

Current evidence suggests that pollen is both chemically and structurally protected. Despite increasing interest in studying bee-flower networks, the constraints for bee development related to pollen nutritional content, toxicity and digestibility as well as their role in the shaping of bee-flower interactions have been poorly studied. In this study we combined bioassays of the generalist bee Bombus terrestris on pollen of Cirsium, Trifolium, Salix, and Cistus genera with an assessment of nutritional content, toxicity, and digestibility of pollen. Microcolonies showed significant differences in their development, non-host pollen of Cirsium being the most unfavorable. This pollen was characterized by the presence of quite rare δ7-sterols and a low digestibility. Cirsium consumption seemed increase syrup collection, which is probably related to a detoxification mixing behavior. These results strongly suggest that pollen traits may act as drivers of plant selection by bees and partly explain why Asteraceae pollen is rare in bee generalist diet.

Influence of the ripening stage and the lyophilization of wild cardoon flowers on their chemical composition, enzymatic activities of extracts and technological properties of cheese curds.

The selection of an appropriate Cynara cardunculus flowers batch is a preliminary step to produce rennet with better clotting properties. For this reason, we proposed to study the influence of the ripening stage and the lyophilization of cardoon flowers on their chemical composition, enzymatic activities of extracts, and technological properties of cheese curds. Results of flowers composition have shown that lyophilized flowers harvested at the middle of ripening stage (A) could be employed to produce mainly proteins or milk-clotting proteases. To confirm this, enzymatic activities of extracts and technological properties of curds were assessed. The experimental findings revealed that flowers lyophilization seems to be an efficient way to produce rennet with better clotting properties, leading to higher yield, moisture, and texture parameters of curd. These findings allowed us to select lyophilized flowers (A) for further cheese making process.

Impact of pollen resources drift on common bumblebees in NW Europe.

Several bee species are experiencing significant population declines. As bees exclusively rely on pollen for development and survival, such declines could be partly related to changes in their host plant abundance and quality. Here, we investigate whether generalist bumblebee species, with stable population trends over the past years, adapted their diets in response to changes in the distribution and chemical quality of their pollen resources. We selected five common species of bumblebee in NW Europe for which we had a precise description of their pollen diet through two time periods ('prior to 1950' and '2004-2005'). For each species, we assessed whether the shift in their pollen diet was related with the changes in the suitable area of their pollen resources. Concurrently, we evaluated whether the chemical composition of pollen resources changed over time and experimentally tested the impact of new major pollen species on the development of B. terrestris microcolonies. Only one species (i.e. B. lapidarius) significantly included more pollen from resources whose suitable area expanded. This opportunist pattern could partly explain the expansion of B. lapidarius in Europe. Regarding the temporal variation in the chemical composition of the pollen diet, total and essential amino acid contents did not differ significantly between the two time periods while we found significant differences among plant species. This result is driven by the great diversity of resources used by bumblebee species in both periods. Our bioassay revealed that the shift to new major pollen resources allowed microcolonies to develop, bringing new evidence on the opportunist feature of bumblebee in their diets. Overall, this study shows that the response to pollen resource drift varies among closely related pollinators, and a species-rich plant community ensures generalist species to select a nutrient-rich pollen diet.

Non Digestible Oligosaccharides Modulate the Gut Microbiota to Control the Development of Leukemia and Associated Cachexia in Mice.

We tested the hypothesis that changing the gut microbiota using pectic oligosaccharides (POS) or inulin (INU) differently modulates the progression of leukemia and related metabolic disorders. Mice were transplanted with Bcr-Abl-transfected proB lymphocytes mimicking leukemia and received either POS or INU in their diet (5%) for 2 weeks. Combination of pyrosequencing, PCR-DGGE and qPCR analyses of the 16S rRNA gene revealed that POS decreased microbial diversity and richness of caecal microbiota whereas it increased Bifidobacterium spp., Roseburia spp. and Bacteroides spp. (affecting specifically B. dorei) to a higher extent than INU. INU supplementation increased the portal SCFA propionate and butyrate, and decreased cancer cell invasion in the liver. POS treatment did not affect hepatic cancer cell invasion, but was more efficient than INU to decrease the metabolic alterations. Indeed, POS better than INU delayed anorexia linked to cancer progression. In addition, POS treatment increased acetate in the caecal content, changed the fatty acid profile inside adipose tissue and counteracted the induction of markers controlling ß-oxidation, thereby hampering fat mass loss. Non digestible carbohydrates with prebiotic properties may constitute a new nutritional strategy to modulate gut microbiota with positive consequences on cancer progression and associated cachexia.