Systematic evaluation of polyphenols composition and antioxidant activity of mulberry cultivars subjected to gastrointestinal digestion and gut microbiota fermentation

Inulin as prebiotic encapsulating agent for the production of spray-dried Hibiscus sabdariffa L. tea microcapsules

Due to the high content of phenolics and anthocyanins of Hibiscus sabdariffa L. tea and the sensibility of these bioactive compounds, this work aimed to optimize the obtention of microcapsules by spray-drying, using inulin as a carrier agent. Using a Box-Behnken Design, the effects of inlet temperature (130, 150, and 170 °C), feed flow rate (5, 10, and 15 mL min-1), and inulin concentration (5, 10, and 15 g L-1) were evaluated. It was possible to obtain pale-rose, slightly sweet instant powders with good total polyphenol content (1.12 mgGAE g-1) and anthocyanins encapsulation efficiency (32.3-60.6%), besides moisture (4.61-17.79%) and water activity (0.221-0.501), indicating physico-chemical and microbiological stability of the microcapsules. A simultaneous optimization with the desirability function was performed to maximize all the response variables analyzed, and the optimum conditions of 5 g L-1 of inulin, inlet temperature of 170 °C, and feed flow rate of 83 mL min-1 were found.

Impact of Pediococcus pentosaceus YF01 on the exercise capacity of mice through the regulation of oxidative stress and alteration of gut microbiota

Using treadmill training, this study replicated human exercise conditions and triggered exercise-induced fatigue in mice to examine the potential of Pediococcus pentosaceus YF01 in delaying this fatigue by regulating oxidative stress and its impact on the exercise capacity and gut microbiota of mice. The exercise capacity of mice was tested by conducting exhaustion tests, determining histopathological changes in mouse tissues, detecting the levels of serum biochemical markers, and evaluating the mRNA expression levels of relevant genes. YF01 prolonged the exhaustion time of mice, increased the serum levels of oxidative stress-related markers T-AOC, CAT, and GSH, as well as GLU and LA levels in the mice. YF01 decreased the levels of hepatic-related markers AST and ALT, as well as exercise-related markers LDH, BUN, UA, and CRE in the mice. YF01 upregulated the mRNA expression of MyHc I, SIRT1, and PGC in muscle tissues, as well as SOD1, SOD2, and CAT in both liver and muscle tissues. YF01 also downregulated the mRNA expression of MyHc IIa, MyHc IIb, and MyHc IIx in muscle tissues. Furthermore, YF01 increased the abundance of beneficial bacteria such as Lactobacillus and Lachnospiraceae in the gut microbiota of mice. In conclusion, P. pentosaceus YF01 may affect the exercise capacity of mice by modulating oxidative stress levels, thereby offering novel ideas for developing of sports science and human health.

Xanthohumol and echinocystic acid induces PSTVd tolerance in tomato

Tomato is a popular vegetable worldwide; its production is highly threatened by infection with the potato spindle tuber viroid (PSTVd). We obtained the full-length genome sequence of previously conserved PSTVd and inoculated it on four genotypes of semi-cultivated tomatoes selected from a local tomato germplasm resource. SC-5, which is a PSTVd-resistant genotype, and SC-96, which is a PSTVd-sensitive genotype, were identified by detecting the fruit yield, plant growth, biomass accumulation, physiological indices, and PSTVd genome titer after PSTVd inoculation. A non-target metabolomics study was conducted on PSTVd-infected and control SC-5 to identify potential anti-PSTVd metabolites. The platform of liquid chromatography-mass spectrometry detected 158 or 123 differential regulated metabolites in modes of positive ion or negative ion. Principal component analysis revealed a clear separation of the global metabolite profile between PSTVd-infected leaves and control regardless of the detection mode. The potential anti-PSTVd compounds, xanthohumol, oxalicine B, indole-3-carbinol, and rosmarinic acid were significantly upregulated in positive ion mode, whereas echinocystic acid, chlorogenic acid, and 5-acetylsalicylic acid were upregulated in negative ion mode. Xanthohumol and echinocystic acid were detected as the most upregulated metabolites and were exogenously applied on PSTVd-diseased SC-96 seedlings. Both xanthohumol and echinocystic acid had instant and long-term inhibition effect on PSTVd titer. The highest reduction of disease symptom was induced by 2.6 mg/L of xanthohumol and 2.0 mg/L of echinocystic acid after 10 days of leaf spraying, respectively. A superior effect was seen on echinocystic acid than on xanthohumol. Our study provides a statistical basis for breeding anti-viroid tomato genotypes and creating plant-originating chemical preparations to prevent viroid disease.

Gut Microbiota Modulation by Bioactive Compounds from Ilex paraguariensis: an In Vivo Study

Yerba-mate (Ilex paraguariensis) is recognized for its biocompounds and bioactive properties. This study aimed to assess the potential of yerba-mate extract to modulate the intestinal microbiota in rats. After the ethical committee approval (CEUA - UPF, number 025/2018), the Wistar rats were given a daily dose of 3.29 mg of phenolic compounds per animal for 45 days. The antioxidant activity of the extract was assessed by ABTS and FRAP assays and the total phenolic compounds was measured at different pH levels. Identification and quantification of chlorogenic acid isomers were carried out using high-performance liquid chromatography (HPLC). Intestinal microbiota modulation was evaluated by administering the yerba-mate extract or water (control) to Wistar rats via intragastric gavage and its efficiency was measured through PCR. The antioxidant capacity of the yerba-mate extract was 64.53 ± 0.26 μmol Trolox/mL (ABTS) and 52.96 ± 0.86 μmol Trolox/mL (FRAP). The total phenolic compounds showed higher levels at pH 7.5 compared to pH 2.0. Chlorogenic acid isomers were found in greater abundance, with a concentration of 14.22 g/100 g. The administration of the extract resulted in positive modulation of the intestinal microbiota, specifically for the genera Lactobacillus sp. and Prevotella sp. The increase of these genera is related to the promotion of homeostasis of the gut microbiota. Therefore, these findings indicate that yerba-mate extract possesses significant antioxidant activity and can effectively modulate the intestinal microbiota in rats. These results support the potential use of yerba-mate as an alternative for controlling and preventing diseases associated with intestinal dysbiosis.

Influence of spontaneous and inoculated fermentation of açai on simulated digestion, antioxidant capacity and cytotoxic activity

This work describes the kinetic study of different types (spontaneous, lactic and alcoholic) of açai fermentation in terms of total phenolics and total anthocyanins, as well as antioxidant capacity, before and after simulated digestion (SD). Cytotoxicity (A549, HCT8 and IMR90 cells) and formation of reactive oxygen species (A549 cells) were also evaluated. The results revealed that spontaneous fermentation (SF) for 24 h, followed by SD, generated a product with greater bioaccessibility of phenolics (52.68%) and cyanidin-3-glucoside (27.01%) than unfermented açai. Likewise, lactic fermentation (LF) for 72 h improved the bioavailability of phenolics (64.49%) and cyanidin-3-rutinoside (20.00%). On the other hand, alcoholic fermentation (AF) decreased the bioaccessibility of phenolic compounds and anthocyanins after SD. The SF 24 h (10.16 ± 1.25 μmol Trolox /g) and LF 72 h (15.90 ± 0.51 μmol Trolox /g) significantly increased the antioxidant capacity after SD, when compared to unfermented açai (SF 0 h, 4.00 ± 0.09 μmol Trolox /g; LF 0 h, 10.57 ± 0.91 μmol Trolox /g). It was concluded that the samples did not show cytotoxicity in the cell lines tested and, in addition, AF 24 h showed antioxidant and antimutagenic effects in vitro, reducing about 40% of chromosomal aberrations. The results obtained provide important information that can be used to produce foods with greater bioaccessibility of bioactive compounds.

Gut microbial metabolites of dietary polyphenols and their potential role in human health and diseases

Polyphenols contribute as one of the largest groups of compounds among all the phytochemicals. Common sources of dietary polyphenols are vegetables, fruits, berries, cereals, whole grains, etc. Owing to their original form, they are difficult to get absorbed. Dietary polyphenols after undergoing gut microbial metabolism form bioaccessible and effective metabolites. Polyphenols and derived metabolites are all together a diversified group of compounds exhibiting pharmacological activities against cardiovascular, cancer, oxidative stress, inflammatory, and bacterial diseases. The formed metabolites are sometimes even more bioavailable and efficacious than the parent polyphenols. Studies on gut microbial metabolism of dietary polyphenols have introduced new approach for the use of polyphenol-rich food in the form of supplementary diet. This review provides insights on various aspects including classification of polyphenols, gut microbiota-mediated metabolism of polyphenols, chemistry of polyphenol metabolism, and pharmacological actions of gut microbial metabolites of polyphenols. It also suggests the use of polyphenols from marine source for the microbial metabolism studies. Till date, gut microbial metabolism of polyphenols from terrestrial sources is extensively studied as compared to marine polyphenols. Marine ecosystem is a profound but partially explored source of phytoconstituents. Among them, edible seaweeds contain high concentration of polyphenols, especially phlorotannins. Hence, microbial metabolism studies of seaweeds can unravel the pharmacological potential of marine polyphenol-derived metabolites.

Development of Probiotic-Fermented Black Mulberry (Morus nigra L.) Juice and Its Antioxidant Activity in C2C12 Cells

Black mulberry (Morus nigra L.) is considered a medicinal and food-homologous plant in China. An obstacle to its widespread use is that its annual season and shelf life are extremely short. In this paper, fermented black mulberry juice (FBMJ) was prepared with various probiotic strains, and response surface methodology was used to determine the optimum production conditions for achieving the maximum active substance content in the resulting product. The fermentation process increased levels of biological enzymes and total phenols in the resulting juice. When the ratios of the Lactobacillus inocula to the total inoculum were 27.96% for L. paracasei, 15.37% for L. casei, 16.64% for L. plantarum, and 5.12% for L. delbrueckii, the B. animalis subsp. lactis content reached 15.83%, the L. fermentum content reached 19.08%, and the superoxide dismutase (SOD) activity reached 310 U/g. To study the antioxidant characteristics of the juice, C2C12 cells were treated with H2O2 to induce oxidative stress and the cytoprotective activity of FBMJ was subsequently evaluated. After treatment with FBMJ for 24 h, cell viability was found to be protected under H2O2 exposure, while SOD and glutathione peroxidase (GSH-Px) levels were increased. The reactive oxygen species level and malondialdehyde content were also decreased. These results provide molecular evidence for the antioxidant effect of FBMJ and demonstrate that lactic acid bacteria fermentation has a positive effect on black mulberry juice (BMJ).

Mulberry plant as a source of functional food with therapeutic and nutritional applications: A review

Medicinal plants from the family Moraceae have diverse applications in agriculture, cosmetics, food, and the pharmaceutical industry. Their extensive spectrum of pharmacological activity for treating numerous inflammatory illnesses, cancer, cardiovascular diseases, and gastrointestinal problems reflects their biological and therapeutic value. This article summarizes the molecular mechanisms related to the biological implications of mulberry extracts, fractions, and isolated bioactive compounds from different parts in various health-related ailments. Additionally, the food industry and animal nutrition applications are summarized. Phytochemicals such as steroids, saponins, alkaloids, glycosides, polysaccharides, and phenolic compounds including terpenoids, flavonoids, anthocyanins, and tannins are found in this medicinal plant. The aqueous, ethanolic, and methanolic extracts, as well as bioactive compounds, have anti-oxidative, hypoglycemic, nephroprotective, antimicrobial, neuroprotective, anti-mutagenic, hepatoprotective, anthelmintic, immune-modulatory, cardioprotective, and skin protecting activities. Mulberry supplementation in food products improves the stability of phenolics, sensory properties, antioxidant activity, and antimicrobial properties. Mulberry leaves in animal feed increase the nutrient digestibility, growth parameters, antimicrobial, and antioxidant properties. PRACTICAL APPLICATIONS: This review summarized the in vivo and in vitro biological activities of the mulberry and isolated constituents in various health conditions. In addition, the food uses such as antioxidant potential, antimicrobial, and physicochemical properties were discussed. Furthermore, in vivo studies revealed mulberry as a significant protein source and its flavonoids as potential animal foliage.

What is the role of phenolic compounds of yerba mate (Ilex paraguariensis) in gut microbiota?

Diet actively influences gut microbiota and body homeostasis. The predominance of beneficial species results in symbiosis, while dysbiosis is characterized by an imbalance between microbial communities. Food plays a key role in this dynamic and in promoting the health of individuals. Ilex paraguariensis, also known as yerba mate, is a traditional plant from Latin America that has a complex matrix of bioactive substances, including methylxanthines, triterpenes, saponins, and phenolics. The consumption of yerba mate is associated with antioxidant, cardioprotective, anti-inflammatory, and anti-obesity effects. However, to the best of our knowledge, there have been no studies on yerba mate as a modulating agent of intestinal microbiota. Phenolics are the major compounds in yerba mate and have been reported to act in modulating the microbiome. In this review, we explore the activity of yerba mate as a possible stimulant of gut microbiota and present its main phenolics and their biological effects. We also propose different mechanisms of action of these phenolics and possible doses for their effectiveness.

Phytochemical characterization of Morus nigra fruit ultrasound-assisted ethanolic extract for its cardioprotective potential

The current work investigated the phytochemical profile of ultrasound-assisted ethanolic extract of Morus nigra (M. nigra) fruit. FTIR analysis of M. nigra fruit extract revealed the presence of alcohols (O-H), alkanes (C-H stretch), alkenes (C=C), and alkynes (C≡C). The HPLC analysis quantified the quercetin, gallic acid, vanillic acid, chlorogenic acid, syringic acid, cinnamic acid, sinapic acid, and kaempferol. Furthermore, the cardioprotective activity of ethanolic extract of M. nigra fruit was investigated. Cholesterol supplementation (2%) in the daily diet and exposure to cigarette smoke (2 cigarettes twice a day) were to induce hypertension in rats. The experimental animals were categorized into four groups: G0 (negative control), G1 (positive control), G2 (standard drug), and G3 (M. nigra fruit). The fruit extract administration at 300 mg/kg BW/day orally for 2 months significantly (p < .001) enhanced the activities of serum and cardiac tissue antioxidants in hypertensive rats. Meanwhile, the fruit extract reduced the elevated serum lipid profile while significantly increasing the high-density lipoproteins in G3 than G1 and G2. The increase in blood pressure, liver transaminases, and serum lactate dehydrogenase also reduced significantly in M. nigra fruit extract-treated rats. Histopathological findings revealed mild normalization of cardiac myocytes with central nuclei, branching, and cross-striations. Consequently, the M. nigra fruit extract exerted the cardioprotective potential via increasing the antioxidant enzymes and reducing the lipids, lactate dehydrogenase, liver transaminases, and blood pressure. The therapeutic potential of M. nigra fruit can be due to flavonols and phenolic acids. PRACTICAL APPLICATIONS: The present work quantified the Morus nigra fruit phytochemicals and its significant role in reducing lipid markers and blood pressure and improving antioxidant status in rats fed a hypercholesterolemic diet and exposed to cigarette smoke. Conclusively, the inclusion of M. nigra fruit in daily diet could improve the cardiac health of the individuals. Furthermore, the therapeutic potential of M. nigra fruit and its isolated constituents in modulating the gene expression against cardiac problems can explore after clinical trials and standardization in higher animals.

Interactions between Gut Microbiota and Polyphenols: New Insights into the Treatment of Fatigue

Fatigue seriously affects people's work efficiency and quality of life and has become a common health problem in modern societies around the world. The pathophysiology of fatigue is complex and not fully clear. To some degree, interactions between gut microbiota and host may be the cause of fatigue progression. Polyphenols such as tannin, tea polyphenols, curcumin, and soybean isoflavones relieve fatigue significantly. Studies have shown that the gut microbiota is able to convert these active compounds into more active metabolites through intestinal fermentation. However, the mechanism of anti-fatigue polyphenols is currently mainly analyzed from the perspective of antioxidant and anti-inflammatory effects, and changes in gut microbiota are rarely considered. This review focuses on gut microecology and systematically summarizes the latest theoretical and research findings on the interaction of gut microbiota, fatigue, and polyphenols. First, we outline the relationship between gut microbiota and fatigue, including changes in the gut microbiota during fatigue and how they interact with the host. Next, we describe the interactions between the gut microbiota and polyphenols in fatigue treatment (regulation of the gut microbiota by polyphenols and metabolism of polyphenols by the gut microbiota), and how the importance of potential active metabolites (such as urolithin) produced by the decomposition of polyphenols by gut microbiota is emerging. Based on the new perspective of gut microbiota, this review provides interesting insights into the mechanism of polyphenols in fatigue treatment and clarifies the potential of polyphenols as targets for anti-fatigue product development, aiming to provide a useful basis for further research and design.

The Ethylene Response Factor ERF5 Regulates Anthocyanin Biosynthesis in 'Zijin' Mulberry Fruits by Interacting with MYBA and F3H Genes

Ethylene promotes ripening in fruits as well as the biosynthesis of anthocyanins in plants. However, the question of which ethylene response factors (ERFs) interact with the genes along the anthocyanin biosynthesis pathway is yet to be answered. Herein, we conduct an integrated analysis of transcriptomes and metabolome on fruits of two mulberry genotypes ('Zijin', ZJ, and 'Dashi', DS, with high and low anthocyanin abundance, respectively) at different post-flowering stages. In total, 1035 upregulated genes were identified in ZJ and DS, including MYBA in the MBW complex and anthocyanin related genes such as F3H. A KEGG analysis suggested that flavonoid biosynthesis and plant hormone signaling transduction pathways were significantly enriched in the upregulated gene list. In particular, among 103 ERF genes, the expression of ERF5 showed the most positive correlation with the anthocyanin change pattern across both genotypes and in the post-flowering stages, with a Pearson correlation coefficient (PCC) of 0.93. Electrophoresis mobility shift assay (EMSA) and luciferase assay suggested that ERF5 binds to the promoter regions of MYBA and F3H and transcriptionally activates their gene expression. We elucidated a potential mechanism by which ethylene enhances anthocyanin accumulation in mulberry fruits and highlighted the importance of the ERF5 gene in controlling the anthocyanin content in mulberry species. This knowledge could be used for engineering purposes in future mulberry breeding programs.

Phytochemicals, Pharmacological Effects and Molecular Mechanisms of Mulberry

There are numerous varieties of mulberry, and each has high medicinal value and is regarded as a promising source of traditional medicines and functional foods. Nevertheless, the nutrients and uses of mulberry differ from species (Morus alba L., Morus nigra L. and Morus rubra L.). Phenolic compounds are prominent among the biologically active ingredients in mulberry, especially flavonoids, anthocyanins and phenolic acids. Epidemiologic studies suggest that mulberry contains a rich, effective chemical composition and a wide range of biological activity, such as antioxidant, anti-inflammatory, anti-tumor and so on. However, compared with other berries, there has been a lack of systematic research on mulberry, and this hinders its further expansion as a functional fruit. The main purpose of this review is to provide the latest data regarding the effective chemical constituents and pharmacological effects of mulberry to support its further therapeutic potential and health functions.

A dynamic view on the chemical composition and bioactive properties of mulberry fruit using an in vitro digestion and fermentation model

Mulberry is a kind of fruit rich in nutrients, however, the beneficial effects of mulberry fruits are related not only to the amount consumed, but also to the bioavailability of these nutrients in the organism. Hence, the aim of this study was to evaluate the bioaccessibility of main bioactive compounds from mulberry fruit using an in vitro digestion model, the changes in bioactivities as well as intestinal flora were also investigated. The results showed that the particle size of the mulberry fruit was gradually reduced (from 196.87 to 60.85 μm), as well as the phenolics and carbohydrates were significantly released during the digestion and maximized in the first 15 min in the intestinal phase (1752 ± 2.80 mg GAE per 100 g, DW; 277.402 ± 2.80 mg GE per 100 g, DW, respectively). Meanwhile, the bioaccessibility indices for phenolic compounds and carbohydrates were 55.49% and 84.62%. The antioxidant activity and α-glucosidase inhibitory effect of the mulberry fruit were positively correlated with their total content of released phenolic compounds. And the phenolic compounds (2,4,6-trihydroxybenzoic acid, cyanidin-3-O-glucoside, 3,4-dihydroxybenzoic acid and gallic acid) were the main compounds that inhibit the α-glucosidase activity by binding to its active cavity through hydrogen bonds. In addition, the mulberry fruit undigested fractions could be further fermented by intestinal microorganisms to produce short-chain fatty acids (SCFAs), which decreased the colon pH value (from 5.93 to 4.79) and the Firmicutes/Bacteroidetes ratio which was beneficial for obesity. Our results indicated that the mulberry fruit exhibited good bioactivity during digestion and fermentation, and could be a promising candidate as a dietary source of functional foods.

Assessing the Nutritional-Value-Based Therapeutic Potentials and Non-Destructive Approaches for Mulberry Fruit Assessment: An Overview

Among different fruits, mulberry is the most highlighted natural gift in its superior nutritional and bioactive composition, indispensable for continuing a healthy life. It also acts as a hepatoprotective immunostimulator and improves vision, anti-microbial, anti-cancer agent, anti-stress activity, atherosclerosis, neuroprotective functions, and anti-obesity action. The mulberry fruits also help reduce neurological disorders and mental illness. The main reason for that is the therapeutic potentials present in the nutritional components of the mulberry fruit. The available methods for assessing mulberry fruits are mainly chromatographic based, which are destructive and possess many limitations. However, recently some non-invasive techniques, including chlorophyll fluorescence, image processing, and hyperspectral imaging, were employed to detect various mulberry fruit attributes. The present review attempts to collect and explore available information regarding the nutritional and medicinal importance of mulberry fruit. Besides, non-destructive methods established for the fruit are also elaborated. This work helps encourage many more research works to dug out more hidden information about the essential nutrition of mulberry that can be helpful to resolve many mental-illness-related issues.

In vitro digestion of the whole blackberry fruit: bioaccessibility, bioactive variation of active ingredients and impacts on human gut microbiota

In vitro digestion and fermentation of blackberry fruit was investigated, and results showed that the phenolics were mainly released in gastric phase while carbohydrates in small intestinal phase. The bioaccessibility for phenolics and carbohydrates were 42.80% and 69.30%, indicating most of phenolics still remain in colon and available for intestinal flora. The total phenolics released during the digestion account for the improvement of antioxidant and hypoglycemic activities. Especially, cyanidin-3-O-glucoside with higher released amount and bioaccessibility index (63.21%), exhibited the strongest α-glucosidase inhibitory activity. After fermentation, the non-digestible fractions of blackberry affected the ecosystem of the intestinal tract by decreasing the colonic pH (△pH = 1.10), enhancing the production of SCFAs and modulating gut microbiota composition (the ratio of Firmicute/Bacteroidetes decreased from13.18 to 0.87). The results provided insights into the digestive properties and health benefits of blackberry fruit after consumption.

Gut microbiota as a potential target for developing anti-fatigue foods

Fatigue has many negative effects on human health. As such, it is desirable to develop anti-fatigue foods and understand the mechanisms of their action. Based on a comprehensive review of the literature, this article discusses the important roles of gut microbiota in fatigue and anti-fatigue. Studies have shown that an increase in pathogenic bacteria and a decrease in beneficial bacteria co-exist when fatigue is present in both rodents and humans, whereas changes in gut microbiota were reported after intervention with anti-fatigue foods. The roles of gut microbiota in the activities of anti-fatigue foods can also be explained in the causes and the effects of fatigue. Among the causes of fatigue, the accumulation of lactic acid, decrease of energy, and reduction of central nervous system function were related to gut microbiota metabolism. Among the harmful effects of fatigue, oxidative stress, inflammation, and intestinal barrier dysfunction were related to gut microbiota dysbiosis. Furthermore, gut microbiota, together with anti-fatigue foods, can inhibit pathogen growth, convert foods into highly anti-oxidative or anti-inflammatory products, produce short-chain fatty acids, maintain intestinal barrier integrity, inhibit intestinal inflammation, and stimulate the production of neurotransmitters that regulate the central nervous system. Therefore, it is believed that gut microbiota play important roles in the activities of anti-fatigue foods and may provide new insights on the development of anti-fatigue foods.

The anti-obesogenic effects of dietary berry fruits: A review

The prevalence of obesity in the world is fearsomely climbing, which has brought about heavy threats on human health and economic development. For coping with this problem, researchers have looked at the profound potentials of natural products for resolving obesity because of their high efficiencies and few undesirable outcomes in the recent years. Berry fruits are huge reservoirs of bioactive components, and their anti-obesity potentials are arousing much interests. In this review, the current main strategies to manage obesity were summarized, including inhibiting appetite and lowering the food intake, improving energy expenditure and thermogenesis, suppressing absorption and digestion, reducing lipid synthesis and storage as well as modulating composition of gut microbiota. In addition, this review discussed the potentials of dietary berry fruits (blueberries, cranberries, raspberries, strawberries, mulberries, lingonberries, blackberries, black chokeberries, elderberries, bilberries, grape, blackcurrants, jaboticabas, red bayberries, sea-buckthorns, goldenberries and goji berries) to counteract obesity or obesity-associated complications based on recent animal experiments and human studies. Then, the bioaccessibility of phenolic compounds present in berry fruits was discussed. On the other hand, several challenges including securing effective dosage, further understanding their interaction with human tissues, improving bioavailability and protection of functional ingredients during delivery should be taken into account and conquered in the coming years.

Phenolic profile of jujube fruit subjected to gut microbiota fermentation and its antioxidant potential against ethyl carbamate-induced oxidative damage

OBJECTIVES

To evaluate the composition of bioactive substances and the antioxidant effects of jujube fruit under gut microbiota fermentation (GMF), and the inhibitory effect on cytotoxicity caused by ethyl carbamate (EC).

METHODS

Changes in the contents of flavonoids, polyphenols, total sugars, and reducing sugars of jujube fruit after GMF (0, 2, 6, 12, 24, and 48 h) were determined. The oxidation resistance of fermented jujube fruits (from 0 to 48 h fermentation) was evaluated using in vitro 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Inhibitory effects of 48 h-fermented jujube fruit at various concentrations (0.25, 0.50, 1.00, and 2.00 mg/mL) on EC-treated toxicity and DNA damage of Caco-2 cells were estimated using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and nuclear staining assays, respectively. Effects of different concentrations of jujube fruit on EC-treated Caco-2 cells' intracellular reactive oxygen species (ROS), glutathione (GSH) levels, and mitochondrial membrane potential (MMP) were also evaluated.

RESULTS

Jujube fruit has rich bioactive components after GMF and shows strong antioxidant capacity. Fermented jujube fruit can inhibit the cytotoxicity and DNA damage of Caco-2 cells caused by EC and reduce intracellular ROS generation, as well as restoring GSH and MMP.

CONCLUSIONS

Fermented jujube fruit extracts produced by GMF still contain biologically active substances which retain biological activity and antioxidation capabilities.

Abnormal expression of bHLH3 disrupts a flavonoid homeostasis network, causing differences in pigment composition among mulberry fruits

Mulberry fruits with high concentrations of anthocyanins are favored by consumers because of their good taste, bright color, and high nutritional value. However, neither the regulatory mechanism controlling flavonoid biosynthesis in mulberry nor the molecular basis of different mulberry fruit colors is fully understood. Here, we report that a flavonoid homeostasis network comprising activation and feedback regulation mechanisms determines mulberry fruit color. In vitro and in vivo assays showed that MYBA-bHLH3-TTG1 regulates the biosynthesis of anthocyanins, while TT2L1 and TT2L2 work with bHLH3 or GL3 and form a MYB-bHLH-WD40 (MBW) complex with TTG1 to regulate proanthocyanidin (PA) synthesis. Functional and expression analyses showed that bHLH3 is a key regulator of the regulatory network controlling mulberry fruit coloration and that MYB4 is activated by MBW complexes and participates in negative feedback control of the regulatory network to balance the accumulation of anthocyanins and proanthocyanidins. Our research demonstrates that the interaction between bHLH3 and MYB4 in the homeostasis regulatory network ensures that the fruits accumulate desirable flavonoids and that this network is stable in pigment-rich mulberry fruits. However, the abnormal expression of bHLH3 disrupts the balance of the network and redirects flavonoid metabolic flux in pale-colored fruits, resulting in differences in the levels and proportions of anthocyanins, flavones, and flavonols among differently colored mulberry fruits (red, yellow, and white). The results of our study reveal the molecular basis of the diversity of mulberry fruit colors.