Evaluation of antioxidant and prooxidant activities of bamboo Phyllostachys nigra var. Henonis leaf extract in vitro

Impact of Bambusa vulgaris-supplemented diet on Nile tilapia challenged with Pseudomonas putida: Hematological, immune, and oxidative responses

This study investigated the effects of bamboo shoot extract (Bambusa vulgaris) as a feed additive on the health profiles and infection resistance of Nile tilapia (Oreochromis niloticus) against Pseudomonas putida. Bamboo shoot extract was added at levels of 0 g, 40 g, and 60 g per 1000 g of diet over a 60-day period. The fish were then challenged with a pathogenic P. putida strain. Chemical analysis of the bamboo shoot extract identified 3,5-dinitrophenol and hydroquinone as the two most abundant compounds. Results showed that fish fed bamboo-enriched diets exhibited significantly enhanced levels of red blood cells, hemoglobin, hematocrit, white blood cells, and platelets, and improved erythrocyte cellular and nuclear morphologies, indicating improved health profiles after the challenge. Liver function indicators, including AST, ALT, and ALP, were notably balanced in fish receiving bamboo shoot extract post-challenge (p < 0.05). Blood levels of K+ were lower in the bamboo-fed groups. Additionally, blood levels of Ca++ and Na+ were reduced in fish fed 40 g and 60 g of bamboo, respectively, compared to the control group (p < 0.01). The bamboo extract also enhanced immune and oxidative capacities, as demonstrated by increased catalase, superoxide dismutase, lysozyme activity, and phagocytic activity, along with reduced malondialdehyde levels and elevated serum immunoglobulin M (p < 0.01). Gene expression analysis revealed significant effects of Bambusa vulgaris extract, Pseudomonas infection, and their interaction on the expression of interleukin-1β, interleukin-10, and NK-lysin genes, with varying expression levels at 1, 3, and 7 days post-challenge (p < 0.05). The liver bacterial load in fish exposed to P. putida significantly decreased in the bamboo-fed groups, with the lowest count observed in the 60 g bamboo group. Additionally, survival rates were markedly higher in the bamboo-fed groups compared to the control, with no significant difference between the two bamboo-fed groups. In conclusion, dietary supplementation with bamboo shoot extract enhances hematological parameters, blood cell and nuclear morphology, and increases survival rates in Nile tilapia following infection.

Uncovering Metabolic Alterations in HCT-116 Colon Cancer Cells upon Exposure to Bamboo Leaf Extract Obtained from Guadua incana Londoño

Metabolic alterations are increasingly recognized as important aspects of colorectal cancer (CRC), offering potential avenues for identifying therapeutic targets. Previous studies have demonstrated the cytotoxic potential of bamboo leaf extract obtained from Guadua incana (BLEGI) against HCT-116 colon cancer cells. However, the altered metabolic pathways in these tumor cells remain unknown. Therefore, this study aimed to employ an untargeted metabolomic approach to reveal the metabolic alterations of the endometabolome and exometabolome of HCT-116 cells upon exposure to BLEGI treatment. First, a chemical characterization of the BLEGI was conducted through liquid chromatography coupled with mass spectrometry (LC-MS). Next, we assessed cell viability via MTT and morphological analysis using an immunofluorescence assay against colon cancer cells, and anti-inflammatory activity using an LPS-stimulated macrophage model. Subsequently, we employed LC-MS and proton nuclear magnetic resonance (1H-NMR) to investigate intra- and extracellular changes. Chemical characterization primarily revealed the presence of compounds with a flavone glycoside scaffold. Immunofluorescence analysis showed condensed chromatin and subsequent formation of apoptotic bodies, suggesting cell death by apoptosis. The results of the metabolomic analysis showed 98 differential metabolites, involved in glutathione, tricarboxylic acid cycle, and lipoic acid metabolism, among others. Additionally, BLEGI demonstrated significant nitric oxide (NO) inhibitory capacity in macrophage cells. This study enhances our understanding of BLEGI's possible mechanism of action and provides fresh insights into therapeutic targets for treating this disease.

Engineering Escherichia coli for efficient and economic production of C-glycosylflavonoids by deleting YhhW and regulating pH

C-glycosylflavonoids have a number of pharmacological activities. An efficient method for the preparation of C-glycosylflavonoids is through metabolic engineering. Thus, it is important to prevent the degradation of C-glycosylflavonoids for producing C-glycosylflavonoids in the recombinant strain. In this study, two critical factors for the degradation of C-glycosylflavonoids were clarified. The quercetinase (YhhW) gene from Escherichia coli BL21(DE3) was expressed, purified, and characterized. YhhW effectively degraded quercetin 8-C-glucoside, orientin, and isoorientin, while the degradation of vitexin and isovitexin was not significant. Zn²⁺ can significantly reduce the degradation of C-glycosylflavonoids by inhibiting the activity of YhhW. pH was another key factor causing the degradation of C-glycosylflavonoids, and C-glycosylflavonoids were significantly degraded with pH exceeding 7.5 in vitro or in vivo. On this basis, two strategies, deleting YhhW gene from the genome of E. coli and regulating pH during the bioconversion, were developed to relieve the degradation of C-glycosylflavonoids. Finally, the total degradation rates for orientin and quercetin 8-C-glucoside decreased from 100 to 28% and 65% to 18%, respectively. The maximum yield of orientin reached 3353 mg/L with luteolin as substrate, and the maximum yield of quercetin 8-C-glucoside reached 2236 mg/L with quercetin as substrate. Therefore, the method described herein for relieving the degradation of C-glycosylflavonoids may be widely used for the biosynthesis of C-glycosylflavonoids in recombinant strains.

Effects of bamboo leaf extract on energy metabolism, antioxidant capacity, and biogenesis of small intestine mitochondria in broilers

The present study was carried out to investigate the effects of bamboo leaf extract (BLE) on energy metabolism, antioxidant capacity, and biogenesis of broilers' small intestine mitochondria. A total of 384 one-day-old male Arbor Acres broiler chicks were randomly divided into four groups with six replicates each for 42 d. The control group was fed a basal diet, whereas the BLE1, BLE2, and BLE3 groups consumed basal diets with 1.0, 2.0, and 4.0 g/kg of BLE, respectively. Some markers of mitochondrial energy metabolism including isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, and malate dehydrogenase and some markers of redox system including total superoxide dismutase, malondialdehyde, and glutathione were measured by commercial colorimetric kits. Mitochondrial and cellular antioxidant genes, mitochondrial biogenesis-related genes, and mitochondrial DNA copy number were measured by quantitative real-time-polymerase chain reaction (qRT-PCR). Data were analyzed using the SPSS 19.0, and differences were considered as significant at P < 0.05. BLE supplementation linearly increased jejunal mitochondrial isocitrate dehydrogenase (P < 0.05) and total superoxide dismutase (P < 0.05) activity. The ileal manganese superoxide dismutase mRNA expression was linearly affected by increased dietary BLE supplementation (P < 0.05). Increasing BLE supplementation linearly increased jejunal sirtuin 1 (P < 0.05) and nuclear respiratory factor 1 (P < 0.05) mRNA expression. Linear (P < 0.05) and quadratic (P < 0.05) responses of the ileal nuclear respiratory factor 2 mRNA expression occurred with increased dietary BLE levels. In conclusion, BLE supplementation was beneficial to the energy metabolism, antioxidant capacity, and biogenesis of small intestine mitochondria in broilers. The dose of 4.0 g/kg BLE demonstrated the best effects.

Structural characteristic of polysaccharide isolated from Nostoc commune, and their potential as radical scavenging and antidiabetic activities

In this paper, Nostoc commune crude polysaccharide was extracted by heating and Ultrasonic-assisted methods separately, homogeneous polysaccharide HNCP3 and UNCP4 were obtained after purified by DEAE-52 cellulose column chromatography and Sephacryl G-100 gel column chromatography. The structures of HNCP3 and UNCP4 were characterized by molecular weight determination, infrared spectroscopy, DSC detection, sodium periodate oxidation, smith degradation reaction and methylation analysis. The conformation of the solution was studied by SEM and AFM. The results showed that the Ultrasonic-assisted extraction had effects on the molecular weight, monosaccharide composition, molar ratio and configuration of Nostoc commune. The main chain of HNCP3 and UNCP4 was → 6)-D-Glcp(1→ and → 2, 6)-D-Glcp, but UNCP4 contained 1, 2, 6-galactose and 2, 3-Me2-D-Ara branches, while HNCP3 did not. The results of the monosaccharides composition of indicated that mannose was presented in both HNCP3 and UNCP4. SEM and AFM showed that the structure of UNCP4 was helical, and the solution conformations of HNCP3 and UNCP4 were different in different solution environments. Studies on DPPH radicals, superoxide anions, and hydroxyl radicals scavenging abilities showed that UNCP4 had higher antioxidant activity, while studies on the antidiabetic activities showed that the hypoglycemic effect of UNCP4 was stronger than that of HNCP3. Therefore, Ultrasonic-assisted extraction (UAE) increases the bioactivity of Nostoc commune polysaccharide (NCP) as well as the extraction rate.

Melanin Synthesis Inhibition Activity of Compounds Isolated from Bamboo Shoot Skin (Phyllostachys pubescens)

This study targets the evaluation of melanin synthesis inhibition activity of the bamboo shoot skin as agro-waste. The total methanolic extract of bamboo peel extract was evaluated for its skin protective effects via measuring its melanin inhibitory activity and its suppression activity on the expression of tyrosinase mRNA levels. Results showed that bamboo peel extract has a good ability for the inhibition of melanin synthesis so further studies were performed for the isolation of its constituents. Twelve compounds have been isolated from the shoot skin of Phyllostachys pubescens. Their structures were elucidated based on extensive spectroscopic methods. The melanin inhibition potential of the isolates was tested with their collagen-production-promoting activity for the determination of active principles. Results showed that Betulinic acid, tachioside, and 1,2-dilinolenin significantly suppressed melanin production per cell compared to control. Triacontanol, tricin, and (+)-lyoniresinol 9'-O-glucoside also tended to decrease melanin production per cell. These findings indicated that the skin of bamboo shoots, a significant agricultural waste, is a useful natural source for further research on its potential for aging problems such hyperpigmentation and cognitive function impairment.

Effects of bamboo leaf extract intervention on the growth performance, antioxidant capacity, and hepatic apoptosis in suckling piglets

This study investigated whether bamboo leaf extract (BLE) could improve the growth performance, antioxidant capacity, and inhibit hepatic apoptosis in suckling piglets. Sixty-four suckling piglets were orally gavaged with vehicle (CON group) or 100, 200, or 300 mg BLE/kg body weight (BL, BM, and BH groups) at 3 days of age for 21 days (n = 8). The results showed that BLE treatment had no effects on the growth performance (P > 0.05). Compared with the CON group, the BM and BH groups decreased (P <0.05) the jejunal and hepatic malondialdehyde (MDA) contents. Supplementation with BLE increased antioxidant enzymes activities and the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and several targeted genes in the jejunum and liver of suckling piglets. The hepatic apoptosis rate was lower (P >0.05) in BLE treatment than in the CON group. Compared with the CON group, the BLE groups showed increased (P <0.05) mRNA levels of B-cell-lymphoma protein 2 (BCL-2), while decreased (P <0.05) BCL-2-associated X (BAX) and cysteine aspartate specific protease-3 (caspase-3) mRNA levels. The results of protein expressions of BCL-2 and caspase-3 were consistent with those of mRNA levels. Altogether, our results indicated that BLE intervention can improve the antioxidant capacity and inhibit hepatic apoptosis in suckling piglets.

Effects of Oral Administration of Bamboo (Dendrocalamus membranaceus) Leaf Flavonoids on the Antioxidant Capacity, Caecal Microbiota, and Serum Metabolome of Gallus gallus domesticus

The consumption of bamboo leaf flavonoids (BLFs) as novel dietary antioxidants has increased owing to their beneficial biological and pharmacological functions. This study assessed the in vivo effects of BLFs on antioxidant capacity, as well as caecal microbiota, serum metabolome, and health status. The Gallus gallus domesticus model and the oral administration approach were used with four treatment groups (basal diet, basal diet with 20 mg bacitracin/kg, basal diet with 50 mg BLF/kg, and basal diet with 250 mg BLF/kg). Ultra-high-performance liquid chromatography triple-quadrupole mass spectrometry analysis indicated that vitexin, fumaric acid, orientin, isoorientin, and p-coumaric acid were the predominant BLF components. From days 1 to 21, BLF increased the average daily gain and decreased the feed:gain of broilers. Moreover, BLF enhanced the serum antioxidant capacity and immune responses. Further, 16S rRNA sequencing showed that BLF modulated the caecal microbial community structure, which was dominated by Betaproteobacteriales, Erysipelatoclostridium, Parasutterella, Lewinella, Lactobacillus, and Candidatus Stoquefichus in BLF broilers. Among the 22 identified serum metabolites in BLF broilers, sphinganine, indole-3-acetaldehyde retinol, choline, 4-methylthio-2-oxobutanoic acid, and L-phenylalanine were recognised as biomarkers. In summary, BLFs appeared to modulate the caecal microbiome, alter the serum metabolome, and indirectly improve antioxidant capacity and health status.

Oreocharioside A-G, new acylated C-glycosylflavones from Oreocharis auricula (Gesneriaceae)

Seven new acylated C-glycosylflavones, oreocharioside A-G, together with two known compounds were isolated from the whole plant of Oreocharis auricula. Their structures were characterized by the comprehensive analysis of their NMR, IR, UV, CD spectra and HRESIMS data. All the new compounds were evaluated for the antioxidant and anti-inflammatory activities. The results showed that compounds 1 and 2 had significant DPPH and ABTS radical scavenging activities, with the IC₅₀ values of 0.32-3.20 μg/mL. Compounds 2 and 3 exhibited the higher potency among all the new compounds in reducing TNF-α production.

Hypoglycemic effect of a novel polysaccharide from Lentinus edodes on STZ-induced diabetic mice via metabolomics study and Nrf2/HO-1 pathways

With the increased worldwide prevalence of diabetes, more and more attentions are focused on the natural drug candidate who could treat diabetes with high efficacy but without undesired side effect....

Orientin and vitexin production by a one-pot enzymatic cascade of a glycosyltransferase and sucrose synthase

Orientin and vitexin, important components of bamboo-leaf extracts, are C-glycosylflavones which exhibit a number of interesting biological properties. In this work, we developed an efficient biocatalytic cascade for orientin and vitexin production consisting of Trollius chinensis C-glycosyltransferase (TcCGT) and Glycine max sucrose synthase (GmSUS). In order to relieve the bottleneck of the biocatalytic cascade, the biocatalytic efficiency, reaction condition compatibilities and the ratio of the enzymes were determined. We found that the specific activity of TcCGT was significantly influenced by enzyme dose and Triton X-100 or Tween 20 (0.2%). Co-culture of BL21-TcCGT-Co and BL21-GmSUS-Co affected the catalytic efficiency of TcCGT and GmSUS, and the maximum orientin production rate reached 47 μM/min at the inoculation ratio of 9:1. The optimal pH and temperature for the biocatalytic cascade were pH 7.5 and 30 °C, respectively. Moreover, the high dose of the enzymes can improve the tolerance of biocatalytic cascade to substrate inhibition in the one-pot reaction. By using a fed-batch strategy, maximal titers of orientin and vitexin reached 7090 mg/L with a corresponding molar conversion of 98.7% and 5050 mg/L with a corresponding molar conversion of 97.3%, respectively, which is the highest titer reported to date. Therefore, the method described herein for efficient production of orientin and vitexin by modulating catalytic efficiencies of enzymes can be widely used for the C-glycosylation of flavonoids.

Recent advances in polysaccharides from Lentinus edodes (Berk.): Isolation, structures and bioactivities

Lentinus edodes, an important edible mushroom cultivated in East Asia for thousands of years, has been widely used as food and medicinal ingredient worldwide. Modern phytochemistry studies have demonstrated that L. edodes is very rich in bioactive polysaccharides, especially the β-glucans. Over the past two decades, the isolation, chemical properties, and bioactivities of polysaccharides from fruiting bodies, mycelium and fermentation broth of L. edodes have been drawing much attention from scholars around the world. It has been demonstrated that L. edodes polysaccharides possess various remarkable biological activities, including anti-oxidant, anti-tumor, anti-aging, anti-inflammation, immunomodulatory, antiviral, and hepatoprotection effects. This review summarizes the recent development of polysaccharides from L. edodes including the isolation methods, structural features, bioactivities and mechanisms, and their structure-activity relationship, which can provide useful research underpinnings and update information for their further application as therapeutic agents and functional foods.

Copper-assisted synthesis of dihydropyrano[2.3-b]indole-4-ones by domino cascade reaction

A novel copper-catalyzed cascade intermolecular and intramolecular oxidation/cyclization domino one-pot reaction process for the regioselective synthesis of dihydropyrano[2.3-b]indol-4(9H)-ones has been successfully developed. In this methodology, it is proposed for the first time that the 4-benzyloxy group of indole substrates can be used as a guiding group to promote cyclization under mild conditions. Meanwhile, reaction mechanism studies indicate that carbonyl oxygen in pyranoindole-4-ones came from water and the guiding group is critical to the progress of the reaction.

Effects of bamboo leaf extract on growth performance, meat quality, and meat oxidative stability in broiler chickens

This study was conducted to investigate the effects of dietary bamboo leaf extract (BLE) on growth performance, meat quality, oxidative stability, and nuclear factor erythroid 2-related factor 2 (Nrf2) related gene expression of breast meat in broilers. A total of 576 one-day-old male Arbor Acres broilers were divided into 6 groups. The control group (CTR) was fed basal diet, while BLE1, BLE2, BLE3, BLE4, and BLE5 were fed basal diet supplemented with 1.0, 2.0, 3.0, 4.0, and 5.0 g BLE per kg feed, respectively. Compared with the CTR group, BLE2 and BLE5 increased average daily feed intake from 1 to 21 D and 22 to 42 D (P < 0.05), BLE1 and BLE2 improved average daily gain (ADG) and feed to gain ratio from 22 to 42 D (P < 0.05). Throughout the trial period, the highest body weight and favorable ADG and feed to gain ratio were observed in the BLE2 group. The drip loss at 24 h and pH at 45 min postmortem of breast meat were linearly improved by BLE supplementation (P < 0.05). Shear force was significantly lower in BLE2 and BLE3 than that in CTR group. Increasing supplementation of BLE linearly improved free radical scavenging capacity and decreased malondialdehyde content of breast meat during 12 D of storage (P < 0.05). Total antioxidant capacity and glutathione peroxidase activity were linearly increased by BLE supplementation (P < 0.05). Compared with the CTR group, the mRNA expression of Nrf2 and glutathione peroxidase in BLE3, BLE4, and BLE5 groups was significantly promoted, and glutathione S-transferase gene expression was increased in BLE2, BLE4, and BLE5 (P < 0.05). The highest (P < 0.05) heme oxygennase-1 gene expression was observed in BLE5. In conclusion, broiler supplemented with BLE improved growth performance and meat quality, BLE supplementation might activate Nrf2 pathway to alleviate lipid oxidation and increase antioxidant capacity of breast meat. The dosage of 2.0 to 3.0 g/kg BLE in broiler diet was recommanded.

Sasa quelpaertensis Nakai extract induces p53-independent apoptosis via the elevation of nitric oxide production in human HCT116 colon cancer cells

Induction of apoptosis in human cancer cells by Sasa quelpaertensis Nakai has been considered to be a potential therapeutic target for cancer treatment; however, the underlying mechanisms of action are not well understood. The present study investigated the role of nitric oxide (NO^•) and inhibitors of apoptosis (IAPs) during apoptosis induced by Sasa quelpaertensis Nakai extracts (SQE) in p53-wild type (WT) and p53-null HCT116 colon carcinoma cells. Trypan blue exclusion and Annexin V/propidium iodide assays were used to test for antiproliferation, and apoptosis and cell cycle. Griess and reverse transcription-polymerase chain reaction and western blotting assays were carried out to assay NO^• production, and to detect the mRNA and protein levels of Bcl-2, PARP and IAPs. A colorimetric assay was utilized to measure the time-dependent increase in caspase-3 activity. SQE inhibited cell growth and promoted apoptosis by the elevation of NO^• in a dose- and time-dependent manner. In addition, both cell types underwent a reduction in mRNA and protein levels of IAPs (survivin, CIAP-1 and -2, and X-linked inhibitor of apoptosis) as well as anti-apoptotic Bcl-2, whereas an increase in protein expression of poly (ADP-ribose) polymerase 1 and caspase 3 activity was observed; however, an equivalent cytotoxic and apoptotic effect by SQE was observed in p53-WT and p53-null cells. Collectively, the results indicated that SQE-induced apoptosis was independent of p53 status and associated with modulation of endogenous NO^• and IAP family gene expression.

Optimization of Microwave-Assisted Extraction of Antioxidants from Bamboo Shoots of Phyllostachys pubescens

Bamboo is a well-known medicinal plant in Southeast Asia that recently has attracted attention for its high polyphenol content and its medical and nutraceutical applications. In this work, polyphenols have been recovered for the first time by microwave-assisted extraction (MAE) from an unusual Italian cultivar of Phyllostachys pubescens bamboo shoots. The effects of three independent variables, such as extraction time, temperature, and solid/liquid ratio, on polyphenol recovery yield were investigated and successfully optimized through the response surface methodology. We demonstrated that MAE is an excellent polyphenols extraction technique from bamboo shoots because the total phenolic content obtained under microwave irradiation optimal conditions (4 min at 105 °C with 6.25 mg/mL ratio) was about eight-fold higher than that obtained with the conventional extraction method. Furthermore, higher total flavonoid content was also obtained under MAE. Consistent with these results, MAE enhanced the extract antioxidant properties with significant improved DPPH, ABTS, and FRAP scavenging ability. Therefore, this innovative extraction process enhances the recovery of biologically active compounds from Phyllostachys pubescens bamboo shoots with a dramatic reduction of time and energy consumption, which paves the way for its industrial application in functional food production.

Effect of Bamboo Leaf Extract on Antioxidant Status and Cholesterol Metabolism in Broiler Chickens

Simple Summary

Cholesterol is an important lipid substance in organisms. As the precursor of bile acid, steroid hormones and vitamin D3, cholesterol plays important roles in lipid metabolism. Chicken is among the most consumed meat products worldwide; however, its cholesterol level is higher than that of other meat products. High cholesterol in a human diet will increase the risk of atherosclerosis. In addition, low-density lipoprotein cholesterol is susceptible to be oxidized, which will cause the death of broilers. Therefore, it is of great significance to enhance the antioxidant capacity and improve cholesterol metabolism in broiler chickens. Bamboo leaf extract (BLE) contains active ingredients such as flavonoids, polyphenols, and active polysaccharides, which possess anti-inflammatory, antioxidant and lipid-lowering effects. Our results show that supplementation of BLE in the basal diet improved growth and slaughter performance, antioxidant status and cholesterol metabolism in broilers. Therefore, the application of BLE as a feed additive has a certain economic value.

Abstract

The objective of this study was to investigate the effects of dietary bamboo leaf extract (BLE) on antioxidant status and cholesterol metabolism in broilers. One-day-old male Arbor Acres (576) broilers were randomly divided into six groups. A control group was fed a basal diet, while five experimental groups were supplemented with 1.0, 2.0, 3.0, 4.0, and 5.0g BLE per kg feed in their basal diets. The result indicated that BLE supplementation linearly improved eviscerated yield and decreased abdominal fat (p < 0.05). A significant decrease of serum triglyceride (TG) and low-density lipoprotein cholesterol (LDL-c) content was observed with BLE supplementation (p < 0.05). BLE supplementation linearly improved the total antioxidant capacity and catalase activity in both serum and liver (p < 0.05). Glutathione peroxidase was quadratically increased in serum and linearly increased in the liver with BLE supplementation (p < 0.05). The malonaldehyde content in liver showed a linear and quadratic decrease with BLE supplementation (p < 0.05). BLE supplementation up-regulated the mRNA expression of cholesterol 7- alpha hydroxylase and low-density lipoprotein receptor and downregulated 3-hydroxy3-methyl glutamates coenzyme A reductase mRNA expression in the liver. The antioxidant enzyme mRNA expressions were all up-regulated by BLE supplementation in the liver. In conclusion, supplemental BLE improved antioxidant status and cholesterol metabolism in broilers, which eventually led to a decrease of serum TG, LDL-c content, and abdominal fat deposition.

Furan formation from ingredient interactions and furan mitigation by sugar alcohols and antioxidants of bamboo leaves in milk beverage model systems

BACKGROUND

Furan is a potential carcinogen that can be formed in various heat-treated foods, including milk beverages. Studies on the formation and mitigation of furan in milk beverages are rare. In the present study, the effects of ingredients on furan formation and the reduction of furan by sugar alcohols and antioxidants of bamboo leaves (AOB) were investigated in a milk beverage model system.

RESULTS

The results obtained demonstrated that the Maillard reaction is the major pathway for furan formation in a milk beverage model system, and the type of sugar has a great influence on furan formation. High fructose corn syrup (HFCS 55) was more favorable for furan formation than sucrose. Thermal oxidation of ascorbic acid and lipids significantly enhanced furan generation. Xylitol, sorbitol and mannitol inhibited furan formation in model systems by replacing sucrose or HFCS. The maximum inhibition percentage of furan formation was observed when sucrose/HFCS was substituted completely by xylitol and the inhibition rate was 78.28% and 88.64% separately for the sucrose/HFCS-containing system. AOB significantly inhibited furan formation and the inhibition rate reached 32.13% and 28.52% separately for the sucrose/HFCS-containing system.

CONCLUSION

The present study demonstrates that the use of sugar alcohols and AOB could be a feasible way of reducing furan formation in thermally processed milk beverages. © 2019 Society of Chemical Industry.

Production of isoorientin and isovitexin from luteolin and apigenin using coupled catalysis of glycosyltransferase and sucrose synthase

Isoorientin and isovitexin, kinds of flavone C-glycosides, exhibit a number of biological properties. In this work, The C-glucosyltransferase (Gt6CGT) gene from Gentiana triflora was cloned and expressed in Escherichia coli BL21(DE3). The optimal activity of Gt6CGT was at pH 7.5 and 50° C. The enzyme was stable over pH range of 6.5-9.0, and had a 1-h half-life at 50° C. The V_max for luteolin and apigenin was 21.1 nmol/min/mg and 31.7 nmol/min/mg, while the K_m was 0.21 mM and 0.22 mM, respectively. Then, we developed an environmentally safe and efficient method for isoorientin and isovitexin production using the coupled catalysis of Gt6CGT and Glycine max sucrose synthase (GmSUS). By optimizing coupled reaction conditions, the titer of isoorientin and isovitexin reached 3820 mg/L with a corresponding molar conversion of 94.7% and 3772 mg/L with a corresponding molar conversion of 97.1%, respectively. The maximum number of UDP-glucose regeneration cycles (RC_max) reached 28.4 for isoorientin and 29.1 for isovitexin. The coupled catalysis reported herein represents a promising method to meet industrial requirements for large-scale isoorientin and isovitexin production in the future. Graphical Abstract.

Structural analysis and antioxidant activity of an arabinoxylan from Malvastrum coromandelianum L. (Garcke)

Malvastrum coromandelianum L. (Garcke) is extensively used in traditional medicinal systems to treat various ailments. In the present study, an alkali-soluble polysaccharide (MAP) was isolated from the leaves of M. coromandelianum in 1.15% (w/w) yield. MAP was composed of l-rhamnose, l-arabinose, d-xylose, d-glucose and d-galactose in a 1.00 : 6.04 : 19.88 : 1.07 : 3.03 molar ratio along with d-glucuronic acid (1.95). Methylation/linkage analysis revealed a backbone of →4)-β-d-Xylp(1→ (30.09 mol%) with a side chain of →3)-α-l-Araf(1→ (15.21 mol%) residues. The structure of MAP was elucidated by a combination of degradative and derivatization techniques, including hydrolysis, alditol acetate derivatization, methylation, GC-MS, partial hydrolysis, ESI-MS and NMR (1D, 2D) spectral analysis. Based on correlation analysis, MAP was found to be an arabinoxylan comprising a backbone of →4)-β-d-linked Xylp(1→ with branching at O-2 by a →3)-α-l-Araf(1→ and →3)-β-d-Xylp(1→ chain. MAP also exhibited ferric ion reducing activity, with a reducing power of 0.914 ± 0.01 (R 2 = 0.972) at 1 mg mL-1 concentration, which showed dose-dependent behavior. MAP can be utilized as a potential antioxidant.

Physico-Chemical Parameters, Phenolic Profile, In Vitro Antioxidant Activity and Volatile Compounds of Ladastacho (Lavandula stoechas) from the Region of Saidona

The aim of the present study was to characterize Lavandula stoechas (Ladastacho) from the region of Saidona by means of physico-chemical parameters, phenolic profile, in vitro antioxidant activity and volatile compounds. Physico-chemical parameters (pH, acidity, salinity, total dissolved solids, electrical conductivity and liquid resistivity) were determined using conventional methods. The phenolic profile was determined using high-performance liquid chromatography electrospray ionization mass spectrometry (HPLC/ESI-MS), whereas a quantitative determination was also accomplished using the total phenolics assay. In vitro antioxidant activity was determined using the 2,2-diphenyl-1-picryl-hydrazyl assay. Finally, volatile compounds were determined using headspace solid phase microextraction coupled to gas chromatography mass spectrometry (HS-SPME/GC-MS). The results showed that Lavandula stoechas aqueous extract had a slightly acidic pH, low salinity content and considerable electrochemical properties (electrical conductivity and liquid resistivity along with electric potential). In addition, aqueous fractions showed a significantly (p < 0.05) higher phenolic content and in vitro antioxidant activity, whereas phenolic compounds, such as caffeic acid, quercetin-O-glucoside, lutelin-O-glucuronide and rosmarinic acid, were identified. Finally, numerous volatile compounds were found to dominate the volatile pattern of this flowering plant, producing a strong, penetrating, cool and menthol-like odour.

Phenolic distribution, antioxidant activity, and enzyme inhibitory properties of eggplant (Solanum aethiopicum) cultivated in two different locations within Nigeria

Solanum aethiopicum is commonly cultivated in Nigeria for its nutritional and medicinal properties. Although, information on the possible effect of location on the biological activities of S. aethiopicum has not been reported, however, present research work investigated the phenolic contents and distribution, antioxidative properties, and enzyme inhibitory activities of S. aethiopicum collected from two locations in Nigeria. HPLC phenolic profile, polyphenol contents, free radical scavenging activities, and inhibitory effect of eggplant extracts on carbohydrate metabolizing enzymes were carried out. Significant variations were observed in the phenolic profile, polyphenol contents, antioxidant activities, and enzymes inhibitory properties of the extracts from different locations. In most of the analyses carried out, extract of eggplant fruit collected from Uyo (UEF) showed higher activities than the one obtained from Ibadan (IEF). Thus, findings from this study revealed that geographical location may influence the phenolic contents, antioxidant, and enzymes inhibitory properties of eggplant fruits. PRACTICAL APPLICATIONS: The geographical location of a particular place determines the nature and biological activities of plants cultivated in the area. Hence, we presented the effect of location on the phenolic profile, antioxidant, and enzyme inhibitory properties of eggplant fruit (S. aethiopicum) cultivated in two different locations in Nigeria. However, data generated in this study showed the effect of location on phenolic composition and biological activities of eggplant fruit cultivated in Nigeria.

Efficient Biotransformation of Luteolin to Isoorientin through Adjusting Induction Strategy, Controlling Acetic Acid, and Increasing UDP-Glucose Supply in Escherichia coli

Isoorientin is a C-glycosylated derivative of luteolin and exhibits a number of biological properties. In this study, multiple strategies were adopted to improve isoorientin production from luteolin in Escherichia coli. Isoorientin production was improved substantially by adjusting induction strategies and controlling acetic acid accumulation, with maximum isoorientin production reaching 826 mg/L. Additionally, a novel UDP-glucose synthesis pathway was reconstructed in E. coli through cellobiose phosphorylase-catalyzed phosphorolysis of cellobiose for the production of glucose 1-phosphate, which serves as a precursor in UDP-glucose formation. The results from two mechanisms of UDP-glucose formation in E. coli, cellobiose phosphorolysis and sucrose phosphorolysis, were compared. Increasing the UDP-glucose supply resulted in maximal isoorientin production reaching 1371 mg/L. Finally, isoorientin (1059 mg) was obtained from 1 L of fermentation broth by simple purification steps with a yield of 81.5%. Therefore, this study provides an efficient method for isoorientin production and a novel UDP-glucose synthesis pathway.

Drying alters the phenolic constituents, antioxidant properties, α-amylase, and α-glucosidase inhibitory properties of Moringa (Moringa oleifera) leaf

Moringa oleifera leaf is a popular green leafy vegetable which has found its usefulness in the preparation of traditional stews and soups. Like most green leafy vegetable which are not around year-round, the leaf is usually dried and pulverized for storage and easier handling, and despite the popularity of this processing technique, there is dearth of information on how drying affects the health-promoting properties of the leaves. Hence, this study sought to investigate the effect of some drying methods (freeze-drying, sun, air and oven drying) on the phytoconstituents, antioxidant properties, and biological activities of moringa leaf. This study revealed that drying methods significantly altered the phytoconstituents (phenolics, flavonoids, vitamin C, tannin, saponin, phytate, oxalate, alkaloid, cardenolides, and cardiac glycosides), antioxidant capacities (reducing power, Fe2+chelating, ABTS •+, DPPH, and • OH scavenging abilities), and enzyme inhibitory (α-amylase and α-glucosidase) effects of the leaf, with freeze-drying being the most promising method for preserving the nutraceutical properties of moringa leaf. However, for practical application, the order of preference of the drying methods which ensures adequate retention of phytoconstituents and possibly biological activities of the leaf as observed in this study is freeze-drying > air drying > sun drying > oven drying, in the order of decreasing magnitude.

Lycium europaeum Linn as a source of polysaccharide with in vitro antioxidant activities and in vivo anti-inflammatory and hepato-nephroprotective potentials

ETHNOPHARMACOLOGICAL RELEVANCE

Lycium europaeum Linn. is widely used to treat the burning of the skin and well-known as a medicinal plant having various biological activities.

AIMS OF THE STUDY

The purpose of the present study is to characterize the polysaccharide from L. europaeum L. leaves (LEP) and to explore its antioxidant, anti-inflammatory and hepato-nephroprotective properties.

MATERIALS AND METHODS

The structural and functional characteristics of LEP were investigated using X-ray diffraction techniques (XRD), Scanning Electron Microscopy (SEM), and FT-IR Spectroscopy. The antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl and hydrogen peroxide scavenging assays. Hepato-renal effects were studied using CCl₄ and cisplatin-induced liver and kidney injuries in mice, respectively. Anti-inflammatory activity was assessed on carrageenan-induced paw edema.

RESULTS

The LEP showed an interesting water-holding capacity and effective foaming and emulsifying properties. XRD analysis suggested that LEP form a semi-crystalline polymer with an amorphous structure. FT-IR profile showed the presence of pyranose ring in LEP. SEM and helix-coil transition analyses indicated that LEP had a lamellar structure with angular edges and didn't present a triple helical conformation in solution. In vitro, LEP indicated significant concentration-dependent antioxidant activity. In vivo, LEP treatment significantly reduced the effects of CCl₄ intoxication on serum liver biomarkers (AST, ALT, LDH, and GGT) and the effect of cisplatin on serum renal biomarkers (urea, blood urea nitrogen, creatinine, and uric acid). Meanwhile, LEP diminishes significantly the effect of CCl₄ and cisplatin on the level of lipid peroxidation in liver and kidney tissues, respectively. Additionally, the normal histological structure of liver and kidney was restored after treatment with the polysaccharide. LEP possessed a significant anti-inflammatory activity on acute inflammation induced by carrageenan in mice.

CONCLUSION

Overall, the findings of this study support the traditional use of L. europaeum L. This plant may also be used as a good agent for protection against inflammatory diseases and hepato-renal injuries in patients with cancer.

Anti-ageing skin effects of Korean bamboo salt on SKH1 hairless mice

Bamboo salt is generated by baking bamboo and sea salt and is used as a traditional food or medicine. The aim of this study was to investigate the anti-ageing skin effects of Korean bamboo salt and to compare the antioxidant, anti-ageing and anti-inflammatory effects of various salts, including purified salt, solar salt, bath solar salt, Masada solar salt, 1-time baked bamboo salt (1× bamboo salt), and 9-times baked bamboo salt (9× bamboo salt). Based on the content of mineral elements, pH, OH groups and redox potential amperometric analysis, the 9× bamboo salt showed the most antioxidant components and characteristics compared to the other salts. The in vitro results showed that the 9× bamboo salt could inhibit oxidative damage by hydrogen peroxide (H₂O₂) treatment in HaCaT keratinocytes, and its effect was better than that of the other salts. In an in vivo experiment, SHK-1 hairless mice were treated with UV (ultraviolet) radiation to induce ageing. The epidermal thickness and epidermal structures were then assessed by phenotypic and histological analyses. The 0.2% 9× bamboo salt- and 1× bamboo salt-treated mice had a thinner epidermis than the control mice, and the sebaceous glands were almost intact with a regular arrangement that was similar to those in the normal group. Compared with the UV-treated group (control group) and other salt-treated groups, the 9× bamboo salt- and 1× bamboo salt-treated groups had higher dermal collagen and elastic fibre content. Fewer mast cells were observed in the 9× bamboo salt- and 1× bamboo salt-treated groups than in the control group. The activities of the skin antioxidant-related enzymes superoxide dismutase (SOD) and catalase (CAT) in the 9× bamboo salt- and 1× bamboo salt-treated groups were higher than those in other groups and similar to those in the normal group, but lipid peroxide (LPO) activity and carbonylated protein levels showed the opposite trends. Furthermore, the 9× bamboo salt- and 1× bamboo salt-treated groups had protein contents similar to those of the normal group. In addition, the 9× bamboo salt and 1× bamboo salt effectively down-regulated the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) and up-regulated the expression of tissue inhibitor expression of matrix metalloproteinase-1 (TIMP-1), matrix metalloproteinase-2 (TIMP-2), SOD and CAT compared to the other salts at a concentration of 0.2% (p < 0.05). These results suggest that at appropriate concentrations, bamboo salt could prevent skin ageing induced by ultraviolet radiation b (UVB) photodamage.

Muli bamboo (Melocanna baccifera) leaves ethanolic extract a non-toxic phyto-prophylactic against low pH stress and saprolegniasis in Labeo rohita fingerlings

Bamboo (Melocanna baccifera) plant plays a significant role in traditional Asian medicine and it can be used as an alternative to various chemo-therapeutics or prophylactic agents used in aquaculture. In the present study, the 1^st experiment was done for the preparation of extracts from bamboo leaves by using 90% alcohol as a solvent. In the 2^nd experiment, toxicity study was carried on Labeo rohita fingerlings (average length of 10.3 ± 1.5 cm and weight 18.5 ± 1.5 g) using BLAL (Bamboo Leaf Alcoholic) extract and it did not show any mortalities in fish even at the dose of 20 g kg^-1 body weight, which can be regarded as virtually non-toxic with minimal effect. The 3^rd experiment was conducted to find out the effect of BLAL extract based isocaloric and isonitrogenous feed (doses: control- 0.0%, diet T1-0.01%, diet T2-0.1%, diet T3-1% BLAL extract kg^-1 feed) on the haemato-immuno-biochemical parameters of L. rohita fingerlings (average length 15.7 ± 1.5 cm and weight 20.2 ± 1.5 g). Regular sampling was done (on 7^th, 15^th, 30^th and 60^th day of feeding) for different haematological, immunological and biochemical parameters. The study revealed that the best response occurred within 7 days of feeding with BLAL extract and long-term feeding have shown immunosuppressive condition in the fish. In the 4^th experiment, fish were exposed to multiple stressors like low pH stress, and Saprolegnia parastica infection after feeding with BLAL extract (0.1%) based feed for 7 days. The study showed that the BLAL extract can make fish resistant to single stress however, not able to reduce the fish mortality under multiple stresses (S. parastica infection under low pH). Thus, it can be concluded that the BLAL has the potentiality to be used as a non-toxic phyto-prophylactic which can induce non-specific immune response, reduces the low pH stress responses and increases the resistance against saprolegniasis under neutral pH condition in rohu fingerlings.

Antioxidant action and protective and reparative effects of lentinan on oxidative damage in HaCaT cells

BACKGROUND

Lentinus edodes is one of the largest edible fungi. Lentinan, extracted from its fruiting body has clinically significant anticancer, antibacterial, antiviral, and anticoagulant effects; however, its preventive effects on skin oxidative damage are unclear.

AIMS

We aimed to evaluate the in vitro antioxidation capability of lentinan and its protective and reparative effects on a model of cell oxidative damage.

METHODS

We evaluated the in vitro antioxidant potential of lentinan by assessing its free-radical quenching ability using DPPH and ABTS and superoxide anions. Using the HaCaT cell line as the experimental system, we tested the protective and reparative effects of lentinan on a model of H₂ O₂ -induced cellular oxidative damage through assessment of cell survival rate, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity.

RESULTS

Lentinan displayed high antioxidant potential: DDPH and ABTS quenching rates were above 60%; superoxide anions, approximately 18%. Furthermore, lentinan could dose-dependently prevent the reduction of activity in HaCaT cells by H₂ O₂ , reduce MDA formation, and increase SOD activity. Moreover, lentinan showed not only a protective effect against oxidative damage but also reparative effects to a certain extent, in HaCaT cells.

CONCLUSIONS

Our findings demonstrated the ability of lentinan to enhance cellular tolerance to oxidative damage, stress resistance, and to have protective and reparative effects on damaged cells. Therefore, with L. edodes as a source for antiaging substances, cosmetics with homology to foods have great potential clinical applications.

Simultaneous and fast separation of three chlorogenic acids and two flavonoids from bamboo leaves extracts using zirconia

Phenolic acids and flavonoids in bamboo leaves are of great importance for their functional attributes, but they can hardly be separated simultaneously. In this study, zirconia was prepared and applied as a potential absorbent for simultaneous separation of these phenolic compounds. Three phenolic acids (neochlorogenic acid, chlorogenic acid and cryptochlorogenic acid) and two flavonoids (isoorientin and orientin) were isolated at the same time. The influence of bamboo leaves extraction conditions, zirconia calcination temperatures, desorption conditions and absorption/desorption dynamics on the separation were further investigated. When zirconia-400 (calcined at 400 °C) was treated with 70% ethanol extract of bamboo leaves for 40 min followed by desorption with 70% acetic acid solution for 60 min, the recovery of three chlorogenic acids and two flavonoids was about 65%. To conclude, the concise method developed here may provide a new way for simultaneous separation of phenolic acids and flavonoids from various plants.

Purification and characterization of a ∼43 kDa antioxidant protein with antitumor activity from Pholiota nameko

BACKGROUND

Pholiota nameko water-soluble protein (PNWSP), isolated from the dried fruiting bodies of Pholiota nameko, was purified by a successive chromatographic process using Q anion exchange column, SP cation exchange column and Superdex 200 gel filtration column. PNWSP was assessed for antioxidant activities in different assay systems, and the effect on cell proliferation of human breast cancer MCF7 cells was investigated.

RESULTS

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analytical ultracentrifugation analysis revealed the homogeneity of PNWSP with apparent molecular weight of ∼43 kDa, and the identification was confirmed by peptide mass fingerprint analysis. It showed potential antioxidant activities in scavenging free radicals, reducing power and chelating effect on Fe(2+), and had a protective effect against DNA amage. Moreover, it inhibited the proliferation of MCF7 cells by inducing apoptosis, in which the change in cell cycle distribution and the loss of mitochondrial transmembrane potential were observed by flow cytometry.

CONCLUSIONS

The results showed that PNWSP could be a natural antioxidant and developed as a potential chemotherapeutic agent candidate against human breast cancer.

Caffeic and chlorogenic acids inhibit key enzymes linked to type 2 diabetes (in vitro): a comparative study

BACKGROUND

Chlorogenic acid is a major phenolic compound that forms a substantial part of plant foods and is an ester of caffeic acid and quinic acid. However, the effect of the structures of both chlorogenic and caffeic acids on their antioxidant and antidiabetic potentials have not been fully understood. Thus, this study sought to investigate and compare the interaction of caffeic acid and chlorogenic acid with α-amylase and α-glucosidase (key enzymes linked to type 2 diabetes) activities in vitro.

METHODS

The inhibitory effect of the phenolic acids on α-amylase and α-glucosidase activities was evaluated. Thereafter, their antioxidant activities as typified by their 1,1-diphenyl-2 picrylhydrazyl radical scavenging ability and ferric reducing antioxidant properties were determined.

RESULTS

The results revealed that both phenolic acids inhibited α-amylase and α-glucosidase activities in a dose-dependent manner (2-8 μg/mL). However, caffeic acid had a significantly (p<0.05) higher inhibitory effect on α-amylase [IC50 (concentration of sample causing 50% enzyme inhibition)=3.68 μg/mL] and α-glucosidase (IC50=4.98 μg/mL) activities than chlorogenic acid (α-amylase IC50=9.10 μg/mL and α-glucosidase IC50=9.24 μg/mL). Furthermore, both phenolic acids exhibited high antioxidant properties, with caffeic acid showing higher effects.

CONCLUSIONS

The esterification of caffeic acid with quinic acid, producing chlorogenic acid, reduces their ability to inhibit α-amylase and α-glucosidase activities. Thus, the inhibition of α-amylase and α-glucosidase activities by the phenolic acids could be part of the possible mechanism by which the phenolic acids exert their antidiabetic effects.