Condensed Tannins Research Articles

Effects of oligomeric proanthocyanidins on growth performance, antioxidant capability, immunity, liver and intestinal health of Channa argus

To determine the effects of proanthocyanidins on the growth, antioxidant capability, immunity, intestinal morphology, intestinal microbiota, and liver health of Channa argus (10.12 ± 0.12 g), four experimental diets with various oligomeric proanthocyanidin (OPC) concentrations (0, 200, 400, and 800 mg/kg) were fed to triplicate groups for 8 weeks. The final body weight (FBW), weight gain (WG), feeding rate (FER), protein efficiency ratio (PER), and specific growth rate (SGR) were significantly improved in the 400 and 800 mg/kg OPC-supplemented diets (P < 0.05). The superoxide dismutase (SOD), glutathione-S-transferase (GST), glutathione (GSH), catalase (CAT), and glutathione peroxidase (GSH-Px) activities in the liver and intestines were increased significantly, whereas the malondialdehyde (MDA) content exhibited the opposite pattern (P < 0.05). The GST, Cu/Zn superoxide dismutase (Cu/Zn SOD), nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H quinone dehydrogenase 1 (NQO-1), and heme oxygenase 1 (HO-1) mRNA expression levels in the intestines and liver were significantly increased, whereas kelch-like ECH-associated protein 1 (Keap1) expression showed the opposite pattern (P < 0.05). Significant increases were noted in the serum lysozyme (LYS), immunoglobulin M (IgM), complement 3 (C3), and complement 4 (C4) levels, and significant decreases were noted in the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bile acid (TBA), and total cholesterol (TC) levels (P < 0.05). The interferon gamma (IFN-γ), interleukin-8 (IL-8), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) mRNA expression levels in the liver and intestines were significantly decreased, whereas the expression of interleukin-10 (IL-10) showed the opposite trend (P < 0.05). Compared with the control diet, the 400 and 800 mg/kg OPC-supplemented diets markedly improved liver and intestinal morphology. With increasing OPC concentration, the relative abundance of the beneficial bacteria, namely, Firmicutes increased, whereas the opposite trend was observed for the potential pathogenic bacteria, namely, Proteobacteria, Actinobacteria, Chlamydiae, Bacteroidetes, Cyanobacteria, and Acidobacteria. Therefore, dietary OPC supplementation facilitates growth performance and enhances antioxidant capability and immunity, as well as improves liver health, intestinal morphology, and microbiota composition of C. argus, of which the optimal level is 400 mg/kg.

Pycnogenol-Assisted Alleviation of Titanium Dioxide Nanoparticle-Induced Lung Inflammation via Thioredoxin-Interacting Protein Downregulation.

Titanium dioxide nanoparticles (TiO2NPs) are used in products that are applied to the human body, such as cosmetics and food, but their biocompatibility remains controversial. Pycnogenol (PYC), a natural extract of pine bark, exerts anti-inflammatory and antioxidant effects. In this study, we investigated whether PYC effectively alleviates pulmonary toxicity induced by airway exposure to TiO2NPs, and the beneficial effects of PYC were explained through the analysis of changes to the mechanism of cytotoxicity. TiO2NPs induced pulmonary inflammation and mucus production, increased the levels of malondialdehyde, and upregulated thioredoxin-interacting protein (TXNIP) and cleaved-caspase 3 (Cas3) in the lungs of mice. However, PYC treatment reduced the levels of all toxicity markers of TiO2NPs and restored glutathione levels. These antioxidant and anti-inflammatory effects of PYC were also demonstrated in TiO2NP-exposed human airway epithelial cells by increasing the mRNA levels of antioxidant enzymes and decreasing the expression of TXNIP, cleaved-Cas3, and inflammatory mediators. Taken together, our results showed that PYC attenuated TiO2NP-induced lung injury via TXNIP downregulation. Therefore, our results suggest the potential of PYC as an effective anti-inflammatory and antioxidant agent against TiO2NP-induced pulmonary toxicity.

Nutritive value and condensed tannins of tree legumes in silvopasture systems

Introducing legumes into C4-dominated tropical pastures, may enhance their sustainability but has some pasture management constraints. One potential alternative is using arboreal legumes, but several of these species have relatively high condensed tannin (CT) concentrations, which negatively impact forage quality. There is limited knowledge, however, on how arboreal legume leaf CT content varies over the year and how this might impact forage quality. The objective of this 2 year study was to assess the seasonal variation of CT and nutritive value for ruminants of the tropical tree legumes gliricidia [Gliricidia sepium (Jacq.) Kunth ex. Walp.] and mimosa (Mimosa caesalpiniifolia Benth). The research was carried out in the sub-humid tropical region of Brazil on well-established pastures in which either legume was present with signalgrass (Urochloa decumbens Stapf.). We determined CT and nitrogen concentrations, in vitro digestible organic matter (IVDOM), and leaf δ13C and δ15N from January to October of 2017 and 2018. All parameters were affected (P < 0.05) by the interaction between legume species and sampling time, with generally higher leaf CT content for mimosa than gliricidia, and both were reduced at the start of the dry season, although much more drastically for mimosa. The IVDOM was strongly affected by CT content and increased at the start of the dry season, coincidentally when C4 grass forage quality typically decreased. There is a marked species effect, with CT from gliricidia impacting IVDOM more than the same CT content from mimosa. While N concentration from mimosa also increased at the start of the dry season, that for gliricidia did not vary over the year. We conclude that although these arboreal legumes have relatively high CT contents, these reduce during the dry season when CT concentrations coinciding with a reduced forage quality as the protein content for C4 grasses is usually inadequate in this season.

Inclusion of the Cistus ladanifer L. plant and its condensed tannin extract in lamb diets - Effects on animal antioxidant status and oxidative stability of meat

This study evaluated whether the incorporation of condensed tannin (CT) extract from Cistus ladanifer in lamb diets induces the same antioxidant protection as the C. ladanifer plant. How dietary CT can enhance the antioxidant status of animals and the oxidative stability of their products was also explored. Thirty-six lambs were used to evaluate the effect of three levels of C. ladanifer CT (without CT enrichment, medium, and high level of CT) and two ways of CT supply (C. ladanifer plant or C. ladanifer CT extract) on meat lipid and colour stability, and antioxidant status of muscle, rumen, abomasum, and faeces. The presence of CT monomers in muscle and CT content in digestive contents and faeces was evaluated. Cistus ladanifer plant and CT extract did not improve the lipid stability and antioxidant status of meat, but both CT sources enhanced the meat colour stability over storage time. Condensed tannin monomers were not identified in muscle. Intake of α-tocopherol decreased with inclusion of CT sources in diets. However, muscle α-tocopherol content was not affected by diets, suggesting that CT increase the α-tocopherol availability in muscle. Both CT sources increased antioxidant activity in the digestive contents, although, in the abomasum, C. ladanifer plant resulted in higher antioxidant activity than CT extract for the same CT level in the diet. No CT were detected in the faeces and both CT sources had a minor effect on the antioxidant activity, which could indicate the CT transformation in the gastrointestinal tract.

Comparison of Chinese medicine additives for antibiotic resistance risks in the Wuding chickens under high stocking density: Advantages and drawbacks

Traditional Chinese medicines (TCMs) with anti-pathogenic properties have been increasingly utilized in animal husbandry as substitutes for antibiotics. However, lingering uncertainties persist regarding the mobility, bacterial hosts, and potential human hazards associated with antibiotic resistance genes (ARGs) in animal husbandry when TCMs are introduced. In this study, cecal digesta from Wuding chickens subjected to varying stocking densities (moderate and high) and treated with different TCMs (dihydroartemisinin, berberine hydrochloride, and oligomeric proanthocyanidins) were collected and subjected to metagenomics-based analysis. A total of 280 ARG subtypes were identified, with multidrug and aminoglycoside resistance genes being the most diverse and abundant. The primary antibiotic resistance bacteria identified belonged to the phyla of Firmicutes (38.68%), Bacteroidetes (22.74%), and Proteobacteria (12.71%); however, some pathogenic antibiotic-resistant bacteria (PARB) were also identified across different samples. Surprisingly, high stocking density was not observed to propagate ARGs, which could be due to the restricted usage of antibiotics. Furthermore, higher proportions of mobile genetic elements and some multidrug-resistant PARB (∼4 times) were observed in high-stocking-density chickens fed berberine hydrochloride than in high-stocking-density chickens fed other TCMs, which could facilitate the horizontal gene transfer (HGT) of ARGs and pose potential human health risks. In contrast, dihydroartemisinin reduced the total abundance of ARGs and the resistome risks to human health (∼10% decrease compared to control). Moreover, rank I ARGs with higher human health risk and the risk index based on ARG risk also ranked lowest (p < 0.05) in high-stocking-density chickens fed dihydroartemisinin. The reduction effect of dihydroartemisinin was achieved by regulating the cecal microbiome of broilers and inhibiting HGT (reducing the contribution from 17.7% to 4.0%). This study provides metagenomic evidence of the development of ARGs in broiler breeding environments. The findings highlight the distinct characteristics of TCMs as feed additives on regulating the antibiotic resistome during broiler farming and demonstrate dihydroartemisinin as an effective additive complying with the environmental safety.

Combined gut microbiome and metabolomics to reveal the mechanism of proanthocyanidins from the roots of Ephedra sinica Stapf on the treatment of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) that primarily affects mucosa and submucosa of colon and rectum. Although the exact etiology of UC remains elusive, increasing evidence has demonstrated that the gut microbiome and its interaction with host metabolism plays an important role in UC development. The objective of this study was to investigate the therapeutic potential and mechanism of dimeric proanthocyanidins (PAC) enriched from ethyl acetate extract of Ephedra roots on UC from the perspective of gut microbiota and metabolic regulation. In this study, a bio-guided strategy integrating LC-MS analysis, DMAC assay, antioxidant screening, and antiinflammation activity screening was used to enrich dimeric PAC from Ephedra roots, then untargeted metabolomics combined with gut microbiota analysis was performed to investigate the therapeutic mechanism of PRE on UC. This is the first study that combines a bio-guided strategy to enrich dimeric PAC from Ephedra roots and a comprehensive analysis of their effects on gut microbiota and host metabolism. Oral administration of PRE was found to significantly relieve dextran sodium sulfate (DSS)-induced ulcerative colitis symptoms in mice, characterized by the reduced disease activity index (DAI), increased colon length and improved colon pathological damage, together with the down-regulation of colonic inflammatory and oxidative stress levels. In addition, 16 S rRNA sequencing combined with untargeted metabolomics was conducted to reveal the effects of PRE on gut microbiota composition and serum metabolites. PRE improved gut microbiota dysbiosis through increasing the relative abundance of beneficial bacteria Lachnospiraceae_NK4A136_group and decreasing the level of potentially pathogenic bacteria such as Escherichia-Shigella. Serum metabolomics showed that the disturbed tryptophan and glycerophospholipid metabolism in UC mice was restored after PRE treatment. Collectively, PRE was proved to be a promising anti-UC candidate, which deserves further investigation in future research.

Evaluation of the Antioxidant and Anti-Inflammatory Activities and Acute Toxicity of Caco Seed (Chrysobalanus icaco L.) in Murine Models.

Chysobalanus icaco L. (C. icaco) is a plant that is native to tropical America and Africa. It is also found in the southeast region of Mexico, where it is used as food and to treat certain diseases. This study aimed to carry out a phytochemical analysis of an aqueous extract of C. icaco seed (AECS), including its total phenol content (TPC), total flavonoid content (TFC), and condensed tannins (CT). It also aimed to examine the antioxidant and metal-ion-reducing potential of the AECS in vitro, as well as its toxicity and anti-inflammatory effect in mice. Antioxidant and metal-ion-reducing potential was examined by inhibiting DPPH, ABTS, and FRAP. The acute toxicity test involved a single administration of different doses of the AECS (0.5, 1, and 2 g/kg body weight). Finally, a single administration at doses of 150, 300, and 600 mg/kg of the AECS was used in the carrageenan-induced model of subplantar acute edema. The results showed that the AECS contained 124.14 ± 0.32 mg GAE, 1.65 ± 0.02 mg EQ, and 0.910 ± 0.01 mg of catechin equivalents/g dried extract (mg EC/g de extract) for TPC, TFC and CT, respectively. In the antioxidant potential assays, the values of the median inhibition concentration (IC50) of the AECS were determined with DPPH (0.050 mg/mL), ABTS (0.074 mg/mL), and FRAP (0.49 mg/mL). Acute toxicity testing of the AECS revealed no lethality, with a median lethal dose (LD50) value of >2 g/kg by the intragastric route. Finally, for inhibition of acute edema, the AECS decreased inflammation by 55%, similar to indomethacin (59%, p > 0.05). These results demonstrated that C. icaco seed could be considered a source of bioactive molecules for therapeutic purposes due to its antioxidant potential and anti-inflammatory activity derived from TPC, with no lethal effect from a single intragastric administration in mice.

Comparative Study of Condensed and Hydrolysable Tannins during the Early Stages of Zebrafish Development.

In this study, we present data on the effects of condensed tannins (CTs) and hydrolysable tannins (HTs), polyphenols extracted from plants, at different concentrations on zebrafish development to identify the range of concentrations with toxic effects. Zebrafish embryos were exposed to CTs and HTs at two different concentration ranges (5.0-20.0 μgL-1 and 5.0-20.0 mgL-1) for 72 h. The toxicity parameters were observed up to 72 h of treatment. The uptake of CTs and HTs by the zebrafish larvae was assessed via HPLC analysis. A qRT-PCR analysis was performed to evaluate the expressions of genes cd63, zhe1, and klf4, involved in the hatching process of zebrafish. CTs and HTs at 5.0, 10.0, and 20.0 μgL-1 were not toxic. On the contrary, at 5.0, 10.0, and 20.0 mgL-1, HTs induced a delay in hatching starting from 48 h of treatment, while CTs showed a delay in hatching mainly at 48 h. The analysis of gene expression showed a downregulation in the group exposed to HTs, confirming the hatching data. We believe that this study is important for defining the optimal doses of CTs and HTs to be employed in different application fields such as the chemical industry, the animal feed industry, and medical science.

Integrating network pharmacology and experimental verification to reveal the anti-inflammatory ingredients and molecular mechanism of pycnogenol.

Introduction: Pycnogenol (PYC), a standardized extract from French maritime pine, has traditionally been used to treat inflammation. However, its primary active components and their mechanisms of action have not yet been determined. Methods: This study employed UPLC-MS/MS (Ultra-high performance liquid chromatography-tandem mass spectrometry) and network pharmacology to identify the potential active components of PYC and elucidate their anti-inflammatory mechanisms by cell experiments. Results: 768 PYC compounds were identified and 19 anti-inflammatory compounds were screened with 85 target proteins directly involved in the inflammation. PPI (protein-protein interaction) analysis identified IL6, TNF, MMP9, IL1B, AKT1, IFNG, CXCL8, NFKB1, CCL2, IL10, and PTGS2 as core targets. KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis suggested that the compound in PYC might exert anti-inflammatory effects through the IL17 and TNF signal pathways. Cell experiments determined that PYC treatment can reduce the expression of IL6 and IL1β to relieve inflammation in LPS (lipopolysaccharide)-induced BV2 cells. Conclusion: PYC could affect inflammation via multi-components, -targets, and -mechanisms.

Acute toxicity and genotoxicity of Schinus molle L. aqueous extract/ethanol-soluble fraction in rats

Ethnopharmacological relevanceSchinus molle L. is a medicinal species belonging to the Anacardiaceae family. It is commonly referred to as "aroeira" and its leaves and roots are utilized for treating different pathological conditions. However, despite its widespread use in traditional medicine, there is a lack of in-depth toxicological studies. AimTo evaluate the acute toxicity and genotoxicity of S. molle aqueous extract/ethanol-soluble fraction in rats. Material and methodsFirst, a purified aqueous extract was obtained from the leaves of S. mole through infusion (referred to as EESM) and its compounds were identified using LC-DAD-MS data. Female rats were then subjected to acute oral toxicity tests using doses of 5, 50, 300, and 2000 mg/kg of ESSM. Studies on genetic material, including the micronucleus test and comet assay, were conducted on male and female Wistar rats using the same doses as in the acute toxicity test. For both assays, ESSM was administered orally. ResultsThe main metabolites annotated from ESSM were dimeric proanthocyanidins, phenylpropanoids acids, flavan-3-ols, simple organic acids (C6–C1), a flavonol di-O-glycosylated (rutin), and O-glycosylated megastigmane. The ESSM did not exhibit any acute toxic effects, such as changes in biochemical, hematologic, or histopathological analysis. Furthermore, no changes were observed in comet assay or micronucleus tests when rats were given doses of 5, 50, 300, or 2000 mg/kg of ESSM. ConclusionThe results showed that the ESSM does not induce acute toxicity or exhibit genotoxicity up to a dose of 2000 mg/kg.

Fatty acid profile, physicochemical composition and carcass traits of young Nellore bulls fed Acacia mearnsii extract

Fatty acid profile, physicochemical composition, and carcass traits of 32 young Nellore bulls were assessed following the supplementation of Acacia mearnsii extract at levels of 0, 10, 30, and 50 g/kg of total dry matter (DM) in a completely randomized experiment with four treatments and eight replicates. Adding 50 g/kg DM of condensed tannins (CT) from Acacia mearnsii in the bulls' diet reduced DM intake, average daily gain, and meat lipid oxidation (P ≤ 0.05). The pH, centesimal composition, collagen, and meat color indexes of the longissimus muscle were not altered by the addition of Acacia mearnsii (P > 0.05). Cooling loss increased (P = 0.049) linearly. Including Acacia mearnsii in diet reduced the Warner-Bratzler shear force (WBSF, P = 0.018) of longissimus muscle of the bulls. The concentration of C16:0, C17:0, C24:0, t9,10,11,16–18:1, c9t11–18:2, C18:2n–6, C20:4n–6, 20:5n–3, 22:5n–3, and 22:6n–3 in the muscle increased due to the addition of Acacia in the diet (P ≤ 0.05), with the highest muscle concentrations caused by the addition of 10 to 30 g Acacia. c9–18:1 and t16–18:1 reduced linearly. ƩSFA, ƩBI, Ʃcis– and ƩMUFA, Ʃn–3, Ʃn–6, and ƩPUFA (P ≤ 0.05) quadratically increased at higher concentrations of addition of Acacia, above 30 g/kg DM. It is recommended to include Acacia mearnsii extract up to 30 g/kg total DM in diets for young bulls as it improves CLA, PUFA and TI and reduces lipid oxidation. Acacia mearnsii extract as source of CT at 50 g/kg DM negatively impacted the young bulls performance.

Natural multi-actives composited hydrogel patches for diabetic wound healing

Biomedical patches have garnered recognition for their efficacy in diabetic wound management. Current research efforts are focused on developing natural and efficient hydrogel patches in order to reduce inherent side effects and enhance therapeutic outcomes. In this study, we present natural multi-actives composited hydrogel patches for diabetic wound management. The novel medical patch was fabricated using freeze-dried grape peel, oligomeric proanthocyanidins (OPC) and puerarin based on spontaneous physical crosslinking. With the incorporation of OPC, the natural patch exhibited favorable photothermal antibacterial properties, effectively inhibiting S. aureus and E. coli under 808 nm near-infrared irradiation. In addition, the grape peel could induce M2 macrophage polarization and scavenge reactive oxygen species, showcasing immunomodulatory effects. Moreover, the puerarin component in the patches was discovered to promote endothelial cell proliferation and migration, thereby facilitating angiogenesis in vitro. Based on these features, we have demonstrated the antibacterial, antioxidant, anti-inflammatory, and angiogenic effects of the patches in vivo. Thus, we believe that the natural multi-actives composite patch holds significant promise for diabetic wound treatment and broader biomedical applications.

Chelating Dual Interface for Efficient and Stable Crystal Growth and Iodine Defect Management in Sn-Pb Perovskite Solar Cells.

Suppressing Sn2+ oxidation and rationally controlling the crystallization process of tin-lead perovskite (Sn-Pb PVK) films by suitable bonding methods have emerged as key approaches to achieving efficient and stable Sn-Pb perovskite solar cells (PSCs). Herein, the chelating coordination is performed at the top and bottom interfaces of Sn-Pb PVK films. The chelation strength is stronger toward Sn2+ than Pb2+ by introducing oligomeric proanthocyanidins (OPC) at the bottom interface. This difference in chelation strength resulted in a spontaneous gradient distribution of Sn/Pb within the perovskite layer during crystallization, particularly enhancing the enrichment of Sn2+ at the bottom interface and facilitating the extraction and separation of photogenerated charge carriers in PSCs. Simultaneously, this top-down distribution of gradually increasing Sn content slowed down the crystallization rate of Sn-Pb PVK films, forming higher-quality films. On the top interface of the PVK, trifluoroacetamidine (TFA) was used to inhibit the generation of iodine vacancies (VI) through chelating with surface-uncoordinated Pb2+/Sn2+, further passivating defects while suppressing the oxidation of Sn2+. Ultimately, the PSCs with simultaneous chelation at both top and bottom interfaces achieved a power conversion efficiency (PCE) of 23.31% and an open-circuit voltage (VOC) exceeding 0.90 V. The stability of unencapsulated target devices in different environments also improved.

Oligomeric proanthocyanidins mitigate acute lung injury by inhibiting NETs and inflammation via the gut-lung axis

Acute lung injury is a common complication of sepsis and characterized by a high mortality rate during hospitalization. Proanthocyanidin, which are abundant compounds found in various plants, have shown promising effects in preventing chronic diseases, and their oligomers have attracted attention for their high bioavailability and strong antioxidant activity. In recent years, there have been suggestions that oligomeric proanthocyanidin may possess lung-protective properties, however, the specific mechanisms involved have not been fully elucidated. This study reveals that the therapeutic efficacy of oligomeric proanthocyanidin in mitigating lung injury during sepsis, achieved through the reduction of neutrophil extracellular traps accumulation and the attenuation of inflammation, can be attributed to the capacity to safeguard the integrity of the intestinal mucus layer and the intestinal barrier. This protective action results in a decrease in endotoxin entry into the bloodstream and bacterial translocation, both of which can trigger neutrophil extracellular traps causing further lung injury.

Quality Studies on Cynometra iripa Leaf and Bark as Herbal Medicines.

Cynometra iripa Kostel. is a Fabaceae species of mangrove used in traditional Ayurvedic medicine for treating inflammatory conditions. The present study aims to establish monographic botanical and chemical quality criteria for C. iripa leaf and bark as herbal substances and to evaluate their in vitro antioxidant potential. Macroscopic and microscopic qualitative and quantitative analyses, chemical LC-UV/DAD-ESI/MS profiling, and the quantification of key chemical classes were performed. Antioxidant activity was evaluated by DPPH and FRAP assays. Macroscopically, the leaf is asymmetrical with an emarginated apex and cuneate base. Microscopically, it shows features such as two-layered adaxial palisade parenchyma, vascular bundles surrounded by 3-6 layers of sclerenchyma, prismatic calcium oxalate crystals (5.89 ± 1.32 μm) along the fibers, paracytic stomata only on the abaxial epidermis (stomatal index-20.15), and non-glandular trichomes only on petiolules. The microscopic features of the bark include a broad cortex with large lignified sclereids, prismatic calcium oxalate crystals (8.24 ± 1.57 μm), and secondary phloem with distinct 2-5 seriated medullary rays without crystals. Chemical profile analysis revealed that phenolic derivatives, mainly condensed tannins and flavonoids, are the main classes identified. A total of 22 marker compounds were tentatively identified in both plant parts. The major compounds identified in the leaf were quercetin-3-O-glucoside and taxifolin pentoside and in the bark were B-type dimeric proanthocyanidins and taxifolin 3-O-rhamnoside. The total phenolics content was higher in the leaf (1521 ± 4.71 mg GAE/g dry weight), while the total flavonoids and condensed tannins content were higher in the bark (82 ± 0.58 mg CE/g and 1021 ± 5.51 mg CCE/g dry weight, respectively). A total of 70% of the hydroethanolic extracts of leaf and bark showed higher antioxidant activity than the ascorbic acid and concentration-dependent scavenging activity in the DPPH assay (IC50 23.95 ± 0.93 and 23.63 ± 1.37 µg/mL, respectively). A positive and statistically significant (p < 0.05) correlation between the phenol content and antioxidant activity was found. The results obtained will provide important clues for the quality control criteria of C. iripa leaf and bark, as well as for the knowledge of their pharmacological potential as possible anti-inflammatory agents with antioxidant activity.

Proanthocyanidins-based tandem dynamic covalent cross-linking hydrogel for diabetic wound healing

Wound healing in diabetic patients presents significant challenges in clinical wound care due to high oxidative stress, excessive inflammation, and a microenvironment prone to infection. In this study, we successfully developed a multifunctional tandem dynamic covalently cross-linked hydrogel dressing aimed at diabetic wound healing. This hydrogel was constructed using cyanoacetic acid functionalized dextran (Dex-CA), 2-formylbenzoylboric acid (2-FPBA) and natural oligomeric proanthocyanidins (OPC), catalyzed by histidine. The resulting Dex-CA/OPC/2-FPBA (DPOPC) hydrogel can be dissolved triggered by cysteine, thereby achieving “controllable and non-irritating" dressing change. Furthermore, the incorporation of OPC as a hydrogel building block endowed the hydrogel with antioxidant and anti-inflammatory properties. The cross-linked network of the DPOPC hydrogel circumvents the burst release of OPC, enhancing its biosafety. In vivo studies demonstrated that the DPOPC hydrogel significantly accelerated the wound healing process in diabetic mice compared to a commercial hydrogel, achieving an impressive wound closure rate of 98 % by day 14. The DPOPC hydrogel effectively balanced the disrupted inflammatory state during the healing process. This dynamic hydrogel based on natural polyphenols is expected to be an ideal candidate for dressings intended for chronic wounds.

Mediterranean Wild Pear Fruits as a Neglected but Valuable Source of Phenolic Compounds

The genus Pyrus has a long history in Sardinia (Italy), where two wild pear species (P. spinosa Forssk. and P. pyraster (L.) Burgsd.) and Pyrus communis L. cultivars are extensively distributed. Even if neglected, these taxa represent well-adapted key resources for redesigning sustainable farming systems. This report aims at shedding light on the phenolic fingerprint and antioxidant properties of wild pear fruits and comparing their traits with those of the studied pear cultivar germplasm (PCG). Fruits of wild pear species were collected, and flesh, peel, and core subsamples were analyzed. Moreover, available data from previous research on PCG were analyzed. The contents of total phenolics (TotP), total flavonoids (TotF), and condensed tannins (CT), as well as the antioxidant capacity, were similar in the flesh of the two wild species. However, P. spinosa had significantly higher values of TotP (89 g GAE kg−1 DM) and CT (33 g DE kg−1 DM) in the peel. Eleven individual phenolic compounds were identified and quantified in the fruit flesh, 14 in both peel and core. For both wild species, arbutin and chlorogenic acid were the main phenolic compounds, followed by the quercetin glycosides. Comparing the antioxidant capacity and TotF fruit flesh values of wild pears with those of PCG, the latter resulted up to 15-fold lower. The wild types showed unique metabolite profiles. Results support novel insights on the phytochemicals of wild pear fruits.

Phytochemicals profiling of Cassia fistula fruit extract and its effect on serum lipids and hematological parameters in high-fat diet-induced hyperlipidemic female rats.

Cassia fistula (C. fistula) has shown strong anti-inflammatory, hepatoprotective, antitussive, antibacterial, and antifungal properties and is being used for healing wounds and gastrointestinal illness. This study was planned to obtain fruit extract from C. fistula using ultrasonic-assisted extraction (UAE) technique and evaluated for phytochemical contents, anti-hyperlipidemia, and hematological parameters. The results showed that total phenolic (TPC), total flavonoids (TFC), condensed tannin (CT), and saponins were 13.07 mg GAE/g, 5.24 mg QE/g, 4.01 mg/g, and 27.55%, respectively, in the extract. Proximate composition of the extract showed 2.48%, moisture, 1.25% fat, 2.80% ash, 4.59% fiber, 11.93% protein, and 76.95% NFE. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power assay (FRAP) activity was 63.30 μg/mL and 15.02 nmol/g, respectively. High-fat diet (HFD)-induced hyperlipidemic rats were orally administrated with 0.5 and 1.0 g of extract/kg body weight (bw) daily. The reduction of total cholesterol (TC: 90.83 ± 8.86 mg/dL), triglycerides (TG; 74.16 ± 9.10 mg/dL), and low-density lipoproteins (LDL; 74.83 ± 4.66 mg/dL) and increase of high-density lipoproteins (HDL; 41.83 ± 8.4 mg/dL) was observed. Significant changes in red blood cells (RBCs; 8.03 ± 0.67106/μL), mean corpuscular hemoglobin concentration (MCHC; 35.02 ± 1.78 g/dL), mean corpuscular hemoglobin (MCH; 18.00 ± 0.26 pg), and mean corpuscular volume (MCV; 55.36 ± 4.01 fL) at 1.0 g extract intake was observed. Extract administration also improved significantly liver enzymes, body weight, and liver morphology. Therefore, C. fistula extract can be effectively used as a therapeutic agent to improve serum biochemistry and hematological values.

Effect of Chinese quince proanthocyanidins on the inhibition of heterocyclic amines and quality of fried chicken meatballs and tofu.

Heterocyclic amines (HCAs) have potential carcinogenic and mutagenic activity and are generated in cooked protein-rich foods. Adding proanthocyanidins (PAs) to these foods before frying is an effective way to reduce HCAs. In this study, polymeric PAs (PPA) and ultrasound-assisted acid-catalyzed/catechin nucleophilic depolymerized PAs (UAPA, a type of oligomeric PA) were prepared from Chinese quince fruits (CQF). Different levels of PPA and UAPA (0.05%, 0.1%, and 0.15%) were added to chicken meatballs and tofu; then these foods were fried, and the content of HCAs in them after frying was investigated. The results showed that PPA and, particularly, UAPA significantly inhibited the formation of HCAs in fried meatballs and tofu, and this inhibition was dose-dependent. The inhibition of HCAs by both PPA and UAPA was stronger in the chicken meatballs than in fried tofu. The level of total HCAs was significantly reduced by 57.84% (from 11.93 to 5.03ng/g) after treatment of meatballs with 0.15% UAPA, with inhibition rates of 78.94%, 50.37%, and 17.81% for norharman, harman, and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), respectively. Of note, there was a negative correlation between water, lipid, protein, creatine, and glucose content and HCA content in the crust, interior, and whole (crust-plus-interior) measurements of all fried samples. Interestingly, PPA and UAPA were found more effective in inhibiting HCAs in the exterior crust than in the interior of the fried chicken meatballs. These results provide evidence that further studies on the reduction of the formation of harmful HCAs in fried foods by adding CQF PAs could be valuable to the fried food industry. PRACTICAL APPLICATION: Chinese quince proanthocyanidins treatments significantly inhibited the generation of heterocyclic amines (HCAs) in chicken meatballs and tofu when deep-fried. These results suggest that Chinese quince proanthocyanidins can be used as natural food additive for reducing HCAs in fried foods, laying the foundation for using Chinese quince fruit proanthocyanidins for HCA inhibition in the food industry.

Review of the pharmacokinetics of French maritime pine bark extract (Pycnogenol®) in humans.

The French maritime pine bark extract Pycnogenol® is a proprietary product from Pinus pinaster Aiton. It complies with the quality specifications in the United States Pharmacopeia monograph "Pine extract" in the section of dietary supplements. Pycnogenol® is standardized to contain 65-75% procyanidins which are a variety of biopolymers consisting of catechin and epicatechin monomeric units. The effects of Pycnogenol® have been researched in a multitude of human studies. The basis for any in vivo activity is the bioavailability of constituents and metabolites of the extract. General principles of compound absorption, distribution, metabolism and elimination as well as specific data from studies with Pycnogenol® are summarized and discussed in this review. Based on plasma concentration profiles it can be concluded that low molecular weight constituents of the extract, such as catechin, caffeic and ferulic acid, taxifolin are readily absorbed from the small intestine into systemic circulation. Procyanidin oligomers and polymers are subjected to gut microbial degradation in the large intestine yielding small bioavailable metabolites such as 5-(3',4'-dihydroxyphenyl)-γ-valerolactone. After intake of Pycnogenol®, constituents and metabolites have been also detected in blood cells, synovial fluid and saliva indicating a substantial distribution in compartments other than serum. In studies simultaneously investigating concentrations in different specimen, a preferential distribution of individual compounds has been observed, e.g., of ferulic acid and 5-(3',4'-dihydroxyphenyl)-γ-valerolactone into synovial fluid compared to serum. The main route of elimination of constituents and metabolites of the French pine bark extract is the renal excretion. The broad knowledge accumulated regarding the pharmacokinetics of compounds and metabolites of Pycnogenol® constitute a rational basis for effects characterized on a cellular level and observed in human clinical studies.