Bamboo Leaf Flavonoids Extracts Alleviate Oxidative Stress in HepG2 Cells via Naturally Modulating Reactive Oxygen Species Production and Nrf2-Mediated Antioxidant Defense Responses

Mixtures of EGCG, bamboo leaf flavonoids, and broccoli seed water extracts exhibit anti-glycation and skin-protective effects

BACKGROUND

Skin aging is a multifaceted process. Glycation significantly contributes to skin aging and the development of complications. Researchers are currently investigating various substances, particularly those from natural sources, to combat skin glycation.

PURPOSE

This study aimed to comprehensively evaluate the anti-glycation effect of a new natural combination, EBB, which includes (-)-epigallocatechin-3 gallate (EGCG), bamboo leaf flavonoids, and broccoli seed water extracts, using cell and animal models and to explore its potential anti-glycation mechanism.

METHODS

The components of EBB were identified using HPLC and UHPLC-MS/MS. Additionally, a glycation cell model induced by glyceraldehyde, advanced glycation end products (AGEs), and methylglyoxal was established in HaCaT cells to evaluate the efficacy of EBB in alleviating glycation. Differential genes, signalling pathways, and biological processes were analysed through RNA sequencing to explore the mechanisms of the anti-glycation effects of EBB, which were further validated using qRT-PCR and Western blotting. Finally, the protective effects of EBB against glycation and skin damage were assessed in zebrafish and mouse in vivo models through histological studies and the measurement of various skin physiological parameters.

RESULTS

Glucoraphanin, Sinapine and orientin were identified in EBB, which effectively reduced the formation of AGEs and decreased the expression level of the RAGE protein in HaCaT cells. Transcriptomic analyses revealed that EBB regulated the expression of 576 differentially expressed genes. These genes were enriched in various biological processes, such as chronic inflammation and immune responses, and participated in the regulation of multiple signalling pathways, including TNF. Glycation upregulated the expression of the ROS1 gene and protein, while EBB reversed this effect. Furthermore, EBB attenuated the glycation response by downregulating the expression levels of proteins such as p-p38, p-ERK1/2, p-p65, and TNF-α. Additionally, the reduction of AGE accumulation by EBB was confirmed in a zebrafish model. Similarly, histological analyses of mouse skin tissue and various physiological parameters demonstrated that EBB significantly mitigated damage induced by glycation.

CONCLUSIONS

Our results show that EBB effectively inhibited glycation reactions. The mechanism of action may involve the reduction of inflammation by downregulating the expression levels of RAGE and ROS1, thereby decreasing the accumulation of AGEs in keratinocytes and alleviating skin damage. This paves the way for the potential application of EBB as a valuable anti-glycation functional ingredient in the food and cosmetic industries.

Bamboo leaf flavonoids ameliorate cyclic heat stress-induced oxidative damage in broiler liver through activation of Keap1-Nrf2 signaling pathway

Heat stress (HS) induces oxidative stress in the liver and affects health and production attributes in poultry birds. Bamboo leaf flavonoid (BLF) is a natural plant flavonoid that is effective in controlling oxidative stress. Therefore, the aim of current study was to investigate the impact of BLF on growth performance, liver index, serum biochemical parameters of liver function, liver antioxidant enzyme activities, and expression of genes and proteins related to the liver Keap1-Nrf2 system in cyclic heat stress (CHS) broilers. Twenty-eight-day old Arbor Acres broilers (n = 200) were randomly assigned to 5 groups. TN group fed basal diet was reared in a thermoneutral environment (24 ± 1 °C); CHS, 400 mg/kg BLF + CHS, 800 mg/kg BLF + CHS, and 1600 mg/kg BLF + CHS groups were reared in high temperature conditions (33 ± 1 °C, 8 h/day), with the basal diet supplemented with 0, 400, 800, and 1600 mg/kg BLF. The results indicated that ADG and ADFI of broilers in 28 to 35d and 36 to 42d CHS groups were significantly lower compared to the TN group. BLF improves growth performance of CHS broilers by increasing ADG, ADFI and decreasing F:G. BLF improved live weight, liver weight, liver index and reduced serum AST, ALP, ALT, T-BIL levels and increased TP levels in CHS broilers. Meanwhile, BLF supplementation enhanced the activity of hepatic antioxidant enzymes, resulting in higher T-AOC, CAT, GSH-PX and T-SOD levels than those of CHS broilers, and significantly reduced MDA levels. In addition, BLF down-regulated the protein levels of Keap1 and P62, increased the expression levels of Nrf2 genes and proteins, and activated the expression of its downstream NQO1, HO-1, and SOD-1 antioxidant genes compared to CHS broilers. In summary, BLF regulates the expression of key genes and proteins in the Keap1-Nrf2 signaling pathway to alleviate liver injury in broilers by inhibiting oxidative stress, thereby promoting the growth performance of broilers with CHS.

Protective impacts of bamboo leaf flavonoids in stressed broilers induced by diquat: Insight of antioxidant, immune response and intestinal barrier function

This research explored the protective impact of bamboo leaf flavonoids (BLF) in diquat (DQ) stressed broilers; providing insight of antioxidant, immune response and intestinal barrier function. This experiment consisted of two parts. In the first, 240 chicks were allotted to 2 groups with 8 replicates and 15 chicks per replicate. Treatments consisted of a basic feed (control group, CON) and the basic feed plus 1000 mg/kg BLF (BLF group, BLF) for 28 d, respectively. Then, following the conclusion of the first part, 16 healthy broilers were selected from the CON group and the BLF group. They formed the second part of the experiment, and were allotted to 4 treatments with 8 broilers each: CON-no stress (CON-NS) group, CON-DQ group, BLF-NS group and the BLF-DQ group. Broilers were separately injected intraperitoneally with DQ solution at 40 mg/kg body weight or the same dose of phosphate buffer saline. The results revealed adding BLF to diet reduced the ratio of feed to weight gain of broilers compared to the basic feed group (P = 0.021). In comparison to the CON-NS group, BLF improved the levels of serum and jejunal mucosa total antioxidant capacity, immunoglobulin M, serum catalase, immunoglobulin A, interleukin 10, jejunal mucosa interleukin 4, cecal butyric acid, valeric acid, isobutyric acid, isovaleric acid, upregulated zonula occludens-1 (ZO-1), occludin (OCLN) and claudin-1 (CLDN1) expressions, and reduced the levels of jejunal mucosa malondialdehyde (MDA), interleukin 1β, interleukin 6 and serum diamine oxidase (P < 0.05). Diquat stress elevated the contents of serum MDA, D-lactate, jejunal mucosa tumor necrosis factor α, reactive oxygen species and unclassified_f_Lachnospiraceae relative abundance, downregulated ZO-1, OCLN and CLDN1 expressions, and reduced Sobs, Chao and Ace indices (P < 0.05). Compared with CON-NS group, the concentration of isovaleric acid in the BLF-DQ group was higher (P < 0.05). In conclusion, by establishing a DQ stress injury model, it was elucidated that BLF may enhance antioxidant capacity, strengthen immunity, regulate volatile fatty acid contents, improve intestinal morphology, microbiota and other intestinal barrier functions, so as to mitigate the injury induced by oxidative stress in broilers.

Characterization and identification of major flavonoids of bamboo leaf extract by HPLC/ESI-QTOF-MS/MS

Bamboo leaf extract (BLE) is a pale brown powder extracted from bamboo leaves, and it is listed in the Chinese Standard GB-2760 as a legal and safe food additive. The present study aims to identify and characterize the major flavonoids in BLE. The identification of major flavonoids was carried out using ultra performance liquid chromatography combined with electrospray ionization quadruple time-of-flight tandem mass spectrometry (HPLC/ESI-QTOF-MS/MS). A total of 31 flavonoid compounds were identified and tentatively characterized base on reference standards and MS dissociation mechanisms. HPLC/ESI-QTOF-MS can serve as an important analytical platform to identification structure of bamboo leaf flavonoids (BLF).

Metabolomic Profiling of Guadua Species and Its Correlation with Antioxidant and Cytotoxic Activities

Bamboo plants are widely used in Asian traditional medicine for various health issues and exhibit therapeutic potential. Guadua species are renowned bamboos for their high phenolic compound content, including flavonoids and hydroxycinnamic acid derivatives, and possess noteworthy biological properties. Despite this, there is a notable scarcity of research on the chemical and biological aspects of Latin American bamboo leaf extracts (BLEs), especially concerning the Guadua genus. This study aimed to employ a metabolomics approach to integrate the phytochemical and activity profiles of BLEs to identify potential bioactive markers. We determined the metabolic fingerprints of 30 BLEs through HPTLC, HPLC-DAD, UHPLC-QTOF-MS, and 1H-NMR analyses and screened for antioxidant and cytotoxic activities using ABTS, DPPH, and MTT methods. Ultimately, correlation analyses were performed by using chemometric methods and molecular networking. Our findings present a comprehensive chemical characterization, encompassing 40 flavonoids and 9 cinnamic acid derivatives. Notably, most of these compounds have been reported for the first time within the genus, signifying novel discoveries. Additionally, certain compounds identified in other species of the subfamily Bambusoideae provide valuable comparative insights. These compounds demonstrated a significant correlation with antioxidant potential, with values exceeding 100 and 30 μmol of TE/g of extract for ABTS and DPPH, respectively, in the samples. Extracts from G. incana and G. angustifolia exhibited potent cytotoxic effects with IC50 values of 1.23 and 4.73 μg/mL against HCT-116 colon cancer cells, respectively. Notably, glycosylated flavones showed a strong correlation with cytotoxicity. These new findings significantly contribute to our understanding of the chemical composition and biological properties of these often overlooked bamboo species, providing them with important added value and alternative use.

Utilization of Nitrogen-Doped Graphene Quantum Dots to Neutralize ROS and Modulate Intracellular Antioxidant Pathways to Improve Dry Eye Disease Therapy

Purpose

Patients afflicted with dry eye disease (DED) experience significant discomfort. The underlying cause of DED is the excessive accumulation of ROS on the ocular surface. Here, we investigated the nitrogen doped-graphene quantum dots (NGQDs), known for their ROS-scavenging capabilities, as a treatment for DED.

Methods

NGQDs were prepared by using citric acid and urea as precursors through hydrothermal method. The antioxidant abilities of NGQDs were evaluated through: scavenging the ROS both extracellular and intracellular, regulating the nuclear factor-erythroid 2-related factor (Nrf2) antioxidant pathway of human corneal epithelial cells (HCECs) and their transcription of inflammation related genes. Furthermore, NGQDs were modified by Arg-Gly-Asp-Ser (RGDS) peptides to obtain RGDS@NGQDs. In vivo, both the NGQDs and RGDS@NGQDs were suspended in 0.1% Pluronic F127 (w/v) and delivered as eye drops in the scopolamine hydrobromide-induced DED mouse model. Preclinical efficacy was compared to the healthy and DPBS treated DED mice.

Results

These NGQDs demonstrated pronounced antioxidant properties, efficiently neutralizing free radicals and activating the intracellular Nrf2 pathway. In vitro studies revealed that treatment of H2O2-exposed HCECs with NGQDs induced a preservation in cell viability. Additionally, there was a reduction in the transcription of inflammation-associated genes. To prolong the corneal residence time of NGQDs, they were further modified with RGDS peptides and suspended in 0.1% Pluronic F127 (w/v) to create RGDS@NGQDs F127 eye drops. RGDS@NGQDs exhibited superior intracellular antioxidant activity even at low concentrations (10 μg/mL). Subsequent in vivo studies revealed that RGDS@NGQDs F127 eye drops notably mitigated the symptoms of DED mouse model, primarily by reducing ocular ROS levels.

Conclusion

Our findings underscore the enhanced antioxidant benefits achieved by modifying GQDs through nitrogen doping and RGDS peptide tethering. Importantly, in a mouse model, our novel eye drops formulation effectively ameliorated DED symptoms, thereby representing a novel therapeutic pathway for DED management.

Protective Effects of Sesamol on Renal Ischemia-Reperfusion Injury Via Regulation of Nuclear Factor Erythroid 2-Related Factor 2 Pathway

BACKGROUND

Sesamol is a natural antioxidant known for its potent antioxidant and free radical scavenging properties. This study aimed to explore the therapeutic effects and underlying mechanisms of sesamol in the development of renal ischemia-reperfusion injury (IRI) in mice.

METHODS

C57BL/6J wild-type mice were divided into 3 groups: IR group, treated with normal saline after undergoing the IRI procedure; Sesamol + IR group, treated with 30 mg/kg/d of sesamol after the IRI procedure; and Sham group, treated with normal saline but not subjected to the IRI process. Renal IRI was induced by performing a right kidney nephrectomy and subjecting the left kidney to 30-minute ischemia, followed by 24-hour reperfusion. Kidney tissues and serum were collected 24 hours post-IRI to assess the impact of sesamol on renal function after IRI. Serum creatinine and blood urea nitrogen levels were assessed, and renal cell apoptosis was detected through terminal deoxynucleotidyl transferase dUTP nick-end labeling staining. The levels of interleukin 1β and interleukin 18 in kidney tissues, as well as indicators of oxidative stress, were also measured. Furthermore, Nrf2-deficient mice were used to examine the protective function of the nuclear factor erythroid 2-related factor 2 (Nrf2)/hemeoxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone 1 (NQO1) signaling pathways induced by sesamol, as determined by western blot assay.

RESULTS

Sesamol demonstrated significant improvement in renal function, along with reductions in renal tubular injury, cell necrosis, and apoptosis in mice. It also effectively lowered key inflammatory mediator levels. Sesamol exhibited antioxidant properties by reducing malondialdehyde levels and enhancing superoxide dismutase activities 24 hours after IRI. Western blot assay revealed increased Nrf2, HO-1, and NQO-1 protein levels with sesamol treatment. Notably, Nrf2-deficient mice did not exhibit the beneficial effects of sesamol.

CONCLUSIONS

This study demonstrates that sesamol effectively alleviates renal IRI by enhancing antioxidant defenses and reducing inflammation potentially through the Nrf2/HO-1 and NQO1 signaling pathways.

Structural properties of Kudzu protein enzymatic hydrolysate and its repair effect on HepG2 cells damaged by H2O2 oxidation

We investigated the structural properties, foaming capacity and foaming stability, antioxidant activity, and amino acid composition of Kudzu protein (KP) and Kudzu protein hydrolysate (KPH). The peptide sequence of KPH was analyzed using ultra performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS), and the binding ability of the peptide sequence to Keap1 was predicted through molecular docking simulations. The electrophoresis and molecular weight distribution analysis results showed that the molecular weight of KPH was significantly lower than that of KP, with a mean molecular weight of approximately 2000-5000 Da. The structures and properties were characterized using Fourier transform infrared spectroscopy, relative fluorescence, and circular dichroism. The results showed that KP exposed a large number of hydrophobic groups after enzymatic hydrolysis, and its structure changed from α-helical to random coils. KPH has a higher foaming capacity (200%) and foaming stability (97.5%) than KP, which may be related to the change in structure. These results indicate that moderate hydrolysis can improve the functional properties of KP, providing a new opportunity for its application as a food ingredient. The antioxidant assay results showed that KP and KPH had a good hydroxyl radical, superoxide anion, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacity and a high reducing capacity. KPH exerted better antioxidant effects than KP. The scavenging rates for DPPH, ABTS, hydroxyl radicals, and superoxide anions were 89.31%, 93.14%, 85.74%, and 58.29%, respectively, and its reducing capacity was 2.191, which may be related to the increase in amino acids with antioxidant activity after enzymolysis. In vitro, KP and KPH could significantly repair H2O2-induced oxidative damage in HepG2 cells, reduce the apoptosis rate, activate the Nrf2-Keap1 signaling pathway, reduce the accumulation of reactive oxygen species and malondialdehyde after oxidative damage, increase the activities of superoxide dismutase and glutathione (GSH) peroxidase, and increase the content of GSH and the total antioxidant capacity. Twenty-one peptide components were identified in KPH using UPLC-MS/MS, and the binding ability of 21 peptide components to Keap1 was analyzed through molecular docking technology. The results showed that all 21 peptides in KPH had good antioxidant activity, and real-time quantitative PCR (qRT-PCR) analysis was conducted to further explain the high antioxidant activity of KPH at the genetic level. These results show that KP and KPH are suitable for preparing antioxidant foods and related health foods to prevent oxidation-related diseases. KPH has more beneficial effects than KP.

Plant Extracts to Alleviating Heat Stress in Dairy Cows

Heat stress (HS) in cows is a critical issue in the dairy industry. Dairy cows accumulate heat from body metabolism, along with that imposed by air temperature, humidity, air flow and solar radiation. HS in animals can occur during hot and humid summers when the ambient temperature is extremely high. Dairy cows have relatively high feed intakes and metabolic heat production and are thus susceptible to HS, leading to reductions in feed intake, lower milk yield, affected milk quality, reduced animal health and even shortening the productive lifespan of cows. Therefore, alleviating HS is a top priority for the dairy industry. Suitable plant extracts have advantages in safety, efficiency and few toxic side effects or residues for applications to alleviate HS in dairy cows. This paper reviews the effects of some plant extract products on alleviating HS in dairy cows and briefly discusses their possible mechanisms of action.

Antioxidant Activities, Phenolic Compounds, and Sensory Acceptability of Kombucha-Fermented Beverages from Bamboo Leaf and Mulberry Leaf

Kombucha is traditional drink made from the fermentation of a black tea infusion, and is believed to offer a variety of health benefits. Recently, exploring kombucha made from alternative substrates has become a research hotspot. In this paper, two novel kombucha beverages were produced with bamboo leaf or mulberry leaf for the first time. Moreover, the effects of fermentation with leaf residues (infusion plus residues) or without leaf residues (only infusion) on the antioxidant properties of kombucha were compared. The ferric-reducing antioxidant power assay, Trolox equivalent antioxidant capacity assay, Folin-Ciocalteu method, and high-performance liquid chromatography were utilized to measure the antioxidant capacities, total phenolic contents, as well as some compound concentrations of the kombucha. The results showed that two types of kombucha had high antioxidant capacities. Moreover, kombucha fermented with bamboo leaf residues (infusion plus residues) significantly enhanced its antioxidant capabilities (maximum increase 83.6%), total phenolic content (maximum increase 99.2%), concentrations of some compounds (luteolin-6-C-glucoside and isovitexin), and sensory acceptability, compared to that without residues (only infusion). In addition, fermentation with leaf residues had no significant effect on mulberry leaf kombucha. Overall, the bamboo leaf was more suitable for making kombucha with residues, while the mulberry leaf kombucha was suitable for fermentation with or without residues.

Anti-Inflammatory and Antioxidant Effects of Leaves and Sheath from Bamboo (Phyllostacys edulis J. Houz)

Bamboo (Phyllostacys edulis J. Houz) has become an emerging forest resource of economic and ecological significance with health benefits. Since the beneficial effects of the non-edible parts of bamboo have not been thoroughly explored, we characterized in this study bamboo leaf (BL) and sheath (BS) extracts. The total phenol and flavonoid content (TPC and TFC), antioxidant activity (ABTS, DPPH, FRAP and β-carotene bleaching test) and anti-inflammatory properties were determined. Leaves exhibited a TPC value of 73.92 mg equivalent (eq) gallic acid/g fresh weight (FW) and a TFC value of 56.75 mg eq quercetin/g FW. Ultra-High-Performance Liquid Chromatography (UHPLC) coupled with photo diode array detector (PDA) analysis revealed evidence for the presence of protocatechuic acid, isoorientin, orientin and isovitexin in BL, whereas BS was rich in phenolic acids. Both samples demonstrated a significant ability to scavenge radicals against ABTS^·+, with an inhibitory concentration of 50% of 3.07 μg/mL for BL and 6.78 μg/mL for BS. At a concentration of 0.1 and 0.2 mg/mL, BS decreased reactive oxygen species production without hampering cell viability in HepG2 liver cells, while at the same concentrations, BL exhibited cytotoxicity in HepG2 cells. In addition, 0.1 and 0.2 mg/mL BS and BL reduced Interleukin-6 and Monocyte Chemoattractant Protein-1 production in human lipopolysaccharide-stimulated THP-1 macrophages, without affecting cell viability. These findings highlight the anti-inflammatory and antioxidant properties of BL and BS, corroborating their different potential applications in the nutraceutical, cosmetic and pharmaceutical industries.

Comparative transcriptomic and metabolomic analyses provide insights into the responses to NaCl and Cd stress in Tamarix hispida

Salinity and heavy metal pollution seriously affect plant growth. Tamarix hispida (T. hispida) has the potential to remediate soil saline-alkali and heavy metal pollution. In this study, the response mechanisms of T. hispida under NaCl, CdCl₂ (Cd) and combined CdCl₂ and NaCl (Cd-NaCl) stresses were explored. Overall, the antioxidant system showed changes under the three stresses. The addition of NaCl inhibited the absorption of Cd²⁺. However, there were obvious differences in the transcripts and metabolites identified among the three stress responses. Interestingly, the number of DEGs was greatest under NaCl stress (929), but the number of differentially expressed metabolites (DEMs) was lowest (48), with 143 and 187 DEMs identified under Cd and Cd-NaCl stress, respectively. It is worth noting that both DEGs and DEMs were enriched in the linoleic acid metabolism pathway under Cd stress. In particular, the content of lipids changed significantly under Cd and Cd-NaCl stress, suggesting that maintaining normal lipid synthesis and metabolism may be an important way to improve the Cd tolerance of T. hispida. Flavonoids may also play an important role in the response to NaCl and Cd stress. These results provide a theoretical basis for cultivating plants with improved salt and cadmium repair abilities.

Bamboo leaf: A review of traditional medicinal property, phytochemistry, pharmacology, and purification technology

ETHNOPHARMACOLOGICAL RELEVANCE

Bamboos are perennial evergreen plants that belong to the subfamily Bambusoideae of the true grass family Poaceae, with more than thousands of species distributed around the world. They are used as a traditional medicine with demonstrated effects of anti-oxidation, free radical scavenging, anti-inflammatory, liver protection and ameliorating cognitive deficits. Bamboo leaf is mainly used for the treatment of atherosclerotic, diabetic and nervous system diseases.

AIM OF THE STUDY

This review aims to provide up-to-date information on the traditional medicinal properties, phytochemistry, pharmacology, and purification technologies of bamboo leaf.

MATERIALS AND METHODS

Relevant information on bamboo leaf was obtained by an online search of worldwide accepted scientific databases (Web of Science, ScienceDirect, Elsevier, SpringerLink, ACS Publications, Wiley Online Library and CNKI).

RESULTS

More than 100 chemical compounds, including flavonoids and flavonoid glycosides, volatile components, phenolic acids, polysaccharide, coenzyme Q10, phenylpropanoid and amino acids have been reported to be present. These compounds were usually extracted by column chromatography and membrane separation technologies. Preparative high performance liquid chromatography (PHPLC), high-speed counter-current chromatography (HSCCC), simulated moving bed chromatography (SMB) and dynamic axial compression chromatography (DAC) were the advanced separation technologies have been used to isolate C-glycosides from bamboo leaf flavonoid, the main bioactive ingredient of bamboo leaf. Currently, bamboo leaf is mainly used for the treatment of atherosclerotic, diabetic, hepatic diseases and nervous system related symptoms, which are attributed to the presence of bioactive components of bamboo leaf.

CONCLUSIONS

Phytochemical and pharmacological analyses of bamboo leaf have been revealed in recent studies. However, most of the pharmacological studies on bamboo leaf have focused on bamboo leaf flavonoids. Further studies need to pay more attention to other phytochemical components of bamboo leaf. In addition, there is lack of sufficient clinical data and toxicity studies on bamboo leaf. Therefore, more clinical and toxicity researches on this plant and constituents are recommended.

Bamboo Shoot and Artemisia capillaris Extract Mixture Ameliorates Dextran Sodium Sulfate-Induced Colitis

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract and is characterized by recurrent chronic inflammation and mucosal damage of the gastrointestinal tract. Recent studies have demonstrated that bamboo shoot (BS) and Artemisia capillaris (AC) extracts enhance anti-inflammatory effects in various disease models. However, it is uncertain whether there is a synergistic protective effect of BS and AC in dextran sodium sulfate (DSS)-induced colitis. In the current study, we tested the combined effects of BS and AC extracts (BA) on colitis using in vivo and in vitro models. Compared with control mice, oral administration of DSS exacerbated colon length and increased the disease activity index (DAI) and histological damage. In DSS-induced colitis, treatment with BA significantly alleviated DSS-induced symptoms such as colon shortening, DAI, histological damage, and colonic pro-inflammatory marker expression compared to single extracts (BS or AC) treatment. Furthermore, we found BA treatment attenuated the ROS generation, F-actin formation, and RhoA activity compared with the single extract (BS or AC) treatment in DSS-treated cell lines. Collectively, these findings suggest that BA treatment has a positive synergistic protective effect on colonic inflammation compared with single extracts, it may be a highly effective complementary natural extract mixture for the prevention or treatment of IBD.

Synergistic protection of quercetin and lycopene against oxidative stress via SIRT1-Nox4-ROS axis in HUVEC cells

Oxidative stress is a potential factor in the promotion of endothelial dysfunction. In this research, flavonoids (quercetin, luteolin) combined with carotenoids (lycopene, lutein), especially quercetin-lycopene combination (molar ratio 5:1), prevented the oxidative stress in HUVEC cells by reducing the reactive oxygen species (ROS) and suppressing the expression of NADPH oxidase 4 (Nox4), a major source of ROS production. RNA-seq analysis indicated quercetin-lycopene combination downregulated inflammatory genes induced by H₂O₂, such as IL-17 and NF-κB. The expression of NF-κB p65 was activated by H₂O₂ but inhibited by the quercetin-lycopene combination. Moreover, the quercetin and lycopene combination promoted the thermostability of Sirtuin 1 (SIRT1) and activated SIRT1 deacetyl activity. SIRT1 inhibitor EX-527 attenuated the inhibitory effects of quercetin, lycopene, and their combination on the expression of p65, Nox4 enzyme, and ROS. Quercetin-lycopene combination could interact with SIRT1 to inhibit Nox4 and prevent endothelial oxidative stress, potentially contributing to the prevention of cardiovascular disease.

Advances on nanoformulation approaches for delivering plant-derived antioxidants: A case of quercetin

Oxidative stress has been implicated in tumorigenic, cardiovascular, neuro-, and age-related degenerative changes. Antioxidants minimize the oxidative damage through neutralization of reactive oxygen species (ROS) and other causative agents. Ever since the emergence of COVID-19, plant-derived antioxidants have received enormous attention, particularly in the Indian subcontinent. Quercetin (QCT), a bio-flavonoid, exists in the glycosylated form in fruits, berries and vegetables. The antioxidant potential of QCT analogs relates to the number of free hydroxyl groups in their structure. Despite presence of these groups, QCT exhibits substantial hydrophobicity. Formulation scientists have tested nanotechnology-based approaches for its improved solubilization and delivery to the intended site of action. By the virtue of its hydrophobicity, QCT gets encapsulated in nanocarriers carrying hydrophobic domains. Apart from passive accumulation, active uptake of such formulations into the target cells can be facilitated through well-studied functionalization strategies. In this review, we have discussed the approaches of improving solubilization and bioavailability of QCT with the use of nanoformulations.

Advancement of Protein- and Polysaccharide-Based Biopolymers for Anthocyanin Encapsulation

Although evidence shows that anthocyanins present promising health benefits, their poor stability still limits their applications in the food industry. Increasing the stability of anthocyanins is necessary to promote their absorption and metabolism and improve their health benefits. Numerous encapsulation approaches have been developed for the targeted release of anthocyanins to retain their bioactivities and ameliorate their unsatisfactory stability. Generally, choosing suitable edible encapsulation materials based on biopolymers is important in achieving the expected goals. This paper presented an ambitious task of summarizing the current understanding and challenges of biopolymer-based anthocyanin encapsulation in detail. The food-grade edible microencapsulation materials, especially for proteins and polysaccharides, should be employed to improve the stability of anthocyanins for effective application in the food industry. The influence factors involved in anthocyanin stability were systematically reviewed and highlighted. Food-grade proteins, especially whey protein, caseinate, gelatin, and soy protein, are attractive in the food industry for encapsulation owing to the improvement of stability and their health benefits. Polysaccharides, such as starch, pectin, chitosan, cellulose, mucilages, and their derivatives, are used as encapsulation materials because of their satisfactory biocompatibility and biodegradability. Moreover, the challenges and perspectives for the application of anthocyanins in food products were presented based on current knowledge. The proposed perspective can provide new insights into the amelioration of anthocyanin bioavailability by edible biopolymer encapsulation.

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.

Alginate-Chitosan Coated Nanoliposomes as Effective Delivery Systems for Bamboo Leaf Flavonoids: Characterization, In Vitro Release, Skin Permeation and Anti-Senescence Activity

The use of bamboo leaf flavonoids (BLF) as functional food and cosmetic ingredients is limited by low bioavailability and difficulty in being absorbed by the intestine or skin. The aim of this study was to prepare BLF-loaded alginate-chitosan coated nanoliposomes (AL-CH-BLF-Lip) to overcome these challenges. The nanocarriers were characterized by dynamic light scattering, high performance liquid chromatography, Fourier transform infrared spectroscopy and differential scanning calorimetry. The biological activity was analyzed by in vitro antioxidant activity, transdermal absorption, cytotoxicity and AAPH induced HaCaT cell senescence model. The results showed that the size of nanocarriers ranged from 152.13 to 228.90 nm and had a low polydispersity index (0.25−0.36). Chitosan (CH) and alginate (AL) were successfully coated on BLF-loaded nanoliposomes (BLF-Lip), the encapsulation efficiency of BLF-Lip, BLF-loaded chitosan coated nanoliposomes (CH-BLF-Lip) and AL-CH-BLF-Lip were 71.31%, 78.77% and 82.74%, respectively. In addition, BLF-Lip, CH-BLF-Lip and AL-CH-BLF-Lip showed better in vitro release and free radical scavenging ability compared with naked BLF. In particular, the skin permeability of BLF-Lip, CH-BLF-Lip, and AL-CH-BLF-Lip increased 2.1, 2.4 and 2.9 times after 24 h, respectively. Furthermore, the use of nanoliposomes could significantly improve the anti-senescence activity of BLF (p < 0.01). Conclusively, alginate-chitosan coated nanoliposomes are promising delivery systems for BLF that can be used in functional foods and cosmetics.

Oligomeric Proanthocyanidins and Bamboo Leaf Flavonoids Improve the Quality of Bull Semen Cryopreservation

It is important to inhibit oxidative stress to maintain sperm motility during cryopreservation. The present study was performed to investigate the effects of supplementing oligomeric proanthocyanidins (OPC) and bamboo leaf flavonoids (BLF) or their combination as an extender for Simmental bull semen freezing. OPC, BLF, or their combination were added to the frozen diluent of bovine semen. Afterwards, computer-assisted semen analysis (CASA), detection of membrane functionality, acrosome integrity, mitochondrial integrity, CAT, SOD, GSH-PX, MDA, and ROS were conducted. The results showed that adding 50 mg/L OPC or 4 mg/L BLF could improve the quality of frozen sperm. Compared with 50 mg/L OPC alone, the combination of 50mg/L OPC and 2 mg/L BLF significantly increased the kinematic parameters of sperm, and sperm CAT, GSH-PX and SOD levels (p < 0.05), whereas the MDA of sperm was decreased (p < 0.05). These results indicated that compared to the addition of 50 mg/L OPC alone, a combination of 50 mg/L OPC and 2 mg/L BLF could further improve the quality of frozen semen. The results could provide theoretical data support for the development of a new protective agent and are significant for the cryopreservation of bovine semen in the future.

Coffee-Derived Phenolic Compounds Activate Nrf2 Antioxidant Pathway in I/R Injury In Vitro Model: A Nutritional Approach Preventing Age Related-Damages

Age-related injuries are often connected to alterations in redox homeostasis. The imbalance between free radical oxygen species and endogenous antioxidants defenses could be associated with a growing risk of transient ischemic attack and stroke. In this context, a daily supply of dietary antioxidants could counteract oxidative stress occurring during ischemia/reperfusion injury (I/R), preventing brain damage. Here we investigated the potential antioxidant properties of coffee-derived circulating metabolites and a coffee pulp phytoextract, testing their efficacy as ROS scavengers in an in vitro model of ischemia. Indeed, the coffee fruit is an important source of phenolic compounds, such as chlorogenic acids, present both in the brewed seed and in the discarded pulp. Therefore, rat brain endothelial cells, subjected to oxygen and glucose deprivation (OGD) and recovery (ogR) to mimic reperfusion, were pretreated or not with coffee by-products. The results indicate that, under OGD/ogR, the ROS accumulation was reduced by coffee by-product. Additionally, the coffee extract activated the Nrf2 antioxidant pathway via Erk and Akt kinases phosphorylation, as shown by increased Nrf2 and HO-1 protein levels. The data indicate that the daily intake of coffee by-products as a dietary food supplement represents a potential nutritional strategy to counteract aging.

Effect of pinolenic acid on oxidative stress injury in HepG2 cells induced by H2O2

To investigate the effect and mechanism of pinolenic acid (PNA) on H2O2-induced oxidative stress injury in HepG2 cells. Methods: PNA was used to regulate oxidative stress injury of HepG2 cells induced by H2O2. Quantification of cell survival rate, accumulation of intracellular reactive oxygen species (ROS), and expression levels of anti-oxidation-related genes were determined using MTT, fluorescent probe technology (DCFH-DA), and real-time quantitative reverse transcription polymerase chain technology (qRT-PCR) method, respectively. Meanwhile, the activity of intracellular antioxidant enzymes was determined by biochemical methods. The results showed that PNA improved the survival rate of HepG2 cells induced by H2O2 (29.59%, high-dose group), reduced the accumulation of intracellular ROS (65.52%, high-dose group), and reduced the level of intracellular malondialdehyde (MDA; 65.52%, high-dose group). All these results were dose-dependent, which indicated that PNA can improve oxidative stress damage of cells. Furthermore, the mechanism of PNA regulating oxidative stress was investigated from the gene level. Results showed that under supplementation of PNA, the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) had been improved (39.74%, 17.58%, and 23.83%, high-dose group). Further studies on gene expression which controls the activity of antioxidant enzymes showed that under the regulation of PNA, the expression level of Keap1 gene was decreased, while Nrf2 gene was increased. The expression levels of HO-1 and NQO1 in the downstream of Nrf2 were increased. Results indicated that under the regulation of PNA, Nrf2 was separated from Keap1, entered the nucleus, bound to ARE, and up-regulated the expression levels of HO-1 and NQO1 genes. Conclusion: PNA has a conspicuous improvement effect on oxidative stress damage induced by H2O2 in HepG2 cells. We also found the antioxidant mechanisms of PNA where it protected cells from oxidative stress damage by causing nuclear translocation of Nrf2 gene and up-regulated the expression levels of antioxidant enzymes in the downstream. This shows that PNA prevented oxidative stress by mediating the Keap1/Nrf2 transcriptional pathway and down-regulating enzyme activities.

Identification of prenylated phenolics in mulberry leaf and their neuroprotective activity

BACKGROUND

Neurodegenerative diseases are becoming increasingly prevalent over the world. Therefore, drug development in this field is urgently required. Neuron impairment leads to the pathogenesis of neurodegenerative diseases, while amelioration of oxidative stress can inhibit the impairment. As a traditional Chinese medicine, mulberry leaf exhibits various pharmacological properties, including neuroprotective activity. But the major components responsible for the neuroprotective activity of mulberry leaf remained unknown. Phytochemicals were potent candidates of neuroprotective drug. Prenylated phenolics are the leading phytochemicals present in mulberry leaf.

PURPOSE

The aim of this study was to investigate the neuroprotective activities and mechanisms of prenylated phenolics.

METHODS

The chemical structure of isolated compounds were elucidated by MS and NMR. UPLC-MS/MS was used to determine the contents of prenylated phenolics in fresh mulberry leaf. Neurotoxicity was induced by erastin in HT22 cells. CCK-8 assay was performed to assess cell viability. ROS production, GSH level and iron release were monitored by using DCFH-DA, monobromobimane, and FeRhoNox™-1, respectively. qRT-PCR and Western blotting assays were performed to assess gene and protein expression, respectively.

RESULTS

Four prenylated phenolics, including isobavachalcone, morachalcone B, moracin N and morachalcone A were isolated and identified from mulberry leaf. Their levels in fresh mulberry leaf were in a decreasing order, moracin N > morachalcone A > morachalcone B > isobavachalcone. Moreover, moracin N showed a good neuroprotective activity with an EC₅₀ < 0.50 µM. The neuroprotective mechanisms of moracin N included inhibition of glutathione depletion, glutathione peroxidase 4 (GPx4) inactivation, reactive oxygen species (ROS) overproduction and iron accumulation, as well as improvement of intracellular antioxidant enzyme activities. Moracin N augmented the transcriptional levels of genes involved in antioxidant defense and glutathione biosynthesis in the early state of ferroptosis induction, and downregulated expression of genes related to iron accumulation and lipid peroxidation.

CONCLUSION

The results confirmed that moracin N was a good ferroptosis inhibitor, which exerted neuroprotective activity through preventing from oxidative stress.

Fecal Microbiota Perspective for Evaluation of Prebiotic Potential of Bamboo Hemicellulose Hydrolysate in Mice: A Preliminary Study

Bamboo hemicellulose hydrolysate (BHH) may possess antihypercholesterolemic activity; however, this activity requires further comprehensive study to assess the prebiotic mechanisms of BHH in vivo. Here, we used high-throughput 16S rRNA gene sequencing to preliminarily investigate the correlations between BHH and the fecal microbiomes of three groups of mice fed either a normal diet, a high-fat diet, or a high-fat diet supplemented with 5% BHH for 5 weeks. Alpha diversity (within community) was nonsignificant for all groups; however, beta diversity analysis among communities showed that 5% BHH suppressed the significant changes induced by the high-fat diet. The Firmicutes/Bacteroidetes ratio, the family S24-7 within the order Bacteroidales, the family Lachnospiraceae and several cellulolytic taxa were slightly ameliorated in the BHH group. These results indicated that BHH supplementation influenced the gut bacterial community and suppressed the high-fat diet-induced alterations. Additionally, BHH significantly lowered the serum cholesterol levels and fecal pH. Improving short-chain fatty acid production for all of the bacterial communities in the mouse guts may induce this effect. Thus, the prebiotic potential of BHH should be evaluated considering the gut microbial communities and their interactions.

Differences in energy metabolism and mitochondrial redox status account for the differences in propensity for developing obesity in rats fed on high-fat diet

Obesity is a metabolic disease that is accompanied by oxidative stress. Mitochondrial dysfunction is closely associated with the occurrence and development of obesity. However, it is unclear if there are differences in mitochondrial redox homeostasis and energy metabolism between obesity-prone (OP) and obesity-resistant (OR) individuals and if these differences account for the different susceptibilities to developing obesity. The present study aimed to compare the regulation of energy metabolism between OP and OR rats during high-fat diet (HFD)-induced oxidative stress. Male Sprague Dawley rats were randomly divided into the control group and the HFD group. The HFD group was further divided into the OP and OR groups based on body weight gain (upper 1/3 for OP; lower 1/3 for OR) after eight weeks on HFD. Rats were sacrificed at the 8th and 20th week, and serum and organs were collected. At 8 weeks, HFD decreased mitochondrial antioxidant enzyme activity and increased the production of ROS in the OP rats, which was accompanied by unusual mitochondrial oxidative phosphorylation, reduced mitochondrial membrane potential (MMP), and decreased ATP production. When the feeding period was extended beyond the 8 weeks, the energy expenditure of the OP rats reduced further, resulting in elevated blood lipids and glucose levels and increased body weight. In contrast, the OR rats had higher mitochondrial antioxidant enzyme activity and normal redox homeostasis throughout the period, which was beneficial in energy utilization and ATP production. Thus, the increase in energy expenditure in the OR rats reduced the HFD-induced weight gain. Mitochondrial function and antioxidant defense might be involved in the different propensities for developing obesity. Consequently, the ability of OR rats to resist obesity may be attributed to their ability to maintain mitochondrial function and redox balance.

Major royal jelly proteins prevents NAFLD by improving mitochondrial function and lipid accumulation through activating the AMPK / SIRT3 pathway in vitro

Nonalcoholic fatty liver disease (NAFLD) is a metabolic syndrome, whose main characteristics are excessive lipid accumulation and oxidative stress. Major royal jelly proteins (MRJPs) is a kind of water-soluble protein, which is abundant in royal jelly (RJ). The aim of this study was to evaluate the effect of MRJPs on lipid accumulation and oxidative stress of liver cells. Here, we first optimized the conditions for extracting MRJPs from RJ and identified the extraction effect and product by SDS-PAGE. Then, we used oleic acid (OA) of 1.0 mM to induce hepatocytes for 24 hr to establish a stable cell models of lipid accumulation, and we found that pre-administration (24 hr) of MRJPs (0.2, 0.5, and 1.0 g/L) could significantly reduce the lipid drop content and triglyceride level in the model cells, and simultaneously reduce the alanine aminotransferase and aspertate aminotransferase levels in the cell culture supernatant. In addition, pre-incubation (24 hr) with MRJPs (0.2, 0.5, and 1.0 g/L) could restore superoxide dismutase (SOD) level and mitochondrial membrane potential as compared with OA group. Furthermore, MRJPs administration significantly upregulated the expression of Silent Information Regulator 2 Associated Protein 3, mitochondrial superoxide dismutase (SOD2), and cytochrome c oxidase subunit IV in OA-treated HepG2 cells. The study for the first time provides evidences on the lipid-lowering effect of MRJPs at the cellular level, which can further provide support for the development and application of polypeptide drugs in the future, and can also provide a choice for the prevention and treatment of liver metabolic diseases represented by NAFLD. PRACTICAL APPLICATION: Our study proved that MRJPs had substantial preventing effect on OA-induced lipid accumulation and mitochondrial dysfunction in HepG2 cells. This research can further provide theoretical support for the development and application of peptide drugs in the future. Besides, it can not only further broaden our understanding of NAFLD and other diseases, but also provide ideas for research on oxidative stress and lipid accumulation in the body.

Bilberry anthocyanins improve neuroinflammation and cognitive dysfunction in APP/PSEN1 mice via the CD33/TREM2/TYROBP signaling pathway in microglia

Alzheimer's disease, characterized by neuroinflammation and beta-amyloid protein plaques, is a memory-threatening neurodegenerative disease with no effective treatment. Here, the effect of bilberry anthocyanins (BA) on cognitive functions was evaluated using APP/PSEN1 transgenic Alzheimer's disease model mice and their WT littermates. Our results revealed that BA appreciably improves learning and memory abilities and reverses defects to cognitive functions in APP/PSEN1 mice. Furthermore, BA reverses brain, liver and kidney damage caused by Alzheimer's disease, with no significant changes in oxidative stress and lipid metabolism-related indicators. In addition, BA decreases serum and brain lipopolysaccharide (LPS) levels and increases fecal short-chain fatty acid content. Immunofluorescence and RT-PCR analysis results showed that BA fully activates the microglia and astrocytes, downregulates the expression of inflammatory factors (TNF-α, NF-Kβ, IL-1β, IL-6, COX-2, iNOS and CD33) and chemokine receptor CX3CR1, and upregulates the expression of microglia homeostatic factors (TREM2 and TYROBP) and Toll-like receptors (TLR2 and TLR4). Moreover, western blot analysis revealed that BA significantly upregulates the expression of synaptic and phagocytotic function-related proteins (CD68, synaptophysin and IRF7) in APP/PSEN1 mice. Altogether, we show for the first time that BA consumption reverses Alzheimer's disease-induced cognitive disfunction, decreases hippocampal neuroinflammatory responses, and induces phagocytosis of microglia to beta-amyloid protein plaques by regulating the CD33/TREM2/TYROBP signaling pathway in microglia.

The antioxidant activity and neuroprotective mechanism of isoliquiritigenin

Glycyrrhizae radix has been widely accepted as a functional food in Asia. Isoliquiritigenin is a characteristic bioactive chemical in this medicinal plant. In this work, the neuroprotective effect of isoliquiritigenin and the possible mechanisms were investigated. The results revealed that isoliquiritigenin exhibited better neuroprotective and antioxidant activities than quercetin, a commercial natural antioxidant. Isoliquiritigenin significantly inhibited the release of lactate dehydrogenase, and the generation of reactive oxygen species in H₂O₂-treated cells. The activities of superoxide dismutase, glutathione peroxidase and catalase were improved. The mRNA expression levels related to oxidative defense and cell apoptosis were reversed by isoliquiritigenin. Moreover, isoliquiritigenin might inhibit the cell apoptosis via ameliorating the loss of mitochondrial membrane potential and the change of nucleus morphology.

Zinc Deficiency Promotes Testicular Cell Apoptosis in Mice

Zinc (Zn) plays an important role in spermatogenesis, and carbon tetrachloride (CCl₄) induces testicular oxidative damage and cell death. The objective of the present study was to define the effects of Zn deficiency in combination with CCl₄ treatment on testicular apoptosis and the associated mechanisms. Mice were fed the following diets with three different Zn levels for 6 weeks: normal zinc (ZN) diet (30 mg Zn/kg), zinc-deficient (ZD) diet (2 mg Zn/kg), and adequate zinc (ZA) diet (100 mg Zn/kg). Beginning in the third week, CCl₄ was intraperitoneally injected into half of the mice in each diet group six times over 3 weeks. We found that Zn was distributed in various tissues and organs in normal mice and that the zinc content in the testis of normal mice was high. The Zn-deficient diet reduced the zinc concentration in the testis tissue, and the testicular/body weight ratio significantly decreased. Moreover, the TUNEL results proved that CCl₄ stimulation of mice fed with a zinc-deficient diet caused marked apoptosis of testicular cells. Furthermore, the ROS levels in the testes obviously increased after Zn-deficient mice were stimulated with CCl₄, whereas reduced glutathione (GSH) and glutathione peroxidase (GSH-Px) showed reduced activities. In addition, proteins associated with the apoptosis signaling pathway were detected with ELISA kits. P-p53, cleaved caspase-3, cleaved PRAP, p-Bad, p-JNK, p-ERK, and p-NF-κB p65 increased by varying degrees under zinc deficiency or CCl₄ stimulation. All the data indicated that Zn deficiency significantly enhanced the harm to the testis induced by oxidative stress and damage, while CCl₄ stimulation exacerbated the oxidative damage in testicular cells, leading to apoptosis through the activation of p53, MAPK, and NF-κB.

Cardioprotective effect of isorhamnetin against myocardial ischemia reperfusion (I/R) injury in isolated rat heart through attenuation of apoptosis

In this study, we investigated the effects of isorhamnetin on myocardial ischaemia reperfusion (I/R) injury in Langendorff‐perfused rat hearts. Isorhamnetin treatment (5, 10 and 20 μg/mL) significantly alleviated cardiac morphological injury, reduced myocardial infarct size, decreased the levels of marker enzymes (LDH and CK) and improved the haemodynamic parameters, reflected by the elevated levels of the left ventricular developed pressure (LVDP), coronary flow (CF) and the maximum up/down velocity of left ventricular pressure (+dp/dt_max). Moreover, isorhamnetin reperfusion inhibited apoptosis of cardiomyocytes in the rats subjected to cardiac I/R in a dose‐dependent manner concomitant with decreased protein expression of Bax and cleaved‐caspase‐3, as well as increased protein expression of Bcl‐2. In addition, I/R‐induced oxidative stress was manifestly mitigated by isorhamnetin treatment, as showed by the decreased malondialdehyde (MDA) level and increased antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH‐Px). These results indicated that isorhamnetin exerts a protective effect against I/R‐induced myocardial injury through the attenuation of apoptosis and oxidative stress.

Identification of two novel prenylated flavonoids in mulberry leaf and their bioactivities

Mulberry leaf is a vegetable used in daily diet. It can bring delicious taste and multiple health benefits. However, the chemicals responsible for these health benefits remain unveiled. In this work, two novel prenylated flavonoids were isolated from mulberry leaf. Their structures were identified and named as morachalcone D and morachalcone E. The protective effects of these two compounds were investigated, against endogenous oxidative damage (oxytosis/ferroptosis) induced by glutamate and erastin in HT22 cells. The results revealed that morachalcone D was much more potent in preventing from glutamate- and erastin-induced cell death than morachalcone E. The neuroprotective effect of morachalcone D was related to the prevention of ROS production, glutathione depletion, and iron accumulation. Morachalcone D upregulated the expression of genes involved in antioxidant defense, including GPx4, CAT, SOD2, Nrf2, HMOX1 and SLC7A11. These findings indicated that morachalcone D was responsible for the health benefits of mulberry leaf, and could be a potent neuroprotective agent for use in dietary supplements and functional foods.

Naringenin Ameliorates Drosophila ReepA Hereditary Spastic Paraplegia-Linked Phenotypes

Defects in the endoplasmic reticulum (ER) membrane shaping and interaction with other organelles seem to be a crucial mechanism underlying Hereditary Spastic Paraplegia (HSP) neurodegeneration. REEP1, a transmembrane protein belonging to TB2/HVA22 family, is implicated in SPG31, an autosomal dominant form of HSP, and its interaction with Atlastin/SPG3A and Spastin/SPG4, the other two major HSP linked proteins, has been demonstrated to play a crucial role in modifying ER architecture. In addition, the Drosophila ortholog of REEP1, named ReepA, has been found to regulate the response to ER neuronal stress. Herein we investigated the role of ReepA in ER morphology and stress response. ReepA is upregulated under stress conditions and aging. Our data show that ReepA triggers a selective activation of Ire1 and Atf6 branches of Unfolded Protein Response (UPR) and modifies ER morphology. Drosophila lacking ReepA showed Atf6 and Ire1 activation, expansion of ER sheet-like structures, locomotor dysfunction and shortened lifespan. Furthermore, we found that naringenin, a flavonoid that possesses strong antioxidant and neuroprotective activity, can rescue the cellular phenotypes, the lifespan and locomotor disability associated with ReepA loss of function. Our data highlight the importance of ER homeostasis in nervous system functionality and HSP neurodegenerative mechanisms, opening new opportunities for HSP treatment.

Activation of reactive oxygen species-mediated mitogen-activated protein kinases pathway regulates both extrinsic and intrinsic apoptosis induced by arctigenin in Hep G2

OBJECTIVES

Arctigenin (ARG) has been proved to inhibit the viability of hepatocellular carcinoma (HCC) via inducing apoptosis. However, the precise mechanism remains unknown. The present study was aimed to further investigate the mechanism of ARG against HCC in vitro and in vivo.

METHODS

Arctigenin was applied in vitro and in vivo. Western blotting, immunohistochemistry, etc., were used to investigate the mechanisms.

KEY FINDINGS

The time-dependent enhancement of Bax/Bcl-2 ratio, cytochrome c release, Fas and FasL levels, caspase cascade activation and the loss in the mitochondrial out membrane potential indicated that both intrinsic and extrinsic apoptotic pathways were triggered by ARG. Moreover, Jun NH2-terminal kinase (JNK) and p38 phosphorylated time-dependently. And inhibition of the phosphorylation of either p38 or JNK led to a significant reduction in HepG2 apoptosis, owing to the crucial roles of p38 and JNK played in regulating the apoptosis pathways. In addition, ARG increased the generation of reactive oxygen species (ROS) in HepG2 cells, while the antioxidant N-acetyl cysteine almost reversed ARG-induced JNK and p38 activation, and dramatically decreased cell apoptosis. In vivo, ARG increased the cell apoptosis in tumour tissues, and p-p38, p-JNK and Bax were significantly upregulated.

CONCLUSIONS

Our findings demonstrated that ARG induced apoptosis in HCC via ROS-mediated mitogen-activated protein kinases apoptosis pathway.

Isolation of the Flavonoid from Bamboo Residues and Its Application as Metal Ion Sensor in Vitro

Fluorescence sensors prepared from natural polymers have received increasing attention based on their luminescence characteristics for bioimaging, cell imaging, and intracellular detection of inorganic metabolites. In this work, flavonoids isolated from bamboo residues (BRF) were applied as fluorescence sensors for different metal cations' detection in vitro. Results showed the optimal flavonoids extraction condition of solid to liquid ratio, ethanol concentration, extraction time and temperature were determined at 1:25, 50%, 240 min and 90 °C, respectively, resulting in an extraction yield with 104.7 mg/100 g bamboo residues. The BRF is mainly composed of isoorientin, isovitexin, pinosylvin, tricin and isorhamnetin by liquid chromatography-mass spectrometry (LC-MS) analysis. It is found that the BRF displayed strong blue-green emission as well as notable excitation, which can selectively and sensitively detect Fe3+ with the limit of detection (LOD) as low as 38.0 nM. In the Fe3+ detection was no obvious interference by other cations except for Al3+. In addition, the BRF displayed excellent biocompatibility that can be applied to bioimages of the intracellular detection of Fe3+ in L02 cells. Finally, it is found that the BRF possessed significant antioxidant properties in scavenging H2O2-induced endogenous reactive oxygen species (ROS) in a zebrafish module (in vivo) and L02 cells (in vitro). These results showed that the flavonoid products sustainably isolated from an abundant lignocellulosic waste appear to be effective fluorescent sensors for Fe3+ detection in biological systems with excellent biocompatibility and antioxidant activity.