Protective effects of Manuka honey on LPS-treated RAW 264.7 macrophages. Part 2: Control of oxidative stress induced damage, increase of antioxidant enzyme activities and attenuation of inflammation

In vitro anti-inflammatory properties of honey flavonoids: A review

Honey is a natural ready-to-eat product rich in flavonoids, which is known by the wound healing properties due to both antibacterial and antioxidant activity. Flavonoids mitigate inflammatory processes, and thus it could currently support studies of anti-inflammatory potential of honeys. In this review, in vitro anti-inflammatory properties of flavonoids found in honey were prioritized. Mechanistic information of specific isolated flavonoids as modulators of inflammatory processes are summarized aiming to stimulate studies regarding the action of honey in inflammatory events. Lastly, a structure-activity relationship (SAR) of flavonoids was also included. Flavonoids found in honey have demonstrated antioxidant properties and ability to inhibit pro-inflammatory enzymes such as COX, LOX, iNOS, and pro-inflammatory mediators, including nitric oxide, cytokines and chemokines. Transcriptional factors such as NF-κB are also modulated by flavonoids, controlling the expression of several inflammatory mediators. SAR studies demonstrate the effect of flavonoids in the prevention of inflammatory cascades. Despite the promising reports of in vitro anti-inflammatory activity, well-designed clinical trials need yet to be performed to confirm the benefits of honeys from different botanical sources in diseases that include episodes of inflammation.

Honey and its nutritional and anti-inflammatory value

Inflammation is the main key role in developing chronic diseases including cancer, cardiovascular diseases, diabetes, arthritis, and neurodegenerative diseases which possess a huge challenge for treatment. With massively compelling evidence of the role played by nutritional modulation in preventing inflammation-related diseases, there is a growing interest into the search for natural functional foods with therapeutic and preventive actions. Honey, a nutritional healthy product, is produced mainly by two types of bees: honeybee and stingless bee. Since both types of honey possess distinctive phenolic and flavonoid compounds, there is recently an intensive interest in their biological and clinical actions against inflammation-mediated chronic diseases. This review shed the light specifically on the bioavailability and bioaccessibility of honey polyphenols and highlight their roles in targeting inflammatory pathways in gastrointestinal tract disorders, edema, cancer, metabolic and cardiovascular diseases and gut microbiota.

Protective effects of crimson snapper scales peptides against oxidative stress on Drosophila melanogaster and the action mechanism

Peptides derived from crimson snapper scales (CSSPs) were reported to possess excellent free radical scavenging activities in vitro. In present study, the anti-aging and anti-oxidative stress effects of CSSPs were evaluated in Drosophila melanogaster models. Results showed that the addition of CSSPs in the diets of normal Drosophila could effectively extend their lifespan and improve the motor ability of aged Drosophila. Moreover, CSSPs could protect Drosophila from oxidative damage induced by H₂O₂, paraquat and UV irradiation. The extension of lifespan was found to be associated with the effects of CSSPs in improving the antioxidant defense system of Drosophila, manifesting as the reduction of oxidation products MDA and PCO, the elevated activities of T-SOD, CAT and GSH-Px, and the upregulated expression of antioxidant related genes after CSSPs supplemented. Furthermore, CSSPs at 6 mg/mL significantly downregulated mTOR signaling pathway and activated autophagy in aged male Drosophila, and the inhibition on mTOR activation was probably mediated by the antioxidant effects of CSSPs. Our findings suggest that CSSPs have the potential in making dietary supplements against natural aging and oxidative stress in organisms.

In Vitro Modulation of Endogenous Antioxidant Enzyme Activities and Oxidative Stress in Autism Lymphoblastoid Cell Line (ALCL) by Stingless Bee Honey Treatment

Autism has been associated with a low antioxidant defense mechanism, while honey has been known for decades for its antioxidant and healing properties. Determination of stingless bee honey (KH) effects on antioxidant enzyme activities and oxidative damage in Autism Lymphoblastoid Cell Line (ALCL) was performed. ALCL and its normal sibling pair (NALCL) were cultured in RPMI-1640 medium at 37°C and 5% CO₂. ALCL was treated with 400 μg/mL KH (24 h), and oxidative stress marker, malondialdehyde (MDA), and antioxidant enzyme activities (catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD)) were measured via enzyme-linked immunosorbent assay (ELISA), while deoxyribonucleic acid (DNA) damage was determined via comet assay. Low SOD activity (p < 0.05) and high MDA level (p < 0.05) were observed in ALCL compared to NALCL. Higher grade (Grades 2 and 3) of DNA damage was highly observed (p < 0.05) in ALCL compared to NALCL, whereas lower grade (Grades 0 and 1) DNA damage was highly detected (p < 0.05) in NALCL compared to ALCL. KH treatment caused a significant increase in SOD and GPx activities (p < 0.05) in ALCL compared to untreated ALCL. Correspondingly, KH treatment reduced the Grade 2 DNA damage (p < 0.05) in ALCL compared to untreated ALCL. CAT activity showed no significant difference between all three groups, while the MDA level showed no significant difference between treated and untreated ALCL. In conclusion, KH treatment significantly reduced the oxidative stress in ALCL by increasing the SOD and GPx antioxidant enzyme activities, while reducing the DNA damage.

Particulate Matter-Induced Inflammation/Oxidative Stress in Macrophages: Fucosterol from Padina boryana as a Potent Protector, Activated via NF-κB/MAPK Pathways and Nrf2/HO-1 Involvement

Fucosterol is a phytosterol that is abundant in marine brown algae and is a renowned secondary metabolite. However, its ability to protect macrophages against particulate matter (PM) has not been clarified with regard to inflammation; thus, this study aimed to illustrate the above. Padina boryana, a brown algae that is widespread in Indo-Pacific waters, was applied in the isolation of fucosterol. Isolation was conducted using silica open columns, while identification was assisted with gas chromatography-mass spectroscopy (GC-MS) and NMR. Elevated levels of PM led the research objectives toward the implementation of it as a stimulant. Both inflammation and oxidative stress were caused due the fact of its effect. RAW 264.7 macrophages were used as a model system to evaluate the process. It was apparent that the increased NO production levels, due to the PM, were mediated through the inflammatory mediators, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and pro-inflammatory cytokines (i.e., interleukin-6 (IL-6), interleukin-1 (IL-1β) and tumor necrosis factor-α (TNF-α), including prostaglandin E2 (PGE2)). Further, investigations provided solid evidence regarding the involvement of NF-κB and mitogen-activated protein kinases (MAPKs) in the process. Oxidative stress/inflammation which are inseparable components of the cellular homeostasis were intersected through the Nrf2/HO-1 pathway. Conclusively, fucosterol is a potent protector against PM-induced inflammation in macrophages and hence be utilized as natural product secondary metabolite in a sustainable manner.

The role of Nrf2 in acute kidney injury: Novel molecular mechanisms and therapeutic approaches

Acute kidney injury (AKI) is a common clinical syndrome that is related to high morbidity and mortality. Oxidative stress, including the production of reactive oxygen species (ROS), appears to be the main element in the occurrence of AKI and the cause of the progression of chronic kidney disease (CKD) into end-stage renal disease (ESRD). Nuclear factor erythroid 2 related factor 2 (Nrf2) is a significant regulator of redox balance that has been shown to improve kidney disease by eliminating ROS. To date, researchers have found that the use of Nrf2-activated compounds can effectively reduce ROS, thereby preventing or retarding the progression of various types of AKI. In this review, we summarized the molecular mechanisms of Nrf2 and ROS in AKI and described the latest findings on the therapeutic potential of Nrf2 activators in various types of AKI.

Therapeutic potential of sulfur-containing natural products in inflammatory diseases

Owing to the prevalence of chronic inflammation and its related disorders, there is a demand for novel therapeutic agents capable of preventing or suppressing inflammation. Natural products (NPs) are well established as an important resource for drug development and provide an almost infinite array of molecular entities. Sulfur-containing NPs (i.e., NPs containing one or more sulfur atoms) are abundant throughout nature, from bacteria to animals. The aim of this review was to survey the emerging evidence on role of sulfur-containing NPs, such as glutathione, garlic-derived sulfur compounds, Epipolythiodioxopiperazines (EPTs), Isothiocyanates (ITCs), and Ergothioneine (EGT), in the control of inflammation and to determine the possible underlying mechanisms. A discussion of how hydrogen sulfide (H₂S), an endogenous gaseous signaling molecule, links sulfur-containing NPs and their anti-inflammatory action is also performed. This review may help to further the development of sulfur-based compounds by providing a guide for structure-activity relationship-based modification for use in modern medicinal chemistry. However, as this field is still in its infancy, the review is concluded by an overview of the progression of these promising entities as therapeutic agents.

The effects of malvidin on oxidative stress parameters and inflammatory cytokines in LPS-induced human THP-1 cells

Malvidin is an anthocyanin which is involved in inhibiting inflammatory-related mediators in inflammatory diseases; however, its mechanism of action in THP-1 cells is not yet known. THP-1 is a human monocytic cell line that is derived from patients with acute monocytic leukemia. The present study aimed to investigate the effect of malvidin on inflammatory responses and oxidative stress in lipopolysaccharide (LPS)-induced THP-1 cells. THP-1 cells were stimulated with LPS (50 ng/ml) to induce inflammation in the presence or absence of malvidin. The anti/proinflammatory cytokines were evaluated by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Total protein levels/phosphorylation of c-Jun N-terminal kinase (JNK), P65-NF-κB, and IKKα/IKKβ were evaluated by western blot analysis. Malondialdehyde (MDA) and nitric oxide (NO) metabolite levels, ferric reducing antioxidant power (FRAP), total thiol (T-SH) content, and superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity were measured to evaluate the antioxidant activity of malvidin in THP-1 cells. Treatment of LPS-stimulated THP-1 cells with malvidin (100 and 200 μM) led to the significant inhibition of interleukin-6 (IL-6), tumor necrosis factor-α, and IL-1β messenger RNA (mRNA) expression and protein levels as well as a significant increase in the IL-10 mRNA expression and protein secretion. Moreover, 200 μM malvidin treatment reduced the phosphorylation of JNK, IKKα/IKKβ, and P65-NF-κB. These findings showed that malvidin not only decreased the MDA and NO metabolite levels but also increased the FRAP and T-SH content as well as SOD and GPx activities. The findings of the present study demonstrated the potential role of malvidin in blocking inflammation and oxidative stress induced by LPS in THP-1 cell line, suggesting that malvidin is likely to be a therapeutic agent for inflammatory diseases.

Association between consumption frequency of honey and non-alcoholic fatty liver disease: results from a cross-sectional analysis based on the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) Cohort Study

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. Recent evidence has suggested the protective effects of honey consumption against the metabolic syndrome, but the association between honey intake and NAFLD is still unclear. We investigated how the consumption frequency of honey was associated with NAFLD in the general population. This was a cross-sectional study of 21 979 adults aged 20-90 years. NAFLD was diagnosed based on the ultrasound-diagnosed fatty liver without significant alcohol intake and other liver diseases. Diet information, including consumption frequency of honey, was assessed by a validated 100-item FFQ. OR with 95 % CI were calculated by the binary logistic regression model, adjusting for confounding factors identified by the directed acyclic graph. Overall, 6513 adults (29·6 %) had NAFLD. Compared with participants consuming ≤1 time/week of honey, the multivariable OR of NAFLD were 0·86 (95 % CI 0·77, 0·97) for 2-6 times/week and 1·10 (95 % CI 0·95, 1·27) for ≥1 times/d (Pfor trend = 0·90). The results were generally similar in subgroups of BMI at a cut-point of 24·0 kg/m2 (Pfor interaction = 0·10). In this large-scale study, consuming honey 2-6 times/week was inversely associated with NAFLD, whereas consuming honey ≥1 times/d had no association with NAFLD. These results need replication in other large-scale prospective studies.

5-Hydroxymethyl-Furfural and Structurally Related Compounds Block the Ion Conductance in Human Aquaporin-1 Channels and Slow Cancer Cell Migration and Invasion

Aquaporin-1 (AQP1) dual water and ion channels enhance migration and invasion when upregulated in leading edges of certain classes of cancer cells. Work here identifies structurally related furan compounds as novel inhibitors of AQP1 ion channels. 5-Hydroxymethyl-2-furfural (5HMF), a component of natural medicinal honeys, and three structurally related compounds, 5-nitro-2-furoic acid (5NFA), 5-acetoxymethyl-2-furaldehyde (5AMF), and methyl-5-nitro-2-furoate (M5NF), were analyzed for effects on water and ion channel activities of human AQP1 channels expressed in Xenopus oocytes. Two-electrode voltage clamp showed dose-dependent block of the AQP1 ion current by 5HMF (IC50 0.43 mM), 5NFA (IC50 1.2 mM), and 5AMF (IC50 ∼3 mM) but no inhibition by M5NF. In silico docking predicted the active ligands interacted with glycine 165, located in loop D gating domains surrounding the intracellular vestibule of the tetrameric central pore. Water fluxes through separate intrasubunit pores were unaltered by the furan compounds (at concentrations up to 5 mM). Effects on cell migration, invasion, and cytoskeletal organization in vitro were tested in high-AQP1-expressing cancer lines, colon cancer (HT29) and AQP1-expressing breast cancer (MDA), and low-AQP1-expressing SW480. 5HMF, 5NFA, and 5AMF selectively impaired cell motility in the AQP1-enriched cell lines. In contrast, M5NF immobilized all the cancer lines by disrupting actin cytoskeleton. No reduction in cell viability was observed at doses that were effective in blocking motility. These results define furans as a new class of AQP1 ion channel inhibitors for basic research and potential lead compounds for development of therapeutic agents targeting aquaporin channel activity. SIGNIFICANCE STATEMENT: 5-Hydroxymethyl-2-furfural (5HMF), a component of natural medicinal honeys, blocks the ion conductance but not the water flux through human Aquaporin-1 (AQP1) channels and impairs AQP1-dependent cell migration and invasiveness in cancer cell lines. Analyses of 5HMT and structural analogs demonstrate a structure-activity relationship for furan compounds, supported by in silico docking modeling. This work identifies new low-cost pharmacological antagonists for AQP1 available to researchers internationally. Furans merit consideration as a new class of therapeutic agents for controlling cancer metastasis.

Manuka Honey Reduces NETosis on an Electrospun Template Within a Therapeutic Window

Manuka honey, a topical wound treatment used to eradicate bacteria, resolve inflammation, and promote wound healing, is a focus in the tissue engineering community as a tissue template additive. However, its effect on neutrophil extracellular trap formation (NETosis) on a tissue engineering template has yet to be examined. As NETosis has been implicated in chronic inflammation and fibrosis, the reduction in this response within the wound environment is of interest. In this study, Manuka honey was incorporated into electrospun templates with large (1.7–2.2 µm) and small (0.25–0.5 µm) diameter fibers at concentrations of 0.1%, 1%, and 10%. Template pore sizes and honey release profiles were quantified, and the effect on the NETosis response of seeded human neutrophils was examined through fluorescence imaging and myeloperoxidase (MPO) analysis. The incorporation of 0.1% and 1% Manuka honey decreased NETosis on the template surface at both 3 and 6 h, while 10% honey exacerbated the NETosis response. Additionally, 0.1% and 1% Manuka honey reduced the MMP-9 release of the neutrophils at both timepoints. These data indicate a therapeutic window for Manuka honey incorporation into tissue engineering templates for the reduction in NETosis. Future in vivo experimentation should be conducted to translate these results to a physiological wound environment.

Anti-inflammatory and antixidant properties of blend formulated with compounds of Malpighia emarginata D.C (acerola) and Camellia sinensis L. (green tea) in lipopolysaccharide-stimulated RAW 264.7 macrophages

The antioxidant and anti-inflammatory properties of Malpighia emarginata D.C (acerola) and Camellia sinensis L. (green tea) have been studied, particularly as an alternative in medicinal approach for different physio pathological conditions. Here we develop an powder blend formulated with both Malpighia emarginata D.C and Camellia sinensis L. which have in the composition higher content of ascorbic acid and epigallatocathechin-3-gallate respectively. Using different conditions for microencapsulation of biocompounds, we performed the powder production through spray-drying process. After, we evaluate the antioxidant and anti-inflammatory properties of blends formulated with Malpighia emarginata D.C and Camellia sinensis L. in an in vitro model of inflammation, using LPS-stimulated RAW-264.7 macrophage cell line. We observed that co-treatment with blends was able to modulate the redox parameters in cells during the in vitro inflammatory response. Moreover, the co-treatment with blends were able to modulate inflammatory response by altering the secretion of cytokines IL-1β, IL-6, IL-10, and TNF-α. Taken together, our results demonstrate for the first time the synergistic effects antioxidant and anti-inflammatory of Malpighia emarginata D.C and Camellia sinensis L. These results warrant further use of the blend powder for use in the products to heath beneficial, principally in terms of prevention of chronic diseases.

Niacin Alleviates Dairy Cow Mastitis by Regulating the GPR109A/AMPK/NRF2 Signaling Pathway

Mastitis is one of three bovine diseases recognized as a cause of substantial economic losses every year throughout the world. Niacin is an important feed additive that is used extensively for dairy cow nutrition. However, the mechanism by which niacin acts on mastitis is not clear. The aim of this study is to investigate the mechanism of niacin in alleviating the inflammatory response of mammary epithelial cells and in anti-mastitis. Mammary glands, milk, and blood samples were collected from mastitis cows not treated with niacin (n = 3) and treated with niacin (30 g/d, n = 3) and healthy cows (n = 3). The expression of GPR109A, IL-6, IL-1β, and TNF-α in the mammary glands of the dairy cows with mastitis was significantly higher than it was in the glands of the healthy dairy cows. We also conducted animal experiments in vivo by feeding rumen-bypassed niacin. Compared with those in the untreated mastitis group, the somatic cell counts (SCCs) and the expression of IL-6, IL-1β, and TNF-α in the blood and milk were lower. In vitro, we isolated the primary bovine mammary epithelial cells (BMECs) from the mammary glands of the healthy cows. The mRNA levels of IL-6, IL-1β, TNF-α, and autophagy-related genes were detected after adding niacin, shRNA, compound C, trans retinoic acid, 3-methyladenine to BMECs. Then GPR109A, AMPK, NRF-2, and autophagy-related proteins were detected by Western blot. We found that niacin can activate GPR109A and phosphorylate AMPK, and promote NRF-2 nuclear import and autophagy to alleviate LPS-induced inflammatory response in BMECs. In summary, we found that niacin can reduce the inflammatory response of BMECs through GPR109A/AMPK/NRF-2/autophagy. We also preliminarily explored the alleviative effect of niacin on mastitis in dairy cows.

Honey and obesity-related dysfunctions: a summary on health benefits

Honey is a natural product, containing flavonoids and phenolic acids, appreciated for its therapeutic abilities since ancient times. Although the bioactive potential is linked to the composition, that is variable depending on mainly the botanical origin, honey has antioxidant and anti-inflammatory properties. Therefore, honey, administered alone or in combination with conventional therapy, might result useful in the management of chronic diseases that are commonly associated with oxidative stress and inflammation state. Obesity is a metabolic disorder characterized by visceral adiposity. The adipose tissue becomes hypertrophic and undergoes hyperplasia, resulting in a hypoxic environment, oxidative stress and production of pro-inflammatory mediators that can be responsible for other disorders, such as metabolic syndrome and neurodegeneration. Experimental evidence from animals have shown that honey improves glycemic control and lipid profile with consequent protection from endothelial dysfunction and neurodegeneration. The purpose of the present review is to summarize the current literature concerning the beneficial effects of honey in the management of the obesity-related dysfunctions, including neurodegeneration. Based on the key constituents of honey, the paper also highlights polyphenols to be potentially responsible for the health benefits of honey. Further well-designed and controlled studies are necessary to validate these benefits in humans.

Ameliorative effects of Magnolia sieboldii buds hexane extract on experimental reflux esophagitis

Gastroesophageal reflux disease (GERD) is a disease that stomach contents continually refluxing into esophagus causes symptoms and/or complications. The study was working to find natural plant extracts with good effects and small side effects to treat reflux esophagitis (RE). The anti-inflammatory effects of hexane extract of Magnolia sieboldii (MsHE) were conducted on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. The ameliorative effects of MsHE on esophageal damage in rats induced by gastric acid reflux was explored in vivo. The results showed that MsHE decreased the production of nitric oxide (NO) and expression levels of iNOS, COX-2 and TNF-α on LPS-stimulated RAW 264.7 cells and MsHE treatment ameliorated the rats' esophageal tissue damage induced by gastric acid and inhibited the increase of inflammatory mediators and pro-inflammatory cytokines by regulating NF-κB signaling pathway. In addition, MsHE protected the function of barrier of epithelial cells against inflammatory conditions through increasing the expression of tight junctions. Furthermore, liquid chromatography-mass spectrometry analysis was used for determine the active ingredients contained in MsHE. The results show that MsHE can alleviate experimental rat RE by regulating NF-κB signaling pathway. In summary, MsHE may be used as a source material of drug candidate for the treatment of RE.

Evaluation and comparison of the effect of honey, milk and combination of honey-milk on experimental induced second-degree burns of Rabit

Introduction:

Burn can happen in any area and causes dominant changes in the quality of normal tissues. The aim of present article is evaluation and comparison the effect of milk, natural honey, and combination of honey–milk on healing of burnt wound.

Method and Material:

A 4-week trial study was carried out on 10 Albino New Zealand rabbits. All dry burned wound was created on the back of the scapula by a 1 * 1 cm metal block. First group received honey dressing, second group milk dressing, third group honey–milk dressing, and the fourth group 5% sulfadiazine dressing. Sampling was performed at days 1, 10, and 20. Measurement of wound size was done in days 1, 7, 14, 21, 28. The obtained data and information were analyzed by two-way ANOVA and Duncan tests using SPSS.

Results:

Result show that combination of milk-honey dressing had most significant effect on the improvement of wound healing in the recipient rabbits after a 4-week study. The size of burn wound in four different group was: Honey milk combination 0.428 cm², honey 0.547 cm², milk 0.579 cm² and sulfadiazine 0.873 cm².

Conclusion:

All dressing can accelerate wound healing and have promotive effect on wound healing but the combination of honey–milk had the greatest effect. Honey, milk, and sulfadiazine had next grade of effectiveness.

Therapeutic and preventive properties of honey and its bioactive compounds in cancer: an evidence-based review

Despite the much improved therapeutic approaches for cancer treatment that have been developed over the past 50 years, cancer remains a major cause of mortality globally. Considerable epidemiological and experimental evidence has demonstrated an association between ingestion of food and nutrients with either an increased risk for cancer or its prevention. There is rising interest in exploring agents derived from natural products for chemoprevention or for therapeutic purposes. Honey is rich in nutritional and non-nutritional bioactive compounds, as well as in natural antioxidants, and its potential beneficial function in human health is becoming more evident. A large number of studies have addressed the anti-cancer effects of different types of honey and their phenolic compounds using in vitro and in vivo cancer models. The reported findings affirm that honey is an agent able to modulate oxidative stress and has anti-proliferative, pro-apoptotic, anti-inflammatory, immune-modulatory and anti-metastatic properties. However, despite its reported anti-cancer activities, very few clinical studies have been undertaken. In the present review, we summarise the findings from different experimental approaches, including in vitro cell cultures, preclinical animal models and clinical studies, and provide an overview of the bioactive profile and bioavailability of the most commonly studied honey types, with special emphasis on the chemopreventive and therapeutic properties of honey and its major phenolic compounds in cancer. The implications of these findings as well as the future prospects of utilising honey to fight cancer will be discussed.

Artemisinin Attenuated Hydrogen Peroxide (H2O2)-Induced Oxidative Injury in SH-SY5Y and Hippocampal Neurons via the Activation of AMPK Pathway

Oxidative stress is believed to be one of the main causes of neurodegenerative diseases such as Alzheimer’s disease (AD). The pathogenesis of AD is still not elucidated clearly but oxidative stress is one of the key hypotheses. Here, we found that artemisinin, an anti-malarial Chinese medicine, possesses neuroprotective effects. However, the antioxidative effects of artemisinin remain to be explored. In this study, we found that artemisinin rescued SH-SY5Y and hippocampal neuronal cells from hydrogen peroxide (H₂O₂)-induced cell death at clinically relevant doses in a concentration-dependent manner. Further studies showed that artemisinin significantly restored the nuclear morphology, improved the abnormal changes in intracellular reactive oxygen species (ROS), reduced the mitochondrial membrane potential, and caspase-3 activation, thereby attenuating apoptosis. Artemisinin also stimulated the phosphorylation of the adenosine monophosphate -activated protein kinase (AMPK) pathway in SH-SY5Y cells in a time- and concentration-dependent manner. Inhibition of the AMPK pathway attenuated the protective effect of artemisinin. These data put together suggested that artemisinin has the potential to protect neuronal cells. Similar results were obtained in primary cultured hippocampal neurons. Cumulatively, these results indicated that artemisinin protected neuronal cells from oxidative damage, at least in part through the activation of AMPK. Our findings support the role of artemisinin as a potential therapeutic agent for neurodegenerative diseases.

The Effect of Manuka Honey on dHL-60 Cytokine, Chemokine, and Matrix-Degrading Enzyme Release under Inflammatory Conditions

A large body of in vivo and in vitro evidence indicates that Manuka honey resolves inflammation and promotes healing when applied topically to a wound. In this study, the effect of two different concentrations (0.5% and 3% v/v) of Manuka honey on the release of cytokines, chemokines, and matrix-degrading enzymes from neutrophils was examined using a differentiated HL-60 cell line model in the presence of inflammatory stimuli. The results indicate that 0.5% honey decreased TNF-α, IL-1β, MIP-1α, MIP-1β, IL-12 p70, MMP-9, MMP-1, FGF-13, IL-1ra, and IL-4 release, but increased MIP-3α, Proteinase 3, VEGF, and IL-8 levels. In contrast, 3% honey reduced the release of all analytes except TNF-α, whose release was increased. Together, these results demonstrate a dose-dependent ability of Manuka honey to modify the release of cytokines, chemokines, and matrix-degrading enzymes that promote or inhibit inflammation and/or healing within a wound. The findings of this study provide further guidance for the future use of Manuka honey in wounds or tissue engineering templates. Future in vivo investigation is warranted to validate the in vitro results and translate these results to physiologically relevant environments.

Dexmedetomidine ameliorates lipopolysaccharide-induced acute kidney injury in rats by inhibiting inflammation and oxidative stress via the GSK-3β/Nrf2 signaling pathway

Acute kidney injury (AKI) is a frequent and serious complication of sepsis; however, there are currently no effective therapies. Inflammation and oxidative stress are the major mechanisms implicated in lipopolysaccharide (LPS)-induced AKI. Dexmedetomidine (DEX) has been reported to have remarkable anti-inflammatory and antioxidant effects. Here, we examined the renoprotective effects of DEX and potential underlying mechanisms in rats with LPS-induced AKI. We analyzed renal function and structure; serum inflammatory cytokine; renal oxidant and antioxidant levels; and renal expression of glycogen synthase kinase-3β (GSK-3β)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway-related proteins in rats 4 hr after administration of LPS. Pretreatment with DEX improved renal function and significantly reduced the levels of inflammatory cytokines and oxidative stress markers. Treatment with DEX and the GSK-3β inhibitor SB216367 promoted phosphorylation of GSK-3β, induced Nrf2 nuclear translocation, and increased transcription of the Nrf2 target genes heme oxygenase-1 and NAD(P)H quinone oxidoreductase-1, primarily in renal tubules. Alpha-2-adrenergic receptor (α2-AR) antagonist atipamezole and imidazoline I ₂ receptor (I ₂ R) antagonist idazoxan reversed the effects of DEX. These results suggest that the renoprotective effects of DEX are mediated via α2-AR and I ₂ R-dependent pathways that reduce inflammation and oxidative stress through GSK-3β/Nrf2 signaling.

Manuka Honey Modulates the Inflammatory Behavior of a dHL-60 Neutrophil Model under the Cytotoxic Limit

Recent work has shown that Manuka honey, an increasingly popular wound additive with potent antibacterial properties, also has anti-inflammatory properties. However, little research has been done examining its effect on neutrophils. This study investigates the hypothesis that Manuka honey reduces neutrophil superoxide release and chemotaxis and reduces the activation of the inflammatory nuclear factor-κB (NF-κB) signaling pathway under honey's cytotoxic limit. A differentiated HL-60 cell line was used as a neutrophil model and cultured in various concentrations of Manuka honey for 3 and 24 hours to measure cytotoxicity via mitochondrial activity and visual trypan-exclusion count. Cytochrome C and Boyden chamber assays were used to measure the effect of Manuka honey on superoxide release and chemotaxis toward fMLP, respectively. Additionally, a Western blot for NF-κB inhibitor α (IκBα) was performed to measure Manuka honey's effect on the NF-κB pathway via IκBα phosphorylation. The results indicate a cytotoxic limit of 3-5% v/v. The presence of 1% honey decreased superoxide release at 24 hours. The 0.5, 1, and 3% honey concentrations reduced chemotaxis and IκBα phosphorylation in a dose-dependent fashion. These results suggest that Manuka honey significantly reduces neutrophil recruitment and inflammatory behavior in the wound site in a dose-dependent fashion under the cytotoxic limit.

Beeswax by-Products Efficiently Counteract the Oxidative Damage Induced by an Oxidant Agent in Human Dermal Fibroblasts

The antioxidant capacity and the phytochemical composition of two by-products from beeswax recycling processes were recently investigated. The aim of the present work was to evaluate the efficacy of one of these by-products, MUD1, against the oxidative stress induced by 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) in human dermal fibroblast (HDF) cells. After a preliminary viability assay, the protective effect of MUD1 was investigated through the measurement of apoptosis level, the reactive oxygen species (ROS) and nitrite (NO₂⁻) production, the level of protein and lipid biomarkers (carbonyl groups, total glutathione and thiobarbituric acid-reactive substance) of oxidative damage, and the measurement of antioxidant enzymes activities (glutatione peroxidase, glutathione reductase, glutathione transferase, superoxide dismutase and catalase). The obtained results showed that MUD1 exerted protective effects on HDF, increasing cell viability and counteracted the oxidative stress promoted by AAPH-treatment, and improved mitochondria functionality and wound healing capacities. This work shows the antioxidant effects exerted by beeswax by-products, demonstrating for the first time their potential against oxidative stress in human dermal fibroblast cells; however, further research will be necessary to evaluate their potentiality for human health by more deeply in vitro and in vivo studies.