Stingless bee honey protects against lipopolysaccharide induced-chronic subclinical systemic inflammation and oxidative stress by modulating Nrf2, NF-κB and p38 MAPK

Acute Inflammation and Oxidative Stress Induced by Lipopolysaccharide and the Ameliorative Effect of Stingless Bee Honey

BACKGROUND

Systemic acute inflammation is the hallmark of sepsis and is associated with multiple organ dysfunction.

OBJECTIVE

This study investigated the potential of Stingless Bee Honey (SBH) to suppress lipopolysaccharide (LPS)-induced systemic acute inflammation in rats and to reveal the probable mechanism of action.

METHODS

Rats received 4.6 and 9.2 g/kg SBH for 7 days followed by a single injection of LPS after which blood samples were taken 6h later.

RESULTS

LPS induced liver, kidney, heart, and lung injury, were manifested by increased serum transaminases, alkaline phosphatase, creatine kinase, creatinine, and urea, along with multiple histological alterations, particularly leukocyte infiltration. Pro-inflammatory cytokines were elevated in the serum, and NF-κB p65, p38 MAPK, and HMGB-1 were significantly increased in different tissues of LPS-challenged rats. SBH prevented tissue injury, ameliorated pro-inflammatory cytokines, and suppressed NF-κB p65, p38 MAPK, and HMGB-1 in rats that had received LPS. In addition, SBH diminished reactive oxygen species (ROS) production, lipid peroxidation, and oxidative DNA damage, and enhanced glutathione and Nrf2 in LPS-treated rats.

CONCLUSION

SBH prevents systemic acute inflammation by suppressing NF-κB, p38 MAPK, HMGB-1, oxidative stress, and tissue injury in rats. Thus, SBH may represent an effective anti-inflammatory nutraceutical, pending further mechanistic studies.

Honey and Chamomile Activate Keratinocyte Antioxidative Responses via the KEAP1/NRF2 System

Introduction

The stratum corneum protects against the entry of pathogens, allergens, and irritants while preventing dehydration. The Kelch-like erythroid cell-derived protein with cap-n-collar homology-associated protein 1 (KEAP1)/NF-E2-related factor 2 (NRF2) system maintains skin barrier homeostasis. Aggregated evidence suggests that NRF2-mediated antioxidative response is hardwired into the stratified squamous epithelia. Honey and chamomile have long been regarded as natural antioxidants. Nonetheless, it is still unclear whether they activate the KEAP1/NRF2 system in the epidermis and could promote epidermal barrier recovery.

Methods

To address the abovementioned issue, we explored the antioxidative property of honey/chamomile extract by using non-cell-based KEAP1-inhibition assay and cultured human epidermal keratinocytes.

Results

Herein we report that the extract inhibited KEAP1-NRF2 interaction and induced keratinocyte production of antioxidant small proline-rich protein.

Conclusion

Our results may offer an opportunity to develop cosmetic products that boost NRF2-mediated antioxidative/antiaging, epidermis-intrinsic bio-responses.

Curcumin and Selenium Prevent Lipopolysaccharide/Diclofenac-Induced Liver Injury by Suppressing Inflammation and Oxidative Stress

Diclofenac (DCL), an anti-inflammatory drug used to reduce pain and inflammation, ranks in the top causes of drug-induced liver injury. The inflammatory stress induced by inflammagens is implicated in DCL-induced liver injury. Curcumin (CUR) and selenium (Se) possess anti-inflammatory effects; therefore, this study evaluated their protective potential against lipopolysaccharide (LPS)/DCL-induced liver injury. Rats received CUR and/or Se for 7 days followed by a single intravenous administration of LPS 2 h before a single injection of DCL and two other doses of CUR and/or Se 2 and 8 h after DCL. Administration of nontoxic doses of LPS and DCL resulted in liver damage evidenced by the significantly elevated liver function markers in serum. LPS/DCL-induced liver injury was confirmed by histological alterations, increased lipid peroxidation and nitric oxide, and diminished glutathione and superoxide dismutase. CUR and/or Se prevented liver injury, histological alterations, and oxidative stress and boosted antioxidant defenses in LPS/DCL-induced rats. In addition, CUR and/or Se reduced serum C-reactive protein, liver pro-inflammatory cytokines, and the expression of TLR4, NF-κB, JNK, and p38, and upregulated heme oxygenase-1 (HO-1). In conclusion, CUR and/or Se mitigated LPS/DCL-induced liver injury in rats by suppressing TLR4 signaling, inflammation, and oxidative stress and boosting HO-1 and other antioxidants. Therefore, CUR and Se can hinder the progression and severity of liver injury during acute inflammatory episodes.

Antioxidant-Based Medicinal Properties of Stingless Bee Products: Recent Progress and Future Directions

Stingless bees are a type of honey producers that commonly live in tropical countries. Their use for honey is being abandoned due to its limited production. However, the recent improvements in stingless bee honey production, particularly in South East Asia, have brought stingless bee products back into the picture. Although there are many stingless bee species that produce a wide spread of products, known since old eras in traditional medicine, the modern medical community is still missing more investigational studies on stingless bee products. Whereas comprehensive studies in the current era attest to the biological and medicinal properties of honeybee (Apis mellifera) products, the properties of stingless bee products are less known. This review highlights for the first time the medicinal benefits of stingless bee products (honey, propolis, pollen and cerumen), recent investigations and promising future directions. This review emphasizes the potential antioxidant properties of these products that in turn play a vital role in preventing and treating diseases associated with oxidative stress, microbial infections and inflammatory disorders. Summarizing all these data and insights in one manuscript may increase the commercial value of stingless bee products as a food ingredient. This review will also highlight the utility of stingless bee products in the context of medicinal and therapeutic properties, some of which are yet to be discovered.

HMGB1 mediates lipopolysaccharide-induced inflammation via interacting with GPX4 in colon cancer cells

Background

Inflammation is one of a main reason for colon cancer progression and poor prognosis. The high-mobility group box-1 (HMGB1) and glutathione peroxidase 4 (GPX4) are responsible for inflammation, but the relationship between HMGB1 and GPX4 remains unknown about inflammation in colon cancer.

Methods

RT-qPCR was carried out to investigate the expression of IL1β, IL6 and TNFα in colon cancer cells stimulated with LPS or siHMGB1. To observe the relationship between HMGB1, GPX4 and inflammation or ROS, Western blot assays were adopted. Pull-down, CoIP and immunohistochemistry assays were performed to further investigate the molecular mechanisms of HMGB1 and GPX4 in colon cancer.

Results

We report that HMGB1 mediates lipopolysaccharide (LPS)-induced inflammation in colon cancer cells. Mechanistically, acetylated HMGB1 interacts with GPX4, negatively regulating GPX4 activity. Furthermore, by utilizing siHMGB1 and its inhibitor, our discoveries demonstrate that HMGB1 knockdown can inhibit inflammation and reactive oxygen species (ROS) accumulation via NF-kB.

Conclusion

Collectively, our findings first demonstrate that acetylated HMGB1 can interact with GPX4, leading to inflammation, and providing therapeutic strategies targeting HMGB1 and GPX4 for colon cancer.

Coumarins as Modulators of the Keap1/Nrf2/ARE Signaling Pathway

The Keap1/Nrf2/ARE system is a central defensive mechanism against oxidative stress which plays a key role in the pathogenesis and progression of many diseases. Nrf2 is a redox-sensitive transcription factor controlling a variety of downstream antioxidant and cytodefensive genes. Nrf2 has a powerful anti-inflammatory activity mediated via modulating NF-κB. Therefore, pharmacological activation of Nrf2 is a promising therapeutic strategy for the treatment/prevention of several diseases that are underlined by both oxidative stress and inflammation. Coumarins are natural products with promising pharmacological activities, including antioxidant, anticancer, antimicrobial, and anti-inflammatory efficacies. Coumarins are found in many plants, fungi, and bacteria and have been widely used as complementary and alternative medicines. Some coumarins have shown an ability to activate Nrf2 signaling in different cells and animal models. The present review compiles the research findings of seventeen coumarin derivatives of plant origin (imperatorin, visnagin, urolithin B, urolithin A, scopoletin, esculin, esculetin, umbelliferone, fraxetin, fraxin, daphnetin, anomalin, wedelolactone, glycycoumarin, osthole, hydrangenol, and isoimperatorin) as antioxidant and anti-inflammatory agents, emphasizing the role of Nrf2 activation in their pharmacological activities. Additionally, molecular docking simulations were utilized to investigate the potential binding mode of these coumarins with Keap1 as a strategy to disrupt Keap1/Nrf2 protein-protein interaction and activate Nrf2 signaling.

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.

Perinatal Exposure to Tartrazine Triggers Oxidative Stress and Neurobehavioral Alterations in Mice Offspring

The use of synthetic azo dyes as coloring agents in food products has dramatically increased. This study evaluated the effect of perinatal exposure to tartrazine (TZ) on mice offspring, focusing on neurobehavioral alterations and oxidative stress. The female mice received TZ (2.5 and 5 mg/kg) via oral gavage during pregnancy and the first 15 days after birth. At days 21 and 35 after birth, male mice were sacrificed, and samples were collected for analyses. Perinatal exposure to TZ triggered tissue injury evidenced by the histological alterations and neuronal damage in the cerebrum, medulla oblongata, and cerebellum. TZ provoked lipid peroxidation and diminished cellular antioxidants in different brain regions of the newborns. In addition, TZ increased hemoglobin content, as well as erythrocytes, leukocytes, and platelets count at days 21 and 35 after birth. Both the locomotor behavior and anxiety reflex were significantly altered in mice exposed to TZ. In conclusion, perinatal exposure to TZ within an adequate daily intake range induced oxidative stress and neurobehavioral and hematological alterations in mice offspring. Therefore, consuming foods containing TZ during pregnancy and lactation warrants public awareness.

Consumption of Terpenoids-Rich Padina pavonia Extract Attenuates Hyperglycemia, Insulin Resistance and Oxidative Stress, and Upregulates PPARγ in a Rat Model of Type 2 Diabetes

Seaweeds are rich in structurally diverse bioactive compounds with promising therapeutic effects. This study aimed to isolate and identify terpenes from the brown alga Padina pavonia and to investigate its antidiabetic activity, pointing to the possible involvement of peroxisome proliferator-activated receptor (PPAR)γ. Type 2 diabetes was induced by feeding rats a high fat diet (HFD) for 4 weeks followed by injection of 35 mg/kg streptozotocin (STZ). The diabetic rats received P. pavonia extract (PPE; 50, 100 and 200 mg/kg) for 4 weeks and samples were collected for analyses. HFD/STZ-induced rats showed hyperglycemia, dyslipidemia, impaired glucose tolerance, decreased insulin, and increased HbA1c and HOMA-IR. PPE ameliorated hyperglycemia and dyslipidemia, and improved glucose tolerance and insulin sensitivity in diabetic rats. Treatment with PPE increased hepatic hexokinase activity and glycogen, suppressed glucose-6-phosphatase, fructose-1,6-biphosphatase, and glycogen phosphorylase, and attenuated oxidative stress, inflammation, and liver injury and lipid infiltration in HFD/STZ-induced rats. In addition, PPE boosted antioxidants and upregulated PPARγ gene and protein expression in the liver of diabetic rats. Phytochemical investigation resulted in the isolation of six terpenes from PPE and in silico analysis revealed their binding affinity toward PPARγ. In conclusion, P. pavonia-derived terpenes attenuated hyperglycemia, dyslipidemia, oxidative stress, and inflammation, and improved insulin sensitivity and carbohydrate metabolism in type 2 diabetic rats. These beneficial effects are mediated via PPARγ activation. However, further studies to explore the exact mechanisms underlying the antidiabetic effect of PPE are recommended.