Cytotoxicity and potential anti-inflammatory activity of velutin on RAW 264.7 cell line differentiation: Implications in periodontal bone loss

Açai (Euterpe oleracea Mart.) supplementation promotes histological and ultrastructural changes in rats' alveolar bone

The açai juice contains high concentrations of phenolic compounds, including cyanidin-3-glucoside and others flavonoids. The aim of this study was to evaluate the impact of açai supplementation on healthy mandibular alveolar bone in male albino rats of the Wistar strain. 24 rats were divided into 3 groups, in which one group received a daily dose of saline solution and the other two groups were treated with daily doses of clarified açai juice for 14 or 28 days. After the experiment, hemimandibles were collected and analyzed using Scanning Electron Microscopy (SEM), histological assessments, and micro-CT. Results showed changes in the integrity of the alveolar bone as seen in SEM, increased osteocyte density and higher collagen matrix area in the açai group compared to the control group as seen in histological analysis, and increased bone volume, trabecular thickness and number, and cortical bone as seen in micro-CT analysis. The space between bone trabeculae showed no difference among the groups. These results suggest that açai supplementation may have a structural change effect on alveolar bone, but further research is needed to confirm these findings in humans and to determine the exact mechanisms behind these effects.

Modulation of Hypoxia-Inducible Factors and Vascular Endothelial Growth Factor Expressions by Superfood Camu-Camu (Myrciaria dubia) Treatment in ARPE-19 and Fetal Human RPE Cells

Background

Anti-vascular endothelial growth factor (anti-VEGF) therapy via intravitreal injection is an effective treatment for patients with abnormal ocular neovascularization, such as age-related macular degeneration (AMD) and diabetic macular edema (DME). However, prolonged and frequent anti-VEGF treatment is associated with a risk of local and systemic adverse events, including geographic atrophy, cerebrovascular disease, and death. Furthermore, some patients do not adequately respond to anti-VEGF therapy. Hypoxia-inducible factor (HIF) is a transcription factor that controls the expression of hypoxia-responsive genes involved in angiogenesis, inflammation, and metabolism. The HIF/VEGF pathway plays an important role in neovascularization, and the inhibition of HIF activation could be an effective biomolecular target for neovascular diseases. The demand for disease prevention or treatment using functional foods such as superfoods has increased in recent years. Few reports to date have focused on the antineovascular effects of superfoods in the retinal pigment epithelium (RPE). In light of the growing demand for functional foods, we aimed to find novel HIF inhibitors from superfoods worked in RPE cells, which could be an adjuvant for anti-VEGF therapy.

Methods

Seven superfoods were examined to identify novel HIF inhibitor candidates using luciferase assay screening. We used the human RPE cell line ARPE-19 and fetal human RPE (fhRPE) to investigate the biomolecular actions of novel HIF inhibitors using quantitative PCR and western blotting.

Results

Under CoCl2-induced pseudohypoxic condition and 1% oxygen hypoxic incubation, camu-camu (Myrciaria dubia) showed HIF inhibitory effects determined by luciferase assays. Camu-camu downregulated HIF-1α and VEGFA mRNA expressions in a concentration-dependent manner. Camu-camu also inhibited HIF-1α protein expressions, and its inhibitory effect was greater than that of vitamin C, which is present at high levels in camu-camu.

Conclusion

The camu-camu extract suppressed the activation of HIF and VEGF in RPE cells. This could assist anti-VEGF therapy in patients with abnormal ocular neovascularization.

Açaí (Euterpe oleracea Mart.) in Health and Disease: A Critical Review

The açaí palm (Euterpe oleracea Mart.), a species belonging to the Arecaceae family, has been cultivated for thousands of years in tropical Central and South America as a multipurpose dietary plant. The recent introduction of açaí fruit and its nutritional and healing qualities to regions outside its origin has rapidly expanded global demand for açaí berry. The health-promoting and disease-preventing properties of this plant are attributed to numerous bioactive phenolic compounds present in the leaf, pulp, fruit, skin, and seeds. The purpose of this review is to present an up-to-date, comprehensive, and critical evaluation of the health benefits of açaí and its phytochemicals with a special focus on cellular and molecular mechanisms of action. In vitro and in vivo studies showed that açaí possesses antioxidant and anti-inflammatory properties and exerts cardioprotective, gastroprotective, hepatoprotective, neuroprotective, renoprotective, antilipidemic, antidiabetic, and antineoplastic activities. Moreover, clinical trials have suggested that açaí can protect against metabolic stress induced by oxidation, inflammation, vascular abnormalities, and physical exertion. Due to its medicinal properties and the absence of undesirable effects, açaí shows a promising future in health promotion and disease prevention, in addition to a vast economic potential in the food and cosmetic industries.

Phenolic Profile and the Antioxidant, Anti-Inflammatory, and Antimicrobial Properties of Açaí (Euterpe oleracea) Meal: A Prospective Study

The mechanical extraction of oils from Brazilian açaí (Euterpe oleracea Mart) produces significant amounts of a byproduct known as "meal", which is frequently discarded in the environment as waste material. Nevertheless, plant byproducts, especially those from oil extraction, may contain residual polyphenols in their composition and be a rich source of natural bioactive compounds. In this study, the phenolic composition and in vitro biological properties of a hydroethanolic açaí meal extract were elucidated. The major compounds tentatively identified in the extract by high-resolution mass spectrometry were anthocyanins, flavones, and flavonoids. Furthermore, rhamnocitrin is reported in an açaí byproduct for the first time. The extract showed reducing power and was effective in scavenging the ABTS radical cation (820.0 µmol Trolox equivalent∙g^-1) and peroxyl radical (975.7 µmol Trolox equivalent∙g^-1). NF-κB activation was inhibited at 10 or 100 µg∙mL^-1 and TNF-α levels were reduced at 100 µg∙mL^-1. However, the antibacterial effects against ESKAPE pathogens was not promising due to the high concentration needed (1250 or 2500 µg∙mL^-1). These findings can be related to the diverse polyphenol-rich extract composition. To conclude, the polyphenol-rich extract obtained from açaí meal showed relevant biological activities that may have great applicability in the food and nutraceutical industries.

Açaí (Euterpe oleracea Mart.) Attenuates Oxidative Stress and Alveolar Bone Damage in Experimental Periodontitis in Rats

Açaí (Euterpe oleracea Mart.) juice is rich in phenolic compounds with high antioxidant capacity. It has been observed that the use of antioxidants may be an additional strategy to nonsurgical periodontal therapy as well as to prevent alveolar bone loss. Thus, the objective of this study was to investigate the effects of açaí supplementation on experimental periodontitis in rats. Twenty male Rattus norvegicus (Wistar) rats were assigned into control, açaí, experimental periodontitis, and experimental periodontitis with açaí supplementation groups. Periodontitis was induced by placing ligatures around the lower first molars. Animals in the açaí groups received 0.01 mL/g of clarified açaí juice for 14 days by intragastric gavage. At the end of the experimental period, blood was collected to assess the reduced glutathione (GSH), Trolox equivalent antioxidant capacity (TEAC), and lipid peroxidation (TBARS) levels. Moreover, hemimandibles were analyzed by micro-computed tomography (micro-CT) for alveolar bone loss and bone quality. Açaí supplementation increased blood total antioxidant capacity and decreased lipid peroxidation. It also reduced alveolar bone loss when compared to the experimental periodontitis group. Moreover, clarified açaí per se modulated the oxidative biochemistry and bone microstructure. Thus, açaí may be considered a viable alternative for managing periodontal oxidative stress and preventing alveolar bone loss.

Radical-scavenging and Pro-/anti-inflammatory Activity of Tetracycline and Related Phenolic Compounds With or Without Visible Light Irradiation

BACKGROUND/AIM

Microbial tetracycline (TC) pastes have been employed to treat oral bacterial infection. In the present study, we investigated the kinetic radical-scavenging and pro-/anti-inflammatory activity of TC with or without visible light irradiation (VLI).

MATERIALS AND METHODS

The radical-scavenging activity of TC and minocycline (MC) was determined by differential scanning calorimetry (DSC). The stoichiometric factor (n) and the rate constant of inhibition and propagation (kinh/kp) were determined. The levels of cyclooxygenase-2 (Cox2), tumor necrosis factor-α (Tnfα) or nitric oxide synthase 2 (Nos2) mRNA in RAW264.7 cells stimulated with lipopolysaccharide (LPS) were investigated using real-time reverse transcriptase-polymerase chain reaction.

RESULTS

The n and kinh/kp values for 1 mM TC in 2,2'-azobisisobutyronitrile and benzoyl peroxide systems were 0.1-0.2 and 119-250, respectively, whereas the corresponding values for quercetin (QU) and resveratrol (RE) were 2-4 and 7-15, respectively. In RAW264.7 cells stimulated with LPS, Cox2 and Tnfα mRNA were over-expressed in the presence of TC. MC down-regulated only the expression of Cox2 by about 50% in LPS-stimulated cells. The anti-inflammatory activity determined on the basis of Cox2 inhibition declined in the order QU>RE>MC>TC. Upon application of VLI, only TC down-regulated the expression of LPS-stimulated Cox2 and Tnfα mRNA. After exposure to VLI, TC, but not MC, markedly up-regulated hemoxygenase-1 (Ho-1) expression.

CONCLUSION

TC is a chain-breaking antioxidant with a large kinh Upon activation by VLI, TC may undergo degradation and its degradation products affect pleiotropic mediators such as Cox2, Tnfα and Ho-1. TC may be useful as a local photodynamic therapy for periodontal diseases.

Digoxin Attenuates Receptor Activation of NF-κB Ligand-Induced Osteoclastogenesis in Macrophages

BACKGROUND

Even though hypoxia-inducible factor-1α (HIF-1α) is among the transcriptional factors demonstrated to contribute to the formation of abdominal aortic aneurysms (AAAs), the precise mechanism has been unclear. Digoxin is known as an inhibitor of HIF-1α, and shows a protective effect against the progression of AAAs.

OBJECTIVES

We tested the effect of digoxin on osteoclastogenesis (OCG) and examined the pathway through which digoxin exerts inhibition of HIF-1α.

MATERIALS AND METHODS

RAW 264.7 macrophage cells were cultured and stimulated by soluble receptor activator of NF-κB ligand (sRANKL) with or without digoxin. First, we tested the effect of digoxin to attenuate macrophage activation, which led to OCG, characterized by tartrate-resistant acid phosphatase (TRAP)-positive macrophages (TPMs).

RESULTS

The activation of TPMs stimulated by sRANKL was attenuated by digoxin treatment. Furthermore, the receptor activator of NF-κB (RANK)/receptor activator of NF-κB ligand (RANKL) complex signaling pathway, which is stimulated by HIF-1α, was downregulated by digoxin treatment.

CONCLUSIONS

These results show that digoxin attenuates OCG. By inhibition of HIF-1α, digoxin decreases OCG through the downregulation of the RANK/RANKL signaling pathway. Therefore, digoxin is a potential candidate for medical treatment of AAAs.

Cytotoxic Properties of Damiana (Turnera diffusa) Extracts and Constituents and A Validated Quantitative UHPLC-DAD Assay

In our continuing search for new cytotoxic agents, we assayed extracts, fractions, and pure compounds from damiana (Turnera diffusa) against multiple myeloma (NCI-H929, U266, and MM1S) cell lines. After a first liquid-liquid solvent extraction, the ethyl acetate layer of an acetone (70%) crude extract was identified as the most active fraction. Further separation of the active fraction led to the isolation of naringenin (1), three apigenin coumaroyl glucosides 2–4, and five flavone aglycones 5–9. Naringenin (1) and apigenin 7-O-(4″-O-p-E-coumaroyl)-glucoside (4) showed significant cytotoxic effects against the tested myeloma cell lines. Additionally, we established a validated ultra-high performance liquid chromatography diode array detector (UHPLC-DAD) method for the quantification of the isolated components in the herb and in traditional preparations of T. diffusa.

Anticancer potential, molecular mechanisms and toxicity of Euterpe oleracea extract (açaí): A systematic review

Cancer is an increasingly frequent malignancy worldwide, and despite the advances in drug development, it is still necessary to develop new plant-derived medicines. Euterpe oleracea (açaí) is abundant in South and Central America and has health benefits due to its high levels of phytochemicals, including lignans and polyphenols. The aim of this review was to systematically describe the safety and antitumor effects of açaí in preclinical models using rodents to provide a more comprehensive assessment of açaí for both therapeutic uses and the development of future clinical studies in cancer. Eligible studies were identified using four international databases (PubMed, Medline, Lilacs and SciELO) from their inception date through December 2017. The included studies were analyzed with methodological rigor (QATRS) to enable better quality control for these experimental studies. Sixty publications were identified in the databases, but only 9 articles were eligible: 6 evaluated the pharmacological effects of açaí in animal models of cancer (1 model each of esophageal cancer, urothelial cancer, melanoma and Walker-256 tumor and 2 models of colon cancer), and 3 were toxicological assays using preclinical models with rodents. Overall, 747 animals were analyzed. On a QATRS score scale of 0-20, the quality of the studies ranged from 16 to 20 points. Pulp was the main fraction of açaí administered, and an oral administration route was most common. The açaí dosage administered by gavage ranged from 30 mg/kg to 40,000 mg/kg, and açaí fed in the diet accounted for 2.5% to 5% of the diet. The anticarcinogenic and chemopreventive activities of açaí were observed in all experimental models of cancer and reduced the incidence, tumor cell proliferation, multiplicity and size of the tumors due to the antiinflammatory, antiproliferative and proapoptotic properties of açaí. No genotoxic effects were observed after açaí administration. The results of this review suggest that açaí is safe and can be used as a chemoprotective agent against cancer development. Açaí therapy may be a novel strategy for treating cancer.