Lupeol Stearate Accelerates Healing and Prevents Recurrence of Gastric Ulcer in Rodents.

Objective: The focus of this study was to evaluate the gastric healing effect of lupeol stearate (LS) and its ability to minimize ulcer recurrence in rodents. Methods: To evaluate the gastric healing properties of LS, rats were subjected to 80% acetic acid-induced ulcer model and treated with vehicle, LS (1 mg/kg, p.o.), or omeprazole (20 mg/kg, p.o.), twice daily by seven days. The gastric ulcers were evaluated macroscopically, histologically, and biochemically. To evaluate the effects of LS in gastric ulcer recurrence, mice were ulcerated with 10% acetic acid and treated with vehicle, LS (1 mg/kg, p.o.), or ranitidine (100 mg/kg, p.o.), twice a day for ten days. Then, ulcer recurrence in these animals was induced by IL-1ß at five days after the treatment period. Results: The oral treatment with LS accelerated gastric healing by 63% in rats compared to the vehicle group, evidenced by histological improvement and increased gastric mucin levels. Moreover, the gastric healing effects of LS in rats were accompanied by an elevation in glutathione S-transferase activity and a reduction in myeloperoxidase activity. Furthermore, the LS treatment reduced the recurred lesions in mice. Conclusions: The oral treatment of LS accelerates gastric healing in rats by favoring mucus production and reducing neutrophil migration, and it also can reduce ulcer recurrence. These data highlighted this compound as promising for developing new pharmacological strategies for the management of gastric ulcer.

Modelling hypersensitivity to trastuzumab defines biomarkers of response in HER2 positive breast cancer.

BACKGROUND: Trastuzumab-based therapies are the therapeutic option for HER2 positive (HER2+) breast cancer. HER2 amplification is the only biomarker validated for trastuzumab-based therapies. However, a proportion of tumors become refractory during treatment course. For this reason, the finding of new biomarkers beyond HER2 overexpression to identify patients who would benefit most from trastuzumab regimens is of outstanding importance. METHODS: Models of trastuzumab-resistant or hypersensitive cells were generated by exposure to trastuzumab. Cell surface, total HER2, and analyses of proteins involved in cell cycle or apoptosis were analyzed by western blotting. Cell proliferation was analyzed by cell counting, cell cycle and apoptosis was evaluated by FACS. Transcriptomic characterization of the cellular models was performed using bioinformatic online tools, and clinico-genomic analyses were performed using the PAMELA clinical trial data. RESULTS: Besides differing in sensitivities to trastuzumab, the different cellular models also showed distinct response to other anti-HER2 drugs (lapatinib, neratinib, pertuzumab and T-DM1) used in the clinic. That differential effect was not due to changes in cell surface, total or activated HER2. Trastuzumab caused important induction of cell death in hypersensitive cells but not in parental or resistant cells. Transcriptomic analyses of these cellular models together with querying of online databases allowed the identification of individual genes and gene signatures that predicted prognosis and trastuzumab response in HER2+ breast cancer patients. CONCLUSION: The identification of trastuzumab response biomarkers may be used to select patients particularly sensitive to facilitate the use of trastuzumab-based therapies and refine follow-up guidelines in patients with HER2+ tumors.

Avaliação da correlação diagnóstica dos níveis de HbA1c e microalbuminúria em pacientes com Diabetes mellitus tipo 2 como marcador de prevenção de complicações renais / Evaluation of the diagnostic correlation of HbA1c and microalbuminuria levels in type 2 Diabetes mellitus patients as a marker of prevention of renal complications

Objetivo: Avaliar a correlação entre os níveis de hemoglobina glicada A1c (HbA1c) e os valores de microalbuminúria como parâmetro auxiliar no diagnóstico precoce de dano renal. Métodos: Analisaram-se 56 pacientes que apresentaram os exames de glicemia de jejum, HbA1c e microalbuminúria, durante o período de um ano em um laboratório do município de Videira-SC. A análise dos dados foi realizada pelo teste de correlação de Pearson's estabelecendo como valores estatisticamente significativos p < 0,05. Resultados: Os valores de glicose de jejum se apresentaram alterados em ambos os sexos e faixa etária. Na hemoglobina glicada indivíduos do sexo feminino com faixa etária de até 60 anos de idade demostraram maiores alterações no controle glicêmico. Para os resultados de micro­albuminúria, 68% dos participantes apresentaram valores normais e 32% exibiram valores acima dos de referência, indicando presença de microalbuminúria e possível dano renal. Os valores mostraram correlação entre microalbuminúria e HbA1c em mulheres e homens respectivamente (p < 0,0001). Conclusão: Quando os valores de HbA1c apresentaram-se aumentados consequentemente os valores de microalbuminúria também estavam elevados. Portanto, a utilização desses marcadores na busca de identificar danos renais é fundamental.

Objective:This study aimed to evaluate the correlation between the levels of glycated hemoglobin A1c (HbA1c) and the values of microalbuminuria as an auxiliary parameter in the early diagnosis of kidney damage. Methods: Fifty-six patients who had fasting blood glucose, HbA1c and microalbuminuria tests were analyzed during a period of one year in a laboratory in the municipality of Videira-SC. Data analysis was performed using Pearson's correlation test, establishing as statistically significant values p < 0.05. Results: Fasting glucose values were altered in both sexes and age groups. In glycated hemoglobin, female individuals aged up to 60 years old showed greater changes in glycemic control. For the results of microalbuminuria, 68% of the participants had normal values and 32% showed values above those of reference, indicating the presence of microalbuminuria and possible kidney damage. The values showed a correlation between microalbuminuria and HbA1c in women and men respectively (p <0.0001). Conclusion: When the HbA1c values were consequently increased, the microalbuminuria values were also high. Therefore, the use of these markers in the search to identify kidney damage is essential.

Topical application of phenolic compounds suppresses Propionibacterium acnes-induced inflammatory responses in mice with ear edema.

Acne vulgaris (AV), a severe chronic inflammatory dermatosis, commonly treated with systemic or topical antibiotics that exacerbate bacterial resistance and pose adverse side effects, new approaches for suppressing or reducing Propionibacterium acnes-induced inflammatory responses and thereby treating AV remain necessary. In response, the goal of our study was to investigate the therapeutic potential of phenolic compounds in the in vivo inflammatory process induced by P. acnes. Mice were intradermally challenged with a suspension containing 1.0 × 107 CFU/mL of P. acnes per ear, after which groups of mice were variously treated with 20 µg of resveratrol, quercetin, gallic acid, or benzoyl peroxide. Mice ears were measured (mm) before each inducement and treatment. At the end of the experiment, activity catalase and superoxide dismutase, levels of myeloperoxidase (MPO), interleukin-1 beta (IL-1ß), tumor necrosis factor alpha, thiobarbituric acid reactive substances (TBARS), and glutathione were evaluated. Mice treated with resveratrol, quercetin, or gallic acid produced a 40%, 40%, and 30% reduction of the edema, respectively, while mice treated with resveratrol or gallic acid produced a 50 and 45% reduction in IL-1ß, also respectively, and a 35% reduction in MPO. Compared to mice in the control group (210 ± 21 µmol/mg protein) and ones treated with benzoyl peroxide (339.7 ± 21.3 µmol/mg protein), mice treated with resveratrol, quercetin, or gallic acid showed low levels of TBARS (71 ± 12 µmol/mg, 62 ± 10 µmol/mg, and 104 ± 15 µmol/mg protein, respectively). Such results suggest that phenolic compounds are a good alternative for the development of cosmetics that can be used to treat AV. Graphical abstract ᅟ.

Solid lipid nanoparticles improve octyl gallate antimetastatic activity and ameliorate its renal and hepatic toxic effects.

Metastasis is the main cause of cancer-related death and requires the development of effective treatments with reduced toxicity and effective anticancer activity. Gallic acid derivatives have shown significant biological properties including antitumoral activity as shown in a previous study with octyl gallate (G8) in vitro. Thus, the aim of this work was to evaluate the antimetastatic effect of free and solid lipid nanoparticle-loaded G8 in mice in a lung metastasis model. Animals inoculated with melanoma cells presented metastasis in lungs, which was significantly inhibited by treatment with G8 and solid lipid nanoparticle-loaded G8, named G8-NVM. However, G8-treated mice showed an increase in several toxicological parameters, which were almost completely circumvented by G8-NVM treatment. This study supports the need for pharmacological studies on new potential medicinal plants to treat cancer and can provide new perspectives on using nanotechnology to improve biological activities while decreasing the chemotherapy toxicological effects of anticancer drugs.

Lycium barbarum Reduces Abdominal Fat and Improves Lipid Profile and Antioxidant Status in Patients with Metabolic Syndrome.

Natural antioxidants present in fruits have attracted considerable interest due to their presumed safety and potential nutritional value. Even though antioxidant activities of many fruits have been reported, the effects of phytochemicals of goji berry (GB) in patients with metabolic syndrome have not been investigated. In this study, we examined anthropometric and biochemical parameters in patients with metabolic syndrome after the consumption of GB. The patients were divided into two groups, control (C) and supplemented (S), and followed up for 45 days. Participants were individually instructed to carry out a healthy diet, but additionally, an inclusion of 14 g of the natural form of goji berry in the diet during 45 days for the S group was proposed. After 45 days of study, a significant reduction in transaminases as well as an improvement in lipid profile in the S group was observed. Likewise, a significant reduction in the waist circumference of the S group was observed when compared with that of the C group, and increased glutathione and catalase levels associated with a reduction of lipid peroxidation. These results suggest that this is an effective dietary supplement for the prevention of cardiovascular diseases in individuals with metabolic syndrome.

Gallic Acid and Dodecyl Gallate Prevents Carbon Tetrachloride-Induced Acute and Chronic Hepatotoxicity by Enhancing Hepatic Antioxidant Status and Increasing p53 Expression.

Gallic acid (3,4,5-trihydroxybenzoic acid, GA), a natural phenolic acid has been reported as a strong antioxidant. Therefore the present study was designed to evaluate the effects of GA and dodecyl gallate (DGA) against acute and chronic carbon tetrachloride (CCl4)-induced hepatotoxicity. For acute model, rats were orally treated with GA and DGA for 7 d prior to CCl4 by intraperitoneally (i.p.) injection. For the chronic model, rats were orally treated with GA or DGA and CCl4 i.p. twice a week for four weeks. In both acute and chronic models, the CCl4-treated groups showed significantly increase in serum hepatic enzyme activities and histopathologic alterations, as well as a disruption in antioxidative status. In contrast, the treatment with GA and DGA restored serum hepatic enzymes activities, improved histopathologic alterations, increased glutathione (GSH) and decreased lipid peroxidation levels. The activities of liver antioxidant enzymes were increased by GA and DGA only in acute model. The expression of p53 gene increased about 3.5 times after GA and DGA treatments, which could result in cell death of damaged hepatocytes preventing of a lifelong liver failure. Thus, these results suggest that GA and DGA has the potential to prevent liver damages as the case of fibrosis condition.

Visceral fat increase and signals of inflammation in adipose tissue after administration of titanium dioxide nanoparticles in mice.

Titanium dioxide nanoparticles (TiO2 NP) are present in several daily use products, and the risks associated with their bioaccumulation must be stablished. Thus, an evaluation of several toxicological-related effects was conducted after intraperitoneal injection of TiO2 NPs in mice. Mice were divided into two groups, which received 2 mg kg-1 day-1 of TiO2 NPs or vehicle saline. Assessments of body and organ weight as well as biochemical, hematological, and histopathological analyses were performed in order to evaluate adverse effects. The results showed that treatment resulted in an increased visceral and abdominal fat deposition, as well as a mononuclear inflammatory infiltrates in the abdominal fat tissue. The TiO2 NPs induced significant decrease in the weight gain and splenomegaly. Additionally, TiO2 NP-treated mice showed altered hematological parameters and significant liver injuries, which were characterized by histopathological and biochemical changes. Our results also indicated that TiO2 NPs were absorbed and significantly accumulated in the spleen, liver, and kidney. These results showed the ability of TiO2 NPs to infiltrate different organs and to induce inflammation and liver and spleen damage with visceral fat accumulation. The data obtained are useful for the governmental authorities to legislate and implement regulations concerning the use and the production of this kind of material that might be hazardous to the living beings, as well as to the environment.

Development and Evaluation of Lipid Nanoparticles for Drug Delivery: Study of Toxicity In, Vitro and In Vivo.

Lipid nanoparticles have received considerable attention in the field of drug delivery, due their ability to incorporate lipophilic drugs and to allow controlled drug release. Solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and nanoemulsion (NE) are three different lipid nanostructured systems presenting intrinsically physical properties, which have been widely studied in recent years. Despite the extensive applicability of lipid nanoparticles, the toxicity of these systems has not been sufficiently investigated thus far. It is generally believed that lipids are biocompatible. However, it is known that materials structured in nanoscale might have their intrinsic physicochemical properties modified. Thus, the aim of this study was to evaluate the cytotoxicity of these three nanoparticle systems. To this end, in vitro and in vivo toxicity studies were carried out. Our results indicate that nanoparticles containing the solid lipid GMS (SLN and NLC) induced an important cytotoxicity in vitro, but showed minimal toxicity in vivo--evidenced by the body weight analysis. The NE did not induce in vitro toxicity and did not induce body weight alteration. On the contrary, the SLN and NLC possibly induce an inflammatory process in vivo. All nanoparticle systems induced lipid peroxidation in the animals' livers, but only SLN and NLC induced a decrease of antioxidant defences indicating that the main mechanism of toxicity is the induction of oxidative stress in liver. The higher toxicity induced by SLN and NLC indicates that the solid lipid GMS could be the responsible for this effect. Nevertheless, this study provides important insights for toxicological studies of different lipid nanoparticles systems.

Anti-inflammatory Activity of Berry Fruits in Mice Model of Inflammation is Based on Oxidative Stress Modulation.

BACKGROUND: Many fruits have been used as nutraceuticals because the presence of bioactive molecules that play biological activities. OBJECTIVE: The present study was designed to compare the anti-inflammatory and antioxidant effects of methanolic extracts of Lycium barbarum (GOJI), Vaccinium macrocarpon (CRAN) and Vaccinium myrtillus (BLUE). MATERIALS AND METHODS: Mices were treated with extracts (50 and 200 mg/kg, p.o.), twice a day through 10 days. Phytochemical analysis was performed by high-performance liquid chromatography. Antioxidant activity was determine by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, reducing power, lipid peroxidation thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and catalase (CAT) activity. Anti-inflammatory activity was evaluated by paw edema followed by determination of myeloperoxidase (MPO) and TBARS. RESULTS: High amount of phenolic compounds, including rutin, were identified in all berries extracts. However, quercetin was observed only in BLUE and CRAN. GOJI presents higher scavenging activity of DPPH radical and reducing power than BLUE and CRAN. The extracts improved antioxidant status in liver; BLUE showed the largest reduction (75.3%) in TBARS when compared to CRAN (70.7%) and GOJI (65.3%). Nonetheless, CAT activity was lower in BLUE group. However, hepatic concentrations of GSH were higher in animals treated with GOJI rather than CRAN and BLUE. Despite all fruits caused a remarkable reduction in paw edema and TBARS, only BLUE and CRAN were able to reduce MPO. CONCLUSION: These results suggest that quercetin, rutin, or other phenolic compound found in these berry fruits extracts could produce an anti-inflammatory response based on modulation of oxidative stress in paw edema model. SUMMARY: Within fruits broadly consumed because of its nutraceuticals properties include, Lycium barbarum (Goji berry), Vaccinium myrtillus (Blueberry or Bilberry) and Vaccinium macrocarpon (Cranberry)The objectives of this study were the investigation and comparison of chemical composition, antioxidant activity "in vitro" and "in vivo" and anti inflammatory property of berry fruits bought dry form.In summary, two main findings can be addressed with this study: (1) Berry fruits presented antioxidant and anti inflammatory activities "in vitro" and "in vivo"; (2) the extracts of GOJI, CRAN, and BLUE modulate the inflammatory process by different mechanisms.

Toxicity and inflammatory response in Swiss albino mice after intraperitoneal and oral administration of polyurethane nanoparticles.

In this work in vivo experiments were conducted in order to characterize the biocompatibility of polyurethane nanoparticles (PU-NPs) after intraperitoneal (i.p.) and oral administration. Additionally, ex vivo assays were performed to assess human blood compatibility as well as in vitro assays to assess protein binding. Our results indicated that administration of three different concentrations of PU-NPs induced a significant increase in visceral fat accumulation after oral dosing. In addition, fat tissue of mice intraperitoneally treated with the highest concentration of nanoparticles showed diffuse mononuclear inflammatory infiltrate in the fat tissue. Histopathological assessment showed inflammatory infiltrate and hepatocyte vacuolization in the liver, inflammatory infiltration and vascular congestion in the lung and glomerular necrosis in the kidney. Hepatic enzymes related with liver function were significantly increased in both groups of mice treated with PU-NPs. The PU-NPs did not affect the human blood cells number as well as coagulation time but showed a susceptibility to bind in proteins commonly found in the blood stream. In addition, increased amounts of pro inflammatory cytokines in vivo, as well as ex vivo in human cells were observed. Further studies to establish the consequences of long-term exposure to PU-NPs are warranted.

Superparamagnetic iron-oxide nanoparticles mPEG350- and mPEG2000-coated: cell uptake and biocompatibility evaluation.

Superparamagnetic iron oxide nanoparticles (SPIONS) were synthesized by thermal decomposition of an organometallic precursor at high temperature and coated with a bi-layer composed of oleic acid and methoxy-polyethylene glycol-phospholipid. The formulations were named SPION-PEG350 and SPION-PEG2000. Transmission electron microscopy, X-ray diffraction and magnetic measurements show that the SPIONs are near-spherical, well-crystalline, and have high saturation magnetization and susceptibility. FTIR spectroscopy identifies the presence of oleic acid and of the conjugates mPEG for each sample. In vitro biocompatibility of SPIONS was investigated using three cell lines; up to 100µg/ml SPION-PEG350 showed non-toxicity, while SPION-PEG2000 showed no signal of toxicity even up to 200µg/ml. The uptake of SPIONS was detected using magnetization measurement, confocal and atomic force microscopy. SPION-PEG2000 presented the highest internalization capacity, which should be correlated with the mPEG chain size. The in vivo results suggested that SPION-PEG2000 administration in mice triggered liver and kidney injury. FROM THE CLINICAL EDITOR: The potential use of superparamagnetic iron oxide nanoparticles (SPIONS) in the clinical setting have been studied by many researchers. The authors synthesized two types of SPIONS here and investigated the physical properties and biological compatibility. The findings should provide more data on the design of SPIONS for clinical application in the future.

Recent trends of chalcones potentialities as antiproliferative and antiresistance agents.

Chalcones are natural compounds found in plants, fruits and vegetables. This class of compounds has shown many biological activities including antioxidant, antimicrobial, anti-inflammatory, antifungal and antihypertensive, among others. In cancer, it has been reported that chalcones interfere in several points of the signal transduction pathways related to cellular proliferation, angiogenesis, metastasis, apoptosis and the reversal of multidrug resistance. The large number of research articles and patents related to chalcones is already an indication of their importance as a lead class of compounds. This article gathers recent efforts to elucidate the molecular mechanisms of action of chalcones, associated with their anticancer and anti resistance potential.

In vitro and in vivo effects of free and chalcones-loaded nanoemulsions: insights and challenges in targeted cancer chemotherapies.

Several obstacles are encountered in conventional chemotherapy, such as drug toxicity and poor stability. Nanotechnology is envisioned as a strategy to overcome these effects and to improve anticancer therapy. Nanoemulsions comprise submicron emulsions composed of biocompatible lipids, and present a large surface area revealing interesting physical properties. Chalcones are flavonoid precursors, and have been studied as cytotoxic drugs for leukemia cells that induce cell death by different apoptosis pathways. In this study, we encapsulated chalcones in a nanoemulsion and compared their effect with the respective free compounds in leukemia and in non-tumoral cell lines, as well as in an in vivo model. Free and loaded-nanoemulsion chalcones induced a similar anti-leukemic effect. Free chalcones induced higher toxicity in VERO cells than chalcones-loaded nanoemulsions. Similar results were observed in vivo. Free chalcones induced a reduction in weight gain and liver injuries, evidenced by oxidative stress, as well as an inflammatory response. Considering the high toxicity and the side effects induced generally by all cancer chemotherapies, nanotechnology provides some options for improving patients' life quality and/or increasing survival rates.

Solid lipid nanoparticles induced hematological changes and inflammatory response in mice.

Solid lipid nanoparticles (SLNs) are an alternative drug delivery system compared to emulsions, liposomes and polymeric nanoparticles. Due to their unique sizes and properties, SLNs offer possibility to develop new therapeutic approaches. The ability to incorporate drugs into nanocarriers offers a new prototype in drug delivery that could be used for drug targeting. However, toxicity of these new formulations has not been investigated thus far. In this study, we carried out an in vivo toxicity study. For that mice were divided into three groups and treated intraperitoneally with triestearin-based SLNs (TN), natural wax-based SLNs (VN) or vehicle for 10 days. After that, necropsies, histopathological and hematological analysis, as well as hepatic and renal functions were performed. Our results indicated that both TN and VN were absorbed post-exposure and induced an inflammatory response in adipose tissue. However, histopathological analysis demonstrated the absence of toxicity in both treated groups. In addition, the body weights were similar among the groups and low toxicity was also indicated by the unchanged serum biochemical parameters. This study provides a preliminary data for toxicological studies of two different SLNs in long-term in vivo exposure. However, further studies should be conducted in order to investigate the inflammatory response in order to establish the safety of these SLNs.

Alkyl esters of gallic acid as anticancer agents: a review.

The current review presents the antitumoral properties of gallic acid and its ester derivatives. Numerous studies have indicated that the alkyl esters are more effective against tumor cell lines than gallic acid, and that this activity is related to their hydrophobic moiety. All related studies have shown that the antitumor activity is interconnected to the induction of apoptosis by different mechanisms and it depends on the cell type. The results presented in this review may help to emphasize that these compounds could be promising as a new alternative for the treatment of cancer, either alone or in combination with other antitumor drugs to potentiate their effects.

Antimetastatic activity and low systemic toxicity of tetradecyl gallate in a preclinical melanoma mouse model.

Gallates with eight or more carbon atoms in the lateral chain show potent anticancer activity against various cell lines. However, studies regarding the in vivo antimelanoma activity of tetradecyl gallate (C(14)) have not yet been reported. In this study an evaluation of the ability of C(14) to inhibit metastasis, using lung metastases as a model, was carried out. The experimental mouse melanoma model was established by intravenous injection of metastatic B16F10 melanoma cells. The systemic toxicity of C(14) was evaluated in vivo by monitoring the weight, survival, biochemical and hematological parameters, and through histological analysis. It was observed that C(14) decreased lung metastasis in vivo by 80% and increased the survival rate of the animals without toxic effects. Additionally, C(14) induced cytotoxic effects on B16F10 cells, inhibited the inter-cellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) expression, and significantly decreased cell adhesion. These results reveal that C(14) has potent antimetastatic ability and is a good candidate for further study as a potential therapeutic agent for tumor metastases.

Evaluation of biochemical, hematological and oxidative parameters in mice exposed to the herbicide glyphosate-Roundup(®).

We evaluated the toxicity of hepatic, hematological, and oxidative effects of glyphosate-Roundup(®) on male and female albino Swiss mice. The animals were treated orally with either 50 or 500 mg/kg body weight of the herbicide, on a daily basis for a period of 15 days. Distilled water was used as control treatment. Samples of blood and hepatic tissue were collected at the end of the treatment. Hepatotoxicity was monitored by quantitative analysis of the serum enzymes ALT, AST, and γ-GT and renal toxicity by urea and creatinine. We also investigated liver tissues histopathologically. Alterations of hematological parameters were monitored by RBC, WBC, hemoglobin, hematocrit, MCV, MCH, and MCHC. TBARS (thiobarbituric acid reactive substances) and NPSH (non-protein thiols) were analyzed in the liver to assess oxidative damage. Significant increases in the levels of hepatic enzymes (ALT, AST, and γ-GT) were observed for both herbicide treatments, but no considerable differences were found by histological analysis. The hematological parameters showed significant alterations (500 mg/kg body weight) with reductions of RBC, hematocrit, and hemoglobin, together with a significant increase of MCV, in both sexes of mice. In males, there was an important increase in lipid peroxidation at both dosage levels, together with an NPSH decrease in the hepatic tissue, whereas in females significant changes in these parameters were observed only at the higher dose rate. The results of this study indicate that glyphosate-Roundup(®) can promote hematological and hepatic alterations, even at subacute exposure, which could be related to the induction of reactive oxygen species.

Octyl and dodecyl gallates induce oxidative stress and apoptosis in a melanoma cell line.

This study investigated the mechanism of cytotoxicity of octyl (G8) and dodecyl (G12) gallates in a murine melanoma cell line (B16F10). For this purpose, several methods to measure cell viability were used to determine if the cytotoxicity induced by these gallates corresponds to a general or an organelle-specific effect. Furthermore, the mechanisms related to apoptosis were examined, by studying the caspase-3 activity, oxidative stress, mitochondrial potential and the expression of anti- or proapoptotic proteins. When comparing the various methods of assessing cell viability, the tested gallates showed a higher cytotoxicity in the assay that indicates lysosomal activity, compared with the assays that indicate mitochondrial and ribosomal activities. Both gallates promoted the release of lactate dehydrogenase into the medium, indicating an effect on cell membrane integrity. The gallates also promoted cellular oxidative stress, mitochondrial depolarization and an increase in caspase-3 activity. Furthermore, the gallates induced an increase in proapoptotic (Bax) and a decrease in antiapoptotic (Bcl-2) proteins expression. Our results indicate that the apoptotic cell death induced by G8 and G12 in B16F10 cells involves lipid membrane damages, lysosomal and mitochondrial dysfunction, which was accompanied by alterations in apoptotic proteins expression and seems to be triggered by cellular oxidative stress.

Gallic acid ester derivatives induce apoptosis and cell adhesion inhibition in melanoma cells: The relationship between free radical generation, glutathione depletion and cell death.

Malignant melanoma is a lethal disease, and the incidence and mortality associated with it are increasing worldwide. It has a significant tendency to develop both metastasis and resistance to chemotherapy. The tumor cells show abnormal redox regulation, and although the molecular mechanisms involved are not well characterized, they seem to be related to oxidative stress. In a previous study, we showed the antitumoral properties of gallic acid ester derivatives in leukemia cells. Here, we show the effect of octyl, decyl, dodecyl and tetradecyl gallates on B16F10 cells, a melanoma cell line. All compounds induced cytotoxic effects, and the IC(50) values obtained were between 7microM and 17microM after 48h of incubation. Cell death occurred through apoptosis, as demonstrated by the genomic DNA fragmentation pattern. The gallates were able to induce significant production of free radicals, deplete both glutathione and ATP, activate NF-kappaB and promote the inhibition of cell adhesion under the experimental conditions. The glutathione depletion induced by these compounds was related to the inhibition of gamma-glutamylcysteine synthase activity. These results suggest that gallates induce tumoral cell death through apoptosis as a consequence of oxidative stress, though they use different mechanisms to do so. These findings are important since melanoma cells are resistant to death because of their high level of antioxidant defense, adhesion capability and propensity to metastasize.