Morphine decreases cytotoxicity and mutagenicity of doxorubicin in vitro: Implications for cancer chemotherapy.

Morphine is the most common opioid analgesic administered to treat pain in patients undergoing cancer chemotherapy. This study aimed to evaluate the cytotoxic and mutagenic effects of morphine alone and in combination with doxorubicin (Dox), an antineoplastic agent largely used in patients with solid cancers. Cytotoxicity was evaluated in neuroblastoma (SH-SY5Y) and fibroblast (V79) cells using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay while mutagenicity was assessed using the Salmonella/microsome assay in the absence and in the presence of S9 mix. Morphine showed a cytotoxic effect mainly on SH-SY5Y cells and reduced the cytotoxic effects of Dox when evaluated in a co-treatment procedure. In the Salmonella/microsome assay, it was observed that morphine did not induce mutations and, in fact, decreased the mutagenic effects induced by Dox in TA98 and TA102 strains in the absence of metabolic activation. Furthermore, in the presence of metabolic activation, no induction of mutations was observed with morphine. In conclusion, morphine decreased Dox cytotoxicity in both neuronal and non-neuronal cells and showed antimutagenic effects in the TA102 strain which detects mutagens inducing DNA oxidative damages. However, morphine decreased frameshift mutations induced by Dox in non-cytotoxic concentrations, an effect suggesting interference of Dox intercalation activity that could decrease its chemotherapeutic efficacy. These compelling findings highlight the importance of conducting further studies to explore the potential implications of co-administering morphine and Dox during cancer chemotherapy.

Toxicological profile of the Hymenaea courbaril stem bark hydroalcoholic extract using in vitro bioassays and an alternative in vivo Caenorhabditis elegans model.

Hymenaea genus has been used in folk medicine in Brazil, but few studies investigated its toxicity profile. Thus, the aim of this study was to determine toxicological parameters of Hymenaea courbaril stem bark hydroalcoholic extract by utilizing three cell lines including murine macrophages (RAW 264.7), mouse fibroblast cells (L929) and human lung fibroblast (MRC-5), as well as Salmonella/microsome assay, and in vivo Caenorhabditis elegans model. The predominant detected phytoconstituents in the extract were coumarins, flavonoids, phenolics, tannins and saponins and by HPLC analysis, astilbin (AST) was found to be the main component. The DPPH assay demonstrated that H. courbaril hydroalcoholic extract exhibited potent antioxidant activity, with an IC50 of 3.12 µg/ml. The extract at concentrations of 400 and 800 µg/ml decreased cell viability 48 hr after treatment in L929 and MRC-5 cell lines. In the Raw 264.7 strain, just the highest concentration (800 µg/ml) lowered cell viability within 48 hr following exposure. The concentration of 100 µg/ml did not markedly affect cell viability in the trypan blue assay. In the alkaline comet assay the extract was found to be non-genotoxic. In the Ames test, the extract exhibited low mutagenic potential without metabolic activation, since only the highest concentrations produced an effect. H. courbaril extract only affected the survival of C. elegans at concentrations of 800 and 1600 µl/ml. These findings demonstrate that H. courbaril extract appears to exert low toxicity as evidenced in vitro and mutagenicity assays; however, the biological relevance of the response of C. elegans survival to safety assessments needs further studies.

Photobiomodulation intervention improves oxidative, inflammatory, and morphological parameters of skeletal muscle in cirrhotic Wistar rats.

Photobiomodulation (PBM) might be an intervention method to mitigate sarcopenia in cirrhotic patients. Given the lack of research on this issue, the goal of this study was to evaluate possible beneficial effects of PBM on the structural and functional properties of skeletal muscle from cirrhotic rats. Cirrhosis was induced by secondary bile duct ligation (BDL). Wistar rats were randomized into four groups: sham-operated control (Sham), Sham + PBM, BDL, and BDL + PBM. After cirrhosis induction, a dose of PBM (1 J; 100mW; 10 s; 880 nm; 6 × per week) was applied to each quadriceps, from the 15th to the 45th day after surgery. The locomotor ability was performed using an open-field task. The muscle structure was analyzed using histological methods. Cell damage was also evaluated assessing oxidative stress and DNA damage markers, and IL-1ß pro-inflammatory interleukin by immunohistochemical analysis. An increase in the number of crossings was observed in the BDL + PBM group in relation to BDL. The BDL group showed muscle atrophy and increased IL-1ß in relation to Sham, while in the BDL + PBM group, the fiber muscle was restructured and there was a decrease of IL-1 ß. TBARS increased in the liver and muscle tissues in the BDL group and decreased it in the BDL + PBM group. SOD increased while CAT decreased in the BDL + PBM group in relation to the BDL group. No genotoxic or mutagenic effect was observed for PBM treatment. PBM improved the locomotion and the morphology of the muscle fibers, decreasing oxidative stress and inflammation, without causing DNA damage in cirrhotic rats.

Targeting thymidine phosphorylase inhibition in human colorectal cancer xenografts.

Human thymidine phosphorylase (hTP) is overexpressed in several solid tumors and is commonly associated with aggressiveness and unfavorable prognosis. 6-(((1,3-Dihydroxypropan-2-yl)amino)methyl)-5-iodopyrimidine-2,4(1H,3H)-dione (CPBMF-223) is a noncompetitive hTP inhibitor, which has been described as a tumor angiogenesis inhibitor. The present study investigated the effects of CPBMF-223 in a xenograft tumor induced by human colorectal carcinoma cells (HCT-116). Additionally, CPBMF-223 capacity to reduce cell migration, its toxicological profile, and pharmacokinetic characteristics, were also evaluated. The intraperitoneal treatment with CPBMF-223 markedly prevented the relative tumor growth with an efficacy similar to that observed for 5-fluorouracil. Interestingly, number of vessels were significantly decreased in the treated groups. Moreover, CPBMF-223 significantly reduced the migration of cell line HCT-116. In the Ames assay and in an acute oral toxicity test, the molecule did not alter any evaluated parameter. Using the zebrafish toxicity model, cardiac and locomotor parameters were slightly changed. Regarding the pharmacokinetics profile, CPBMF-223 showed clearance of 9.42 L/h/kg after intravenous administration, oral bioavailability of 13.5%, and a half-life of 0.75 h. Our findings shed new light on the role of hTP in colorectal cancer induced by HCT-116 cell in mice, pointing out CPBMF-223 as, hopefully, a promising drug candidate.

Gamma-Decanolactone Alters the Expression of GluN2B, A1 Receptors, and COX-2 and Reduces DNA Damage in the PTZ-Induced Seizure Model After Subchronic Treatment in Mice.

Gamma-decanolactone (GD) has been shown to reduce epileptic behavior in different models, inflammatory decreasing, oxidative stress, and genotoxic parameters. This study assessed the GD effect on the pentylenetetrazole (PTZ) model after acute and subchronic treatment. We evaluated the expression of the inflammatory marker cyclooxygenase-2 (COX-2), GluN2B, a subunit of the NMDA glutamate receptor, adenosine A1 receptor, and GD genotoxicity and mutagenicity. Male and female mice were treated with GD (300 mg/kg) for 12 days. On the tenth day, they were tested in the Hot Plate test. On the thirteenth day, all animals received PTZ (90 mg/kg), and epileptic behavior PTZ-induced was observed for 30 min. Pregabalin (PGB) (30 mg/kg) was used as a positive control. Samples of the hippocampus and blood were collected for Western Blotting analyses and Comet Assay and bone marrow to the Micronucleus test. Only the acute treatment of GD reduced the seizure occurrence and increased the latency to the first stage 3 seizures. Males treated with GD for 12 days demonstrated a significant increase in the expression of the GluN2B receptor and a decrease in the COX-2 expression. Acute and subchronic treatment with GD and PGB reduced the DNA damage produced by PTZ in males and females. There is no increase in the micronucleus frequency in bone marrow after subchronic treatment. This study suggests that GD, after 12 days, could not reduce PTZ-induced seizures, but it has been shown to protect against DNA damage, reduce COX-2 and increase GluN2B expression.

Anti-hyperlipidemic effects of Campomanesia xanthocarpa aqueous extract and its modulation on oxidative stress and genomic instability in Wistar rats.

The use of natural products from herbs may be a therapeutic option in dyslipidemia treatment. Campomanesia xanthocarpa (Mart.) O. Berg (Myrtaceae) leaves have been used to decrease cholesterol levels. However, studies to determine activities of this plant on triglycerides metabolism have received little attention. The aim of this study was to examine anti-hyperlipidemic effects of a C. xanthocarpa aqueous leaf extract (CxAE) and assess protective actions against oxidative stress and DNA damage. The tyloxapol-induced hyperlipidemia model was used in Wistar rats. Rats were treated orally with CxAE either 250 or 500 mg/kg/day for 7 days prior to tyloxapol administration. Biochemical parameters, oxidative stress levels, and genomic instability were assessed in several tissues. CxAE decreased cholesterol and triglyceride levels in serum and hepatic and renal DNA damage in tyloxapol-treated rats. There was no marked effect on the micronucleus frequency in bone marrow. The extract increased catalase activity and decreased glutathione S-transferase activity in kidney tissue. CxAE showed anti-hyperlipidemic effects, improved oxidative parameters, and protected DNA against damage induced by tyloxapol-induced hyperlipidemia, suggesting C. xanthocarpa leaves may be useful in preventing dyslipidemias.Abbreviations: ALP: Alkaline phosphatase; ALT: Aspartate aminotransferase; ANOVA: Analysis of variance; AST: Aspartate aminotransferase; Ator: Atorvastatin; CAT: Catalase; Chol: Cholesterol; CxAE: Campomanesia xanthocarpa aqueous extract; GST: Glutathione S-transferase; HDL: High density cholesterol; i.p.: Intraperitoneal; NCE: Normochromatic erythrocyte; PBS: Phosphate buffer solution; PCE: Polychromatic erythrocyte; ROS: Reactive oxygen species; SD: Standard deviation; SOD: Superoxide dismutase; T: Tyloxapol; TBARS: Thiobarbituric acid reacting substances; TG: Triglyceride.

Toxicological aspects of Campomanesia xanthocarpa Berg. associated with its phytochemical profile.

Campomanesia xanthocarpa leaves are used as tea to treat diarrhea, inflammation, and hypercholesterolemia. Some pharmacological studies noted its beneficial uses of C. xanthocarpa; however, few investigations examined the toxicological profile of this plant. The aim of this study was to determine the chemical composition, genotoxic, and mutagenic potential of an aqueous extract of C. xanthocarpa leaves (CxAE), and potential protective effects against oxidative damage. Phytochemical constituents were determined using HPLC, and antioxidant effect in vitro was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. Genotoxic effects and chromosomic mutations were assessed using comet assay and micronucleus (MN) test in Wistar rats treated with CxAE at 250, 500 or 1000 mg/kg for 7 consecutive days. Lipid peroxidation and antioxidant enzyme activities were measured in several tissues. CxAE induced mutations in TA98, TA97a, and TA102 strains. However, in the presence of metabolic activation, data were negative for all strains tested. Lack of mutagenicity was also observed in the MN test. This extract did not induce DNA damage, except when the highest concentration was used. DNA oxidative damage induced by hydrogen peroxide (H2O2) decreased in blood after treatment with CxAE. Lipid peroxidation levels were reduced while superoxide dismutase (SOD) activity increased in kidneys. The inhibitory concentration of CxAE required to lower DPPH levels to 50% was 38.47 ± 2.06 µg/ml. In conclusion, frameshift and oxidative mutations were observed only in the absence of metabolic activation which may be attributed to the presence of flavonoids such as quercetin. It is of interest that CxAE also showed protective effects against DNA oxidative damage associated with presence of ellagic acid, a phenolic acid with antioxidant activities. CxAE did not induce in vivo mutagenicity, suggesting that this extract poses a low toxic hazard over the short term.