Synthesis and antiviral activities of a novel class of thioflavone and flavonoid analogues

A novel class of thioflavone and flavonoid derivatives has been prepared and their antiviral activities against enterovirus 71 (EV71) and the coxsackievirus B3 (CVB3) and B6 (CVB6) were evaluated. Compounds 7d and 9b showed potent antiviral activities against EV71 with IC₅₀ values of 8.27 and 5.48 μM, respectively. Compound 7f, which has been synthesized for the first time in this work, showed the highest level of inhibitory activity against both CVB3 and CVB6 with an IC₅₀ value of 0.62 and 0.87 μM. Compounds 4b, 7a, 9c and 9e also showed strong inhibitory activities against both the CVB3 and CVB6 at low concentrations (IC₅₀=1.42?7.15 μM), whereas compounds 4d, 7c, 7e and 7g showed strong activity against CVB6 (IC₅₀=2.91–3.77 μM) together with low levels of activity against CVB3. Compound 7d exhibited stronger inhibitory activity against CVB3 (IC₅₀=6.44 μM) than CVB6 (IC₅₀>8.29 μM). The thioflavone derivatives 7a, 7c, 7d, 7e, 7f and 7g, represent a new class of lead compounds for the development of novel antiviral agents.     

Structure-activity relationships of phthalates in inhibition of human placental 3β-hydroxysteroid dehydrogenase 1 and aromatase

Phthalates are associated with preterm delivery. However, the mechanism is unclear. Progesterone formed by 3β-hydroxysteroid dehydrogenase 1 (HSD3B1) and estradiol by aromatase (CYP19A1) in placenta are critical for maintaining pregnancy. In this study, we compared structure-activity relationships (SAR) of 14 phthalates varied in carbon atoms in alcohol moiety to inhibit human HSD3B1 in COS1 and CYP19A1 in JEG-3 cells. There were responses in that only diphthalates with 4–7 carbon atoms were competitive HSD3B1 inhibitors and diphthalates with 6 carbon atoms were CYP19A1 inhibitors. IC₅₀s of dipentyl (DPP), bis(2-butoxyethyl) (BBOP), dicyclohexyl (DCHP), dibutyl (DBP), and diheptyl phthalate (DHP) were 50.12, 32.41, 31.42, 9.69, and 4.87 μM for HSD3B1, respectively. DCHP and BBOP inhibited CYP19A1, with IC₅₀s of 64.70 and 56.47 μM. DPP, BBOP, DCHP, DBP, and DHP inhibited progesterone production in JEG-3 cells. In conclusion, our results indicate that there is clear SAR for phthalates in inhibition of HSD3B1 and CYP19A1.     

Anti-allergic activity of emodin on IgE-mediated activation in RBL-2H3 cells

BackgroundEmodin (1,3,8-trihydroxy-6-methylanthraquinone) is a Chinese herbal anthraquinone derivative from the rhizome of rhubarb (Rheum palmatum L.) that exhibits numerous biological activities, such as antitumor, antibacterial, antiinflammatory, and immunosuppressive. In the present studies, the anti-allergic activities of emodin were investigated to elucidate the underlying active mechanisms.MethodsThe inhibitory effects of emodin on the IgE-mediated allergic response in rat basophilic leukemia (RBL-2H3) cells were evaluated by measuring the release of granules and cytokines. The Ca²⁺ mobilization in RBL-2H3 cells loaded with the Ca²⁺-reactive fluorescent probe Fluo-4 AM was also measured by laser scanning confocal microscope.ResultsEmodin inhibited the release of β-hexosaminidase (β-HEX; IC₅₀ = 5.5 μM) and tumor necrosis factor (TNF)-α (IC₅₀ = 11.5 μM) from RBL-2H3 cells induced by 2,4-dinitrophenylated bovine serum albumin (DNP-BSA) and displayed stronger inhibition of β-HEX release than ketotifen fumarate salt (IC₅₀ = 63.8 μM). Emodin at a concentration of 12.5 μM also inhibited the DNP-BSA-induced influx of extracellular Ca²⁺ in RBL-2H3 cells.ConclusionsThese results suggested that emodin likely exhibits anti-allergic activities via increasing the stability of the cell membrane and inhibiting extracellular Ca²⁺ influx.     

The interactions of azure B,a metabolite of methylene blue,with acetylcholinesterase and butyrylcholinesterase

Methylene blue (MB) is reported to possess diverse pharmacological actions and is attracting increasing attention for the treatment of neurodegenerative disorders such as Alzheimer's disease. Among the pharmacological actions of MB, is the significant inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). These activities may, at least in part, underlie MB's beneficial effects in Alzheimer's disease. MB is metabolized to yield N-demethylated products of which azure B, the monodemethyl metabolite, is the predominant species. Azure B has been shown to be pharmacologically active and also possesses a variety of biological actions. Azure B therefore may contribute to the pharmacological profile of MB. Based on these considerations, the present study investigates the possibility that azure B may, similar to MB, act as an inhibitor of human AChE and BuChE. The results document that azure B inhibits AChE and BuChE with IC₅₀ values of 0.486 μM and 1.99 μM, respectively. The results further show that azure B inhibits AChE and BuChE reversibly, and that the modes of inhibition are most likely competitive. Although the AChE and BuChE inhibitory activities of azure B are twofold and fivefold, respectively, less potent than those recorded for MB [IC₅₀(AChE) = 0.214 μM; IC₅₀(BuChE) = 0.389 μM] under identical conditions, azure B may be a contributor to MB's in vivo activation of the cholinergic system and beneficial effects in Alzheimer's disease.     

Cytotoxicity and genotoxicity of phenazine in two human cell lines

Phenazine was recently identified as a drinking water disinfection byproduct (DBP), but little is known of its toxic effects. We examined in vitro cytotoxicity and genotoxicity of phenazine (1.9–123 μM) in HepG2 and T24 cell lines. Cytotoxicity was determined by an impedance-based real-time cell analysis instrument. The BrdU (5-bromo-2′-deoxyuridine) proliferation and MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) viability assays were used to examine mechanisms of cytotoxicity. Genotoxicity was determined using the alkaline comet assay. Concentration-dependent cytotoxicity was observed in HepG2 cells, primarily due to an antiproliferative effect (BrdU 24 h IC₅₀: 11 μM; 48 h IC₅₀: 7.8 μM) observed as low as 1.9 μM. T24 cells experienced a minor antiproliferative effect (BrdU 24 h IC₅₀: 47 μM; 48 h IC₅₀: 17 μM). IC₅₀ values for HepG2 proliferation and viability were 54–77% lower compared to T24 cells. In both cell lines, IC₅₀ values for proliferation were 66–90% lower than those for viability. At phenazine concentrations producing equivalent cytotoxicity, HepG2 cells (1.9–30.8 μM) experienced no significant genotoxic effects, while T24 cells (7.7–123 μM) experienced significant genotoxicity at ⩾61.5 μM. While these effects were seen at phenazine concentrations above those found in disinfected water, the persistence of the antiproliferative effect and the differential toxicity in each cell line deserves further study.     

Inhibitory effects of astaxanthin, β-cryptoxanthin,canthaxanthin, lutein,and zeaxanthin on cytochrome P450 enzyme activities

Astaxanthin, β-cryptoxanthin, canthaxanthin, lutein and zeaxanthin, the major xanthophylls, are widely used in food, medicine, and health care products. To date, no studies regarding the inhibitory effects of these xanthophylls on the nine CYPs isozymes have been reported. This study investigated the reversible and time-dependent inhibitory potentials of five xanthophylls on CYPs activities in vitro. The reversible inhibition results showed that the five compounds had only a weak inhibitory effect on the nine CYPs. Lutein did not inhibit the nine CYPs activities. Astaxanthin weakly inhibited CYP2C19, with an IC₅₀ of 16.2 μM; and β-cryptoxanthin weakly inhibited CYP2C8, with an IC₅₀ of 13.8 μM. In addition, canthaxanthin weakly inhibited CYP2C19 and CYP3A4/5, with IC₅₀ values of 10.9 and 13.9 μM, respectively. Zeaxanthin weakly inhibited CYP3A4/5, with an IC₅₀ of 15.5 μM. However, these IC₅₀ values were markedly greater than the C_max values reported in humans. No significant IC₅₀ shift was observed in the time-dependent inhibition screening. Based on these observations, it is unlikely that these five xanthophylls from the diet or nutritional supplements alter the pharmacokinetics of drugs metabolized by CYPs. These findings provide some useful information for the safe use of these five xanthophylls in clinical practice.     

Mitochondrial toxicity of selective COX-2 inhibitors via inhibition of oxidative phosphorylation (ATP synthesis) in rat liver mitochondria

Cyclooxygenase-2 (COX-2) inhibitors (coxibs) are non-steroidal anti-inflammatory drugs (NSAIDs) designed to selectively inhibit COX-2. However, drugs of this therapeutic class are associated with drug induced liver injury (DILI) and mitochondrial injury is likely to play a role. The effects of selective COX-2 inhibitors on inhibition of oxidative phosphorylation (ATP synthesis) in rat liver mitochondria were investigated. The order of potency of inhibition of ATP synthesis was: lumiracoxib (IC₅₀: 6.48 ± 2.74 μM) > celecoxib (IC₅₀: 14.92 ± 6.40 μM) > valdecoxib (IC₅₀: 161.4 ± 28.6 μM) > rofecoxib (IC₅₀: 238.4 ± 79.2 μM) > etoricoxib (IC₅₀: 405.1 ± 116.3 μM). Mechanism based inhibition of ATP synthesis (K_inact 0.078 min^− 1 and K_I 21.46 μM and K_inact/K_I ratio 0.0036 min^− 1 μM^− 1) was shown by lumiracoxib and data suggest that the opening of the MPT pore may not be the mechanism of toxicity. A positive correlation (with r² = 0.921) was observed between the potency of inhibition of ATP synthesis and the log P values. The in vitro metabolism of coxibs in rat liver mitochondria yielded for each drug substance a major single metabolite and identified a hydroxy metabolite with each of the coxibs and these metabolites did not alter the inhibition profile of ATP synthesis of the parent compound. The results suggest that coxibs themselves could be involved in the hepatotoxic action through inhibition of ATP synthesis.     

Apoptosis induction by 4-nerolidylcatechol in melanoma cell lines

Pothomorphe umbellata, a native Brazilian plant, is popularly known to be effective in the treatment of skin lesions. This benefit is attributed to 4-nerolidylcatechol (4-NC), a compound extracted from P. umbellata. Since melanomas show prominent resistance to apoptosis and exhibit extreme chemoresistance to multiple forms of therapy, novel compounds addressing induction of cell death are worth investigating. Here, we evaluated effects on cell cycle progression and possible cytotoxic activity of 4-NC in melanoma cell lines as well as human dermal fibroblasts. Inhibitory effects on cell invasion and MMP activity were also investigated. 4-NC showed cytotoxic activity for all melanoma cell lines tested (IC₅₀ = 20–40 μM, 24 h for tumoral cell lines; IC₅₀ = 50 μM for fibroblast cell line) associated with its capacity to induce apoptosis. Furthermore, this is the first time that 4-NC is described as an inhibitor of cell invasiveness, due mainly to a G1 cell cycle arrest and inhibition of MMP-2 activity in melanoma cell lines.     

Toxic effects of xylazine on endothelial cells in combination with cocaine and 6-monoacetylmorphine

The use of xylazine as a drug of abuse has emerged worldwide in the last 7 years, including Puerto Rico. Clinical findings reported that xylazine users present greater physiological deterioration, than heroin users. The aim of this study was to assess the xylazine toxicity on endothelial cells, as this is one of the first tissues impact upon administration. Human umbilical vein endothelial cells in culture were treated with xylazine, cocaine, 6-monoacetylmorphine (heroin metabolite) and its combinations, at concentrations of 0.10–400 μM, for periods of 24, 48 and 72 h. IC₅₀ were calculated and the Annexin V assay implemented to determine the cell death mechanism. Results indicated IC₅₀ values at 24 h as follow: xylazine 62 μM, cocaine 210 μM, 6-monoacetylmorphine 300 μM. When these drugs were combined the IC₅₀ value was 57 μM. Annexin V results indicated cell death by an apoptosis mechanism in cells treated with xylazine or in combination. Results demonstrated that xylazine use inhibits the endothelial cell proliferation, at lower concentrations than cocaine and 6-monoacetylmorphine. These findings contribute to the understanding of the toxicity mechanisms induced by xylazine on endothelial cells.     

Discovery of cyclooxygenase inhibitors from medicinal plants used to treat inflammation

Eleven authenticated botanicals used in the traditional Chinese medicine Huo-Luo-Xiao-Ling Dan were screened for ligands to cyclooxygenase (COX) using pulsed ultrafiltration liquid chromatography–mass spectrometry, and a mass spectrometry-based enzyme assay was used to determine the concentration of each of 17 ligands that inhibited COX-1 or COX-2 by 50% (IC₅₀). Acetyl-11-keto-β-boswellic acid, β-boswellic acid, acetyl-α-boswellic acid, acetyl-β-boswellic acid, and betulinic acid were COX-1 selective inhibitors with IC₅₀ values of approximately 10 μM. Senkyunolide O and cryptotanshinone were COX-2 selective inhibitors with IC₅₀ values of 5 μM and 22 μM, respectively. Roburic acid and phenethyl-trans-ferulate inhibited COX-1 and COX-2 equally. COX inhibition and the IC₅₀ values of most of these natural product ligands have not been reported previously.     

Peroxisome proliferator-activated receptor gamma (PPARγ) in brown trout: Interference of estrogenic and androgenic inputs in primary hepatocytes

Peroxisome proliferator-activated receptor gamma (PPARγ) is a pivotal regulator of lipid and glucose metabolism in vertebrates. Here, we isolated and characterized for the first time the PPARγ gene from brown trout (Salmo trutta f. fario). Hormones have been reported to interfere with the regulatory function of PPARγ in various organisms, albeit with little focus on fish. Thus, primary hepatocytes isolated from juveniles of brown trout were exposed to 1, 10 and 50 μM of ethinylestradiol (EE2) or testosterone (T). A significant (3 fold) decrease was obtained in response to 50 μM of EE2 and to 10 and 50 μM of T (13 and 14 folds), while a 3 fold increase was observed at 1 μM of EE2. Therefore, trout PPARγ seems a target for natural/synthetic compounds with estrogenic or androgenic properties and so, we advocate considering PPARγ as another alert sensor gene when assessing the effects of sex-steroid endocrine disruptors.     

Inhibitory vs. protective effects of N-acetyl-l-cysteine (NAC) on the electromechanical properties of the spontaneously beating atria of the frog (Rana ridibunda): An ex vivo study

The results of this study have shown that N-acetyl-l-cysteine (NAC), a compound used for protection of tissues or cell cultures against the deleterious effects of various environmental pollutants, has certain unusual effects on the contraction of the spontaneously beating atria of the frog isolated in saline (ex vivo): (1) NAC, 6.0 and 10.0 mM, eliminated, in a concentration-dependent manner, the contractile properties of the atria (force and frequency) within minutes, without affecting its electrical properties; (2) the IC₅₀ of NAC for the force was 5.09 ± 1.01 mM (n = 6) [4.98–5.19 mM, 95% confidence interval (CI)], significantly lower than the IC₅₀ for the frequency, 6.15 ± 1.01 mM, (6.02–6.29 mM, 95% CI), indicating that working atria cells are more sensitive to NAC than autorhythmic cells. The no-observed-effect concentration (NOEC) was 1–2 mM; (3) the pattern of NAC-induced inhibition of electromechanical activity was similar to that of verapamil, an indication that NAC possibly affects L-type voltage-gated calcium channels; (4) NAC at 2 mM protected against cadmium-induced inhibition of atria contraction. The IC₅₀ for cadmium was 17.9 ± 1.1 μM (n = 6) (16.9–19.0 μM, 95% CI), while in the presence of 2 mM NAC, it became 123.3 ± 1.0 μΜ (n = 6) (114.8–132.4 μM, 95% CI). The same concentration of NAC failed to exert any protective effects against rotenone (5 μM)-induced inhibition of atria contraction. The protective effects of NAC are probably due to chelation of cadmium, rather than scavenging of oxidants.     

1-(2-(2-(2-(1-Aminoethyl)phenyl)diselanyl)phenyl)ethanamine: An amino organoselenium compound with interesting antioxidant profile

Free radical scavenging and antioxidant activities of 1-(2-(2-(2-(1-aminoethyl)phenyl)diselanyl)phenyl)ethanamine (compound A) and diphenyl diselenide (PhSe)2 were examined and compared for inhibition of Fe(II) and sodium nitroprusside (SNP) stimulated lipid peroxidation in rat brain, interaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH) stable free radical and their glutathione peroxidase (GPx) like antioxidant activities with H₂O₂ or tBuOOH as substrates and with PhSH as thiol co-substrates as well as their ability to oxidize mono- and di-thiols were also evaluated. This study revealed that an amino group in amino diselenide drastically enhances their catalytic activities in the aromatic thiol (PhSH) assay system. Compound A was ∼2-fold more active than (PhSe)2 in both tBuOOH and H₂O₂ assay systems. In addition, the present results showed that (PhSe)2 exhibited an increased ability to oxidize di-thiols, compound A was not a good substrate for the oxidation of thiol used namely DTT, cystine and DMPS. The antioxidant potency against Fe(II) and SNP-induced brain TBARS were in this order [(compound A); IC₅₀ 2 μM and 4 μM] > [(PhSe)2; IC₅₀ 19 μM and 27.5 μM. Compound A showed DPPH radical-scavenging activity. This study provides in vitro evidence anti-oxidant action of the tested organoselenium compounds, that the nitrogen atom in the organochalcogens can have a profound effect on their antioxidant activity.     

Development of novel N-linked aminopiperidine-based mycobacterial DNA gyrase B inhibitors: Scaffold hopping from known antibacterial leads

DNA gyrase of Mycobacterium tuberculosis (MTB) is a type II topoisomerase that ensures the regulation of DNA topology and has been genetically demonstrated to be a bactericidal drug target. We present the discovery and optimisation of a novel series of mycobacterial DNA gyrase inhibitors with a high degree of specificity towards the mycobacterial ATPase domain. Compound 5-fluoro-1-(2-(4-(4-(trifluoromethyl)benzylamino)piperidin-1-yl)ethyl)indoline-2,3-dione (17) emerged as the most potent lead, exhibiting inhibition of MTB DNA gyrase supercoiling assay with an IC₅₀ (50% inhibitory concentration) of 3.6 ± 0.16 μM, a Mycobacterium smegmatis GyrB IC₅₀ of 10.6 ± 0.6 μM, and MTB minimum inhibitory concentrations of 6.95 μM and 10 μM against drug-sensitive (MTB H37Rv) and extensively drug-resistant strains, respectively. Furthermore, the compounds did not show any signs of cardiotoxicity in zebrafish ether-à-go-go-related gene (zERG), and hence constitute a major breakthrough among the otherwise cardiotoxic N-linked aminopiperidine analogues.     

Zinc enhances CDKN2A,pRb1 expression and regulates functional apoptosis via upregulation of p53 and p21 expression in human breast cancer MCF-7 cell

Zinc (Zn) is an essential trace elements, its deficiency is associated with increased incidence of human breast cancer. We aimed to study the effect of Zn on human breast cancer MCF-7 cells cultured in Zn depleted and Zn adequate medium. We found increased cancer cell growth in zinc depleted condition, further Zn supplementation inhibits the viability of breast cancer MCF-7 cell cultured in Zn deficient condition and the IC_25, IC₅₀ value for Zn is 6.2 μM, 15 μM, respectively after 48 h. Zn markedly induced apoptosis through the characteristic apoptotic morphological changes and DNA fragmentation after 48 h. In addition, Zn deficient cells significantly triggered intracellular ROS level and develop oxidative stress induced DNA damage; it was confirmed by elevated expression of CYP1A, GPX, GSK3β and TNF-α gene. Zinc depleted MCF-7 cells expressed significantly (p ≤ 0.001) decreased levels of CDKN2A, pRb1, p53 and increased the level of mdm2 expression. Zn supplementation (IC₅₀ = 15 μM), increased significantly CDKN2A, pRB1 & p53 and markedly reduced mdm2 expression; also protein expression levels of CDKN2A and pRb1 was significantly increased. In addition, intrinsic apoptotic pathway related genes such as Bax, caspase-3, 8, 9 & p21 expression was enhanced and finally induced cell apoptosis. In conclusion, physiological level of zinc is important to prevent DNA damage and MCF-7 cell proliferation via regulation of tumor suppressor gene.     

Comparative in vitro and ex-vivo myelotoxicity of aflatoxins B1 and M1 on haematopoietic progenitors (BFU-E,CFU-E,and CFU-GM): Species-related susceptibility

Haemato- and myelotoxicity are adverse effects caused by mycotoxins. Due to the relevance of aflatoxins to human health, the present study, employing CFU-GM-, BFU-E- and CFU-E-clonogenic assays, aimed at (i) comparing, in vitro, the sensitivity of human vs. murine haematopoietic progenitors to AFB1 and AFM1 (0.001–50 μg/ml), (ii) assessing whether a single AFB1 in vivo treatment (0.3–3 mg/kg b.w.) alters the ability of murine bone marrow cells to form myeloid and erythroid colonies, and (iii) comparing the in vitro with the in vitro ex-vivo data.We demonstrated (i) species-related sensitivity to AFB1, showing higher susceptibility of human myeloid and erythroid progenitors (IC₅₀ values: about 4 times lower in human than in murine cells), (ii) higher sensitivity of CFU-GM and BFU-E colonies, both more markedly affected, particularly by AFB1 (IC₅₀: 2.45 ± 1.08 and 1.82 ± 0.8 μM for humans, and 11.08 ± 2.92 and 1.81 ± 0.20 μM for mice, respectively), than the mature CFU-E (AFB1 IC₅₀: 12.58 ± 5.4 and 40.27 ± 6.05 μM), irrespectively of animal species, (iii) regarding AFM1, a species- and lineage-related susceptibility similar to that observed for AFB1 and (iv) lack of effects after AFB1 in vivo treatment on the proliferation of haematopoietic colonies.     

Chemical composition and anticancer,antiinflammatory, antioxidant and antimalarial activities of leaves essential oil of Cedrelopsis grevei

The essential oil from Cedrelopsis grevei leaves, an aromatic and medicinal plant from Madagascar, is widely used in folk medicine. Essential oil was characterized by GC–MS and quantified by GC–FID. Sixty-four components were identified. The major constituents were: (E)-β-farnesene (27.61%), δ-cadinene (14.48%), α-copaene (7.65%) and β-elemene (6.96%). The essential oil contained a complex mixture consisting mainly sesquiterpene hydrocarbons (83.42%) and generally sesquiterpenes (98.91%). The essential oil was tested cytotoxic (on human breast cancer cells MCF-7), antimalarial (Plasmodium falciparum), antiinflammatory and antioxidant (ABTS and DPPH assays) activities. C. grevei essential oil was active against MCF-7 cell lines (IC₅₀ = 21.5 mg/L), against P. falciparum, (IC₅₀ = 17.5 mg/L) and antiinflammatory (IC₅₀ = 21.33 mg/L). The essential oil exhibited poor antioxidant activity against DPPH (IC₅₀ > 1000 mg/L) and ABTS (IC₅₀ = 110 mg/L) assays. A bibliographical review was carried out of all essential oils identified and tested with respect to antiplasmodial, anticancer and antiinflammatory activities. The aim was to establish correlations between the identified compounds and their biological activities (antiplasmodial, anticancer and antiinflammatory). According to the obtained correlations, 1,4-cadinadiene (R² = 0.61) presented a higher relationship with antimalarial activity. However, only (Z)-β-farnesene (R² = 0.73) showed a significant correlation for anticancer activity.     

Cytotoxic activity of sanguinarine and dihydrosanguinarine in human promyelocytic leukemia HL-60 cells

The benzo[c]phenanthridine alkaloid sanguinarine has been studied for its antiproliferative activity in many cell types. Almost nothing however, is known about the cytotoxic effects of dihydrosanguinarine, a metabolite of sanguinarine. We compared the cytotoxicity of sanguinarine and dihydrosanguinarine in human leukemia HL-60 cells. Sanguinarine produced a dose-dependent decline in cell viability with IC₅₀ (inhibitor concentration required for 50% inhibition of cell viability) of 0.9 μM as determined by MTT assay after 4 h exposure. Dihydrosanguinarine showed much less cytotoxicity than sanguinarine: at the highest concentration tested (20 μM) and 24 h exposure, dihydrosanguinarine decreased viability only to 52%. Cytotoxic effects of both alkaloids were accompanied by activation of the intrinsic apoptotic pathway since we observed the dissipation of mitochondrial membrane potential, induction of caspase-9 and -3 activities, the appearance of sub-G₁ DNA and loss of plasma membrane asymmetry. This aside, sanguinarine also increased the activity of caspase-8. As shown by flow cytometry using annexin V/propidium iodide staining, 0.5 μM sanguinarine induced apoptosis while 1–4 μM sanguinarine caused necrotic cell death. In contrast, dihydrosanguinarine at concentrations from 5 μM induced primarily necrosis, whereas apoptosis occurred at 10 μM and above. We conclude that both alkaloids may cause, depending on the alkaloid concentration, both necrosis and apoptosis of HL-60 cells.     

Effect of [Cu(4,7-dimethyl-1,10-phenanthroline)(acetylacetonato)]NO3, Casiopeína III-Ea,on the activity of cytochrome P450

Casiopeína III-Ea (Cas III-Ea¹) is a copper complex with antiproliferative and antitumor activities, designed to act via alternative mechanisms of action different from Cisplatin. This compound has also been well characterized in preclinical test and pharmacokinetic analysis, being a good candidate for clinical phases. Since very little is known about the processes of biotransformation of therapeutic metal based drugs, this paper report the first approach to the study of the interaction between metal complex Cas III-Ea and cytochromes P450 with the aim to find out possible biotransformation pathways for this complexes and feasible drug–drug interactions. Results showed that Cas III-Ea is a strong irreversible competitive inhibitor of CYP1A1 (IC₅₀ = 7.5 ± 1.0 μM; Ki = 240 nM). The magnitude of values indicate that it is necessary to be taken into account such effect when analyzing possible drug interactions with these new drugs in order to prevent adverse reactions derived from this inhibition.     

Phthalate and di-(2-ethylhexyl) adipate (DEHA) intake by German infants based on the results of a duplicate diet study and biomonitoring data (INES 2)

Phthalates as well as di-(2-ethylhexyl) adipate (DEHA) are used as plasticizers in diverse applications and are of toxicological concern.The study was conducted with a study population of 25 German subjects aged between 15 and 21 months. Overall, 16 phthalates and DEHA were measured by gas chromatography–mass spectrometry in a total of 171 duplicate diet samples collected over 7 consecutive days, and 20 phthalate metabolites were analyzed in the urine samples collected over 7 consecutive days using a liquid chromatography–tandem mass spectrometry method.The median “high” daily dietary intake based on 95th percentiles was 4.66 μg/kg b.w. for di-2-ethylhexyl phthalate (DEHP), 1.03 μg/kg b.w. for di-isobutyl phthalate (DiBP), and 0.70 μg/kg b.w. for di-n-butyl phthalate (DnBP), and 1.0 μg/kg b.w. for DEHA. The “high” daily total intake from biomonitoring data was 4.9 μg/kg b.w. for DEHP, 2.2 μg/kg b.w. for DnBP, 3.9 μg/kg b.w. for DiBP, and 2.6 μg/kg b.w. for di-isononyl phthalate.The comparison of the two intake estimates indicates that the dominant intake source of DEHP was food ingestion, whereas other sources considerably contributed to the total intake of other phthalates. Using our “high” intake scenario, none of the analyzed phthalates reached the recommended tolerable daily intake levels.