Butylate hydroxytoluene pretreatment protects against cytotoxicity and reduces covalent binding of aflatoxin B1 in primary hepatocyte cultures

Primary cultures of adult rat hepatocytes were used to characterize the effect of butylated hydroxytoluene (BHT) pretreatment on the metabolic disposition and cytotoxicity of a single dose of aflatoxin B₁ (AFB₁). Four male Sprague-Dawley rats were fed a control diet, and five were fed a diet containing 0.5% BHT. After 10 days, hepatocytes were prepared and cultured in chemically defined, hormone-supplemented medium. After 20–22 hr in culture, 120–150 ng of [¹⁴C]aflatoxin B₁ was added to dishes containing 2.5 × 10⁶ cells. By 10 hr, control cells had converted 59% of the AFB₁ to aqueous metabolites, while 15.5% was bound covalently. During the same interval, cells from BHT-fed rats produced 69% aqueous metabolites, and only 6.6% was bound covalently. The rate of AFB₁ disappearance in the two groups was not statistically different. AFB₁ produced marked cytotoxicity in hepatocyte cultures from control rats but had no apparent toxic effect on hepatocyte cultures from BHT-pretreated rats, as indicated by light microscopic examination and release of lactate dehydrogenase into the medium. These results suggest that reduction of cytotoxicity by BHT was associated with increased output of nontoxic, water-soluble metabolites and decreased binding of metabolites to macromolecules. These results also indicate that BHT may protect against the acute toxicity and carcinogenicity of aflatoxin B₁in vivo.     

Synergistic and antagonistic interactions of methotrexate and 1-β-D-arabinofuranosylcytosine in hepatoma cells: The modulating effect of purines

A 4-hr pretreatment with methotrexate antagonized the cytotoxic effect of subsequent arabinosylcytosine treatment in rat hepatoma cells of lines N₁S₁ and 3924A, but in the hepatoma line 8999R and the fibroblast line BF5, MTX pretreatment was synergistic with the arabinosylcytosine treatment. Measurement of cellular deoxyribonucleoside triphosphate concentrations showed that in those lines in which antagonism was found the dCTP increased, whereas in the lines where the drugs were synergistic the dCTP pool was decreased. Conversely, dATP levels were high when the drugs were synergistic and low when antagonism was obtained. Although methotrexate pretreatment antagonized arabinosylcytosine in N₁S₁ and 3924A cells, pretreatment of these cells with the combination of methotrexate plus a purine (either hypoxanthine or 2′-deoxyadenosine) resulted in synergism with arabinosylcytosine. Deoxynucleotide pool measurements showed that methotrexate in combination with either hypoxanthine or 2′-deoxyadenosine increased dATP and decreased dCTP in the N₁S₁ and 3924A hepatoma cells. In N₁S₁ cells, pretreatment with 2′-deoxyadenosine alone for 4 hr was synergistic with arabinosylcytosine. It was concluded that elevated dATP pools enhanced arabinosylcytosine cytotoxicity by depleting the dCTP pool, through feedback inhibition of ribonucleotide reductase, thus causing greater inhibition of DNA biosynthesis and greater incorporation of AraCTP into nucleic acid. Methotrexate was synergistic in those cell lines where dATP accumulated and dCTP was decreased, but when methotrexate had a potent antipurine effect dCTP pools increased and arabinosylcytosine was antagonized. The synergistic interaction was more marked at cytocidal drug concentrations than it was at growth-inhibitory doses.     

Lectin-mediated cytotoxicity and specificity of 5-fluorouracil conjugated with peanut agglutinin (5-Fu-PNA) in vitro

In order to take advantage of the biorecognition between lectin and carbohydrate for targeted drug delivery, the lectin of peanut (Arachis hypogaea) agglutinin (PNA) was coupled by fixing its amino groups to the carbodiimide-activated carboxylic groups of 5-fluorouracil (5-Fu) derivative (N₁-substituted 5-Fu acetate) to form 5-Fu-PNA conjugate. When the coupling reaction was carried out in the presence of _d-galactose (_d-gal, specific sugar for PNA), the affinity of PNA was maintained after its coupling to N₁-substituted 5-Fu acetate, which was confirmed by the result of the haemagglutination test. Otherwise, PNA would lose its affinity after the cross-linking reaction. The cytotoxicity, specificity and selectivity of 5-Fu-PNA were examined on the human colorectal cancer cell line LoVo and the human normal liver cell line Chang using MTT assay. Compared with free drug, the active conjugate, which maintained the affinity of lectin, had similar cytotoxic effect on LoVo cells with much lower cytotoxicity on Chang cells (p < 0.05). On the other hand, lower cytotoxic effects on LoVo cells were observed for the non-active conjugate even at higher drug concentrations. The cytotoxic effect of conjugate was specific because only the active conjugate could inhibit the growth of LoVo cells in a dose- and time-dependent manner as that of the free drug. The achieved results indicate the significance to maintain the affinity of lectin for lectin-mediated cytotoxicity. Still, the potential of 5-Fu-PNA conjugate as a targeting agent for colorectal cancer needs to be further investigated in vivo.     

Effect of polyphenols on enniatins-induced cytotoxic effects in mammalian cells

Enniatins (ENs) are fungal secondary metabolites produced by genus Fusarium. The ENs exert antimicrobial and insecticidal effect, and has also been demonstrated cytotoxic effects on several mammalian cell lines. On the other hands, it has been proved that natural polyphenols have antioxidant effect. In this study, cell effects at low levels of exposure of four ENs (A, A₁, B and B₁) and five polyphenols (quercetin, quercetin-3-β-D-glucoside, rutin, myricetin and t-pterostilbene) present in wine; and the cytoprotective effect of these polyphenols exposed simultaneously with ENs in Chinese Hamster Ovary (CHO-K1) cells, were studied. Cell effects were determined by the MTT test after 24?h of exposure. All ENs showed cytotoxic effect. The IC₅₀ obtained ranged from 4.5?±?1.2 to 11.0?±?2.7 µM. The concentration of polyphenols tested ranged from 5 to 50 µM. Polyphenols did not show cytotoxicity and the cytoprotective effect of polyphenols varies depending on the EN tested. The cytoprotective effect of polyphenols in CHO-K1 cells exposed to ENs was as follow: quercetin, from 24 to 84%; quercetin-3-β-D-glucoside, from 12 to 76%; rutin, from 17 to 83%; myricetin, from 16 to 92% and pterostilbene from 25 to 100%. All polyphenols protected CHO-K1 cells against EN A₁ exposure.     

Antiproliferative and cytotoxic effects of sesquiterpene lactones isolated from Ambrosia artemisiifolia on human adenocarcinoma and normal cell lines

ContextAmbrosia artemisiifolia L. (Asteraceae) contains sesquiterpene lactones as characteristic secondary metabolites. Many of these compounds exert antiproliferative and cytotoxic effects.ObjectiveTo isolate the sesquiterpene lactones from the aerial part of A. artemisiifolia and to elucidate their cytotoxic, antiproliferative and antibacterial effects.Materials and methodsThe compounds were identified by one-dimensional (1D) and 2D NMR, HR-MS spectroscopy from the methanol extract. Isolated compounds were investigated for their cytotoxic and antiproliferative effects on human colonic adenocarcinoma cell lines and human embryonal lung fibroblast cell line using MTT assay. The selectivity of the sesquiterpenes was calculated towards the normal cell line. To check the effect of drug interactions between compounds and doxorubicin, multidrug-resistant Colo 320 cells were used.ResultsA new seco-psilostachyinolide derivative, 1,10-dihydro-1′-noraltamisin, and seven known compounds were isolated from the methanol extract. Acetoxydihydrodamsin had the most potent cytotoxic effect on sensitive (Colo205) cell line (IC₅₀ = 7.64 µM), also the strongest antiproliferative effect on Colo205 (IC₅₀ = 5.14 µM) and Colo320 (IC₅₀ = 3.67 µM) cell lines. 1′-Noraltamisin (IC₅₀ = 8.78 µM) and psilostachyin (IC₅₀ = 5.29 µM) showed significant antiproliferative effects on the multidrug-resistant Colo320 cell line and had moderate selectivity against human embryonal lung fibroblast cell line. Psilostachyin C exhibited cytotoxic effects on Colo205 cells (IC₅₀ = 26.60 µM). None of the isolated compounds inhibited ABCB1 efflux pump (EP; P-glycoprotein) or the bacterial EPs.Discussion and conclusionsAcetoxydihydrodamsin, 1′-noraltamisin, and psilostachyin showed the most remarkable cytotoxic and antiproliferative activity on tumour cell lines and exerted selectivity towards MRC-5 cell line.     

Toxicity profiles of four metals and 17 xenobiotics in the human hepatoma cell line HepG2 and the protozoa Tetrahymena pyriformis—A comparison

We performed an interspecies comparison for the human hepatoma cell line HepG2 and the eukaryotic single cell organism Tetrahymena pyriformis (T. pyriformis) for 17 xenobiotics with diverse structures and four metals. The cytotoxicity was assessed by four different cell viability assays (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyl tetrazolium bromide reduction (MTT), neutral red uptake (NRU), resazurin dye (AlamarBlue), 5‐carboxyfluorescein diacetate acetoxymethyl ester (CFDA‐AM)) for the HepG2 and by cell count and MTT for T. pyriformis. For HepG2 cells, the results revealed interassay variations depending on the compound. The highest assay conformity was found for the metal Hg²⁺ and the fungicide prochloraz. The AlamarBlue assay was the most sensitive assay according to low‐effect concentrations. By contrast, the NRU assay was comprised of more frequent whole concentration response relationships and was more susceptible to EC₅₀. For T. pyriformis the EC₅₀ values of the two applied assays displayed a high conformity (R² = 0.97). Comparing the EC₅₀ values obtained by the MTT assay for the two cell models, a direct correlation was absent for the xenobiotics and only present for the metals (Cd²⁺, Cu²⁺, and Ni²⁺). Moreover, the protozoa T. pyriformis displayed a 20 times higher sensitivity than the cell line. The highest interspecies difference of three log degrees was obtained for the polycyclic aromatic hydrocarbon fluoranthene. In addition, a correlation of the EC₅₀ values and octanol‐water partition coefficient (log K_OW) of the xenobiotics was performed. No correlation was found for HepG2, and a weak one for T. pyriformis. Interestingly, the interspecies difference of logarithmized EC₅₀ correlated positive with the log K_OW (R² = 0.65). In conclusion, to obtain reliable evidence for human cytotoxicity, more than one viability/cytotoxicity assay had to be applied for cell lines. Second, the human hepatoma cell line was less affected by the organic compounds than the eukaryotic single‐cell organism and was also less dependent on the log K_OW of the xenobiotic. © 2009 Wiley Periodicals, Inc. Environ Toxicol 26: 171–186, 2011.     

抗癌抗生素C1027与单克隆抗体Fab片段偶联物的抗肝癌作用

抗人肝癌单克隆抗体(单抗)3A₅用木瓜蛋白酶消化得到Fab片段。单抗3A₅和Fab片段分别与抗癌抗生素C1027偶联,偶联物经克隆生成法测定对肝癌细胞有很强的杀伤作用,C1027,Fab-C1027和3;3A₅-C1027的IC₅₀分别为6.5×10^-16,8.6×10^-16和4.2×10^-14mol·L^-1;Fab-C1027偶联物对非靶细胞(KB)的IC₅₀值为1.4×10^-13mol·L^-1,与靶细胞(BEL-7402)的IC₅₀值相比,两者相差160倍。说明Fab-C1027的杀伤活性强于3A₅-C1027,并对靶细胞呈选择性杀伤作用。给皮下移植人肝癌的裸鼠iv剂量0.1 mg·kg^-1,结果C1027和Fab-C1027的抑瘤率分别为59和85%,说明Fab片段与C1027偶联物比游离C1027的疗效更高。     

A new triterpenoid from <Emphasis Type="Italic">Panax ginseng</Emphasis> exhibits cytotoxicity through p53 and the caspase signaling pathway in the HepG2 cell line

A new triterpenoid, 20(R),22(ξ),24(S)-dammar-25(26)-ene-3β,6α,12β,20,22,24-hexanol (1), and three known triterpenoids, β-D-glucopyranoside,(3β,12β)-12,20-dihydroxydammar-24-en-3-yl,6-acetate (2), 20(R)-ginsenoside Rg₃ (3), and 20(R)-ginsenoside Rh₂ (4), were isolated from the leaves of Panax ginseng. Their structures were determined by chemical analysis and spectral methods (IR, 1D and 2D NMR, HR-ESI-MS). Compounds 1–4 were exhibited various degrees of cytotoxicity in the human hepatoma cell line, HepG2. Compound 1 had the highest cytotoxic potency, with an IC₅₀ value of 20.1 μM, by stimulating p53-mediated cell cycle arrest at the G1 to S phase transition, leading to apoptosis via activation of the caspase signaling pathway.     

Comparative Evaluation of Cytotoxicity and Metabolism of Four Aldehydes in Two Hepatoma Cell Lines

ABSTRACT

The metabolism of acetaldehyde (ACA), benzaldehyde (BA), propionaldehyde (PA) and valeraldehyde (VA) has been studied in two hepatoma cell lines, the rat HTC and mouse Hepa 1c1c7 cells. The cytotoxicity of the four aldehydes to these two cell lines has been compared. The end-points for evaluating cytotoxicity were 1) total macromolecular content (TMC) of confluent cultures, and 2) colony forming ability of dividing cells. These two assay systems had different sensitivities for the toxicity of aldehydes, probably due to different numbers of target cells.

The activities of aldehyde dehydrogenases (NAD- and NADP-dependent, ALDH), alcohol dehydrogenase and aldehyde reductase were markedly greater in the HTC cell line compared to the Hepa 1c1c7 cell line, especially with BA as substrate.

The cytotoxicities of aldehydes were generally stronger in the HTC cell line than in the Hepa 1c1c7 cell line, with the CF test. Particularly, BA was highly toxic to the HTC cells, which possessed the highest ALDH levels. Moreover, the treatment with (diethylamino)benzaldehyde, an ALDH inhibitor, completely abolished the toxicity of BA.

Taken together, all these findings suggest that several cell lines expressing different aldehyde metabolizing activities could be used especially in the prescreening phase to distinguish the metabolism-dependent cytotoxic effects from the metabolism independent effects.     

Evaluation of the cytotoxicity of cigarette smoke total particulate matter using three in vitro assays and two types of cells

Abstract

In vitro cytotoxicity assays can be used to evaluate potential toxicological effects of tobacco products. Total particulate matter (TPM) from mainstream cigarette smoke trapped by a Cambridge filter is used widely for biological evaluation of smoke. This study compared neutral red uptake (NRU), lactate dehydrogenase (LDH) activity and WST-1 assays for assessing the cytotoxicity of TPM, and evaluated the sensitivity of Chinese hamster ovary (CHO) cells and human lung adenocarcinoma epithelial cell line (A549 cells) to TPM-induced cytotoxic effects. The results indicate that NRU and WST-1 assays are preferable to LDH activity assay for assessing the TPM-induced cytotoxicity, and NRU assay might be more sensitive than WST-1 assay. The cytotoxicity of 3R4F reference cigarettes and two commercial brands of cigarettes were tested by NRU assay in CHO and A549 cells. The results showed that EC₅₀ values in CHO cells treated with TPM were lower than EC₅₀ values in A549 cells, indicating CHO cells are more sensitive to TPM-induced cytotoxic effects than A549 cells.     

Influence of vitamin D3 metabolites on cell proliferation and cytotoxicity of adriamycin in human normal and neoplastic cells

The common features of biological activity displayed by vitamin D family members and adriamycin suggest the possibility of synergistic effects of the combination of these compounds. Until now, the mechanisms responsible mainly for adriamycin cytotoxic action have not been indicated. Therefore, observation of the possible common cell targets for adriamycin and vitamin D metabolites could shed more light on the mechanisms of cytotoxic activity of adriamycin. In the present study, the influence of calcidiol (25-hydroxyvitamin D₃) and calcitriol (1α,25-dihydroxyvitamin D₃) on the proliferation and cytotoxicity of adriamycin was studied. The following cell lines were tested: normal human fibroblasts—CRL 1502, human melanoma cells—ME18 and its subline—ME18/R, resistant to adriamycin. As was shown, 72 h of incubation with calcidiol or calcitriol, both at 10 μ , inhibited growth (to approx. 60%) only of the ME18 cells. Dose and time dependence of this effect has been confirmed. Antiproliferative events did not correlate with an increase of adriamycin cytotoxicity. It was noted that calcidiol and calcitriol had no significant influence on the adriamycin IC₅₀ values in any cell lines tested. These results point to the divergent mechanisms of action of adriamycin and vitamin D₃ metabolites.     

Comparative cytotoxicity induced by bulk and nanoparticulated ZnO in the fish and human hepatoma cell lines PLHC-1 and Hep G2

Abstract

The increasing presence of ZnO nanoparticles (NPs) in consumer products may be having a dramatic impact in aquatic environments. The evaluation of ZnO NP toxicity represents a great challenge. This study aimed at evaluating the cytotoxic effect of micro- and nanosized ZnO in a fish and a mammalian hepatoma cell line. A detailed characterisation of the particles in exposure media showed that ZnO NPs formed large aggregates. ZnO cytotoxicity was evaluated with a battery of in vitro assays including LUCS, a new approach based on DNA alteration measurements. In fish cells, ZnO NP aggregates contributed substantially to the cytotoxic effects whereas toxicity in the human cells appeared to be mainly produced by the dissolved fraction. ROS production did not contribute to the observed cytotoxicity. This work also showed that measuring concentrations of NPs is essential to understand the mechanisms underlying their toxicity.     

Glucocorticoids regulate the expression of angiotensin AT1 receptors,in the human hepatoma cell line,PLC-PRF-5

The effects of different steroids on the expression of angiotensin AT₁ receptors by the human hepatoma cell line, PLC-PRF-5 was studied. Dexamethasone and aldosterone decreased the specific binding of [³H]angiotensin II to intact PLC-PRF-5 cells by 57 ± 4% and 54 ± 2%, respectively, compared to control, untreated cells. EC₅₀ values for dexamethasone, cortisol and aldosterone were 1.8 ± 0.6, 40 ± 6, and 310 ± 20 nM, respectively, suggesting that these effects were mediated via a glucocorticoid receptor. Scatchard analysis revealed that dexamethasone decreased the number of angiotensin AT₁ receptors expressed (50 ± 4% relative to control) with no change in receptor affinity. Treating cells with dexamethosane in the presence of either an angiotensin converting enzyme inhibitor or an angiotensin II receptor antagonist did not prevent the reduction in angiotensin AT₁ receptor expression, ruling out a mechanism involving a dexamethasone induced increase in endogenous angiotensin II production. A ribonuclease protection assay established that the steady state level of angiotensin AT₁ receptor mRNA in dexamethasone treated cells was reduced to 34.7 ± 8.4% of untreated cells. The decrease in the number of angiotensin AT₁ receptors expressed on the cell surface after treatment with dexamethasone therefore seems likely to reflect the decreased steady state level of the mRNA coding for this receptor.     

The comparative metabolism and toxic potency of aflatoxin B1 and aflatoxin M1 in primary cultures of adult-rat hepatocytes

Both aflatoxin B₁ (AFB₁) and a hydroxylated metabolite, aflatoxin M₁ (AFM₁), were potent cytotoxins and genotoxins to primary cultures of rat hepatocytes. However, AFB₁ stimulated the release of lactate dehydrogenase into the culture medium and the loss of viable cells from the monolayer at lower doses than did AFM₁. The lowest toxic doses of AFB₁ and AFM₁ were 0·05–0·1 and 0·6 μg/ culture, respectively. Genotoxicity, determined by an assay for stimulation of DNA repair, was apparent at lower doses than was cytotoxicity. AFB₁ was again more potent than AFM₁, stimulating DNA repair at 0·025 μg/culture. compared to the lowest genotoxic dose of AFM₁ of 0·05 μg/culture. At higher doses (1·2–2·4 μg/culture) the responses due to both aflatoxins in the cytotoxicity and DNA-repair assays were approximately equal. The metabolism of a low dose (c. 0·17 μg/culture) of [¹⁴C]AFB₁ and [³H]AFM₁ by cultured hepatocytes differed significantly. After 1 hr, 50% of the [¹⁴C]AFB₁ remained unchanged in the culture medium, whereas about 18 hr were required for the same amount of [³H]AFM₁ metabolism to occur. [¹⁴C]AFB₁ was metabolized to AFM₁, to polar metabolites recovered in the aqueous phase after chloroform extraction, and to metabolites covalently bound to hepatocyte macromolecules. [³H]AFM₁ was also metabolized to polar metabolites and to forms bound to macromolecules. The degree of covalent binding of the aflatoxins correlated with their cytotoxicity and genotoxicity at lower doses. After a 24-hr incubation, 12·5% of the dose of [¹⁴C]AFB₁ was covalently bound to macromolecules compared to 1·5% of [³H]AFM₁. Although AFM₁ was less potent than AFB₁ in cytotoxicity, DNA-repair and covalent-binding assays using primary cultures of hepatocytes, AFM₁ was still active at relatively low doses and therefore is probably a potent hepatotoxin in vivo.     

Physicochemical,Pharmacokinetic and Cytotoxicity of the Compounds Isolated from an Endophyte Fusarium oxysporum: In Vitro and In Silico Approaches

The present study was intended to characterize the secondary metabolites of the endophyte Fusarium oxysporum isolated from the plant Aglaonema hookerianum Schott. And to investigate the cytotoxic and other pharmacological properties of the isolated compounds as part of the drug discovery and development process. Different chromatographic techniques were adopted to isolate the bioactive compounds that were identified by spectroscopic techniques. The cytotoxic properties of the compounds were assessed in the Vero cell line via the trypan blue method. Moreover, physicochemical, pharmacokinetic, bioactivity and toxicity profiles of the compounds were also investigated through in silico approaches. After careful spectral analysis, the isolated compounds were identified as 3β,5α-dihydroxy-ergosta-7,22-dien-6-one (1), 3β,5α,9α-trihydroxy-ergosta-7,22-dien-6-one (2), p-hydroxybenzaldehyde (3), 3-(R)-7-butyl-6,8-dihydroxy-3-pent-11-enylisochroman-1-one (4) and beauvericin (5). An in vitro study in the Vero cell line revealed that the presence of the compounds reduced the number of cells, as well as the percentage of viable cells, in most cases. An in silico cytotoxic analysis revealed that compounds 1, 2 and 5 might be explored as cytotoxic agents. Moreover, compounds 3 and 4 were found to be highly mutagenic. The present study suggested that further thorough investigations are necessary to use these molecules as leads for the cytotoxic drug development process.     

The effects of the anti-tumor agent mezerein on the cytotoxic capacity and oxidative metabolism of human blood cells

Summary Mezerein, the most active antitumor compound isolated from the daphne species of plants, has a structural similarity to phorbol myristate acetate (PMA), the major active compound isolated from croton oil. PMA is known to have tumor promoting activity and is a potent inflammatory agent. Mezerein has similarly been reported to have potent inflammatory properties but appears to be a weaker tumor promoter than PMA. While the effect of PMA on the function and metabolism of human blood cells has been extensively studied, there is little similar information concerning mezerein. Therefore, in these studies, we have compared the capacities of mezerein and PMA to activate the cytotoxic capacity and oxidative metabolism of human granulocyte (PMNs), monocyte, lymphocyte, and mononuclear cell (lymphocytes and monocytes) cultures in vitro. Mezerein stimulated the oxidative metabolism of PMNs in an identical manner to PMA as indicated by a burst in the activity of the HMPS pathway, the production of H₂O₂, hydroxyl radical and stable oxidants. Mezerein also stimulated the release of thromboxane B₂ from PMNs. Both compounds activated the oxidative metabolism of monocytes but not the oxidative metabolism of lymphocytes. The enhanced oxidative metabolism of the phagocytic cells was associated with an increased cytotoxicity against human red cells which are sensitive to oxidant damage but not against the NK resistant Raji lymphoblast cell line or the SW1116 colon tumor cell line.Of interest is that mezerein did not augment significantly the minimal cytotoxic capacity (NK activity) of mononuclear cells, monocytes or freshly isolated lymphocyte cultures against the tumor cell targets used in our experiments. However, lymphocyte cultures preincubated for 15 hours with mezerein had a marked enhancement of cytotoxicity against the tumor targets. This activation was not observed in similarly treated mononuclear cell cultures suggesting a suppressor activity of the monocytes.Our data suggest that the potent inflammatory activity of mezerein similar to PMA, may be related to its capacity to activate the oxidative and arachidonic metabolism of phagocytic cells. In addition, the capacity of mezerein to activate the cytotoxic capacity of lymphocytes may relate to its reported in vivo antitumor activity.Dr. Barton is currently a resident in Medicine at the Unviersity of Chicago.     

Schiff base-nickel,palladium, and platinum complexes derived from N-cyclohexyl hydrazine carbothioamide and 3-hydroxy-4-methoxybenzaldehyde: Selective antiproliferative and proapoptotic effects against colorectal carcinoma

The bidentate N-cyclohexyl-2-(3-hydroxy-4-methoxybenzylidene)hydrazine-1-carbothioamide Schiff base ligand (HL) was coordinated to divalent nickel, palladium and platinum ions to form square planar complexes. The nickel and palladium complexes, [NiL₂], [PdL₂] form square planar complexes with 2:1 ligand to metal ratio. The platinum complex, [PtL(dmso)Cl] formed a square planar complex with 1:1 ligand to metal ratio. Platinum undergoes in situ reaction with DMSO before complexing with the ligand in solution. The cytotoxicity of HL, [NiL₂], [PdL₂], and [PtL(dmso)Cl] were evaluated against human colon cancer cell line (HCT-116), human cervical cancer (Hela) cell line, melanoma (B16F10) cells, and human normal endothelial cell lines (Eahy926) by MTT assay. The [NiL₂] complex displayed selective cytotoxic effect against the HCT 116 cancer cell line with IC₅₀ of 7.9 ± 0.2 μM. However, HL, [PdL₂], and [PtL(dmso)Cl] only exhibited moderate cytotoxic activity with IC₅₀ = 75.9 ± 2.4, 100.0 ± 1.8, and 101.0 ± 3.6 μM, respectively. The potent cytotoxicity of [NiL₂] was characterized using Hoechst and Rhodamine assays. The nickel complex, [NiL₂], caused remarkable nuclear condensation and reduction in mitochondrial membrane potential. In addition, molecular docking studies confirms that [NiL₂] possesses significant binding efficiency with Tyrosine kinase. Altogether, the results revealed that [NiL₂] exhibits cytotoxicity against the cancer cells via Tyrosine kinase-induced proapoptosis pathway. This study demonstrates that the [NiL₂] complex could be a promising therapeutic agent against colorectal carcinoma.     

基于代谢组学和网络药理学分析福建金线莲叶和台湾银线兰叶治疗肝纤维化作用差异

目的 初步分析福建金线莲(Anoectochilus roxburghii)和台湾银线兰(Anoectochilus formosanus)的叶片在治疗肝纤维化疾病的作用机制差异，为分析两者的临床疗效差异及其资源的精准利用提供参考信息。方法 利用代谢组学技术分析福建金线莲叶(the leaves of A.roxburghii，Arl)和台湾银线兰叶(the leaves of A.formosanus，Afl)的差异代谢物；并结合网络药理学方法分析其差异代谢物治疗肝纤维化疾病的作用差异。结果 利用代谢组学的方法分析初步得到Arl和Afl的46个差异代谢物，主要为黄酮类、糖苷类和甘油磷脂类等，其中有23种差异化合物具有潜在药用活性。基于网络药理学的方法，预测了23种差异化合物的759个相关靶点，与肝纤维化疾病的相关靶点进行映射，得到交集靶点249个，其中AKT1、STAT3、VEGFA等48个关键靶点被预测为治疗肝纤维化的主要差异靶点；作用靶点较多的关键差异化合物为Arl相比Afl含量较高的化合物，预示Arl中富含更多可以用于治疗肝纤维化的有效化合物。GO富集功能和KEGG富集分析表明，福建金线莲与台湾银线兰的差异成分参与治疗肝纤维化疾病的信号通路有所不同，VEGF信号通路为Arl相比Afl含量较高的差异化合物的主要差异信号通路，磷脂酰肌酶3-激酶-蛋白激酶B(PI3K-Akt)信号通路为Arl相比Afl含量较低的差异化合物治疗肝纤维化疾病的主要差异信号通路。分子对接结果表明各差异成分与其对应的关键靶点均有较好的结合活性。结论 本研究表明福建金线莲与台湾银线兰叶片中存在一些差异代谢物，预测了其治疗肝纤维化疾病作用机制差异，并初步验证了其作用靶点，为金线莲资源的精准利用具有指导性意义。     

Synthesis and cytotoxicity of novel 4-(4-(substituted)-1H-1,2,3-triazol-1-yl)-N-phenethylbenzenesulfonamides

A new series of 4-(4-(substituted)-1H-1,2,3-triazol-1-yl)-N-phenethylbenzenesulfonamide derivatives 5 were synthesized through the Click approach and evaluated for their cytotoxic activity against four cancer cell lines (HuCCA-1, HepG2, A549, and MOLT-3). Most of the synthesized triazoles 5 displayed cytotoxicity against MOLT-3 cell line, except for analogs 5a–c and 5e. Significantly, 4-phenyltriazoles (5a and 5n), 4-(naphthalen-2-yloxy)methyltriazole 5d, as well as 4-((2-oxo-2H-chromen-7-yl)oxy)methyltriazole 5l showed higher cytotoxic activity against HepG2 cells than the reference drug, etoposide. Interestingly, the 4-phenyltriazole 5a was the most potent and promising compound with IC₅₀ value of 9.07 μM against HepG2 cell line. The analog 5a also exerted the highest cytotoxic activity against HuCCA-1 cells. This finding provides the novel lead molecules for further development.     

Mechanism of the antileukemic effects of 1-p-carboxamidophenyl3,3-dimethyltriazene and its in vitro metabolites

DM-CONH₂, a dimethyltriazene active in prolonging the survival time of mice bearing TLX5 lymphoma, requires metabolic activation by liver homogenate supernatant and cofactors in order to exert in vitro cytotoxic effects on the same tumor cells, as determined by in vivo bioassay of their viability. From the examination of the metabolites produced during these in vitro experiments, it is found that in vitro cytotoxicity is attributable to the generation of MM-CONH₂ by oxidative N-demethylation of DM-CONH₂. Also the generation of DM-COO^? is observed, although this compound is not cytotoxic in vitro. The in vivo effects of DM-CONH₂ and CM-COOK on TLX5 lymphoma are not caused exclusively by cytotoxic effects of the drugs, since they are evident also when no reduction in the number or viability of peritoneal tumor cells is evident, whereas these parameters are significantly reduced by MM-CONH₂. The increase in survival time of mice bearing TLX5 lymphoma caused by the dimethyltriazenes used appears to be caused by the drugs without being subjected to metabolic activation, with a mechanism different from cytotoxicity for tumor cells.