Associations of inflammatory cytokines with palmoplantar pustulosis: a bidirectional Mendelian randomization study.

Background: Variations in circulatory cytokine levels have been observed during the onset and course of palmoplantar pustulosis (PPP); however, whether these changes are due to etiological or secondary factors is unclear. To clarify the causal relationship, we conducted a summarized-level bidirectional Mendelian randomization (MR) analysis in this study. Methods: A FinnGen biobank genome-wide association study (GWAS) of 212,766 individuals (524 PPP patients and 212,242 controls) provided summary data for PPP, whereas genetic instrumental variables (IVs) linked to circulation cytokine levels were gathered from a GWAS of 14,824 European individuals. The inverse-variance weighted (IVW), weighted median (WME), simple mode, and MR-Egger methods were used to ascertain the changes in PPP pathogenic cytokine taxa. Sensitivity analysis, which included horizontal pleiotropy analysis, was then conducted. The reliability of the results was assessed using the leave-one-out approach and the MR Steiger test, which evaluated the strength of a causal relationship. To evaluate the reverse causality between PPP and circulating cytokine levels, a reverse MR analysis was carried out. Results: Our study demonstrated positive associations between C-X-C motif chemokine 6 (CXCL6) and PPP (odds ratio, OR 1.257, 95%CI: 1.001-1.570, p = 0.043). C-C motif chemokine 19 (CCL19) and interleukin-6 (IL-6) were suggested to be protectively associated with the development of PPP (OR: 0.698,95% CI: 0.516-0.944, p = 0.020; OR: 0.656, 95%CI:0.437-0.985, p = 0.042). The results were steady after sensitivity and heterogeneity analyses. Conclusion: At the genetic prediction level, we identified causally connected inflammation-related variables that contributed to the onset and development of PPP. The therapeutic options for some refractory PPP have expanded due to tailored cytokine therapy, generating fresh concepts for PPP diagnostics and mechanism investigation.

A Mendelian randomization study on the causal effects of circulating cytokines on the risk of vitiligo.

Background: Accumulating evidence reveals an association between circulating cytokine levels and vitiligo. However, the causal association between circulating cytokine levels and vitiligo remains unrevealed. Methods: We performed a two-sample Mendelian randomization (MR) analysis using a genome-wide association study of the 41 cytokines dataset, which was conducted with 3 Finnish cohorts (n = 8,293). Vitiligo data were acquired from strictly defined vitiligo data collected by FinnGenbiobank analysis, which included 207,613 European ancestors (131 vitiligo patients, 207,482 controls). The inverse-variance weighted (IVW) method, weighted median (WME), simple model, weighted model, and MR-Egger were used to determine the changes in vitiligo pathogenic cytokine taxa, followed by sensitivity analysis, including horizontal pleiotropy analysis. The MR Steiger test evaluated the strength of a causal association, and the leave-one-out method was used to assess the reliability of the results. The possibility of reverse causality was also investigated using a reverse MR study. Results: We observed that rising IL-4 levels generated an enhanced probability of vitiligo in IVW (OR 2.72, 95%CI 1.19-6.22, p = 0.018). According to the results of the MR analysis, there were causal links between IL-4 and vitiligo. Results were steady after sensitivity and heterogeneity analyses. Conclusion: Our research reveals that a genetically determined increased level of circulating IL-4 may be linked to a higher risk of developing vitiligo. The development of innovative treatment approaches (such as tofacitinib or dupilumab) that focus on blocking IL-4 as a novel way of preventing and treating vitiligo is significantly impacted by our findings.

Causal relationship between circulating cytokines and follicular lymphoma: a two-sample Mendelian randomization study.

Follicular lymphoma (FL), derived from germinal centre (GC) B cells, is a kind of systemic neoplasm. Even though FL is indolent, it remains an incurable haematology Neoplasm. Accumulating evidence has suggested that the circulating cytokine is associated with the development of FL, yet the causal relationship between FL and circulating cytokines remains undetermined. Therefore, we conducted a two-sample Mendelian randomization (MR) to confirm the causal link between FL and levels of circulating cytokines with the use of summary data on circulating cytokines and FL. All these data from genome-wide association study were derived from the Genome-wide pQTL mapping which contains 14,824 individuals. FL data were acquired exclusively from FinnGen, where 218,792 individuals (522 cases vs. 218,270 controls) were involved. Various statistical methods, including the inverse variance weighted method (IVW), weighted median (WME), simple model, weighted model (WM) and MR-Egger, were used to evaluate the potential causal connection between circulating cytokines and FL. Sensitivity analysis, which involves the examination of the heterogeneity, pleiotropy, and leave-one-out method, was also performed to ensure more trustworthy results. A bidirectional MR test was performed to evaluate the direction of causal association between circulating cytokines and FL. Combining all the steps of MR analysis, we revealed four causal cytokines: C-X-C motif chemokine ligand 5 (CXCL5), interleukin-15 receptor A (IL15RA), interleukin-20 (IL20), and neurotrophin-3 (NT-3). The risk of FL may be inversely linked to CXCL5 (OR=0.73, CI: 0.545-0.979, P=0.036), IL-15RA (OR=0.669, CI: 0.451-0.993, P=0.046), and IL-20 (OR=0.565, CI: 0.325-0.981, P=0.043) but positively linked to NT-3 (OR=1.872, CI: 1.063-3.297, P=0.03). In addition, in our study, no causal effect of FL on cytokines was demonstrated and no significant heterogeneity and pleiotropy were found. Our research revealed the causal relationship between cytokines and FL, along with both the anti-protective effect of CXCL5, IL-15RA, and IL-20 and the protective effect of neurotrophin-3 on FL. These findings aim to provide new clues regarding the pathogenesis of FL and to extend the potential of circulating cytokines to therapeutic interventions.

Causal relationship between gut microbiota and hidradenitis suppurativa: a two-sample Mendelian randomization study.

Background: Accumulating evidence suggests that alterations in gut microbiota composition are associated with the hidradenitis suppurativa (HS). However, the causal association between gut microbiota and HS remain undetermined. Methods: We performed a bidirectional two-sample Mendelian randomization (MR) analysis using genome-wide association study summary data of gut microbiota and hidradenitis suppurativa from the MiBioGen consortium which concluded 18,340 individuals analyzed by the MiBioGen Consortium, comprising 211 gut microbiota. HS data were acquired from strictly defined HS data collected by FinnGenbiobank analysis, which included 211,548 European ancestors (409 HS patients, 211,139 controls). The inverse variance weighted method (IVW), weighted median (WME), simple model, weighted model, weighted median, and MR-Egger were used to determine the changes of HS pathogenic bacterial taxa, followed by sensitivity analysis including horizontal pleiotropy analysis. The MR Steiger test evaluated the strength of a causal association and the leave-one-out method assessed the reliability of the results. Additionally, a reverse MR analysis was carried out to seek for possible reverse causality. Results: By combining the findings of all the MR steps, we identified four causal bacterial taxa, namely, Family XI, Porphyromonadaceae, Clostridium innocuum group and Lachnospira. The risk of HS might be positively associated with a high relative abundance of Clostridium innocuum group (Odds ratio, OR 2.17, p = 0.00038) and Lachnospira (OR 2.45, p = 0.017) but negatively associated with Family XI (OR 0.67, p = 0.049) and Porphyromonadaceae (OR 0.29, p = 0.014). There were no noticeable outliers, horizontal pleiotropy, or heterogeneity. Furthermore, there was no proof of reverse causation found in the reverse MR study. Conclusion: This study indicates that Clostridium innocuum group and Lachnospira might have anti-protective effect on HS, whereas Family XI and Porphyromonadaceae might have a protective effect on HS. Our study reveals that there exists a beneficial or detrimental causal effect of gut microbiota composition on HS and offers potentially beneficial methods for therapy and avoidance of HS.

Effect of Sonication and Ceria Doping on Nanoparticles Fabricated by Laser Marker Ablation of Ti in Water.

By employing the laser marker fast ablation technique in water, combined with the innovative inclusion of sonication, we successfully developed Ti-based nanoparticles with improved characteristics. sonication increased the nanoparticle concentration in the colloid, reduced nanoparticle size, and also narrowed size distribution. Our findings also provide valuable insights into the influence of laser parameters, such as wavelength and fluence, on nanoparticle properties. UV laser led to small nanoparticles compared with 1064 nm laser. Additionally, high laser fluence appeared to increase the ablated particle size until a plateau fluence at 28.5 J/cm2; at 38 J/cm2, the particle size decreased. Notably, all synthesized particles exhibited a regular spherical shape, as confirmed by energy dispersive X-ray spectroscopy (EDS) mapping, which also indicated that the majority of Ti-based particles were in an oxidized state. Additionally, the presence of rutile TiO2 in the particles was further confirmed by X-ray diffraction (XRD) analysis. Ceria doping Titania nanoparticles was also attempted.

A Novel NCSTN Mutation in a Three-Generation Chinese Family with Hidradenitis Suppurative.

Objective: Hidradenitis suppurativa (HS) is a rare autosomal dominant condition characterized by inflamed nodules, cysts, deep abscesses, draining sinuses in the axillae, inguinal, and anogenital regions. Mutations in the NCSTN gene have been perceived to be responsible for the major underlying changes in the disorder. The purpose of this study is to identify a novel gene mutation in a Chinese family with HS. Methods: A Chinese family with HS present was investigated. The proband had manifested with multiple draining sinuses on the posterior neck, chest, bilateral axillae, and perineal regions. DNA was isolated from the peripheral blood of the family members. The encoding exons with introns of the NCSTN gene were analyzed by polymerase chain reactions (PCR) and direct DNA sequencing. Sanger sequencing was performed to confirm the next-generation sequencing results and to analyze each mutation's familial segregation. Furthermore, the identified mutation was localized onto a 3D structure model using the DeepView Swiss-PdbViewer 4.1 software. Results: In this family comprising 10 HS patients, one novel mutation of the NCSTN gene was identified, involving a deletion mutation (c.447delC(p.N150Ifs∗52)) in the NCSTN gene resulting in a frameshift and the new formation of a hydrogen bond. Conclusion: Our study reports the identification of a novel mutation that causes familial HS and could expand the spectrum of mutations in the γ-secretase genes underlying HS.

Cell-substrate traction force regulates the fusion of osteoclast precursors through cell-cell interaction.

The adhesion morphology of a cell monolayer results in a mechanical force inside cells, between cells, or between cells and substrates. The mechanical force regulates the differentiation of stem cells, but its influence on cell fusion is seldom studied. The present study is focused on osteoclast precursors, RAW264.7 monocytes, which can fuse into multinucleated cells (MNCs) responsible for bone resorption. Cells were cultured on circular and ring-like patterned substrates. Then, cell fusion, cell-substrate traction force, and force-sensitive molecules in different regions were measured and analyzed. Results showed that MNCs mainly appeared in the interior of the ring-like pattern and the central zone of the circular pattern, where both cell-substrate traction force and in-plane maximal shear stress were smaller than that at the patterns' edge. The immunostaining results revealed that F-actin, vinculin, ß-catenin, and E-cadherin were highly distributed at the edge of patterns. High seeding density of cells promoted mechanical force-dependent fusion. When calcium-dependent cell-cell connections were inhibited by E-cadherin antibody or low-calcium medium, the fusion into MNCs was greatly reduced. Thus, the morphology of cell monolayer decides the mechanical state of cell-substrate interaction and cell-cell connection, ultimately regulating the fusion of osteoclast precursors.

Anatomical study of the extraocular check ligament system.

AIM: To clarify the gross anatomy structure of the check ligament of the palpebra superior in relation to congenital blepharoptosis operation. METHOD: Seven fixed and three fresh cadavers of Chinese adults (between 53 and 76 years old; 5 males and 5 females) were used. Gross dissection was performed on fourteen eyes in seven cadavers. In three fixed cadavers, six bulbus oculi received histological sections for immunohistochemical tests. RESULT: Below the levator upon the superior rectus, the check ligament described by Lockwood is found. It extends bilaterally and attaches to the orbital wall behind the inner and lateral canthus tendon. Between the inferior obliquus and the inferior rectus, we also found a sheath structure similar to the check ligament extending bilaterally to the orbital wall. These two structures form an annular fascial system surrounding the eyeball. The medial half of the fascial sheath is tenacious, and the immunohistochemical test proves that smooth muscle cells are found in this part. CONCLUSION: We call this whole fascial sheath surrounding the circumocular muscle the Extraocular Check Ligament System (ECLS), and it plays a restricting and checking role in the movement of the eyeball. Surgeons should be aware of the ECLS when performing ptosis or other blepharal surgery.

Aging-dependent DNA hypermethylation and gene expression of GSTM1 involved in T cell differentiation.

This study investigated whether aging was associated with epigenetic changes of DNA hypermethylation on immune gene expression and lymphocyte differentiation. We screened CG sites of methylation in blood leukocytes from different age populations, picked up genes with age-related increase of CG methylation content more than 15%, and validated immune related genes with CG hypermethylation involved in lymphocyte differentiation in the aged population. We found that 12 genes (EXHX1、 IL-10、 TSP50、 GSTM1、SLC5A5、SPI1、F2R、LMO2、PTPN6、FGFR2、MMP9、MET) were associated with promoter or exon one DNA hypermethylation in the aged group. Two immune related genes, GSTM1 and LMO2, were chosen to validate its aging-related CG hypermethylation in different leukocytes. We are the first to validate that GSTM1_P266 and LMO2_E128 CG methylation contents in T lymphocytes but not polymorphonuclear cells (PMNs) or mononuclear cells (MNCs) were significantly increased in the aged population. The GSTM1 mRNA expression in T lymphocytes but not PMNs or MNCs was inversely associated with the GSTM1 CG hypermethylation levels in the aged population studied. Further studies showed that lower GSTM1 CG methylation content led to the higher GSTM1 mRNA expression in T cells and knockdown of GSTM1 mRNA expression decreased type 1 T helper cell (Th1) differentiation in Jurkat T cells and normal adult CD4 T cells. The GSTM1_P266 hypermethylation in the aged population associated with lower GSTM1 mRNA expression was involved in Th1 differentiation, highlighting that modulation of aging-associated GSTM1 methylation may be able to enhance T helper cell immunity in the elders.

Anti-inflammatory properties of lipoxin A4 protect against diabetes mellitus complicated by focal cerebral ischemia/reperfusion injury.

Lipoxin A4 can alleviate cerebral ischemia/reperfusion injury by reducing the inflammatory reaction, but it is currently unclear whether it has a protective effect on diabetes mellitus complicated by focal cerebral ischemia/reperfusion injury. In this study, we established rat models of diabetes mellitus using an intraperitoneal injection of streptozotocin. We then induced focal cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery for 2 hours and reperfusion for 24 hours. After administration of lipoxin A4 via the lateral ventricle, infarction volume was reduced, the expression levels of pro-inflammatory factors tumor necrosis factor alpha and nuclear factor-kappa B in the cerebral cortex were decreased, and neurological functioning was improved. These findings suggest that lipoxin A4 has strong neuroprotective effects in diabetes mellitus complicated by focal cerebral ischemia/reperfusion injury and that the underlying mechanism is related to the anti-inflammatory action of lipoxin A4.

Effects of music aerobic exercise on depression and brain-derived neurotrophic factor levels in community dwelling women.

A randomized clinical trial was utilized to compare the improvement of depression and brain-derived neurotrophic factor (BDNF) levels between community women with and without music aerobic exercise (MAE) for 12 weeks. The MAE group involved 47 eligible participants, whereas the comparison group had 59 participants. No significant differences were recorded in the demographic characteristics between the participants in the MAE group and the comparison group. Forty-one participants in the MAE group and 26 in the comparison group completed a pre- and posttest. The MAE group displayed significant improvement in depression scores (p = 0.016), decreased depression symptoms in crying (p = 0.03), appetite (p = 0.006), and fatigue (p = 0.011). The BDNF levels of the participants significantly increased after the 12-week MAE (p = 0.042). The parallel comparison group revealed no significant changes in depression scores or BDNF levels. In summary, the 12-week MAE had a significant impact on the enhancement of BDNF levels and improvement of depression symptoms. Middle-aged community women are encouraged to exercise moderately to improve their depression symptoms and BDNF levels.

Fucoxanthin enhances cisplatin-induced cytotoxicity via NFκB-mediated pathway and downregulates DNA repair gene expression in human hepatoma HepG2 cells.

Cisplain, a platinum-containing anticancer drug, has been shown to enhance DNA repair and to inhibit cell apoptosis, leading to drug resistance. Thus, the combination of anticancer drugs with nutritional factors is a potential strategy for improving the efficacy of cisplatin chemotherapy. In this study, we investigated the anti-proliferative effects of a combination of fucoxanthin, the major non-provitamin A carotenoid found in Undaria Pinnatifida, and cisplatin in human hepatoma HepG2 cells. We found that fucoxanthin (1-10 µΜ) pretreatment for 24 h followed by cisplatin (10 µΜ) for 24 h significantly decreased cell proliferation, as compared with cisplatin treatment alone. Mechanistically, we showed that fucoxanthin attenuated cisplatin-induced NFκB expression and enhanced the NFκB-regulated Bax/Bcl-2 mRNA ratio. Cisplatin alone induced mRNA expression of excision repair cross complementation 1 (ERCC1) and thymidine phosphorylase (TP) through phosphorylation of ERK, p38 and PI3K/AKT pathways. However, fucoxanthin pretreatment significantly attenuated cisplatin-induced ERCC1 and TP mRNA expression, leading to improvement of chemotherapeutic efficacy of cisplatin. The results suggest that a combined treatment with fucoxanthin and cisplatin could lead to a potentially important new therapeutic strategy against human hepatoma cells.

Trapping of methylglyoxal by curcumin in cell-free systems and in human umbilical vein endothelial cells.

Curcumin, the most active compound of curcuminoids, has been shown to inhibit formation of advanced glycation end products (AGEs) in streptozotocin-induced diabetic rats. However, little is known on whether curcumin may trap methylglyoxal (MGO), a major reactive dicarbonyl compound, to inhibit AGE formation. We found that one molecule of curcumin effectively trapped one molecule of MGO at a 1:3 ratio at 24 h of incubation under physiological conditions (pH 7.4, 37 °C). Curcumin decreased N(ε)-(carboxymethyl)lysine (CML) expression in human umbilical vein endothelial cells. We further used two curcumin analogues, dimethoxycurcumin (DIMC) and ferulic acid, to investigate the possible MGO-trapping mechanism of curcumin. Results reveal that DIMC, but not ferulic acid, exhibited MGO-trapping capacity, indicating curcumin traps MGO at the electron-dense carbon atom (C10) between the two keto carbon groups. Thus, curcumin may prevent MGO-induced endothelial dysfunction by directly trapping MGO.

Sesamin: A Naturally Occurring Lignan Inhibits CYP3A4 by Antagonizing the Pregnane X Receptor Activation.

Inconsistent expression and regulation of drug-metabolizing enzymes (DMEs) are common causes of adverse drug effects in some drugs with a narrow therapeutic index (TI). An important cytochrome, cytochrome P450 3A4 (CYP3A4), is predominantly regulated by a nuclear receptor, pregnane X receptor (PXR). Sesamin, a major lignan constituent in sesame seeds and oil, exhibits a variety of biological functions; however, the effect of sesamin on the modulation of CYP3A4 is not well understood. In this study, the effects of sesamin on the PXR-CYP3A4 pathway were characterized, as well as the underlying mechanisms of those effects. Sesamin potently attenuated CYP3A4 induction in a dose-dependent manner by blocking the activation of PXR. The PXR inducer-mediated inhibition of CYP3A4 was further evidenced by the ability of sesamin to attenuate the effects of several PXR ligands in the CYP3A4 reporter assay. Further mechanistic studies showed that sesamin inhibited PXR by interrupting the interacting with coregulators. These results may lead to the development of new therapeutic and dietary approaches to reduce the frequency of inducer-drug interaction. Sesamin was established as a novel inhibitor of PXR and may be useful for modulating DMEs expression and drug efficacies. Modification of CYP3A4 expression and activity by consumption of sesamin may have important implications for drug safety.

Fucoxanthin attenuates rifampin-induced cytochrome P450 3A4 (CYP3A4) and multiple drug resistance 1 (MDR1) gene expression through pregnane X receptor (PXR)-mediated pathways in human hepatoma HepG2 and colon adenocarcinoma LS174T cells.

Pregnane X receptor (PXR) has been reported to regulate the expression of drug-metabolizing enzymes, such as the cytochrome P450 3A (CYP3A) family and transporters, such as multiple drug resistance 1 (MDR1). Fucoxanthin, the major carotenoid in brown sea algae, is a putative chemopreventive agent. In this study, we determined whether fucoxanthin could overcome drug resistance through attenuation of rifampin-induced CYP3A4 and MDR1 gene expression by PXR-mediated pathways in HepG2 hepatoma cells. We found that fucoxanthin (1-10 µM) significantly attenuated rifampin (20 µM)-induced CYP3A4, MDR1 mRNA and CYP3A4 protein expression at 24 h of incubation. Mechanistically, fucoxanthin strongly attenuated the PXR-mediated CYP3A4 promoter activity in HepG2 cells. In addition, fucoxanthin attenuated constitutive androstane receptor (CAR)- and rPXR-mediated CYP3A4 promoter activity in this cell line. Using the mammalian two-hybrid assay, we found that fucoxanthin significantly decreased the interaction between PXR and SRC-1, a PXR co-activator. Thus, fucoxanthin can decrease rifampin-induced CYP3A4 and MDR1 expression through attenuation of PXR-mediated CYP3A4 promoter activation and interaction between PXR and co-activator. These findings could lead to potentially important new therapeutic and dietary approaches to reduce the frequency of adverse drug reactions.

Apo-8'-lycopenal induces expression of HO-1 and NQO-1 via the ERK/p38-Nrf2-ARE pathway in human HepG2 cells.

Lycopene and its metabolite apo-10'-lycopenoic acid have been shown to induce phase II detoxifying/antioxidant enzymes through activation of the nuclear factor erythroid-derived 2-like 2 (Nrf2)-antioxidant response element (ARE) transcription system. However, little is known about whether apo-8'-lyocpenal, one of the main metabolites of lycopene in rat livers, in lycopene-containing food, and in human plasma, has similar effects. This study investigated the effect of apo-8'-lycopenal on Nrf2-ARE system-mediated heme oxygenase 1 (HO-1) and NAD(P)H:quinine oxidoreductase 1 (NQO-1) expression in human HepG2 cells. It was found that apo-8'-lycopenal (1-10 µM) significantly increased nuclear Nrf2 accumulation, ARE-luciferase activity, Nrf2-ARE binding activity, chymotrypsin-like activity, and downstream HO-1 and NQO-1 expression, but decreased cytosolic Kelch-like ECH-associated protein 1 (Keap1) expression. Results also revealed that the ERK/p38-Nrf2 pathway is involved in activation of HO-1 and NQO-1 expression by apo-8'-lycopenal using Nrf2 siRNA and ERK/p38 specific inhibitors. In addition, the activation time of lycopene on nuclear Nrf2 accumulation is slower than that of apo-8'-lycopenal, suggesting that the chemopreventive effects of lycopene may be partially attributed to its metabolites.

Fucoxanthin enhances HO-1 and NQO1 expression in murine hepatic BNL CL.2 cells through activation of the Nrf2/ARE system partially by its pro-oxidant activity.

To determine whether fucoxanthin, a major carotenoid in brown sea algae, may activate cellular antioxidant enzymes via up-regulation of the Nrf2/antioxidant-response element (ARE) pathway, we incubated mouse hepatic BNL CL.2 cells with fucoxanthin (0.5-20 µM) for 0-24 h. We found that fucoxanthin (≥5 µM) significantly increased cellular reactive oxygen species (ROS) at 6 h of incubation, whereas preincubation with α-d-tocopherol (30 µM) significantly attenuated the increase of ROS, indicating the pro-oxidant nature of fucoxanthin. Fucoxanthin significantly increased the phosphorylation of ERK and p38 and markedly increased nuclear Nrf2 protein accumulation after incubation for 12 h. Moreover, fucoxanthin significantly enhanced binding activities of nuclear Nrf2 with ARE and increased mRNA and protein expression of HO-1 and NQO1 after incubation for 12 h. siRNA inhibition of Nrf2 led to markedly decreased HO-1 and NQO1 protein expression. Thus, fucoxanthin may exert its antioxidant activity, at least partly, through its pro-oxidant actions.

Protective effects of fucoxanthin against ferric nitrilotriacetate-induced oxidative stress in murine hepatic BNL CL.2 cells.

Fucoxanthin is a carotenoid that is rich in some seaweed. Although fucoxanthin has been reported to possess radical-scavenging activities in vitro, little is known whether it may protect against iron-induced oxidative stress in cultured cells. In this study, we examined the protection of fucoxanthin against oxidative damage in BNL CL.2 cells induced by ferric nitrilotriacetate (Fe-NTA). The data show that incubation of BNL CL.2 cells with Fe-NTA for 30 min significantly decreased cell proliferation, whereas pretreatment with fucoxanthin (1-20 µΜ) for 24h significantly recovered cell proliferation in a dose-dependent manner. In addition, fucoxanthin pretreatment significantly decreased intracellular reactive oxygen species (ROS) and DNA damage in BNL CL.2 cells incubated with Fe-NTA for 30 min. Moreover, fucoxanthin markedly decreased the level of thiobarbituric acid-reactive substances (TBARS) and protein carbonyl contents in BNL CL.2 cells induced by Fe-NTA. By contrast, fucoxanthin significantly increased the levels of GSH in a concentration-dependent manner. These results demonstrate that fucoxanthin at 1-20µΜ effectively prevents cytotoxicity in BNL CL.2 cells treated with Fe-NTA, and that the protective effect is likely associated with decreased intracellular ROS, TBARS, protein carbonyl contents and increased GSH levels.

Inhibition of proliferation of a hepatoma cell line by fucoxanthin in relation to cell cycle arrest and enhanced gap junctional intercellular communication.

Fucoxanthin is one of the most abundant carotenoids found in Undaria pinnatifida and has been shown to inhibit tumor proliferation in vitro. However, the mechanisms underlying the anti-cancer effects of fucoxanthin are unclear. In this study, we hypothesized that fucoxanthin may cause cell cycle arrest and enhance gap junctional intercellular communication (GJIC) in SK-Hep-1 human hepatoma cells. Data revealed that fucoxanthin (1-20microM) strongly and concentration-dependently inhibited the proliferation of SK-Hep-1 cells at 24h of incubation, whereas fucoxanthin facilitated the growth of a murine embryonic hepatic (BNL CL.2) cells at 24h of incubation and only slightly slowed the cell proliferation at 48h. In SK-Hep-1 cells, fucoxanthin caused cell cycle arrest at G0/G1 phase and induced cell apoptosis, as evidenced by increased subG1 cells and induction of DNA strand breaks. Using scrape loading-dye-transfer assay, fucoxanthin was found to significantly enhance GJIC of SK-Hep-1 cells without affecting that of BNL CL.2 cells. In addition, fucoxanthin significantly increased protein and mRNA expressions of connexin 43 (Cx43) and connexin 32 (Cx32) in SK-Hep-1 cells. Moreover, fucoxanthin markedly increased the concentration of intracellular calcium levels in SK-Hep-1 cells. Thus, fucoxanthin is specifically antiproliferative against SK-Hep-1 cells, and the effect is associated with upregulation of Cx32 and Cx43, which enhances GJIC of SK-Hep-1 cells. The enhanced GJIC may be responsible for the increase of the intracellular calcium level, which then causes cell cycle arrest and apoptosis.