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Molecular Medicine Reports Sep 2017Chondrocyte hypertrophy is a physiological process in endochondral ossification. However, the hypertrophic‑like alterations of chondrocytes at the articular surface...
Chondrocyte hypertrophy is a physiological process in endochondral ossification. However, the hypertrophic‑like alterations of chondrocytes at the articular surface may result in osteoarthritis (OA). In addition, the generation of fibrocartilage with a decreased biological function in tissue engineered cartilage, has been attributed to chondrocyte hypertrophy. Therefore, suppressing chondrocyte hypertrophy in OA and the associated regeneration of non‑active cartilage is of primary concern. The present study examined the effects of xanthotoxin (XAT), which is classified as a furanocoumarin, on chondrocyte hypertrophic differentiation of mesenchymal stem cells. Following XAT treatment, the expression levels of genes associated with chondrocyte hypertrophy were detected via immunohistochemistry, western blotting and reverse transcription‑quantitative polymerase chain reaction. The results revealed that XAT inhibited the expression of various chondrocyte hypertrophic markers, including runt related transcription factor 2 (Runx2), matrix metalloproteinase 13 and collagen type X α1 chain. Further exploration indicated that XAT reduced the activation of p38‑mitogen activated protein kinase and then increased the expression of histone deacetylase 4 to suppress Runx2. The findings indicated that XAT maintained the chondrocyte phenotype in regenerated cartilage and therefore may exhibit promise as a potential drug for the treatment of OA in the future.
Topics: Animals; Cell Differentiation; Cell Line; Chondrocytes; Chondrogenesis; Cross-Linking Reagents; Histone Deacetylases; Hypertrophy; Mesenchymal Stem Cells; Methoxsalen; Mice; Signal Transduction; p38 Mitogen-Activated Protein Kinases
PubMed: 28677757
DOI: 10.3892/mmr.2017.6886 -
The Journal of Toxicological Sciences 2017Previously, we showed that phototoxicity assessments in Sprague-Dawley (SD) rats can detect phototoxic potential to the same degree as those in guinea pigs. In this...
Previously, we showed that phototoxicity assessments in Sprague-Dawley (SD) rats can detect phototoxic potential to the same degree as those in guinea pigs. In this study, we examined whether phototoxicity assessments can be incorporated into general toxicology studies, using SD rats. Three phototoxic compounds were tested. Acridine and 8-methoxypsoralen (8-MOP) were transdermally administered, and 8-MOP and lomefloxacin were orally administered. The animals were allocated to three groups for each compound: single-dose, repeated-dose, and repeated-dose plus toxicokinetics (TK). The single-dose group was irradiated with UV-A and UV-B after a single administration of the drug. The repeated-dose and TK groups were irradiated after 8 days of repeated administration of the drug. Blood samples were also collected from the TK group on days 1 and 7 after administration. The phototoxic compounds resulted in skin reactions in all the groups, with no difference in the degree of skin reaction among the three groups. In the TK measurements, all of the phototoxic compounds were detected in the plasma samples, and the irradiation timing was close to the T. These results indicate that phototoxic potential could be evaluated in the TK group, and phototoxicity assessments could be incorporated into general toxicology studies. This reduces the number of studies and animals required, thus shortening the research and development period, and supporting the 3Rs principle of animal experiments. The study also provides information regarding appropriate irradiation timings, differences between the sexes, and dose-response, in turn enabling the phototoxic risk of the compounds to be clearly evaluated.
Topics: Acridines; Administration, Cutaneous; Administration, Oral; Animals; Dermatitis, Phototoxic; Fluoroquinolones; Male; Methoxsalen; Photosensitizing Agents; Rats, Sprague-Dawley; Skin; Toxicity Tests
PubMed: 28321041
DOI: 10.2131/jts.42.145 -
International Journal of Molecular... Dec 2016Diabetes, as a serious metobolic disorder, poses global threat to human health. It is estimated that over 50 million individuals are already affected by diabetes....
Bergapten exerts inhibitory effects on diabetes-related osteoporosis via the regulation of the PI3K/AKT, JNK/MAPK and NF-κB signaling pathways in osteoprotegerin knockout mice.
Diabetes, as a serious metobolic disorder, poses global threat to human health. It is estimated that over 50 million individuals are already affected by diabetes. Currently, diabetes-related osteoporosis has been a research hotspot due to its high incidence rate in older individuals. Osteoprotegerin, as an important protein for the prevention of osteoporosis, has been proven to be key to the suppression of osteoporosis. Hence, the loss of function of osteoprotegerin may promote the development of osteoporosis. Bergapten, as a natural anti-inflammatory and anti-tumor agent isolated from bergamot essential oil, other citrus essential oils, and grapefruit juice, has been proven to have the ability to attenuate a number of metabolic disorders. In view of these findings, in this study, we used a high-fat diet to construct a mouse model of diabetes-related osteoporosis and a mouse model of diabetes-related osteoporosis using osteoprotegerin knockout mice. Enzyme-linked immunosorbent assay (ELISA), qPCR, western blot analysis, immunohistochemical assay, H&E staining, Oil Red O staining, Masson's staining and other biochemical analyses were used to evaluate the related signaling pathways involved in the development of diabetes-related osteoporosis. We also examined the role of osteoprotegerin in the activation of these pathways and in the development of osteoporosis, as well as the protective effects of bergapten against diabetes-related osteoporosis and on the activation of related signaling pathways. Our results revealed that in diabetes-related osteoporosis, the phosphoinositide 3-kinase (PI3K)/AKT, c-Jun N-terminal kinase (JNK)/mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways were activated and the expression levels of related indicators were increased. At the same time, osteoprotegerin knockout further promoted the activation of these pathways. By contrast, bergapten exerted effects similar to those of osteoprotegerin. Bergapten exhibited the ability to significantly inhibit RANKL-RANK signaling transduction, and to suppress the activation of the PI3K/AKT, JNK/MAPK and NF-κB signaling pathways, thus protecting trabecular structure and decreasing osteoclastogenic differentiation.
Topics: 5-Methoxypsoralen; Animals; Anti-Inflammatory Agents; Biomarkers; Diabetes Complications; Disease Models, Animal; JNK Mitogen-Activated Protein Kinases; Male; Methoxsalen; Mice; Mice, Knockout; NF-kappa B; Osteoporosis; Osteoprotegerin; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction
PubMed: 27840967
DOI: 10.3892/ijmm.2016.2794 -
Applied and Environmental Microbiology Dec 2016A defining feature of mycobacterial redox metabolism is the use of an unusual deazaflavin cofactor, F This cofactor enhances the persistence of environmental and...
A defining feature of mycobacterial redox metabolism is the use of an unusual deazaflavin cofactor, F This cofactor enhances the persistence of environmental and pathogenic mycobacteria, including after antimicrobial treatment, although the molecular basis for this remains to be understood. In this work, we explored our hypothesis that F enhances persistence by serving as a cofactor in antimicrobial-detoxifying enzymes. To test this, we performed a series of phenotypic, biochemical, and analytical chemistry studies in relation to the model soil bacterium Mutant strains unable to synthesize or reduce F were found to be more susceptible to a wide range of antibiotic and xenobiotic compounds. Compounds from three classes of antimicrobial compounds traditionally resisted by mycobacteria inhibited the growth of F mutant strains at subnanomolar concentrations, namely, furanocoumarins (e.g., methoxsalen), arylmethanes (e.g., malachite green), and quinone analogues (e.g., menadione). We demonstrated that promiscuous FH-dependent reductases directly reduce these compounds by a mechanism consistent with hydride transfer. Moreover, strains unable to make FH lost the capacity to reduce and detoxify representatives of the furanocoumarin and arylmethane compound classes in whole-cell assays. In contrast, mutant strains were only slightly more susceptible to clinical antimycobacterials, and this appeared to be due to indirect effects of F loss of function (e.g., redox imbalance) rather than loss of a detoxification system. Together, these data show that F enhances antimicrobial resistance in mycobacteria and suggest that one function of the FH-dependent reductases is to broaden the range of natural products that mycobacteria and possibly other environmental actinobacteria can reductively detoxify. This study reveals that a unique microbial cofactor, F, is critical for antimicrobial resistance in the environmental actinobacterium We show that a superfamily of redox enzymes, the FH-dependent reductases, can reduce diverse antimicrobials and strains unable to make or reduce F become sensitive to inhibition by these antimicrobial compounds. This suggests that mycobacteria have harnessed the unique properties of F to reduce structurally diverse antimicrobials as part of the antibiotic arms race. The FH-dependent reductases that facilitate this process represent a new class of antimicrobial-detoxifying enzymes with potential applications in bioremediation and biocatalysis.
PubMed: 27637879
DOI: 10.1128/AEM.02500-16 -
Journal of Insect Science (Online) 2016For some polyphagous insects, adaptation to phytochemically novel plants can enhance resistance to certain pesticides, but whether pesticide resistance expands tolerance...
For some polyphagous insects, adaptation to phytochemically novel plants can enhance resistance to certain pesticides, but whether pesticide resistance expands tolerance to phytochemicals has not been examined. Amyelois transitella Walker (navel orangeworm) is an important polyphagous pest of nut and fruit tree crops in California. Bifenthrin resistance, partially attributable to enhanced cytochrome P450 (P450)-mediated detoxification, has been reported in an almond-infesting population exposed to intense pesticide selection. We compared the toxicity of bifenthrin and three phytochemicals-chlorogenic acid, and the furanocoumarins xanthotoxin and bergapten-to three strains of A. transitella: pyrethroid-resistant R347 (maintained in the laboratory for ∼10 generations), fig-derived FIG (in the laboratory for ∼25 generations), and CPQ-a laboratory strain derived from almonds ∼40 years ago). Whereas both Ficus carica (fig) and Prunus dulcis (almond) contain chlorogenic acid, furanocoumarins occur only in figs. Both R347 and FIG exhibited 2-fold greater resistance to the three phytochemicals compared with CPQ; surprisingly, bifenthrin resistance was highest in FIG. Piperonyl butoxide, a P450 synergist, increased toxicity of all three phytochemicals only in CPQ, implicating alternate tolerance mechanisms in R347 and FIG. To test the ability of the strains to utilize novel hostplants directly, we compared survival on diets containing seeds of Wisteria sinensis and Prosopis pallida, two non-host Fabaceae species; survival of FIG was highest and survival of R347 was lowest. Our results suggest that, while P450-mediated pesticide resistance enhances tolerance of certain phytochemicals in this species, it is only one of multiple biochemical adaptations associated with acquiring novel hostplants.
Topics: 5-Methoxypsoralen; Animals; Antibiosis; Chlorogenic Acid; Food Chain; Furocoumarins; Insecticide Resistance; Insecticides; Larva; Methoxsalen; Moths; Phytochemicals; Pyrethrins
PubMed: 27620560
DOI: 10.1093/jisesa/iew063 -
Psychopharmacology Jun 2016Nicotine, a dominant alkaloid found in tobacco, is responsible for physical dependence, as well as addiction to cigarette smoking; consequently, smoking cessation is a...
RATIONALE
Nicotine, a dominant alkaloid found in tobacco, is responsible for physical dependence, as well as addiction to cigarette smoking; consequently, smoking cessation is a very difficult process. Hepatic cytochrome P-450 2A6 (CYP2A6) is involved in the 70-80 % of the initial metabolism of nicotine and its co-metabolites. As this metabolism is slowed by inhibitors of CYP2A6, this kind of enzymatic inhibition has been proposed as a novel target for smoking cessation.
OBJECTIVES
Nicotine administered alone improved memory acquisition and consolidation as well as exerted antidepressive activity in animal models. These effects persist for 24 h. However, they are completely extinguished 48 h after administration.
METHODS
To investigate if the coumarins prolong the behavioral effects of nicotine, the forced swimming test (FST)-animal models of depression, and passive avoidance (PA) test-memory and learning paradigm were used.
RESULTS
This study revealed that three CYP2A6 inhibitors: two furanocoumarins, xanthotoxin (15 mg/kg) and bergapten (25 mg/kg), and the simple coumarin umbelliferone (25 mg/kg), prolonged the antidepressive and procognitive effects of nicotine.
CONCLUSIONS
These natural products may offer a new approach to the treatment of nicotinism as antidepressant and memory improvement actions are one of the main factors of nicotine dependence.
Topics: 5-Methoxypsoralen; Animals; Antidepressive Agents; Avoidance Learning; Behavior, Animal; Coumarins; Cytochrome P-450 CYP2A6; Depression; Locomotion; Male; Memory; Methoxsalen; Mice; Nicotine; Nicotinic Agonists; Nootropic Agents; Swimming; Umbelliferones
PubMed: 27080866
DOI: 10.1007/s00213-016-4279-9 -
Molecules (Basel, Switzerland) Jan 2016This study designed and synthesized a series of new graveoline analogs on the basis of the structural characteristics of acetylcholinesterase (AChE) dual-site...
This study designed and synthesized a series of new graveoline analogs on the basis of the structural characteristics of acetylcholinesterase (AChE) dual-site inhibitors. The activity of these analogs was also evaluated. Results showed that the synthesized graveoline analogs displayed stronger inhibitory activity against AChE and higher selectivity than butyrylcholine esterase (BuChE) (Selectivity Index from 45 to 486). When the two sites in the graveoline parent ring substituting phenyl and amino terminal had six chemical bonds (n = 3) and the terminal amino was piperidine, compound 5c showed the best activity. Furthermore, the mechanism of action and binding mode were explored by enzyme kinetic simulation, molecular docking, and thioflavin T-based fluorometric assay. Cytotoxicity assay showed that the low concentration of the analogs did not affect the viability of the neurocyte SH-SY5Y.
Topics: Acetylcholinesterase; Alzheimer Disease; Binding Sites; Butyrylcholinesterase; Cell Line; Cell Proliferation; Cholinesterase Inhibitors; Humans; Methoxsalen; Models, Molecular; Molecular Docking Simulation; Structure-Activity Relationship
PubMed: 26805806
DOI: 10.3390/molecules21020132 -
Experimental Dermatology Mar 2016Senescent cells accumulate during ageing in various tissues and contribute to organismal ageing. However, factors that are involved in the induction of senescence in...
Senescent cells accumulate during ageing in various tissues and contribute to organismal ageing. However, factors that are involved in the induction of senescence in vivo are still not well understood. SNEV(P) (rp19/) (PSO) (4) is a multifaceted protein, known to be involved in DNA damage repair and senescence, albeit only in vitro. In this study, we used heterozygous SNEV(+/-) mice (SNEV-knockout results in early embryonic lethality) and wild-type littermate controls as a model to elucidate the role of SNEV(P) (rp19/) (PSO) (4) in DNA damage repair and senescence in vivo. We performed PUVA treatment as model system for potently inducing cellular senescence, consisting of 8-methoxypsoralen in combination with UVA on mouse skin to induce DNA damage and premature skin ageing. We show that SNEV(P) (rp19/) (PSO) (4) expression decreases during organismal ageing, while p16, a marker of ageing in vivo, increases. In response to PUVA treatment, we observed in the skin of both SNEV(P) (rp19/) (PSO) (4) and wild-type mice an increase in γ-H2AX levels, a DNA damage marker. In old SNEV(P) (rp19/) (PSO) (4) mice, this increase is accompanied by reduced epidermis thickening and increase in p16 and collagenase levels. Thus, the DNA damage response occurring in the mouse skin upon PUVA treatment is dependent on SNEV(P) (rp19/) (PSO) (4) expression and lower levels of SNEV(P) (rp19/) (PSO) (4) , as in old SNEV(+/-) mice, result in increase in cellular senescence and acceleration of premature skin ageing.
Topics: Aging, Premature; Animals; Cellular Senescence; Collagen; Collagenases; Cyclin-Dependent Kinase Inhibitor p16; DNA Damage; Epidermis; Female; Genotype; Heterozygote; Histones; Male; Methoxsalen; Mice; Mice, Inbred C57BL; Mice, Knockout; PUVA Therapy; RNA Splicing Factors; Skin; Skin Aging
PubMed: 26663487
DOI: 10.1111/exd.12910 -
Iranian Journal of Reproductive Medicine Aug 2015Different investigation showed that 5-methoxypsoralen and 8- methoxypsoralen reduce birth rates in the rats.
BACKGROUND
Different investigation showed that 5-methoxypsoralen and 8- methoxypsoralen reduce birth rates in the rats.
OBJECTIVE
In this study we worked out the effect of methoxsalen together with ultraviolent A (UVA) radiation on mature Balb/C mice spermatogenesis.
MATERIALS AND METHODS
The LD50 standard was determined 160 mg/kg and the UVA dose which causes erythema was calculated 0.046 J/cm2. A sub-lethal dose of 80 mg/kg of methoxsalen solution was injected intrapritoneally to mature mice and after one hour they were exposed to UVA radiation for 20 minutes. Experiments applied included methoxsalen alone, methoxsalen with UVA, UVA alone, sham group (a group received Tween 80), and control group (N=6). In all experimental groups except UVA alone group, injections were carried out, during two consecutive weeks. Serial cross sections (5 µm thickness) were prepared for morphological and histological studies. Tunica albuginea diameter, and number of type A and type B spermatogonia and histological investigation of the testes were measured.
RESULTS
Microscopical and statistical analyses showed significant anomalies among the experimental groups compared to control and sham group. These anomalies included decrease the body weight; increase the relative testis weight; and decrease the number of spermapogonia (type A and B), primary spermatocytes, spermatids and sperms in experimental groups I and II compared to control group. Our results showed the number of spermatozoa in experimental group I was 22.6±2.12, in experimental group II was 33.6±2.05 and in control group was 44.3±2.77 (p<0.05). Moreover in some experimental groups (I and II) shrinkage of seminiferous tubules and release of primary spermatocyte and spermatids were observed to the lumen of them.
CONCLUSION
It is concluded from the results of this work that treatment with methoxsalen with UVA can damage and disorganize seminiferous tubules and decrease spermatogenic cells.
PubMed: 26568751
DOI: No ID Found -
The Journal of Toxicological Sciences Dec 2015Guinea pigs are the most frequently used animals in phototoxicity studies. However, general toxicity studies most often use Sprague-Dawley (SD) rats. To reduce the...
Guinea pigs are the most frequently used animals in phototoxicity studies. However, general toxicity studies most often use Sprague-Dawley (SD) rats. To reduce the number of animals needed for drug development, we examined whether skin phototoxicity studies could be performed using SD rats. A total of 19 drugs that had previously been shown to have phototoxic potential and 3 known phototoxic compounds were administered transdermally to guinea pigs and SD rats. Eleven of the potentially phototoxic drugs and 2 of the known phototoxic compounds were also administered orally to guinea pigs and SD rats. After administration, the animals were irradiated with UV-A (10 J/cm(2)) and UV-B (0.25 J/cm(2) in guinea pigs and 0.031 J/cm(2) in SD rats) with doses based on standard phototoxicity study guidelines and the results of a minimum erythema dose test, respectively. In the transdermal administration study, all of the known phototoxic compounds and 7 of the drugs induced phototoxic reactions. In the oral administration study, both known phototoxic compounds and 5 drugs induced phototoxic reactions in both species; one compound each was found to be toxic only in SD rats or guinea pigs. The concordance rate of guinea pigs and SD rats was 100% in the transdermal administration study and 85% in the oral administration study. This study demonstrated that phototoxicity studies using SD rats have the same potential to detect phototoxic compounds as studies using guinea pigs.
Topics: Administration, Cutaneous; Administration, Oral; Animals; Anthracenes; Dermatitis, Phototoxic; Female; Guinea Pigs; Male; Methoxsalen; Radiation Dosage; Rats, Sprague-Dawley; Skin; Ultraviolet Rays
PubMed: 26558448
DOI: 10.2131/jts.40.667