[Studies of smoking habits among students of the secondary schools of Crotone].
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Adolescent↗
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The tumor-enhancing principles of Croton tiglium L.
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Acetates↗
[Studies of the incidence of carriers of A-beta-hemolytic streptococci in the school population of Crotone (Calabria)].
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Carrier State↗
[Alcmeone from Croton].
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Greece, Ancient↗
Modified phenol chemical face peels: recognizing the role of application technique.
To determine the relative roles of phenol concentration, croton oil concentration, and application techniques, the authors obtained three additional human biopsy studies. The last study was a randomized, controlled, prospective study with surgeon, pathologist, and third-party evaluators blinded during the application process and during the gross and histologic evaluations. Conclusions drawn from the findings of the studies included the following: Rubbing more coats of phenol, with or without croton oil, produces more inflammation and fibrosis. Adding croton oil reduces the threshold of injury from 20 to 50 coats to 5 to 20 coats applied with a cotton tip applicator, confirming the clinical impression that croton oil resin facilitates injury pattern of wounding when used with phenol in 35% to 88% concentrations. 48% phenol without croton oil can provide the same long-term results as 48% phenol with croton oil. The data suggest that the application technique is more important than the concentration of phenol or croton oil alone.
Chemexfoliation↗
Cytokine induction in human epidermal keratinocytes exposed to contact irritants and its relation to chemical-induced inflammation in mouse skin.
In response to exogenous stimuli such as phorbol-12-myristate 13-acetate, ultraviolet B radiation, and lipopolysaccharide, human keratinocytes produce soluble mediators that are important in primary contact irritancy including cytokines that are associated with proinflammatory properties (interleukin-1 alpha [IL-1 alpha], tumor necrosis factor alpha), chemotaxis (IL-8), and growth activation (granulocyte/macrophage colony stimulating factor, IL-6, transforming growth factor alpha). We examined qualitative and quantitative changes in selected intracellular and secreted cytokines in human keratinocyte cultures in response to non-sensitizing contact irritants (croton oil, sodium lauryl sulfate, methyl salicylate, ethyl phenylpropiolate), sensitizing irritants (oxazolone, dinitrofluorobenzene), and ulcerative agents (phenol, benzalkonium chloride, chromium trioxide). The chemicals were also applied to mouse skin to assess whether the chemical-specific pattern of inflammation correlated with the in vitro production of keratinocyte-derived cytokines. Although all agents elicited neutrophils to the site of chemical application, time dependent and chemical-specific patterns of inflammation could be detected. Sodium lauryl sulfate, phenol, and croton oil induced increases in IL-8 production at non-cytotoxic concentrations in semi-confluent human keratinocyte cultures. Phenol and croton oil stimulated tumor necrosis factor alpha production, whereas croton oil was the only agent found to induce granulocyte/macrophage colony-stimulating factor production. Croton oil, phenol, benzalkonium chloride, and dinitrofluorobenzene induced the intracellular production of IL-1 alpha without a concomitant release into the medium. The release of cytokines occurred in parallel with a relative increase in cytokine-specific mRNA transcripts. Studies using neutralizing antibodies to tumor necrosis factor alpha and IL-1 alpha demonstrated that IL-8 induction by croton oil and phenol occurred directly rather than through autocrine circuits. These data suggest that a given pattern of cytokine production is chemical-specific and may predict the contribution of keratinocytes to skin inflammation.
Animals↗
Tephrosia purpurea alleviates phorbol ester-induced tumor promotion response in murine skin.
In recent years, considerable emphasis has been placed on identifying new cancer chemopreventive agents, which could be useful for the human population. Tephrosia purpurea has been shown to possess significant activity against hepatotoxicity, pharmacological and physiological disorders. Earlier we showed that Tephrosia purpurea inhibits benzoyl peroxide-mediated cutaneous oxidative stress and toxicity. In the present study, we therefore assessed the effect of Tephrosia purpurea on 12-O-tetradecanoyl phorbal-13-acetate (TPA; a well-known phorbol ester) induced cutaneous oxidative stress and toxicity in murine skin. The pre-treatment of Swiss albino mice with Tephrosia purpurea prior to application of croton oil (phorbol ester) resulted in a dose-dependent inhibition of cutaneous carcinogenesis. Skin tumor initiation was achieved by a single topical application of 7,12-dimethyl benz(a)anthracene (DMBA) (25 microg per animal per 0.2 ml acetone) to mice. Ten days later tumor promotion was started by twice weekly topical application of croton oil (0.5% per animal per 0.2 ml acetone, v /v). Topical application of Tephrosia purpurea 1 h prior to each application of croton oil (phorbol ester) resulted in a significant protection against cutaneous carcinogenesis in a dose-dependent manner. The animals pre-treated with Tephrosia purpurea showed a decrease in both tumor incidence and tumor yield as compared to the croton oil (phorbol ester)-treated control group. In addition, a significant reduction in TPA-mediated induction in cutaneous ornithine decarboxylase (ODC) activity and [3H]thymidine incorporation was also observed in animals pre-treated with a topical application of Tephrosia purpurea. The effect of topical application of Tephrosia purpurea on TPA-mediated depletion in the level of enzymatic and non-enzymatic molecules in skin was also evaluated and it was observed that topical application of Tephrosia purpurea prior to TPA resulted in the significant recovery of TPA-mediated depletion in the level of these molecules, namely glutathione, glutathione S-transferase, glutathione reductase and catalase. From these data we suggest that Tephrosia purpurea can abrogate the tumor-promoting effect of croton oil (phorbol ester) in murine skin.
9,10-Dimethyl-1,2-benzanthracene↗
A new method for measuring auricular inflammation in the mouse.
The croton oil ear test is widely used to identify prospective topical antiinflammatory drugs. Ear inflammation is produced by applying a 2% solution of croton oil on the ears of mice or rats. The effectiveness of the drug that is dissolved in the croton oil solution can be gauged by comparing the croton oil treated ears with the croton oil plus drug treated ears. The effect is measured following sacrifice of the animal by weighing either the excised ear (Tonelli et al., 1965; Glenn et al., 1978; Swingle et al., 1981; Soliman et al., 1983; Mantione and Rodriguez 1990) or a plug taken from the ear (Tubaro et al., 1985; Davis et al., 1989a; Davis et al., 1989b). Use of this technique for the generation of a time-course evaluation of antiinflammatory activity requires a large amount of the chemical to be tested and the sacrifice of many animals. In other assays, ear thickness has been measured by caliper (Carlson et al., 1985; Maloff et al., 1989) or by dial micrometer (Griswold et al., 1987), which allow multiple measurements to be made, but the pressure on the ear was not reported. In a recent review of pharmacological methods, Chang and Lewis (1989) caution that using calipers to measure ear thickness is subject to operator error and bias. Furthermore, they emphasize care must be taken to not leave the calipers in contact with the ear too long, as it is possible to squeeze substantial amounts of edema fluid out of the ear tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Nuclear enlargement and DNA synthesis in mouse epidermis treated with carcinogen and promotor.
An autoradiographic investigation was made into the causes of nuclear size increase observed in the mouse epidermis within a few days of topical benzpyrene treatment. The effects of croton oil pretreatment of posttreatment in combination with benzpyrene were examined to see what effect a growth stimulus had on this response. The degree of nuclear size increase induced in the epidermis suggested that some ploidy level increase resulted from combined croton oil and benzpyrene treatment and evidence was found of a G2 block occurring in association with this. Enhancement of nuclear size increase by croton oil highlighted the importance of a growth stimulus in carcinogen induced nuclear enlargement and the implications of this are discussed. Disappearance of enlarged nuclei was seen when mice were kept for 5 days after combined croton oil and benzpyrene treatment in spite of a reduced cell loss compared with croton oil treatment alone.
Animals↗
Cannabinoid CB1-receptor mediated regulation of gastrointestinal motility in mice in a model of intestinal inflammation.
1. We have studied the effect of cannabinoid agonists (CP 55,940 and cannabinol) on intestinal motility in a model of intestinal inflammation (induced by oral croton oil in mice) and measured cannabinoid receptor expression, endocannabinoids (anandamide and 2-arachidonylglycerol) and anandamide amidohydrolase activity both in physiological and pathophysiological states. 2. CP 55,940 (0.03 - 10 nmol mouse(-1)) and cannabinol (10 - 3000 nmol mouse(-1)) were more active in delaying intestinal motility in croton oil-treated mice than in control mice. These inhibitory effects were counteracted by the selective cannabinoid CB(1) receptor antagonist SR141716A (16 nmol mouse(-1)). SR141716A (1 - 300 nmol mouse(-1)), administered alone, increased intestinal motility to the same extent in both control and croton oil-treated mice. 3. Croton oil-induced intestinal inflammation was associated with an increased expression of CB(1) receptor, an unprecedented example of up-regulation of cannabinoid receptors during inflammation. 4. High levels of anandamide and 2-arachidonylglycerol were detected in the small intestine, although no differences were observed between control and croton oil-treated mice; by contrast anandamide amidohydrolase activity increased 2 fold in the inflamed small intestine. 5. It is concluded that inflammation of the gut increases the potency of cannabinoid agonists possibly by 'up-regulating' CB(1) receptor expression; in addition, endocannabinoids, whose turnover is increased in inflamed gut, might tonically inhibit intestinal motility.
Analgesics↗
Assignment of fatty acid-beta-oxidizing syntrophic bacteria to Syntrophomonadaceae fam. nov. on the basis of 16S rRNA sequence analyses.
After enrichment from Chinese rural anaerobic digestor sludge, anaerobic, sporing and nonsporing, saturated fatty acid-beta-oxidizing syntrophic bacteria were isolated as cocultures with H2- and formate-utilizing Methanospirillum hungatei or Desulfovibrio sp. strain G-11. The syntrophs degraded C4 to C8 saturated fatty acids, including isobutyrate and 2-methylbutyrate. They were adapted to grow on crotonate and were isolated as pure cultures. The crotonate-grown pure cultures alone did not grow on butyrate in either the presence or the absence of some common electron acceptors. However, when they were reconstituted with M. hungatei, growth on butyrate again occurred. In contrast, crotonate-grown Clostridium kluyveri and Clostridium sticklandii, as well as Clostridium sporogenes, failed to grow on butyrate when these organisms were cocultured with M. hungatei. The crotonate-grown pure subcultures of the syntrophs described above were subjected to 16S rRNA sequence analysis. Several previously documented fatty acid-beta-oxidizing syntrophs grown in pure cultures with crotonate were also subjected to comparative sequence analyses. The sequence analyses revealed that the new sporing and nonsporing isolates and other syntrophs that we sequenced, which had either gram-negative or gram-positive cell wall ultrastructure, all belonged to the phylogenetically gram-positive phylum. They were not closely related to any of the previously known subdivisions in the gram-positive phylum with which they were compared, but were closely related to each other, forming a new subdivision in the phylum. We recommend that this group be designated Syntrophomonadaceae fam. nov.; a description is given.
Bacteria, Anaerobic↗
New steroidal anti-inflammatory antedrugs: methyl 3,20-dioxo-9 alpha-fluoro-11 beta,17 alpha,21-trihydroxy-1,4-pregnadiene-16 alpha-carboxylate and methyl 21-acetyloxy-3,20-dioxo-11 beta, 17 alpha-dihydroxy-9 alpha-fluoro-1,4-pregnadiene-16 alpha-carboxylate.
Focused efforts have been made to increase local-to-systemic activity ratios of potent anti-inflammatory steroids for local and/or topical applications. The approach taken in the present investigation is based upon the concept of "antedrug," defined as a locally active compound that exerts its action at the application site but rapidly undergoes a predictable biotransformation to an inactive metabolite that is readily excreted upon entry into the systemic circulation. In continuing efforts to synthesize potent, anti-inflammatory steroids without systemic glucocorticoid activities, 9 alpha-fluoro-methyl 11 beta, 17 alpha, 21-trihydroxy-3,20-dioxo-pregna-1,4-diene-16 alpha-carboxylate (FP16CM) and its 21-acetate derivative (FP16CMAc) have been synthesized and screened. Novel antedrugs were evaluated for antiinflammatory activity in the acute croton oil-induced ear edema bioassay, adverse systemic effects in the 5-day croton oil model, receptor binding, and concomitant L-tyrosine-2-oxoglutarate aminotransferase (EC 2.6.1.5) (TAT) enzyme induction in HTC cells in culture. Following a single topical application in the croton oil-induced ear edema bioassay, treatment with all compounds resulted in dose-dependent inhibition of edema. From these dose-response profiles, the following ID50 values (nmol resulting in a 50% reduction of edema) were calculated: 817, 540, 266, and 67 for hydrocortisone (HC), prednisolone (P), FP16CM, and FP16CMAc, respectively. Calculated relative potencies, setting HC = 1.0, were P, 1.5; FP16CM, 3.1, and FP16CMAc, 12.2. Results of the 5-day rat croton oil ear edema bioassay indicated that, in contrast to the parent compound P, the novel steroidal antedrugs did not significantly alter body weight gain, thymus weights, or plasma corticosterone levels. Relative binding potencies for cytosolic HTC glucocorticoid receptors were 1.0, 20.1, 5.4, and 2.5 for HC, P, FP16CM, and FP16CMAc, respectively. As predicted by the antedrug concept, FP16CM and FP16CMAc were very weak agonists for induction of TAT in HTC cells. Collectively, results of these investigations suggest that modification of P, which included addition of the 9-fluoro and 16-methoxycarbonyl group alone or in conjunction with a 21-acetoxy moiety, increase topical anti-inflammatory activity without significant adverse systemic effects. These new antedrugs may be useful as anti-inflammatory steroids for local applications.
Administration, Topical↗
Low-dose dithranol treatment and tape stripping induce tolerance to dithranol in a mouse ear oedema model.
BACKGROUND: It is well known from clinical practice that repeated treatment with dithranol leads to the development of tolerance. OBJECTIVES: To investigate the characteristics and mechanism of such dithranol tolerance. METHODS: The mouse ear was pretreated with a low dose of dithranol or croton oil or, in previously sensitized animals, with dinitrofluorobenzene (DNFB). Twenty-four hours later irritant dermatitis was elicited by painting the mouse ear with a high dose of dithranol, croton oil or DNFB, and the dermatitis was characterized by measurement of ear thickness. RESULTS: Low-dose dithranol significantly suppressed dithranol-induced oedema, whereas it had no effect on croton oil- or DNFB-induced dermatitis, suggesting that dithranol-induced tolerance is specific. Tolerance to dithranol could not be induced by pretreatment of the mouse ear with a low dose of croton oil or DNFB. Mild tape stripping of the mouse ear also inhibited the inflammatory effect of dithranol applied 24 h later. Superoxide dismutase treatment abolished the tolerance-inducing effect of low-dose dithranol or stripping. CONCLUSIONS: These results suggest that superoxide anion radicals are involved not only in the inflammatory effect of dithranol, but also in the induction of tolerance.
Administration, Topical↗
Identification of ovotransferrin as an acute phase protein in chickens.
Inflammation is homeostatic process associated with a variety of cellular injuries resulting from infections, toxicosis, and physical trauma. The studies on inflammation in avian species are limited. To understand the inflammation-induced changes, 4-wk-old male broiler chickens were subjected to experimental inflammation by a subcutaneous injection of croton oil (inflammatory) with changes in serum measured over time and were compared with birds treated similarly with olive oil (injected control). Croton oil treatment significantly elevated serum interleukin (IL)-6 concentrations and heterophil counts by 6 and 16 h postinjection, respectively, which returned to the basal levels of controls at 16 and 24 h, respectively. Croton oil treatment affected the serum protein profiles of chickens as assessed by SDS-PAGE and densitometric analyses. Compared with olive oil-injected or noninjected chicken sera, there were increases in the density of protein bands corresponding to molecular weights (MW) of 42, 65, 200, and 219 kDa and decreases in bands corresponding to 49 kDa (serum albumin) and a 56-kDa protein in chickens treated with croton oil. Most of these changes were evident at 24 h and lasted through 48 h. The protein band corresponding to 65 kDa was further characterized using two-dimensional gel electrophoresis and N-terminal sequence analyses. A sequence similarity search in the Genbank database using the first 22 amino acids yielded a complete homology with chicken ovotransferrin. Western blot analysis using antichicken serum transferrin or antichicken ovotransferrin antibodies also confirmed the 65-kDa protein band to be ovotransferrin. Under nonreducing conditions, the ovotransferrin standard also showed an apparent MW corresponding to 65 kDa, like the serum transferrin. The serum ovotransferrin was found to be glycosylated using a glycoprotein stain. Although the significance of ovotransferrin in avian inflammation is not clear, these results show that it is a major acute phase protein (APP) in chickens.
Acute-Phase Proteins↗
Comparative potencies of nutraceuticals in chemically induced skin tumor prevention.
Four nutraceuticals, sugar beet roots, cucumber fruits, New Zealand spinach leaves, and turmeric rhizomes, were evaluated for their comparative effectiveness against dimethylbenz[a]anthracene (DMBA)-initiated and croton oil-promoted skin tumors. Three different protocols were used. The most effective protocol (Protocol 2) is the topical application of the nutraceuticals 1 h before croton oil. There was a decrease in the percent skin tumor incidence, a decrease in multiplicity of skin tumors, and a later onset of skin tumors compared with the positive control for all the nutraceuticals tested, with turmeric being the most potent, as evidenced by 30% skin tumor incidence, 87.2% decrease in skin tumors, and a 5-wk delay in skin tumor formation compared with the positive control. Topical application of the nutraceuticals daily for 5 days before DMBA and 1 h before croton oil (Protocol 1) and immediately after croton oil (Protocol 3) did not have an additional protective effect against skin tumors compared with Protocol 2. Kruskal-Wallis analysis of variance by ranks showed that Protocol 2 is the most effective, with the treatment groups belonging to different populations at the 0.05 level of significance compared with alpha = 0.20 for Protocols 1 and 3. Turmeric is the most potent nutraceutical, because the average number of tumors formed after application of tumeric is statistically different from the positive control at alpha = 0.01.
9,10-Dimethyl-1,2-benzanthracene↗
Effect of stalk and leaf extracts from Euphorbiaceae species on Aedes aegypti (Diptera, Culicidae) larvae.
The objective of this study was to evaluate the larvicidal activity of essential oil aqueous solutions (hydrolates) obtained by steam distillation of stalks and leaves of Croton argyrophylloides, Croton nepetaefolius, Croton sonderianus and Croton zehntneri against Aedes aegypti larvae. Twenty-five larvae of third instar were placed in plastic beckers, containing the hydrolates (50 mL), in a four repetitions scheme. Water was used as control and the number of dead larvae was counted after 24 hours. The data obtained were submitted to Variance Analysis and Tukey test. Significant differences were observed among the hydrolates from different species and from different parts of each plant (p < 0.001). The hydrolates of stalk and leaf from C. nepetaefolius and C. zehntneri and leaf hydrolate of C. argyrophylloides presented 100% mortality against larvae. The compounds present in C. zenhtneri and C. nepetaefolius are oxygenated phenylpropanoids that are more soluble in water than the monoterpenes and sesquiterpenes detected in the oils of C. argyrophylloides and C. sonderianus. This study showed that all species analyzed presented compounds with larvicidal properties, with differences between each plant parts.
Aedes↗
Nonbacterial inflammation as a means of enhancing skin flap survival.
Painting the skin of the dorsum of a rat with croton oil improved the survival length of caudally based skin flaps. No vasodilation was demonstrated in the deeper layers of skin treated with croton oil. The mechanism by which the application of croton oil leads to improvement of the skin flap survival is thought to be the nonbacterial inflammation produced by the croton oil (a chemical burn). This inflammatory effect probably acts upon the microcirculation via arachidonic acid metabolite mediators.
Animals↗
Change of polyamine content in mouse skin by leupeptin, a protease inhibitor, during early stage of tumorigenesis.
The effect of a microbial protease inhibitor, leupeptin, on the content of polyamine in the mouse skin was examined during the early stage of tumorigenesis induced by a single application of 7,12-dimethylbenz[a]anthracene (DMBA) and repeated application of croton oil thereafter. Polyamine content in the skin was measured at 3, 5, 7, and 9 weeks during tumorigenesis. The mice with no visible tumor were selected for measurement of polyamine content at 9 weeks. Mice were left untreated for at least 1 week before measurement of polyamine. Polyamine in the skin was extracted with ice-cold 0.4N HClO4 and separated into putrescine, spermidine, and spermine fractions through CM-cellulose column. Polyamine concentration was determined by fluorometry with fluorescamine. Group A mice painted with croton oil 3 times a week did not develop tumors. Group B mice painted with a single DMBA developed skin tumors, and group C mice painted with a single DMBA and croton oil 3 times a week showed higher development of skin tumors than group B. Group D mice treated as group C and then painted with leupeptin about 2 hr after croton oil treatment. Animals in groups B, C, and D had higher spermidine content as group A at 3 and 5 weeks. Content of spermidine in group B decreased at 7 and 9 weeks compared with group C which had a high content throughout the time tested. Leupeptin treatment in group D inhibited spermidine content in the skin after 7 weeks without affecting until 5 weeks.
Animals↗