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At least 577 records · Page 32Linked to original sources
PubMed2004

Modulatory effect of Morus indica against two-stage skin carcinogenesis in Swiss albino mice: possible mechanism by inhibiting aryl hydrocarbon hydroxylase.

The modulatory effect of the methanolic extract of Morus indica on 12-O-tetradecanoyl-phorbol-13-acetate (TPA) induced oxidative stress and 7,12-dimethylbenz(a)anthracene induced and croton oil (0.5% per mouse/0.2 mL acetone, v/v) promoted skin tumourigenesis in Swiss albino mice was studied. The efficacy of the M. indica extract was also evaluated in-vitro by studying the inhibition of the activity and level of aryl hydrocarbon hydroxylase, cytochrome P450, DNA sugar damage in calf thymus DNA and Fe(++)/ascorbate-induced lipid peroxidation in microsomes of mice. Significant increases in the activity of antioxidant enzymes (P <0.001) and a concomitant decrease (P <0.001) in the cutaneous malondialdehyde level were observed at three doses of plant extract (2.5, 5.0 and 7.5 mg kg(-1)). Application of M. indica 1 h before each application of croton oil showed inhibitory effects on tumour promotion in terms of a reduction in the number of tumours/mouse and percentage of mice with tumours. It was also accompanied by an extension of the tumour latency period. TPA, which resulted in a rapid and transient stimulation of mouse epidermal ornithine decarboxylase activity (P <0.001), was inhibited dose dependently by pre-treatment with M. indica extract (P <0.001). The results suggest that M. indica extract may be useful as a therapeutic agent for cancer control as it blocks or suppresses events associated with chemical carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1995

Effects of alkaloids extracted from the stem bark of Hunteria zeylanica on acute inflammation in experimental animals.

The effects of crude alkaloids extracted from the stem bark of Hunteria zeylanica GARD. (H. zeylanica) on acute inflammatory responses such as carrageenin-induced paw edema in rats and croton oil- and arachidonic acid-induced ear edema in mice were investigated. Oral administration of H. zeylanica alkaloid extract (200-400 mg/kg) significantly suppressed the paw swelling induced by carrageenin. In the croton oil-induced ear edema, topically applied H. zeylanica alkaloid extract, at doses of 200 and 400 mg/ml, also significantly reduced ear edema. Moreover, the extract (50-200 mg/kg, p.o.) reduced in a dose-dependent manner the ear swelling induced by topically applied arachidonic acid (2 mg/ear). These results suggest that the inhibitory effects of H. zeylanica alkaloid extract on acute edema formation are partly due to inhibition of 5-lipoxygenase and cyclooxygenase activity.

Alkaloids↗
PubMed1991

[Anti-inflammatory effects of methylprednisolone aceponate in animals].

In the case of dermal application of the drugs to croton oil-induced ear edema in rats and picryl chloride-induced delayed type hypersensitivity in mice, the anti-inflammatory effect of methylprednisolone aceponate (MPA) was slightly weaker than those of clobetasol 17-propionate and diflucortolone 21-valerate, but stronger than those of hydrocortisone 17-butyrate and hydrocortisone 17-butyrate 21-propionate. Betamethasone 17-valerate applied dermally was less and more effective than MPA to ear edema in rats and delayed type hypersensitivity in mice, respectively. The anti-inflammatory effect of MPA was weaker in subcutaneous administration than in topical application to the two inflammatory models. It was suggested that MPA has strong anti-inflammatory effects and weak systemic effects by topical application. Methylprednisolone 17-propionate (MP-17P) and methylprednisolone (MP), unesterified in only the C-21 position and in both the C-17 and 21 positions of MPA, respectively, showed weaker anti-inflammatory activities than MPA by topical application to croton oil-induced ear edema. The ratio of the anti-inflammatory effects by topical application to subcutaneous administration of MPA was higher than those of MP-17P and MP. The excellent characteristics of MPA as a dermal anti-inflammatory drug are suggested to be derived from di-esterification of MP, which has a weak activity intrinsically.

Administration, Topical↗
PubMed1975

Inflammation of the skin. I. Phospholipid metabolism in some experimental inflammations of mouse skin.

Phospholipid metabolism in inflamed tissue of the mouse skin which had been induced by the application of 1-chloro-2, 4-dinitrobenzene (DNCB), croton oil, or irradiation of ultraviolet rays was examined, and it was found that phospholipid levels had increased in theinflamed tissues. In the case of ultraviolet rays, the increase was temporary, and the level returned to that of control after 3 or 4 days. In the case of DNCB or croton oil, the level increased after a decrease for a short period. The pattern of the increase between physical and chemical irritation was different. Increase of incorporation of 32-P into phospholipid in inflamed tissue was examined, and it was observed that the level reached a maximum after one day. It is thus assumed that phospholipid plays an important role in the mechanism of inflammation.

Animals↗
PubMedDate not supplied

Changes in serum ovotransferrin levels in chickens with experimentally induced inflammation and diseases.

A competitive enzyme immunoassay was developed to measure the changes in serum levels of ovotransferrin (OTF) during inflammation and infectious diseases in chickens. The assay is based on the competition of serum OTF with a fixed concentration of biotin-labeled OTF to bind to a rabbit anti-chicken transferrin antibody immobilized on microtiter wells. After several washing steps, the antibody-bound biotinylated OTF is probed with streptavidin-horseradish peroxidase conjugate (HRP) followed by a colorimetric detection of the HRP activity. The relative changes in the optical density of color are plotted against the competing concentrations of OTF with logarithmic regression to generate a standard curve that is used to determine the concentrations of OTF in unknown samples. Serum had no effect on the measurement of OTE By this method, the time course changes of serum OTF levels in 4-wk-old male broiler chickens that were subjected to inflammation by croton oil injection were measured. The results showed croton oil-induced inflammation elevated serum OTF levels at 16 hr postinjection. OTF levels reached a peak by 72 hr, remained high through 120 hr, and returned to a basal level of olive oil-injected controls by 240 hr. There were no changes in serum OTF levels at any of the above time points in olive oil-injected control chickens. For studies with poultry diseases, specific-pathogen-free (SPF) male chickens were challenged with known bacterial and viral pathogens, and serum was collected at the height of the infection, i.e., 7 days after the challenge. Compared with uninjected controls, the SPF chickens challenged with Escherichia coli, fowl poxvirus, respiratory enteric orphan virus, infectious bursal disease virus, infectious bronchitis virus, or infectious laryngotracheitis virus had higher levels of OTF in serum. Inflammation-induced changes in serum OTF levels were also evident in the changes in the density of a 65-kD band protein corresponding to OTF. These results demonstrate that serum OTF may be a nonspecific clinical marker of inflammation associated with traumatic or infectious avian diseases.

Animals↗
PubMed1995

Topical cis-urocanic acid suppresses both induction and elicitation of contact hypersensitivity in BALB/C mice.

Cis-urocanic acid, converted from trans-urocanic acid in stratum corneum by ultraviolet B irradiation, has been shown to impair contact hypersensitivity induction. To study whether topical cis-urocanic acid also alters contact hypersensitivity elicitation, as well as immediate hypersensitivity and acute irritation, we treated mice with 1% topical cis-urocanic acid or vehicle prior to induction or elicitation of hypersensitivity to contact allergen oxazolone or respiratory allergen trimellitic anhydride or prior to acute irritation from croton oil. Topical cis-urocanic acid suppressed both induction and elicitation of contact hypersensitivity to oxazolone. However, no effect by cis-urocanic acid on induction or elicitation of trimellitic anhydride allergy or croton oil irritation was seen. The possible efficacy of topical cis-urocanic acid as a treatment of inflammatory skin diseases responsive to ultraviolet B irradiation may be worthwhile to investigate.

Administration, Topical↗
PubMed1990

Immunogenicity and cross-reactivity of syngeneic murine melanomas.

Non-melanoma skin cancers induced in mice by chemical carcinogens or ultraviolet radiation are often antigenic but rarely induce cross-protective immunity when tested by in vivo transplantation methods. We wished to determine whether melanocytic skin tumors behave similarly or whether they exhibit cross-reactive antigens in vivo. Three melanomas induced in C3H/HeNCr(MTV-) mice by initiation with ultraviolet radiation and promotion with croton oil or initiation with 7,12-dimethyl-benz[a]anthracene and promotion with 12-O-tetradecanoyl-phorbol-13-acetate or croton oil plus ultraviolet radiation were tested for immunogenicity and cross-reactivity in vivo. The three melanomas were highly immunogenic, and all induced some degree of protection against the other melanomas. Non-melanoma skin cancers induced by the same carcinogens were less immunogenic and did not immunize against the melanomas. We conclude that unlike other skin cancers, melanocytic tumors induced by chemical carcinogens and ultraviolet radiation are highly cross-reactive in vivo and thus represent a unique subset of murine skin cancers.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2001

Modified phenol chemical face peels: recognizing the role of application technique.

The use of phenol to achieve chemexfoliation of facial tissue, following the standard Baker-Gordon formula or modifications of that formula, can produce a range of results depending on a variety of factors. This article-based on 16 new cases of modified phenol peels, three human biopsy studies, and one triple-blind study-examines the relative roles of phenol concentration, croton oil concentration, and application technique in the production of the chemical peel result. Results of this data suggest that the application technique is more important than the concentration of phenol or croton oil and underscore the importance of standardizing the application process.

Biopsy↗
PubMed2001

Anti-inflammatory effect and mechanism of proanthocyanidins from grape seeds.

AIM: To investigate the anti-inflammatory effect and mechanism of proanthocyanidins (PA) from grape seeds. METHODS: Croton oil-induced ear swelling in mice and carrageenan-induced hind paw edema in rats were prepared. The nitric oxide synthase (NOS) activity was measured by NADPH-diaphoras stain assay, nitric oxide (NO) content by Griess diazotization assay, N-acetyl-beta- D-glucosaminidase (beta-NAG) activity by spectrophotography, malondialdehyde (MDA) content by thiobarbituric acid (TBA) fluorescence technique, and IL-1beta, TNFalpha, and PGE2 content by radioimmunoassay (RIA). RESULTS: PA 10-40 mg/kg ip inhibited carrageenan-induced paw edema in rats and croton oil-induced ear swelling in mice in a dose-dependent manner. PA 10 mg/kg reduced MDA content in inflamed paws, inhibited beta-NAG and NOS activity, and lowered the content of NO, IL-1beta, TNFalpha, and PGE2 in exudate from edema paws of rats induced by carrageenan. The inhibitory effect of PA on all above indices was more evident than that of dexamethasone 2 mg/kg. CONCLUSION: PA has anti-inflammatory effect on experimental inflammation in rats and mice. Its mechanisms of anti-inflammatory action are relevant to oxygen free radical scavenging, anti-lipid peroxidation, and inhibition of the formation of inflammatory cytokines.

Animals↗
PubMed1975

[On the specifity and stereospecificity of the conversion of different 2,3-unsaturated acids by Clostridium kluyveri (author's transl)].

Further 2,3-unsaturated acids are revealed which can be reduced by Clostridium kluyveri with crotonate or butyrate as hydrogen donors. Unsaturated and saturated 3-halogenated acids are transformed into the saturated halogen-free acids. The following reaction sequence is proposed: a) hydrogenation, b) elumination of HX and c) again hydrogenation. Tiglinate ((E)-2-methyl-2-butenoate) and (E)-2-methyl-2-pentenoate are stereospecifically reduced to the (S)-2-methyl substituted acids. C. kluyveri contains endogenous material; in the presence of hydrogen acceptors such as 2,3-unsaturated acids this is degraded to acetate, and the reducing equivalents liberated hydrogenate the unsaturated acid. In a transient phase the hydration products of the unsaturated acids are present in the non-activated form in appreciable amounts. Tiglinate as well as crotonate is partially converted to ethyl methyl ketone and aceton and/or propanol, respectively.

Butyrates↗
PubMed2002

Anti-inflammatory effect of recombinant human superoxide dismutase in rats and mice and its mechanism.

AIM: To investigate the anti-inflammatory effects and mechanism of recombinant human superoxide dismutase (rhSOD). METHODS: Inflammation models such as croton oil-induced ear swelling and carrageenan-induced hind paw edema in mice and rats were prepared. The nitric oxide synthase (NOS ) activity was measured by NADPH-diaphoras stain assay, N-acetyl-beta-D-glucosaminidase (beta-NAG) activity by spectrophotography, malondialdehyde (MDA) content by thiobarbituric acid (TBA) fluorescence technique, and interleukin-1beta (IL -1beta), tumor necrosis factor alpha (TNF alpha), and IL-8 content by radioimmunoassay (RIA). RESULTS: rhSOD 20-80 mg/kg ip, 40-80 mg/kg im, and 80 mg/kg ip significantly inhibited carrageenan-induced paw edema in rats, croton oil-induced ear swelling in mice, and carrageenan-induced hind paw edema in mice, respectively. In the rat arthritis induced by carrageenan, rhSOD 40 mg/kg reduced MDA content in inflamed paws, inhibited NOS activity, and lowered the content of IL-1beta and TNFalpha in exudate significantly. The inhibitory effect of rhSOD 40 mg/kg ip on IL-1beta production was more evident than that of dexamethasone 2 mg/kg ip. Also rhSOD obviously inhibited neutrophil infiltration; However, rhSOD had no effect on beta-NAG activity in exudate. CONCLUSION: rhSOD has anti-inflammatory effect on experimental inflammation in rats and mice, and its mechanisms are relevant to oxygen free radical scavenging, anti-lipid peroxidation, inhibition of neutrophil infiltration, and formation of inflammatory cytokines.

Animals↗
PubMedDate not supplied

Parathyroid hormone fragment 1-34 and anti-inflammatory effect.

We have studied the possible activity of the rat parathyroid hormone fragment 1-34, peripherally or centrally injected, on the vascular permeability induced by local administration of croton oil. Our study considered also the possible interference of parathyroid hormone fragment 1-34 on the release of histamine by mast cells and on the content of histamine in paw tissue. Parathyroid hormone fragment 1-34 significantly reduced the increase in vascular permeability produced in mice by local croton oil injection, as well as the serotonin-induced paw edema in the rat. These effects of parathyroid hormone fragment 1-34 were present only after peripheral administration. At the dose of 3.3 micrograms/kg, it decreased the histamine content in paw tissue. Peripheral administration of a calcium antagonist, such as nimodipine, at the dose of 50 micrograms/kg, or a metal-chelating agent, such as ethylene-diaminetetraacetic acid, at the dose of 10 micrograms/kg, antagonized the anti-inflammatory effect of parathyroid hormone fragment 1-34. Moreover, at 10-100 microliters/ml it significantly decreased the histamine release by mast cells.

Anaphylaxis↗
PubMed1976

Carcinogenesis by carbamic acid esters and their binding to DNA.

The tumor-initiating potency of three simple alkyl carbamates and mono-N-substituted ethyl carbamates was examined in Hall strain mice. The binding of 14C-labeled carbamates of DNA was measured in Crackenbush mice. Ethyl carbamate was the most potent carcinogen for the epidermis, liver, and lung, followed by its N-alkyl derivatives. Methyl carbamate was without effect but n-propyl and n-butyl were possible carcinogens. The ethyl esters bound to a greater extent to DNA in liver and skin than the methyl, n-propyl, and n-butyl esters and only this binding persisted. A preliminary application of croton oil increased the yield of skin tumors but not of liver or lung tumors. It also increased the binding of the alkyl carbamates to DNA in skin, the increase being greatest with ethyl carbamate. The binding persisted longer in treated than in non-croton oil-treated mice.

Adenoma↗
PubMed1991

[Immunogenic properties of neomycin conjugates with macromolecular carriers].

To obtain diagnostic antibodies to neomycin, immunogenic properties of the neomycin conjugates with macromolecular carriers were studied. Bovine serum albumin and copolymers of N-vinylpyrrolidone with crotonic acid and N-hydroxyphthalimide ether of crotonic acid were used as carriers. It was shown that immunization of mice by the conjugates in combination with Freund's adjuvant resulted in production of neomycin antibodies, the titer being 1/80 to 1/130. When the antibiotic conjugates with the copolymers of N-vinylpyrrolidone were used and not the neomycin conjugates with the carrier of the protein nature, the neomycin antibodies were produced in the absence of Freund's full adjuvant. With the use of the isolated antibodies to neomycin a method for indirect solid phase enzyme immunoassay of neomycin was developed at the minimum detectable level of 25 ng/ml.

Animals↗
PubMed1988

Contact thermography for assessment of skin damage due to experimental irritants.

Irritant dermatitis after application of experimental irritants was studied by means of contact thermography. Sixteen healthy persons were patch-tested, using the following irritants: Sodium lauryl sulphate, benzalkonium chloride, nonanoic acid, hydrochloric acid, croton oil, sapo kalinus and sodium hydroxide. A main finding was that croton oil after 24 h caused a warm skin lesion, and sodium lauryl sulphate after 96 h caused a cold skin lesion. This study emphasizes the differences in the skin reactions to different irritants.

Croton Oil↗
PubMed1974

The effect of edema, hydrocortisone acetate, concurrent viral infection and immunization on the clearance of Pasteurella hemolytica from the bovine lung.

The influence of pulmonary edema, hydrocortisone, immunization against Pasteurella hemolytica and concurrent infection with parainfluenza-3 virus upon pulmonary clearance of aerosolized P. hemolytica was studied in 31 calves. Following the various treatments calves were challenged with an aerosol of P. hemolytica. One control calf was killed immediately after the aerosol and the numbers of bacteria in the lung taken as 100%. Two calves were killed four hours after challenge and the numbers of bacteria in the lungs were compared to the 100% of the control calf. The result was the percentage clearance of bacteria at four hours. PULMONARY EDEMA WAS INDUCED BY THREE DIFFERENT METHODS: by an aerosol of histamine, by intravenous injection of endotoxin and by intravenous injection of croton oil emulsion. The edema impaired the clearance of P. hemolytica, which was reflected in high numbers of P. hemolytica present in the lungs at four hours after challenge: 260% after histamine, 300% and 400% after endotoxin and 92% after croton oil. SIX DAYS OF TREATMENT OF FOUR CALVES WITH HIGH DOSES OF HYDROCORTISONE ACETATE PRODUCED INCONSISTENT RESULTS: two calves treated with a higher daily dose (36 mg/kg) had normal clearance whereas two calves treated with a lower dose had pulmonary edema and displayed lowered clearance with 111% and 31% respectively of P. hemolytica retained in the lungs four hours after challenge. Immunization of calves by three different methods, a subcutaneously injected bacterin of P. hemolytica (2 calves), single aerosol (2 calves) and four aerosols (4 calves) of live P. hemolytica was reflected in an accelerated pulmonary clearance of P. hemolytica (with a mean of 1.55% of bacteria retained at four hours). Concurrent infection with parainfluenza-3 virus did not lower the clearance of P. hemolytica in the lungs of 12 calves over 15 days except on the first day following the exposure to parainfluenza-3 virus. These calves had hemagglutinating antibodies against P. hemolytica before exposure.

Aerosols↗
PubMed1975

Induction of the polyamine-biosynthetic enzymes in mouse epidermis by tumor-promoting agents.

A single topical application of 1.0 mg of crotol oil or 17 nmoles of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) resulted in a rapid, transient stimulation of mouse epidermal ornithine decarboxylase activity. The activity reached a peak (230-fold greater than control after TPA) at 4 to 5 hr after croton oil or TPA treatment and returned to control level by 12 hr. The stimulation of S-adenosyl-L-methionine decarboxylase activity was less pronounced, reaching a peak of activity (6- to 7-fold greater than control) at 9 to 12 hr after TPA or croton oil and slowly declining to control level. The stimulation of both enzyme activities was dependent on the dose of TPA applied and correlated well with the promoting ability of these doses on mouse skin. Phorbol, the nonpromoting parent alcohol of TPA, did not affect the enzymes activities. Cycloheximide pretreatment abolished the increase in enzyme activities after TPA application. By measuring the decline of enzyme activity following cycloheximide treatment, enzyme half-lives of 17 and 41 min were obtained for ornithine and S-adenosyl-L-methionine decarboxylase, respectively. 5-Azacytidine pretreatment prevented the stimulation of enzyme activities by TPA, while actinomycin D had no effect. Cordycepin (3'-deoxyadenosine) partially blocked the rise in enzyme activities.

Adenosylmethionine Decarboxylase↗
PubMed1980

Measurement and differentiation of the cellular infiltrate in experimental toxic contact dermatitis.

Toxic (irritant) contact dermatitis was elicited by epicutaneous application of dinitrochlorobenzene (DNCB) and croton oil in unsensitized guinea pigs. The course of the skin reaction was studied with the naked eye, low-power microscopy, and a method based on counting of infiltrating cells in the upper corium. A weakly toxic dose of DNCB (100 microgram/cm2) gave marked erythema and moderate swelling, more pronounced 6 h after application of the DNCB than at 24 h or 48 h. A significant increase in mononuclear cells in particular but also in neutrophil and eosinophil granulocytes was noted in the upper corium. A more strongly toxic dose (500 microgram/cm2) gave a similar visible reaction, this too most marked at 6 h, but here there was an increase in neutrophil granulocytes in particular. Over and above predominant mononuclear-cell infiltration, croton oil (10 microgram/cm2) caused a slight increase in basophil cells. The reaction thus resembled a contact allergic reaction. In the light of earlier findings in allergic contact reactions the results suggest that weak stimuli, toxic or allergenic, elicit a non-specific skin response. With stronger stimulation the histological picture is modified and the cellular response acquires a pattern characteristic of toxic or allergic contact dermatitis.

Animals↗