C-type natriuretic peptide (CNP) inhibits 7,12-Dimethylbenz[a]anthracene (DMBA)/Croton oil-induced skin tumor growth by modulating inflammation in Swiss albino mice.

C-type natriuretic peptide (CNP) exhibits anti-inflammatory activity besides its natriuretic and diuretic functions. The present study aimed to determine the anticancer and synergistic therapeutic activity of CNP against a 7,12-Dimethylbenz[a]anthracene (DMBA)/Croton oil-induced skin tumor mouse model. CNP (2.5 µg/kg body weight) was injected either alone and/or in combination with Cisplatin (CDDP) (2 mg/kg body weight) for 4 weeks. The dorsal skin tumor incidences/growth and mortality rate were recorded during the experimental period of 16 weeks. The serum C-reactive protein (CRP), and lactate dehydrogenase (LDH) levels, infiltrating mast cells, and AgNORs proliferating cells count were analyzed in control and experimental mice. Further, the expression profile of marker genes of proliferation, inflammation, and progression molecules were analyzed using Reverse transcriptase-polymerase chain reaction (RT-PCR)/quantitative PCR (qPCR), western blot, and immunohistochemistry. The DMBA/Croton oil-induced mice exhibited 100% tumor incidence. Whereas, CNP alone, CDDP alone, and CNP+CDDP combination-treated mice exhibited 58%, 46%, and 24% tumor incidence, respectively. Also, a marked reduction in the levels of serum CRP and LDH, the number of infiltrating mast cells count and AgNORs proliferating cells count were noticed in the mice skin sections. Further, a significant reduction in both mRNA and protein expression levels of proliferation, inflammation, and progression markers were noticed in CNP (p < 0.01), CDDP (p < 0.01), and CNP+CDDP combination (p < 0.001) treated mice, respectively. The results of the present study suggest that CNP has anticancer activity. Further, the CNP+CDDP treatment has more promising anticancer activity as compared with CNP or CDDP alone treatment, probably due to the synergistic antiproliferative and anti-inflammatory activities of CNP and CDDP.

Oral Intake of Combined Natural Immunostimulants Suppresses the 7,12-DMBA/ Croton Oil Induced Two-step Skin Carcinogenesis in Swiss Albino Mice.

BACKGROUND: The immune system is critical in fighting cancer, so is it possible that the natural stimulation of this system can slow down or stop the evolution of cancer? Our in vivo study aimed to evaluate the protective effect of the combination of five types of immunostimulants, which are Beta-glucan and Arabinogalactan as polysaccharides and three mushroom extracts (Reishi, Maitake, and Shiitake), on 7,12-Dimethyl Benz[a]anthracene (DMBA)/ Croton oil-induced papilloma in Swiss albino mice. METHODOLOGY: We used blood count analyses to estimate broadly the immunological reaction and biochemical techniques to determine the oxidative stress variations in the enzymatic activity of Superoxide dismutase (SOD), Catalase (CAT), and Glutathion peroxidase (GPx), which could have a preventive function against cancer development. RESULTS: The cutaneous application of the DMBA/Croton oil caused precancerous hyperplasia in squamous cells (papilloma) on the back of the mice. Tumor development was accompanied by a decrease in SOD and GPx activities. The treatment with the immunostimulants led to the total disappearance of the incidence of skin papillomas and also showed a nearly back to normal SOD activity but not CAT and GPx activities. The increase in the level of immune cells (lymphocytes, monocytes, and white blood cells) reflected a clear enhancement of the immune system activity. DISCUSSION: The healthy epidermis observed with treated mice simultaneously subjected to the cancerogenosis protocol suggests the inhibition of spinous cell proliferation leading to the total suppression of the hyperplasia. Moreover, the increase in the level of immune cells in this batch reflects an inflammatory reaction. Indeed, previous studies reported that immunostimulants, including Betaglucan involve a release of some inflammatory mediators who would be at the origin of its anticancer activity. Cancerogenesis has clearly disrupted the activities of the antioxidant enzymes, but the relationship between the two process is often complex. Bibliographic data led us to suggest that low catalytic activities of CAT and GPx observed in treated mice simultaneously subjected to the cancerogenesis protocol, would have induce an accumulation of H2O2 which has often been described as an inducer of cancer cells apoptosis. CONCLUSION: Immunostimulants used in our study could have an effective protective effect against skin carcinogenesis via the enhancement of the global function of the immune system and modulation of the antioxidant defense. KEYWORDS: Immunostimulants, Beta-glucan, Arabinogalactan, Reishi, Maitake, Shiitake, DMBA, Croton oil, Oxidative stress, Carcinogenesis. ABBREVIATIONS: C, control group; Dc, drug control group; Pc, positive control group; St, sick treated group;DMBA, 7,12 Dimethyl Benz[a]anthracene; NK, natural killer; CAT, catalase; SOD, superoxide dismutase, GPx, glutathione peroxidase; IS, immunostimulants; WBC, White blood cells; LY, Lymphocytes; MO, Monocytes; ROS, Reactive oxygen species; ONAB, Office national des aliments de bétail.

Depth Map for Face and Neck Deep Chemical Peel Resurfacing.

BACKGROUND: Chemical peels are applied to the face and neck to improve rhytides and the photoaged appearance of the skin. Peels can be applied to different skin depths depending on the types of chemicals, the volume of solution, and the amount of pressure or friction applied. If a peel is applied too superficially, rhytides will not be removed. If a peel is applied too deeply, scarring or hypopigmentation could occur. OBJECTIVE: To create face and neck depth maps for chemical peeling, which can guide safety when removing rhytides and improving the skin's appearance. MATERIALS AND METHODS: A multicenter retrospective review of records was conducted of patients who underwent phenol-croton oil peeling, from January 1, 2018, to December 31, 2018. Information was collected on facial and neck cosmetic units peeled, peel formula and strength used, outcomes, and complications. RESULTS: A total of 410 patients received deep peels. Two depth maps were created that corresponded to the most common patterns of deep chemical peel applications. CONCLUSION: Different areas of the face and neck are treated with different chemical peel application depths to safely improve rhytides and appearance. Depth maps are created to balance safety and efficacy.

Histological case-control study of peeling-induced skin changes by different peeling agents in surgically subcutaneous undermined skin flaps in facelift patients.

A histological evaluation of peeling-induced skin changes in subcutaneous undermined preauricular facial skin flaps of nine patients was performed. There were three treatment groups: Trichloroacetic acid (TCA) 25%, TCA 40% and phenol/croton oil; one group served as control. Two independent evaluators determined the epidermal and dermal thickness and the depth of necrosis (micrometre). The percentual tissue damage due to the peeling was calculated, and a one-sample t-test for statistical significance was performed. On the basis of the histomorphological changes, peeling depth was classified as superficial, superficial-partial, deep-partial and full thickness chemical burn. The histological results revealed a progression of wound depth for different peeling agents without full thickness necrosis. TCA peels of up to 40% can be safely applied on subcutaneous undermined facial skin flaps without impairing the vascular patency, producing a predictable chemical burn, whereas deep peels such as phenol/croton oil peels should not be applied on subcutaneous undermined skin so as to not produce skin slough or necrosis by impairing vascular patency.

Ethnopharmacological study and topical anti-inflammatory activity of crude extract from Poikilacanthus glandulosus (Nees) Ariza leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Ethnopharmacological studies are important tools as records and documentation of the empirical uses of medicinal plants in traditional communities with the purpose of generating useful knowledge to lead to the development of new medicines, biodiversity conservation and enhancement of knowledge and local culture. Poikilacanthus glandulosus is widely used by the population of City of Santiago, in Brazil, nevertheless, it does not have any validation regarding its use and its medicinal effects. AIM: The objective of this study was to perform one ethnopharmacological survey about P. glandulosus in the City of Santiago and determine the anti-inflammatory activity in order to prove its uses in popular medicine. METHODS: Personal and ethnopharmacological data were collected through a prepared questionnaire. The phytochemical analysis was performed observing the individual methodology for each reaction and by HPLC-UV. The antiedematogenic and anti-inflammatory (cell infiltration and histological procedure) activities of the P. glandulosus (0.01-1000µg/ear) were evaluated in the ear edema model induced by topical application of croton oil. RESULTS: P. glandulosus is known in City of Santiago as "Gaiana" and its macerated leaves and branches are prepared with alcohol or sugarcane liquor especially for insect bites, cicatrization and inflammation. HPLC analysis revealed the presence of maslinic acid (2.024±0.10mg/g), uvaol (0.124±0.02mg/g) and sitosterol (0.502±0.05mg/g). The topical application of crude extract of P. glandulosus reduced in a dose-dependent manner the croton oil-induced ear edema and myeloperoxidase activity (neutrophils infiltration marker) with maximum inhibition of 87±2% and 64±12%, respectively at 1000µg/ear. Dexamethasone (100µg/ear), used as a positive control, inhibited croton oil-induced ear edema in 89±3% and decreased myeloperoxidase activity in 50±3%. Both P. glandulosus as dexamethasone reduced cell infiltration when evaluated by histological procedure CONCLUSION: This work allowed us to understand the specie P. glandulosus through ethnopharmacological study and it showed that the crude extract presented antiedematogenic and anti-inflammatory actions, proving their traditional use as anti-inflammatory.

4D intravital microscopy uncovers critical strain differences for the roles of PECAM and CD99 in leukocyte diapedesis.

Leukocyte transendothelial migration (TEM) is an essential component of the inflammatory response. In vitro studies with human cells have demonstrated that platelet/endothelial cell adhesion molecule (PECAM) functions upstream of CD99 during TEM; however, results in vivo with mice have been apparently contradictory. In this study we use four-dimensional (4D) intravital microscopy to demonstrate that the site and order of function of PECAM and CD99 in vivo are dependent on the strain of mice. In FVB/n mice, PECAM functions upstream of CD99, as in human cells in vitro, and blocking antibodies against either molecule arrest neutrophils before they traverse the endothelium. However, in C57BL/6 mice, PECAM and CD99 appear to function at a different step, as the same antibodies arrest leukocyte migration through the endothelial basement membrane. These results are the first direct comparison of PECAM and CD99 function in different murine strains as well as the first demonstration of the sequential function of PECAM and CD99 in vivo.

Chemomodulatory Potential of Flaxseed Oil Against DMBA/Croton Oil-Induced Skin Carcinogenesis in Mice.

The present study was conducted to evaluate the potential of flaxseed oil to prevent chemically induced skin cancer in mice. Cancer was induced on 2-stage skin carcinogenesis model by single topical application of 7,12 dimethylbenz [a]anthracene (DMBA), as, initiator, and two weeks later it was promoted by croton oil treatment thrice a week on the dorsal surface of mice for 16 weeks. Flaxseed oil (FSO; 100µL/animal/d) was orally administered 1 week before and 1 week after DMBA application (Peri-initiation stage). The animals of the FSO-administered group showed a significant reduction in tumor incidence (76.67%), cumulative number of tumors (37), tumor yield (3.7), and tumor burden (4.81) when compared with the carcinogen-treated control animals. Biochemical parameters in skin and liver tissue such as LPO and phase I enzymes were significantly (P < .01) reduced in the FSO-treated experimental group, whereas the phase II enzymes (GST, DT-diaphorase) and antioxidant parameters (GSH, GPx, SOD, catalase, and vitamin C) exhibited a significant (P < .01) elevation when compared with the animals of the carcinogen-treated control group. Histopathological alterations in the carcinogen-treated control animals were also observed in the form of epidermal hyperplasia, keratinized pearl formation, and acanthosis in skin and tumors, whereas these were found to be reduced after FSO administration. The results of the present study demonstrate that the oral administration of FSO has the potential to modulate the levels of LPO, antioxidants, and detoxification enzymes in the DMBA-croton oil-induced skin carcinogenesis in mice.

Epidermal RelA specifically restricts contact allergen-induced inflammation and apoptosis in skin.

Strong inhibition of NF-κB signaling in the epidermis results in spontaneous skin inflammation in mice and men. As there is evidence for linkage between polymorphisms within the NF-κB signaling pathway and human inflammatory skin phenotypes, we asked whether partial functional inhibition of NF-κB signaling in epidermal keratinocytes can modulate clinically relevant skin inflammation. We therefore mutated rela specifically in the epidermis of mice (RelA(E-MUT) mice). These mice show no inflammatory phenotype. Induction of contact allergy, but not croton oil-induced irritant dermatitis, resulted in stronger ear swelling and increased epidermal thickness in RelA(E-MUT) mice. Both contact allergen and croton oil treatment led to increased expression of calgranulins A and B (S100A8/A9) in RelA(E-MUT) mice. Epidermal hyperproliferation in RelA(E-MUT) mice was non-cell autonomous as cultured primary epidermal keratinocytes from RelA(E-MUT) mice showed reduced proliferation compared with controls. These results demonstrate that epidermal RelA specifically regulates delayed-type hypersensitivity-induced skin inflammation. In addition, we describe here an essential but nonspecific function of RelA in the protection of epidermal keratinocytes from apoptosis. Our study identifies functions of NF-κB signaling in the epidermis and corroborates a specific role of epidermal keratinocytes in the regulation of skin inflammation.

Anti-inflammatory effects of anthocyanins-rich extract from bilberry (Vaccinium myrtillus L.) on croton oil-induced ear edema and Propionibacterium acnes plus LPS-induced liver damage in mice.

Bilberry (Vaccinium myrtillus L.) has been known to play a protective role in human health due to its high anthocyanin content. This study investigated the anti-inflammatory effects of bilberry extract (BE, containing 42.04% anthocyanin) on Propionibacterium acnes (P. acnes) plus lipopolysaccharide (LPS) induced liver injury and croton oil-induced ear edema in mice. Results showed that BE could effectively inhibit croton oil-induced ear edema and liver inflammation provoked by P. acnes plus LPS, as reflected by the reduced plasma alanine aminotransferase and aspartate aminotransferase activities. These findings were confirmed by hepatic pathological examination. Moreover, BE administration markedly suppressed the increase of liver mRNA levels of iNOS, TNF-α, IL-1ß and IL-6, and the protein levels of iNOS, TNF-α and NF-κB. In addition, liver malondialdehyde and NO contents were significantly reduced by BE treatment. These results indicated that BE has potent protective effects on acute and immunological inflammation, which might contribute to the study of the anti-inflammatory effects of natural products and healthy food.

Chemical peels: panel discussion.

Edwin Cortez, Fred Fedok, and Devinder Mangat address questions for discussion and debate. Do you agree or disagree, and why, with the following: "The best method to improve moderate to deep rhytids is the croton oil-phenol peel." "There are no problems with cardiotoxicity with croton oil-phenol peels if done appropriately." "Do not do spot testing with chemical peel agents." How do you handle peels in advanced Fitzpatrick skin types III, IV, V? What is the main factor for rate of reepithelialization: (1) depth of peel, (2) depth of laser, (3) depth of dermabrasion? How has your approach to or technique in chemical peels evolved over the past several years?

Chemopreventive effect of Lagenaria siceraria in two stages DMBA plus croton oil induced skin papillomagenesis.

Cancer chemoprevention is a dietary or therapeutic strategy to prevent, suppress, or delay carcinogenesis either at initiation or progression level with nontoxic agents. Use of natural dietary compounds has been a major chemopreventive approach to modulate tumorigenic pathways. In the present study, we have evaluated Lagenaria siceraria (bottle gourd), a common vegetable of Indian household for its chemomodulatory potential. The fruit has been used in traditional medicine for a very long time for health benefits and to cure pain, ulcers, fever, cough, asthma, and other bronchial disorders. However, despite its reported beneficial effect the chemo modulatory potential of this plant has not been reported. Therefore chemopreventive effect of bottle gourd juice (BGJ) was studied against 7,12-dimethylbenz(a)anthracene (DMBA) plus croton oil induced skin papillomagenesis in Swiss albino mice. The effect was studied both at antiinitiation and antiinitiation/promotion level followed by histopathological study. A dose of 2.5% and 5% given in drinking water showed significant decrease in papilloma number, papilloma incidence, papilloma multiplicity, papilloma latency, papilloma volume, and papilloma size in different size range. Histopathological study showed chemopreventive effect by minimizing loss of stratification, a decrease in number of epithelial layers, reducing dermal infiltration and protection for various cytoplasmic changes. Higher dose of BGJ was found to be more effective than lower dose and the chemopreventive effect was maximum for antiinitiation/promotion treatment. Altogether, this study reports the chemopreventive effect of Lagenaria siceraria on skin papillomagenesis for the first time and suggests that its consumption may help in suppression of skin cancer.

P2X7 receptor is required for neutrophil accumulation in a mouse model of irritant contact dermatitis.

Irritant contact dermatitis (ICD) is an inflammatory reaction caused by chemical toxicity on the skin. The P2X7 receptor (P2X7R) is a key mediator of cytokine release, which recruits immune cells to sites of inflammation. We investigated the role of P2X7R in croton oil (CrO)-induced ICD using in vitro and in vivo approaches. ICD was induced in vivo by CrO application on the mouse ear and in vitro by incubation of murine macrophages and dendritic cells (DCs) with CrO and ATP. Infiltrating cells were identified by flow cytometry, histology and myeloperoxidase (MPO) determination. Effects of the ATP scavenger apyrase were assessed to investigate further the role of P2X7R in ICD. Animals were also treated with N-1330, a caspase-1 inhibitor, or with clodronate, which induces macrophage apoptosis. CrO application induced severe inflammatory Gr1(+) cell infiltration and increased MPO levels in the mouse ear. Selective P2X7R antagonism with A438079 or genetic P2X7R deletion reduced the neutrophil infiltration. Clodronate administration significantly reduced Gr1(+) cell infiltration and local IL-1ß levels. In vitro experiments confirmed that A438079 or apyrase treatment prevented the increase in IL-1ß that was evoked by macrophage and DC incubation with CrO and ATP. These data support a key role for P2X7 in ICD-mediated inflammation via modulation of inflammatory cells. It is tempting to suggest that P2X7R inhibition might be an alternative ICD treatment.

Extraction optimization of Tinospora cordifolia and assessment of the anticancer activity of its alkaloid palmatine.

OBJECTIVE: To optimize the conditions for the extraction of alkaloid palmatine from Tinospora cordifolia by using response surface methodology (RSM) and study its anticancerous property against 7,12-dimethylbenz(a)anthracene (DMBA) induced skin carcinogenesis in Swiss albino mice. METHODS: The effect of three independent variables, namely, extraction temperature, time, and cycles was investigated by using central composite design. A single topical application of DMBA (100 µg/100 µL of acetone), followed 2 weeks later by repeated application of croton oil (1% in acetone three times a week) for 16 weeks, exhibited 100 percent tumor incidence (Group 2). RESULTS: The highest yield of alkaloid from Tinospora cordifolia could be achieved at 16 hours of extraction time under 40°C with 4 extraction cycles. Alkaloid administration significantly decreases tumor size, number, and the activity of serum enzyme when compared with the control (Group 2). In addition, depleted levels of reduced glutathione (GSH), superoxide dismutase (SOD), and catalase and increased DNA damage were restored in palmatine treated groups. CONCLUSION: The data of the present study clearly indicate the anticancer potential of palmatine alkaloid in DMBA induced skin cancer model in mice.

Mechanisms of olive leaf extract-ameliorated rat arthritis caused by kaolin and carrageenan.

Olive leaf extract (OLE) has antioxidant and antiinflammatory actions. However, the role of OLE in mechanical inflammatory arthritis (osteoarthritis, OA) is unclear. This study investigated the effect of OLE on the development of kaolin and carrageenan-induced arthritis, a murine model of OA. Administration of OLE significantly ameliorated paw swelling, the paw Evans blue content and the histopathological scores. In the human monocyte cell line, THP-1, the OLE reduced the LPS-induced TNF-α production and was dose dependent. Croton oil-induced ear edema in mice also revealed that treatment with OLE suppressed ear edema, myeloperoxidase (MPO) production and was dose dependent. These results indicated that OLE is an effective antiarthritis agent through an antiinflammation mechanism. Also OLE may be beneficial for the treatment of OA in humans.

Evaluation of soybean methanol fraction on acute inflammation.

Soybeans have been of interest of researchers because of the presence of isoflavones, a subclass of flavonoids, which have demonstrated anti-inflammatory activity. The aim of this study was investigate the anti-inflammatory activity of the methanol fraction from soybean, which contains mainly isoflavone glucosides and malonylglucosides. The anti-inflammatory activity of the methanol fraction from soybean was studied using croton oil-induced mouse ear edema and carrageenan-induced pleurisy models. The methanol fraction inhibited the ear edema in a dose-dependent manner: 0.625 mg/kg by 44.23% (P<.05), 1.25 mg/kg by 60.68% (P<.01), and 2.5 mg/kg by 65.68% (P<.01). Myeloperoxidase enzyme activity was reduced at the dose of 2.5 mg/kg (64.79%, P<.05). No effects were seen on carrageenan-induced pleurisy at different doses of the methanol fraction (100 or 400 mg/kg). These results demonstrated that the methanol fraction containing conjugated isoflavones showed topical anti-inflammatory activity. There was no acute toxicity in Swiss mice after oral administration of the fraction, at doses of 1,000, 2,000, 3,000, and 4,000 mg/kg.

Novel sulfated polysaccharides disrupt cathelicidins, inhibit RAGE and reduce cutaneous inflammation in a mouse model of rosacea.

BACKGROUND: Rosacea is a common disfiguring skin disease of primarily Caucasians characterized by central erythema of the face, with telangiectatic blood vessels, papules and pustules, and can produce skin thickening, especially on the nose of men, creating rhinophyma. Rosacea can also produce dry, itchy eyes with irritation of the lids, keratitis and corneal scarring. The cause of rosacea has been proposed as over-production of the cationic cathelicidin peptide LL-37. METHODOLOGY/PRINCIPAL FINDINGS: We tested a new class of non-anticoagulant sulfated anionic polysaccharides, semi-synthetic glycosaminoglycan ethers (SAGEs) on key elements of the pathogenic pathway leading to rosacea. SAGEs were anti-inflammatory at ng/ml, including inhibition of polymorphonuclear leukocyte (PMN) proteases, P-selectin, and interaction of the receptor for advanced glycation end-products (RAGE) with four representative ligands. SAGEs bound LL-37 and inhibited interleukin-8 production induced by LL-37 in cultured human keratinocytes. When mixed with LL-37 before injection, SAGEs prevented the erythema and PMN infiltration produced by direct intradermal injection of LL-37 into mouse skin. Topical application of a 1% (w/w) SAGE emollient to overlying injected skin also reduced erythema and PMN infiltration from intradermal LL-37. CONCLUSIONS: Anionic polysaccharides, exemplified by SAGEs, offer potential as novel mechanism-based therapies for rosacea and by extension other LL-37-mediated and RAGE-ligand driven skin diseases.

Elimination of deleterious effects of DMBA-induced skin carcinogenesis in mice by Syzygium cumini seed extract.

The inhibition of tumor incidence by hydro-alcoholic extract of S.cumini seed was evaluated in mice on two stage process of skin carcinogenesis induced by single application of 7, 12-dimethyl benz(a)anthracene (100 µg/100µl of acetone), and 2 weeks later promoted by repeated application of croton oil (1% acetone/thrice in a week) till the end of the experiment (i.e. 16 weeks). Oral administration of extract at a dose of 250mg/kg b.wt./day at the peri-initiational stage (i.e. 7 days before and 7 days after DMBA application), promotional stage (i.e. from the time of croton oil application) and at both the stages (i.e. 7 days prior to DMBA application & continued till the end of experiment) to the mice, recorded a significant reduction in tumor incidence to 37.5, 50 & 25% respectively in comparison to the carcinogen treated control, where tumor incidence was found as 100%. Tumor yield and Tumor burden were also significantly reduced by SCE. Similarly, the cumulative number of papillomas after 16 weeks was 68 in the control group, which was reduced to 15, 21 & 8 in the animals treated with the SCE continuously at peri-, post- and peri- & post- initiation stage respectively. A significant impairment was noticed in the levels of reduced glutathione, superoxide dismutase, catalase & protein and enhancement in LPO in liver and skin of carcinogen treated control mice as compared with vehicle treated mice. All such parameters were returned to near normal value by administration of SCE to DMBA treated mice. These results suggest a possible chemopreventive property of S.cumini against DMBA induced skin carcinogenesis in mice.

Antiinflammatory activity of coumarins from Ligusticum lucidum Mill. subsp. cuneifolium (Guss.) Tammaro (Apiaceae).

Four coumarin derivatives [selidinin 1, (+)-praeruptorin A 2, visnadin 3 and (R)-(+)-7-(2',3'-epoxy-3'-methylbutoxy)-coumarin 4] were isolated from the aerial parts of Ligusticum lucidum Mill. subsp. cuneifolium (Guss.) Tammaro (Apiaceae). This is the first report on the identification of these compounds in the Ligusticum genus. Their topical antiinflammatory activity was evaluated as the inhibition of croton oil-induced ear dermatitis in mice. Each compound (0.3 µmol/cm(2) ) induced a significant oedema reduction and compound 4 exerted an effect similar to that of the equimolar dose of the reference drug indomethacin.