Effect of topically applied cyclosporin A on arachidonic acid (AA)- and tetradecanoylphorbol acetate (TPA)-induced dermal inflammation in mouse ear

In Vivo Anti-inflammatory and Antiallergic Activity of Pure Naringenin, Naringenin Chalcone, and Quercetin in Mice

Flavonoids, found in almost all fruits and vegetables, belong to a class of plant secondary metabolites with a polyphenolic structure and have properties with health-improving potential. However, few experimental studies on the effects of flavonoids have been carried out in vivo after external application and using pure compounds. Aiming to fill this gap, in this study we tested the topical anti-inflammatory and antiallergic activity of three flavonoids of high purity, naringenin, naringenin chalcone, and quercetin, in mouse models. The topical anti-inflammatory effects were assessed against arachidonic acid- (AA) and tetradecanoylphorbol-13-acetate- (TPA) induced ear edema. The anti-inflammatory effect of naringenin against ear edema was noticeable at a 1% dose in the AA model and at half this dose in the TPA model. Quercetin (1.3%) did not exert any topical anti-inflammatory activity in the AA model, but its inhibitory effect in the TPA model was similar to that of naringenin (2%); in contrast, naringenin chalcone was more active against the AA-induced than TPA-induced inflammation. The flavonoid effect on IgE-mediated passive cutaneous anaphylaxis was also studied in mice, both intravenously and topically. Naringenin, naringenin chalcone, and quercetin all showed strong antiallergic activity after intravenous dosing (0.02%) and when applied topically (2%). The results of this study suggest that the flavonoids naringenin, naringenin chalcone, and quercetin may be useful alternatives for the topical treatment of inflammatory and allergic skin disorders.

Anti-Helicobacter pylori, gastroprotective, anti-inflammatory, and cytotoxic activities of methanolic extracts of five different populations of Hippocratea celastroides collected in Mexico

ETHNOPHARMACOLOGICAL RELEVANCE

The root barks of Hippocratea celastroides have been used for decades in Mexican traditional medicine to treat gastritis and ulcers. To investigate the anti-Helicobacter pylori, gastroprotective, anti-inflammatory, and cytotoxic activities of methanolic extracts obtained from the leaves, stems, and root bark of Hippocratea celastroides collected in five different localities in Mexico, during the winter of 2009, in order to establish differences in biological activities in terms of plant organs, as well as places of collection.

MATERIALS AND METHODS

Whole individuals were collected in five separate localities in Mexico: La Mancha, Veracruz (VL), Yautepec, Morelos (MY), Jojutla, Morelos (MJ), Temalac, Guerrero (GT), and Landa de Matamoros, Querétaro (QL). Methanolic crude extracts from wild plant specimens were tested using in vivo ethanol-induced mice gastric ulcer model, and 12-O-tetradecanoylphorbol-13-acetate (TPA) induced ear edema in mice assay, and in vitro anti-Helicobacter pylori model, and carcinoma cell line cytotoxic assays.

RESULTS AND CONCLUSIONS

The leaves, stems, and root bark from MY specimens, as well as the leaves and root bark of materials from VL, presented the highest activity against Helicobacter pylori (MIC values ranging from 7.81 to 31.25 μg/ml). Most gastroprotective effects were displayed by the leaves of plants collected in MY, with 89.85±1.91% of protection (300 mg/kg) and an ED50=27 mg/kg, which was corroborated by histological analysis. The root bark extracts from MY achieved the highest edema inhibition values (ED50=0.18 mg/ear), which were comparable to indomethacin (ED50=0.16 mg/ear). Finally, all extracts from MY (three plant parts) were cytotoxic against nasopharyngeal (KB), breast (MCF-7), and colon (HCT-116) carcinoma cell lines with IC50 values between 1.18 and 9.77 μg/ml, except that no activity was detected for root bark extracts against HCT-116 normal fibroblasts. The activities of methanolic extracts from leaves, stems and root bark of plants collected in five different locations varied considerably, representing a notable problem facing the quality control of the plant material from Hippocratea celastroides used for medicinal purposes. The ethnomedical information of this plant in regards to treating gastritis and ulcers was strongly evidenced by the findings of the experimental models employed in this study.

Anti-inflammatory effect of crude extract and isolated compounds from Baccharis illinita DC in acute skin inflammation

ETHNOPHARMACOLOGYCAL RELEVANCE: The tea from the leaves of Baccharis illinita DC (Asteraceae family) is commonly used by the population as anti-inflammatory (including topically), protective gastric and anti-infectious. However, no studies have been done with this species to confirm its topical anti-inflammatory action.

AIM

This study evaluated he topical effects of crude extract of leaves (CE) and its active constituents in 12-O-tetradecanoylphorbol acetate (TPA)-induced ear oedema.

METHODOLOGY

CE and compounds effects were tested in commonly used models of TPA-, arachidonic acid (AA)- and capsaicin-ear oedema. Polymorphonuclear (PMN) cell migration was evaluated by mieloperoxidase and analyzed histologically.

RESULTS

CE (0.1-1 mg/ear) caused a dose-related inhibition of TPA-induced ear oedema and PMN influx similarly to that produced by topical application of the steroidal anti-inflammatory drug dexamethasone. The active constituents of the AcOEt fraction kaurenoic acid, alpha-spinasterol, oleanolic acid and baurenol also inhibited TPA-induced ear edema. Histological analysis of the ear of CE-treated animals confirmed the reduction of edema and of PMN infiltration. Both CE and the nosteroidal anti-inflammatory drug indomethacin inhibited the AA-induced ear oedema, but did not change capsaicin-induced oedema.

CONCLUSION

These results indicate that the CE and the active constituents have a topical anti-inflammatory effect and the possible mechanisms for the pharmacological effects are discussed.

Anti-inflammatory effects of locally applied enzyme-loaded ultradeformable vesicles on an acute cutaneous model

Superoxide dismutase (SOD) and catalase (CAT) are active scavengers of reactive oxygen species and were incorporated into ultradeformable vesicles with the aim of increasing enzyme bioavailability (skin delivery). These special very adaptable vesicles have been formulated and optimized for enzyme transport in order to penetrate into or across the intact skin barrier. Anti-inflammatory activity of SOD-loaded, CAT-loaded and of SOD- and CAT-loaded ultradeformable vesicles applied epicutaneously was measured using different protein doses on the skin, on an arachidonic acid-induced mouse ear oedema. The biological anti-oedema activity is a measurement of drug-targeting potentiation in the organ. Delivery by means of deformable vesicles was compared to conventional vesicles or the absence of an enzyme carrier mediated transport. This was done at various times following prophylactic application of the test formulations. Positive reference groups were treated epicutaneously with several low molecular weight non-steroidal anti-inflammatory drugs (NSAIDs). The latter included indomethacin (3 mg kg(-1)), etofenamate (30 mg kg(-1)) and piroxicam (1 mg kg(-1)) and reduced the oedema by 94 +/- 4%, 81 +/- 4% and 42 +/- 5%, respectively, if measured 30 min after ear treatment with a NSAID. Of the enzyme-loaded carriers tested, only the enzyme-loaded ultradeformable vesicles reduced the swelling of ears significantly: SOD (90 microg kg(-1)), CAT (250 microg kg(-1)) and SOD (90 microg kg(-1)) plus CAT (250 microg kg(-1)) reduced the oedema by 70 +/- 12%, 65 +/- 10% and 61 +/- 19%, respectively, at t = 30 min. Aqueous enzyme solutions and empty carriers had no such effect. The combination of two enzymes resulted in no increased therapeutic effect, but the results are inconclusive since only two dose combinations were tested. The results presented in this study suggest that antioxidant enzymes delivered by means of ultradeformable lipid vesicles can serve as a novel region-specific treatment of inflammation.

Critical roles of PPAR beta/delta in keratinocyte response to inflammation

The immediate response to skin injury is the release of inflammatory signals. It is shown here, by use of cultures of primary keratinocytes from wild-type and PPAR beta/delta(-/-) mice, that such signals including TNF-alpha and IFN-gamma, induce keratinocyte differentiation. This cytokine-dependent cell differentiation pathway requires up-regulation of the PPAR beta/delta gene via the stress-associated kinase cascade, which targets an AP-1 site in the PPAR beta/delta promoter. In addition, the pro-inflammatory cytokines also initiate the production of endogenous PPAR beta/delta ligands, which are essential for PPAR beta/delta activation and action. Activated PPAR beta/delta regulates the expression of genes associated with apoptosis resulting in an increased resistance of cultured keratinocytes to cell death. This effect is also observed in vivo during wound healing after an injury, as shown in dorsal skin of PPAR beta/delta(+/+) and PPAR beta/delta(+/-) mice.

Arachidonic acid (AA) and tetradecanoylphorbol acetate (TPA) exert systemic effects when applied topically in the mouse

We studied the systemic actions of topically applied arachidonic acid (AA) and tetradecanoylphorbol acetate (TPA) in the mouse. AA or TPA-induced ear edema, increases in vascular permeability, eicosanoid levels, neutrophil and mononuclear influx were determined in both phlogogen-treated and contralateral vehicle-treated ear of each mouse and were compared with vehicle-treated ears from control mice. Edema and vascular permeability increases appeared only in AA- or TPA-applied ears. Moreover, in contralateral ears from AA-treated mice an increase in 6-keto-PGF1 alpha and LTB4 was found. Only LTB4 increased in the contralateral ear after TPA. Contralateral ears from AA- or TPA-treated mice also showed a significant increase in MPO levels. The increased levels of 6-keto-PGF1 alpha but not those of LTB4 in contralateral ears were reduced by indomethacin applied simultaneously with the phlogogen. AA also increased plasma and serum levels of LTB4, but not those of 6-keto-PGF1 alpha. In contrast, TPA increased plasma and serum levels of 6-keto-PGF1 alpha and LTB4. The results show that both AA and TPA applied topically exert systemic effects.