Hederagenin Induces Apoptosis in Cisplatin-Resistant Head and Neck Cancer Cells by Inhibiting the Nrf2-ARE Antioxidant Pathway.

Acquired resistance to cisplatin is the most common reason for the failure of cisplatin chemotherapy. Hederagenin, triterpenoids extracted from ivy leaves, exhibits antitumor activity in various types of cancer. However, the therapeutic potential of hederagenin in head and neck cancer (HNC) has remained unclear. Therefore, we examined the effects of hederagenin in cisplatin-resistant HNC cells and characterized its molecular mechanisms of action in this context. We evaluated the effects of hederagenin treatment on cell viability, apoptosis, reactive oxygen species (ROS) production, glutathione levels, mitochondrial membrane potential (ΔΨm), and protein and mRNA expression in HNC cells. The antitumor effect of hederagenin in mouse tumor xenograft models was also analyzed. Hederagenin selectively induced cell death in both cisplatin-sensitive and cisplatin-resistant HNC cells by promoting changes in ΔΨm and inducing apoptosis. Hederagenin inhibited the Nrf2-antioxidant response element (ARE) pathway and activated p53 in HNC cells, thereby enhancing ROS production and promoting glutathione depletion. These effects were reversed by the antioxidant trolox. Hederagenin activated intrinsic apoptotic pathways via cleaved PARP, cleaved caspase-3, and Bax. The selective inhibitory effects of hederagenin were confirmed in cisplatin-resistant HNC xenograft models. These data suggest that hederagenin induces cell death in resistant HNC cells via the Nrf2-ARE antioxidant pathway.

[Cutaneous reactivity to common ivy (Hedera helix) pollen extract in allergic patients]. / Reactividad cutánea al extracto del polen de hiedra común (Hedera helix) en pacientes con enfermedades alérgicas.

BACKGROUND: Common ivy is an ubiquitous ornamental plant found indoors and outdoors. It may cause occupational contact dermatitis and asthma. Many traditional and naturistic preparations may contain their extracts, hence sensitization may occur by several routes. OBJECTIVE: To determine the prevalence of sensitization to Hedera helix pollen by skin prick test on allergic subjects. METHODS: Skin prick tests (SPT) with 24 pollen extracts, including Hedera helix extract, were performed on 62 patients with allergic rhinitis, asthma, allergic conjunctivitis and atopic dermatitis. It was determined the frequency of sensitization to pollen extracts and the differences in the reactivity patterns among patients who showed a positive or negative result with Hedera helix extract. A cluster analysis was made to identify cross-allergenicity among pollen extracts. RESULTS: Eleven out of 62(17.7%) patients had a positive SPT with common ivy pollen extract. The main differences found were the number of pollen species to which patients were allergic. Patients with atopic dermatitis had a nine-fold higher frequency of positive skin tests with Hedera extracts, than subjects with other allergic diseases. CONCLUSIONS: Hedera helix pollen extract is a frequent cause of sensitization among allergic patients, and show cross-allergenicity with pollen from different sources. There is a higher frequency of positive skin tests with Hedera extract in patients with atopic dermatitis than with other allergies.

[Anaphylaxis Due to Ingestion of Ivy Syrup (Hedera hÈlix). Report of two Cases]. / Anafilaxia por ingesta de jarabe de hiedra (Hedera helix). Reporte de dos casos.

Common ivy is an ornamental plant, that is ubiquitous in Mexico. Its allergens can cause contact dermatitis, asthma and allergic rhinitis. We describe two cases of anaphylaxis related to common ivy syrup ingestion. We performed skin prick test with Hedera helix syrup, and using a dialized and ultrafiltered of common ivy syrup commercial presentation (dry common ivy extract: 7mg/ml), as well as using Hedera helix pollen extract. We describe two cases of anaphylaxis related to ingestion of Hedera helix syrup. Skin prick test with the commercial presentation and with the pollen extract were positive in both patients. In this study we confirmed the causal relationship of anaphylaxis due to the ingestion of ivy syrup in two patients through skin prick tests with ivy syrup and ivy pollen extract. Common ivy can cause contact dermatitis, asthma and allergic rhinitis, but we do not know the allergens that could be related to systemic and respiratory reactions, then, more studies in this topic are requiered.

High incidence of sensitization to ornamental plants in allergic rhinitis.

BACKGROUND: A few indoor plants have been described as potential allergens, in single case reports of allergic rhinitis. There is no data evaluating the prevalence of allergic sensitization to these plants. AIM: The relationship between owning indoor ornamental plants with the risk to be sensitized has been evaluated in atopic rhinitis. METHODS: A group of 59 patients with allergic rhinitis were submitted to skin prick tests (SPT) using both the leafs of their own plant and commercial extracts of the most frequent airborne allergens. A control group of 15 healthy subjects was tested with the same allergens. RESULTS: While no subject from the control group developed a significant SPT to any of the tested plants, 78% of allergic rhinitis had positive SPT to at least one plant, the most frequent sensitization being Ficus benjamina, yucca, ivy and palm tree. CONCLUSION: In allergic rhinitis, indoor plants should be considered as potential allergens.

[Allergic contact dermatitis to common ivy (Hedera helix L.)]. / Allergische Kontaktdermatitis auf Efeu (Hedera helix L.).

Common ivy (Hedera helix L.) is a ubiquitous plant in Europe whose major allergen falcarinol has moderate allergic potential. It is not related to poison ivy (Toxicodendron spp.). There are no cross reactions between the allergens of common ivy (falcarinol) and poison ivy (urushiol). Contact with common ivy or falcarinol may lead to sensitization and then a delayed hypersensitivity reaction. There are only few cases described in the literature. We report on a male hobby gardener with appropriate clinical history and positive patch test. The pathogenic mechanism is a type IV reaction following a sensitization exposure. Gardeners and landscape architects with frequent exposure to common ivy and thus a high risk of sensitization should wear appropriate protective clothing.