RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: 3ß,6ß,16ß-Trihydroxylup-20(29)-ene (TTHL) is a triterpene isolated from the flowers of Combretum leprosum, a plant used in folk medicine in the north of Brazil for the treatment of skin disorders. AIM OF THE STUDY: In the present study, TTHL was evaluated as a potential topical anti-inflammatory and anti-proliferative agent through in vivo and in vitro models. MATERIAL AND METHODS: Anti-inflammmatory and anti-proliferative effects of TTHL were assessed using Swiss mice in acute and chronic models of skin inflammation induced by 12-O-tetradecanoylphorbol-acetate (TPA) application. Anti-proliferative activity was proved through in vitro experiments with the HaCaT human keratinocyte cell line. RESULTS: Treatment with TTHL inhibited inflammatory parameters such as oedema formation and cellular infiltration in acute and chronic models. In the chronic model, TTHL also inhibited epidermal hyperproliferation, as evidenced by reduction of epidermis thickness and proliferating cell nuclear antigen expression. The anti-proliferative effect was confirmed by the capability of TTHL in reducing the proliferation and inducing cell apoptosis of HaCaT cells. Suggesting a mechanism of action, TTHL showed activation of corticosteroid receptors, but without the induction of corticosteroid-related cutaneous side effects. CONCLUSION: Our results demonstrate consistent anti-inflammatory and anti-proliferative activity and assign TTHL as a valuable tool in the development of a new treatment for skin inflammatory and proliferative diseases, such as psoriasis.
Assuntos
Anti-Inflamatórios/farmacologia , Proliferação de Células/efeitos dos fármacos , Dermatite de Contato/prevenção & controle , Queratinócitos/efeitos dos fármacos , Psoríase/prevenção & controle , Pele/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Doença Crônica , Dermatite de Contato/etiologia , Dermatite de Contato/metabolismo , Dermatite de Contato/patologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Edema/prevenção & controle , Feminino , Antagonistas de Hormônios/farmacologia , Humanos , Queratinócitos/metabolismo , Queratinócitos/patologia , Camundongos , Mifepristona/farmacologia , Antígeno Nuclear de Célula em Proliferação/metabolismo , Psoríase/induzido quimicamente , Psoríase/metabolismo , Psoríase/patologia , Receptores de Glucocorticoides/efeitos dos fármacos , Receptores de Glucocorticoides/metabolismo , Pele/metabolismo , Pele/patologia , Acetato de Tetradecanoilforbol , Fatores de TempoRESUMO
It has been demonstrated that the cytotoxic effect of BJcuL, the lectin isolated from Bothrops jararacussu venom, on human gastric carcinoma is accompanied by the inhibition of extracellular matrix adhesion, cytoskeleton disassembly and apoptosis induction. The present study aimed to evaluate the apoptosis mechanisms triggered by the BJcuL interaction with specific glycans on the surface of HT29 human colon adenocarcinoma cells. The results demonstrated that BJcuL interacts with glycoligands targets on the cell, which were inhibited in the presence of d-galactose. It shows a dose-dependently cytotoxic effect that is inhibited in the presence of d-galactose. A dose-dependent cell aggregation decrease was also observed for the HT29 cells. Analysis of cell proliferation inhibition was assessed by anti-PCNA and demonstrated that lectin diminishes PCNA expression when compared with untreated cells. Differences in apoptotic marker expression estimated by immunohistochemistry revealed that the lectin promotes an increase in TRAIL expression, leading to an increase in the expression of FADD, caspase-8 and Bax. Besides the increased expression of apoptosis-related proteins, our results revealed that the lectin promotes a mitochondrial respiration decrease and a 75% increase in the amount of cytochrome c released. Together these results suggest that the cytotoxicity of BJcuL can sensitize pro-apoptotic proteins in the cytoplasm and mitochondria, leading to the apoptotic cascade.
Assuntos
Apoptose/efeitos dos fármacos , Caspases/metabolismo , Neoplasias do Colo/patologia , Venenos de Crotalídeos/toxicidade , Mitocôndrias/efeitos dos fármacos , Permeabilidade/efeitos dos fármacos , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Neoplasias do Colo/enzimologia , Neoplasias do Colo/metabolismo , Células HT29 , Humanos , Lectinas Tipo CRESUMO
We show that BJcuL, a lectin purified from Bothrops jararacussu venom, exerts cytotoxic effects to gastric carcinoma cells MKN45 and AGS. This effect was due to the direct interaction with specific glycans on the cells surface and was observed by cell viability decrease, disorganization of actin filaments and apoptosis. In addition, BJcuL was able to reduce tumor cell adhesion to matrigel, what was inhibited by specific carbohydrate or partially inhibited when cells were pre-incubated with matrigel. Our results suggest that BJcuL was able to promote apoptosis in both tumor cells lines and therefore has a prospect for potential use in cancer therapy.