Therapeutic potential of omega fatty acids in breast cancer. Review / Potencial terapéutico de ácidos grasos omega en cáncer de mama. Revisión

Background: Breast cancer is the second cause of death in women in developed and undeveloped countries, including Colombia. A high percentage of these tumors is estrogen dependent, for which the hormonal treatment is the most used therapy in breast cancer. Currently, the first line treatment for breast tumor in postmenopausal women is the letrozole, an aromatase enzyme inhibitor that avoids the transformation of androgens to estrogens. Since letrozole produced adverse effects on patients, there is a requirement for new alternative treatments. Furthermore, omega fatty acids (ω-FA), essential as they are obtained from the normal diet or from dietary supplements, have demonstrated nutraceutical potential because of their anti-inflammatory or pro-inflammatory activity. Nonetheless, there is controversy in in vitro, in vivo and epidemiologic reports regarding their preventive or inducing activities of carcinogenesis in animals and humans, depending on the structure of the ω-FA. Objectives: This review aims to show the main in vitro, in vivo and epidemiologic evidences of the chemotherapeutic potential of ω-3 and ω-6 FA in different types of neoplasm, particularly in breast cancer, in individual or combined treatments with diverse antineoplastics. Methods: PubMed and Science Direct databases revealed the most representative studies, published during the last two decades, about ω-3 and ω-6 FA, breast cancer and the principal therapeutic strategies for this neoplasm. Findings were presented in separated topics to provide an overview of ω-FA and their potential in treatments for breast cancer. Results: Patients treated with estrogens and progesterone derivate have shown predisposition to develop breast cancer after two years of continued therapy. Furthermore, ω-FA with known nutraceutical potential have demonstrated their potential as adjuvants in the treatment against different neoplasms, like hepatic and colon cancer. Conclusions: Current therapies for breast cancer and their low efficacy in the long term led to explore new alternative treatments with ω-FA. These essential fatty acids in daily consumption could enhance the antineoplastic agent effect. Nevertheless, metabolism of the ω-FA must be considered for this use.

Antecedentes: el cáncer de mama es la segunda causa de muerte de mujeres en países desarrollados y no desarrollados, incluido Colombia. La mayoría de estos tumores son dependientes de estrógeno por esa razón, la terapia más utilizada es la hormonal. Actualmente, el tratamiento de primera línea en mujeres posmenopáusicas es el letrozol, inhibidor de la enzima aromatasa, que evita la conversión de andrógenos en estrógenos. El letrozol causa efectos adversos en las pacientes, lo cual motiva la búsqueda de nuevas alternativas que disminuyan estos efectos. Los ácidos grasos omega, esenciales en la dieta regular o suplementaria, han mostrado su potencial nutracéutico ambivalente, como antiinflamatorios o proinflamatorios. Debido a esto, existe controversia en distintos reportes a nivel in vitro, in vivo y epidemiológicos sobre la actividad preventiva o quimioterapéutica de los ω-3 y ω-6 AGOs. Objetivos: el aporte de este artículo, es mostrar las principales evidencias in vitro, in vivo y epidemiológicas del potencial quimioterapéutico de los AGOs en tratamientos individuales y combinados con antineoplásicos, en distintos tipos de cánceres, particularmente en el cáncer de mama. Métodos: se revisaron las bases de datos PubMed y Science Direct y se seleccionaron los estudios más representativos de las dos últimas décadas sobre ω-3 y ω-6 AGOs y las principales estrategias usadas en el cáncer de mama. Los hallazgos se presentan en temas separados, primero una visión general de los AGOs y luego su potencial bioactivo en tratamientos contra el cáncer de mama. Resultados: la mayoría de los estudios en pacientes con cáncer de mama, tratadas con estrógenos y derivados de progesterona, han mostrado predisposición a desarrollar cáncer de mama después de dos años de terapia continua. De otro lado, los AGOs han demostrado su potencial como adyuvantes en el tratamiento en diferentes cánceres como el de colon y hepático. Conclusiones: las terapias actuales para el cáncer de mama y su baja eficacia a largo plazo exigen explorar nuevas alternativas de terapias, que incluyen los AGOs podrían potenciar fármacos, no obstante, es necesario tener en cuenta, el metabolismo de los AGOs, para uso

Níveis séricos de 25-hidroxi vitamina D em pacientes portadores de insuficiência renal crônica em tratamento dialítico / 25-hydroxy vitamin D levels in chronic kidney disease patients on dialysis therapy

JUSTIFICATIVA E OBJETIVOS: A contribuição da deficiência de vitamina D para o desenvolvimento do hiperparatireoidismo secundário e da osteodistrofia renal motiva a racional suplementação de vitamina D. A sua deficiência tem sido associada,ainda, a elevado risco cardiovascular. O objetivo deste estudo foi descrever os níveis séricos de 25-hidroxi vitamina D em pacientes portadores de insuficiência renal terminal em terapia dialítica.MÉTODO: Dados clínicos e laboratoriais foram coletados em novembro de 2009 em 168 pacientes em terapia dialítica em um único centro. Os níveis séricos de 25-hidroxi vitamina D foram medidos utilizando o método automatizado de imunoensaio desenvolvido por DiaSorin. De acordo com o Kidney Disease Outcomes and Quality Initiative Guidelines, os pacientes foram classificados em três grupos: suficientes (> 30 ng/mL), insuficientes(15 a 30 ng/mL); e deficientes (< 15 ng/mL). A prevalência de deficiência ou insuficiência de vitamina D foi calculada. Para comparar as variáveis foram usados os seguintes testes: Qui-quadrado,Exato de Fisher e t de Student. O coeficiente de correlação de Spearman foi utilizado para variáveis contínuas. O valor de p < 0,05 foi considerado estatisticamente significativo.RESULTADOS: A média ± desvio padrão de 25-hidroxi vitaminaD foi 23,8 ± 13,3 ng/mL. A prevalência de deficiência devitamina D foi de 23,9% e de insuficiência foi de 47,8%. Quando se compararam as diferenças entre homens e mulheres, idade,albumina e fósforo foram inferiores nas mulheres (p < 0,05). Os níveis de 25-hidroxi vitamina D foram significantemente inferiores em pacientes em diálise peritoneal quando comparados aos em hemodiálise (p < 0,05). Na análise univariada houve pequena correlação positiva entre 25-hidroxi vitamina D e Kt/V.CONCLUSÃO: Os níveis de 25-hidroxi vitamina D foram baixos nesta população. Estudos prospectivos para avaliar o impacto desta deficiência se fazem necessários.(AU)

BACKGROUND AND OBJECTIVES: The contribution of vitamin D deficiency to the development of secondary hyperparathyroidism and renal osteodystrophy contributes the rationale for vitamin D supplementation. Vitamin D deficiency has been associated with elevated cardiovascular risk. This study aimed investigates the serum levels of vitamin D among patients undergoing dialysis.METHOD: In November 2009, we examined clinical and laboratory data from 168 patients in dialytic therapy in a unit. Serum level of vitamin D was included in laboratory data. Serum levels of vitamin D were measured using an automated, antibody and microparticle, chemiluminescence immunoassay method developedby DiaSorin. According to the Kidney Disease Outcomes and Quality Initiative guidelines, patients were assigned to thefollowing 3 groups: sufficient vitamin D serum level (> 30 ng/mL), insufficient level (15 to 30 ng/mL) and with severe deficiency(< 15 ng/mL). Prevalence of deficiency or insufficiency of vitamin D was calculated. To compare the variables were usedthe Chi-square, Fisher Exact or Student's t tests. Spearman correlation coefficient was used for continuous variables. A p value < 0.05 was considered statistically significant.RESULTS: Patient's serum vitamin D mean level was 23.8 ± 13.3 ng/mL. Prevalence of vitamin D deficiency was 23.9%. Prevalence of vitamin D insufficiency was 47.8%. When compared differences between men and women, age, albumin and phosphorus were inferior in women (p < 0.05). Levels of vitamin D were greatly inferior in peritoneal dialysis when compared with hemodialysis (p < 0.05). In the univariate analysis there were weak positive correlations between vitamin D and Kt/V.CONCLUSION: Serum vitamin D levels in this population were low. Prospective studies to assess the impact of low level of vitamin D in patients undergoing dialysis are warranted.(AU)

Inhibition of P. falciparum by steroids isolated from Solanum nudum.

Resistance to antimalarials has been widely reported and constitutes a major problem around the world. In Colombia, resistance of P. falciparum to chloroquine has been reported as 47%-97%, to amodiaquine 3%-7% and to sulfadoxine-pyrimethamine as 9%-13%. The search for new antimalarials is a priority and with this aim we studied the in vitro antimalarial activity of plants used by traditional healers. Incorporation of (3)H-hypoxanthine by the strain FCB-2 of P. falciparum was used to measure the degree of inhibition produced by the steroids SN-1 tumacone A (C(29)H(44)O(5)), SN-2 tumacone B (C(27)H(42)O(4)), SN-3 tumacoside A (C(35)H(54)O(10)), and SN-4 tumacoside B (C(33)H(52)O(9)). All compounds were obtained from the dried stems and leaves of Solanum nudum. The mean growth inhibition of P. falciparum was 71%, 56%, 21% and 12% with each of the compounds SN-1, SN-2, SN-3 and SN-4. These results constitute an important discovery since they may account for the antimalarial properties of extracts of Solanum nudum by a sensitive method. Future work should include study of the in vivo anti-malarial effect of these extracts.