Evaluación in vitro de la viabilidad de microorganismos colonizadores primarios de la cavidad oral frente a un sustituto salival casero en base a manzanilla (Matricaria chamomilla) y semillas de linaza (Linum usitatissimum) / In vitro evaluation of the viability of primary colonizing microorganisms of the oral cavity against a homemade saliva substitute based on chamomile (Matricaria chamomilla) and flax seeds (Linum usitatissimum)

Introducción: La sensación de boca seca o xerostomía es la sensación subjetiva de sequedad bucal, que se produce cuando la tasa de producción de flujo salival es menor que la tasa de pérdida de fluidos de la boca. Como terapia para la sensación de boca seca se indica el uso de sustitutos salivales, que lubrican de forma transitoria las estructuras bucales. Algunos productos utilizados para aliviar la sensación de boca seca en su formulación incluyen sustancias con efectos antimicrobianos que pueden causar importantes desequilibrios en la microbiota comensal de la cavidad oral. Esta microbiota entre otras cosas se encarga de impedir la colonización de otros microorganismos (potencialmente patógenos), activar el sistema inmune y producir nutrientes necesarios para otras especies también protectoras. En el área de Bioquímica de la Facultad de Odontología de la Universidad de Chile, se ha desarrollado un sustituto salival formulado en base a manzanilla y linaza. Este sustituto se caracteriza por ser un producto de elaboración casera, económica, no tóxico, reconocido como alimento, por tanto puede ser ingerido. Cuenta con evidencia clínica de ser un buen reductor de la sensación de boca seca. El objetivo de este trabajo fue estudiar el posible efecto protector del sustituto salival recién descrito, sobre microorganismos colonizadores primarios de la cavidad oral. Material y métodos: Para evaluar la viabilidad de microorganismos colonizadores primarios de la cavidad oral frente al contacto con un colutorio en base a manzanilla y linaza se realizaron ensayos de difusión, dilución y ensayos de contacto (Killing test), utilizándose como medios de cultivo placas de agar TYCS y TSB. Se utilizó como producto de comparación un colutorio comercial formulado para aliviar la xerostomía (Xeros, Dentaid), como control positivo Clorhexidina 0,12% y como control negativo suero fisiológico. Se realizó medición de zonas de inhibición de crecimiento bacteriano para los distintos productos en el ensayo de difusión, recuento de unidades formadoras de colonias (UFC) en los ensayos de dilución y contacto. Los resultados fueron analizados mediante el test de Shapiro Wilk y ANOVA no paramétrico para el análisis de normalidad y el test de Kruskal Wallis para afirmar o refutar la hipótesis de igualdad de rango promedio. En el ensayo de Dilución las comparaciones se evaluaron empleando el test U de Mann Whitney para muestras independientes con la corrección de Bonferroni. En el ensayo de contacto, se utilizó el análisis ANOVA para ver la distribución de la normalidad de las muestras y además, debido a que se trabajó con 2 variables independientes, se utilizaron modelos de regresión lineal múltiple para ver la distribución del recuento de colonias bacterianas en relación al volumen de los colutorios y al tiempo de contacto entre ellos. Resultados: Xeros® generó una variación significativa en el recuento de colonias bacterianas pertenecientes a la microbiota comensal oral del género Streptococcus, específicamente S. salivarius, S. sanguinis, S. oralis, S. gordonii y S. mitis, siendo éste menor en comparación con el recuento de colonias bacterianas obtenidos con el sustituto salival casero y con el suero fisiológico. El efecto de Xeros® se mantiene en el tiempo. El sustituto en base a manzanilla y linaza no generó una variación significativa en el recuento de colonias bacterianas estudiadas en comparación con suero fisiológico (control negativo), lo que se mantiene en el tiempo. Conclusiones: El sustituto salival en base a manzanilla y linaza no modificó los recuentos bacterianos de microorganismos comensales orales, a diferencia del sustituto comparado, Xeros®, lo que representa una ventaja frente a éste. Se requiere de investigaciones adicionales en relación a otros posibles efectos de manzanilla y linaza sobre una variedad mayor de microorganismos orales, de modo de generar mayor evidencia sobre la interacción de estos productos naturales con la microbiota comensal y patógena de la cavidad oral. Esta evidencia sería fundamental para la toma de decisiones en el tratamiento paliativo de sequedad bucal de los pacientes xerostómicos en Chile y permitiría efectivamente mejorar su calidad de vida.

Flaxseed in lupus nephritis: a two-year nonplacebo-controlled crossover study.

OBJECTIVE: The objective of this study was to determine the renoprotective effects of ground flaxseed in patients with lupus nephritis. METHODS: Forty patients with lupus nephritis were asked to participate in a randomized crossover trial of flaxseed. Twenty-three agreed and were randomized to receive 30 grams of ground flaxseed daily or control (no placebo) for one year, followed by a twelve-week washout period and the reverse treatment for one year. At baseline and six month intervals, serum phospholipids, flaxseed sachet counts, serum creatinine, 12-hour urine albumin excretion and urine albumin to creatinine ratios, serum viscosity and plasma lipids were measured. RESULTS: There were eight drop-outs and of the 15 remaining subjects flaxseed sachet count and serum phospholipid levels indicated only nine were adherent to the flaxseed diet. Plasma lipids and serum viscosity were unaltered by the flaxseed supplementation whereas serum creatinine in the compliant patients during flaxseed administration declined from a mean of 0.97+/-0.31 mg/dL to a mean of 0.94+/-0.30 mg/dL and rose in the control phase to a mean of 1.03+/-0.28 mg/dL [p value <0.08]. Of the fifteen patients who completed the study, similar changes were noted [p value <0.1]. The nine compliant patients had lower serum creatinines at the end of the two-year study than the 17 patients who refused to participate [p<0.05]. Microalbumin at baseline declined in both control and flaxseed time periods, but there was a trend for a greater decline during flaxseed administration [p<0.2]. CONCLUSIONS: Flaxseed appears to be renoprotective in lupus nephritis, but this interpretation is affected by under powering due to poor adherence and potential Hawthorne effects.

Functional foods and cardiovascular disease.

Functional foods are foods that, by virtue of physiologically active food components, provide health benefits beyond basic nutrition. Many functional foods have been found to be potentially beneficial in the prevention and treatment of cardiovascular disease, the leading cause of mortality in the United States. These foods include soybeans, oats, psyllium, flaxseed, garlic, tea, fish, grapes, nuts, and stanol- and sterol ester enhanced margarine. When eaten in adequate amounts on a consistent basis, these foods may aid in decreasing the risk of cardiovascular disease by several potential mechanisms: lowering blood lipid levels, improving arterial compliance, reducing low-density lipoprotein oxidation, decreasing plaque formation, scavenging free radicals, and inhibiting platelet aggregation.

Lupus erythematosus and nutrition: a review of the literature.

The purpose of this review was to search the scientific literature for dietary compounds that alleviate or exacerbate symptoms of lupus erythematosus (LE) in both animal and human models. A detailed literature review was undertaken to find articles showing a relationship between LE and nutrition by using MEDLINE/INDEX MEDICUS (1950-March 2000) for English-language articles, followed by cross-referencing. Aggravating substances appear to include excess calories, excess protein, high fat (especially saturated and omega-6 polyunsaturated fatty acids), zinc, iron, and L-canavanine found in alfalfa tablets. Possible beneficial dietary compounds include vitamin E, vitamin A (beta-carotene), selenium, fish oils (omega-3 polyunsaturated fatty acids), evening primrose oil, flaxseed, a plant herb (Tripterygium wilfordii), dehydroepiandrosterone, and calcium plus vitamin D (if taking corticosteroids). Some people with systemic LE placed on food allergy elimination diets reported improvement in their LE symptoms; however, this may be related to a decrease of other substances in the diet. Also, although no direct evidence was reported on the beneficial effects of either bromelain or a vegetarian diet (possibly allowing fish), it is suggested that they might be beneficial. Limitations to this research are that the findings are based on relatively few studies, many of which were without control groups or extrapolated from animal models. No large-scale studies have been performed with LE patients to substantiate the benefit, if any, of these individual dietary interventions, and if they were conducted, the remission and exacerbation pattern of LE may interfere with elucidating their effectiveness. Also, dietary changes should not be attempted without a physician's approval/monitoring.

A novel treatment for lupus nephritis: lignan precursor derived from flax.

BACKGROUND: Flaxseed has renoprotective effects in animal and human lupus nephritis. We have recently extracted the lignan precursor (secoisolariresinol diglucoside) (SDG) to determine if this more palatable derivative of flaxseed would exert renoprotection similar to the whole flaxseed in the aggressive MRL/lpr lupus mouse model. METHODS: 131 MRL/lpr mice were randomly assigned to saline gavage, 600, 1,200 and 4,800 microg lignan gavage groups. At 7 weeks, 6 animals underwent platelet aggregating factor (PAF) lethal challenge and 40 were studied with urine collection to determine the levels of secoisolariresinol, enterodiol and enterolactone in the gavaged animals. A baseline study of 10 saline gavaged animals took place at 6 weeks. 25 animals in the saline gavage, 600 and 1200 microg lignan groups were studied at 14 and 22 weeks for GFR, spleen lymphocyte S-phase and organ weight studies. RESULTS: Metabolic studies indicated that secoisolariresinol is the major metabolite absorbed and the lowest lignan dose provides a lengthening in survival for the PAF lethal challenge. Body weight, fluid and water intake studies demonstrated that the lignan was well tolerated. Changes in proteinuria, GFR and renal size showed a time- and dose-dependent protection for the lignan precursor. Cervical lymph node size and spleen lymphocyte cells in the S-phase demonstrated modest dose-dependent reductions in the lignan gavaged groups. CONCLUSION: SDG was converted in the gut to secoisolariresinol, which was absorbed and well tolerated by the MRL/lpr mice. Renoprotection was evidenced, in a dose-dependent fashion, by a significant delay in the onset of proteinuria with preservation in GFR and renal size. This study suggests that SDG may have a therapeutic role in lupus nephritis.

Dose effects of flaxseed and its lignan on N-methyl-N-nitrosourea-induced mammary tumorigenesis in rats.

Dietary supplementation with flaxseed or its lignan secoisolariciresinol diglycoside (SDG) has reduced dimethylbenz[a]anthracene-induced mammary tumor size and number in rats. The objective of this study was to determine whether flaxseed has a dose-dependent effect on N-methyl-N-nitrosourea (MNU)-induced mammary tumor promotion and whether this effect can be attributed to its SDG. Two days after injection with MNU (50 mg/kg body wt i.p.), female Sprague-Dawley rats were fed a high-fat (20% soybean oil) AIN-93G basal diet alone (BD) or supplemented with flaxseed (2.5% F and 5% F) or SDG by gavage [SDG in 2.5% F (LSDG) and SDG in 5% F (HSDG)] for 22 weeks. Although tumors tended to be smallest in the 5% F group throughout the experimental period, flaxseed feeding did not significantly affect tumor size, multiplicity, or incidence in comparison to BD. However, there was a dose-dependent effect of SDG on tumor multiplicity. Tumor multiplicity was lowest in the HSDG group and highest in the LSDG group throughout treatment (p < 0.05), indicating that HSDG inhibited, whereas LSDG promoted, MNU-induced mammary tumor development. Tumor invasiveness and grade were decreased in all treatment groups compared with the BD (p < 0.032). Thus, although flaxseed feeding had no significant effect on tumor growth indexes, flaxseed and SDG treatment, regardless of dose, appeared to delay the progression of MNU-induced mammary tumorigenesis. Disparities between this study and previous studies on flaxseed may be related to differences in experimental design, the use and dose of a different carcinogen, and protective effects by the alpha-linolenic acid present in the BD.