Dietary modulation of cytokine production and biologic functions

Impact of the anti-inflammatory diet on serum high-sensitivity C-Reactive protein and new-onset frailty in community-dwelling older adults: A 7-year follow-up of the Kashiwa cohort study

AIM

Chronic inflammation is a pathophysiological cause of age-related diseases, including frailty. Although diet is a determinant of inflammation, few prospective studies have investigated its role in frailty onset. This study used the dietary inflammatory index to investigate whether a proinflammatory diet affects the incidence of frailty in a 7-year follow-up of older Japanese adults.

METHODS

We enrolled community-dwelling older adults without frailty from the 2014 Kashiwa cohort study. Energy-adjusted dietary inflammatory index (E-DII) scores were calculated using a brief self-administered diet history questionnaire. Serum high-sensitivity C-reactive protein (hsCRP) levels were measured by immunoassays. Frailty was defined as meeting three of Fried's five phenotypic criteria. Cox regression was used to analyze associations between E-DII scores and new-onset frailty after adjusting for relevant confounders.

RESULTS

Overall, 95 (11.7%) of 811 participants (73.7 ± 4.8 years, women 47.3%) developed new-onset frailty during the 7-year follow-up. The baseline E-DII scores significantly correlated with log-hsCRP levels, even after adjustment (β = 0.075, P = 0.035). The highest tertile of E-DII scores (proinflammatory diet) showed a 2.03 times (95% confidence interval, 1.22-3.36) higher risk of new-onset frailty than that associated with the lowest tertile (P = 0.006). When E-DII was calculated on the basis of anti-inflammatory food parameters only, the highest tertile showed a 2.32 times (95% confidence interval, 1.36-3.95) higher risk than that associated with the lowest tertile (P = 0.002).

CONCLUSIONS

E-DII scores significantly correlated with serum hsCRP levels. High E-DII scores caused by low intake of anti-inflammatory foods are associated with frailty incidence. For community-dwelling older adults, dietary interventions that lower E-DII scores (e.g., encouraging dietary fiber intake) may help prevent frailty. Geriatr Gerontol Int 2024; 24: 189-195.

Immunity-Enhancing Effect of Extracts Extracted from Leaves of Rubia hexaphylla, Cymbopogon citratus, and Dioscorea japonica for Sustainable Healthy Life

The COVID-19 era requires research and development into eco-friendly immune technologies in human life. However, such research is limited because of a lack of interest. Therefore, in this study, sub-critical extracts extracted from Rubia hexaphylla leaves, Cymbopogon citratus, and Dioscorea japonica with physiological effects were tested for their ability to enhance immunitye and antioxidant activity in the body. Cell viability experiments, cytokine secretion induction experiments, nitrogen oxide induction experiments, and cytokine content measurements in mouse serum and NK activation experiments were conducted to verify the effects of improving immunitye and antioxidant activity in the body. First, the cell survival rate of all samples was found to be over 95%. Second, it was confirmed that the contents of IL-6 and TNF-α in the macrophages of all samples were increased, especially for RCD 3, at concentrations of 1000 μg/mL. Third, the nitrogen oxide content of all samples was increased in the nitrogen oxide induction evaluation, especially for RCD 3, at the highest concentration of 1000 μg/mL. Fourth, for RCD 3, IL-2 and TNF-γ were the highest measured in the measurement of the cytokine content in the mouse serum. Fifth, in the NK activation experiments, the positive control group of the samples was all found to have higher activity than the negative control group, with more than 60% cell activity in RCD 3.

A proinflammatory diet is associated with increased odds of frailty after 12-year follow-up in a cohort of adults

BACKGROUND

Frailty occurs in 10-15% of community-living older adults and inflammation is a key determinant of frailty. Though diet is a modulator of inflammation, there are few prospective studies elucidating the role of diet-associated inflammation on frailty onset.

OBJECTIVES

We sought to determine whether a proinflammatory diet was associated with increased odds of frailty in adults from the Framingham Heart Study (FHS).

DESIGN AND METHODS

This study was nested in a prospective cohort that included individuals without frailty. Diet was assessed in 1998-2001 using a valid FFQ, and frailty was measured in 2011-2014. FFQ-derived energy-adjusted dietary inflammatory index (E-DII®) scores were computed, with higher E-DII scores indicating a more proinflammatory diet. Frailty was defined as fulfilling ≥3 of 5 Fried Phenotype criteria. Information on potential mediators, serum IL-6 and C-reactive protein was obtained in 1998-2001. Logistic regression estimated ORs and 95% CIs for E-DII (as continuous and in quartiles) and frailty onset adjusting for relevant confounders.

RESULTS

Of 1701 individuals without frailty at baseline (mean ± SD age: 58 ± 8 y; range: 33-81 y; 55% female), 224 developed frailty (13% incidence) over ∼12 y. The mean ± SD E-DII score was -1.95 ± 2.20; range: -6.71 to +5.40. After adjusting for relevant confounders, a 1-unit higher E-DII score was associated with 16% increased odds of developing frailty (95% CI: 1.07, 1.25). In categorical analyses, participants in the highest (proinflammatory) compared with lowest quartile of E-DII had >2-fold increased odds of frailty (ORquartile4vs.1: 2.22; 95% CI: 1.37, 3.60; P-trend < 0.01). IL-6 and C-reactive protein were not major contributors in the pathway.

CONCLUSIONS

In this cohort of middle-aged and older adults, a proinflammatory diet was associated with increased odds of frailty over ∼12 y of follow-up. Trials designed to increase consumption of anti-inflammatory foods for frailty prevention are warranted.

Cytokines and metabolic regulation: A framework of bidirectional influences affecting Leishmania infection

Leishmania, a protozoan parasite inflicting the complex of diseases called Leishmaniases, resides and replicates as amastigotes within mammalian macrophages. As macrophages are metabolically highly active and can generate free radicals that can destroy this parasite, Leishmania also devise strategies to modulate the host cell metabolism. However, the metabolic changes can also be influenced by the anti-leishmanial immune response mediated by cytokines. This bidirectional, dynamic and complex metabolic coupling established between Leishmania and its host is the result of a long co-evolutionary process. Due to the continuous alterations imposed by the host microenvironment, such metabolic coupling continues to be dynamically regulated. The constant pursuit and competition for nutrients in the host-Leishmania duet alter the host metabolic pathways with major consequences for its nutritional reserves, eventually affecting the phenotype and functionality of the host cell. Altered phenotype and functions of macrophages are particularly relevant to immune cells, as perturbed metabolic fluxes can crucially affect the activation, differentiation, and functions of host immune cells. All these changes can deterministically direct the outcome of an infection. Cytokines and metabolic fluxes can bidirectionally influence each other through molecular sensors and regulators to dictate the final infection outcome. Our studies along with those from others have now identified the metabolic nodes that can be targeted for therapy.

Interaction of dietary fatty acids with tumour necrosis factor family cytokines during colon inflammation and cancer

Intestinal homeostasis is precisely regulated by a number of endogenous regulatory molecules but significantly influenced by dietary compounds. Malfunction of this system may result in chronic inflammation and cancer. Dietary essential n-3 polyunsaturated fatty acids (PUFAs) and short-chain fatty acid butyrate produced from fibre display anti-inflammatory and anticancer activities. Both compounds were shown to modulate the production and activities of TNF family cytokines. Cytokines from the TNF family (TNF- α, TRAIL, and FasL) have potent inflammatory activities and can also regulate apoptosis, which plays an important role in cancer development. The results of our own research showed enhancement of apoptosis in colon cancer cells by a combination of either docosahexaenoic acid (DHA) or butyrate with TNF family cytokines, especially by promotion of the mitochondrial apoptotic pathway and modulation of NF κ B activity. This review is focused mainly on the interaction of dietary PUFAs and butyrate with these cytokines during colon inflammation and cancer development. We summarised recent knowledge about the cellular and molecular mechanisms involved in such effects and outcomes for intestinal cell behaviour and pathologies. Finally, the possible application for the prevention and therapy of colon inflammation and cancer is also outlined.

Effect of quercetin on impaired immune function in mice exposed to irradiation

Radiation used in cancer treatment may cause side effects such as inflammation. Quercetin is a polyphenol that reduces inflammation. This study evaluated the recovery efficacy of quercetin on impaired immune function in irradiation-induced inflammatory mice. Quercetin administered at two concentrations of 10 and 40 mg/kg body weight was initiated 2 weeks before irradiation and was continued 30 days after irradiation. The animals exposed/not exposed to radiation were sacrificed on radiation days 10 and 30. Splenocyte proliferation, which was diminished after irradiation, was enhanced significantly by quercetin supplementation after 30 days of irradiation. Cytokine secretion increased in the radiation group compared to that in the non-radiation control group. After 30 days of radiation, interleukin (IL)-1β and IL-6 secretion decreased significantly in the radiation-quercetin groups. When quercetin was administered for 44 days, it showed a possible protective effect against irradiation-induced inflammation in mice. Quercetin could be beneficial in the recovery of irradiation-induced increases in cytokine secretion.

Effects of Elm Bark (Ulmus davidianavar.japonica) Extracts on the Modulation of Immunocompetence in Mice

The immunomodulative effects of elm bark extract were studied in vitro by the proliferation of splenocytes and the production capacity of three kinds of cytokines [interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha] by mouse peritoneal macrophages cultured with various fractions (methanol, hexane, chloroform, ethyl acetate, butanol, and water) of elm bark extract. Splenocyte proliferation and cell viability of peritoneal macrophages were increased with concentrations of polar fractions, such as butanol and water, in the range of 1-500 microg/mL. Significantly higher levels of the production of all three cytokines were detected with supplementation of methanol extract compared with other fractions. In order to elucidate its effect in vivo, elm bark water extract was orally administrated every other day for 2 weeks. Proliferation of splenocytes and the production capacity of cytokines (IL-1beta, IL-6, and TNF-alpha) by mouse peritoneal macrophages were used as indices for immune activity. Splenocyte proliferation induced by elm bark with lipopolysaccharide or concanavalin A stimulation was enhanced at 500 mg/kg of body weight concentrations compared to that of the control group. In the case of cytokines, the highest production of IL-6 and TNF was detected at 500 mg/kg of body weight concentrations. In conclusion, this study suggests through in vitro and in vivo experiments that Ulmus davidiana var. japonica (elm bark) extracts may enhance the immunocompetent properties such as splenocyte proliferation and cytokine production capacity by activated macrophages and have a protective effect in mice.

Modulation of immune response through nutraceutical interventions: implications for canine and feline health

Mounting research demonstrates that certain nutraceutical compounds interact with the immune system. These interactions may be positive or negative depending on the compound or dose administered to the individual. Understanding the mechanisms by which these compounds work should provide opportunities to design nutritional interventions to bolster the health of dogs and cats.

Prooxidant diet provides protection during murine infection with Toxoplasma gondii

Toxoplasmosis, particularly toxoplasmic encephalitis, has emerged as a major cause of morbidity and mortality in patients with acquired immunodeficiency syndrome. Patients infected with human immunodeficiency virus typically experience chronic oxidative stress, and concurrent infection with the intracellular parasite Toxoplasma gondii would be expected to further exacerbate this condition. The present study was conducted to determine whether vitamin E and selenium supplementation might be beneficial in a murine model of toxoplasmosis. To investigate the effect of these antioxidants on the severity of parasitic infection. Swiss Webster (SW) or C57Bl/6J mice infected with oocysts of the ME49 strain of T. gondii were maintained on diets containing no vitamin E or selenium, no vitamin E and 8 ppm selenium, 400 IU/kg vitamin E plus 8 ppm selenium, or vitamin E and selenium at the levels present in standard rodent chow (16 IU/kg and 0.2 ppm, respectively). The results of the study showed that increased dietary supplementation with vitamin E and selenium resulted in trends toward increased tissue cyst number, tissue pathology, and weight loss during infection. In contrast, both resistant SW and susceptible C57Bl/6J mice fed a deficient diet (complete absence of vitamin E and selenium) showed the lowest mean numbers of tissue cysts and very little evidence of tissue pathology during chronic infection.

Tumour necrosis factor-alpha transcription in transferrin-stimulated human blood mononuclear cells: is transferrin receptor involved in the signalling mechanism?

Transferrin (Tf) and tumour necrosis factor-alpha (TNF-alpha) participate in immune response regulation. We studied the capacity of Tf to modulate 'in vitro' TNF-alpha secretion, membrane expression and transcription by human blood mononuclear cells (BMNC). Women 25-45 years of age with normal iron status (n = 20) or with iron deficiency (ID, n = 20) due to gynaecological bleeding were studied. BMNC were incubated with different proportions of Fe-exempt and Fe-saturated Tf (apo-Tf:holo-Tf). Apo-Tf or holo-Tf uniformly induced TNF-alpha secretion in the cell supernatants from both groups. Nevertheless, cytokine levels were significantly lower in ID subjects. For all Tf-Fe saturations assayed, mean TNF-alpha levels varied between 1.4-1.6 ng/ml and 0.4-0.7 ng/ml for normal and ID women respectively (P < 0.001). The addition of apo-Tf enhanced TNF-alpha secretion in a dose-dependent manner, but the cytokine levels were lower in ID group. Tf did not induce pro-TNF-alpha expression in monocytes and lymphocytes from either group. Tf-treated cells from normal individuals expressed approximately two to three times more TNF-alpha mRNA than cells from ID subjects. Mean values ranged 96-110 atmol/ml in normal women and 24-31 atmol/ml in ID women for all Tf-Fe saturation levels tested (P < 0.001). These results show that Tf-induced TNF-alpha secretion is transcriptionally regulated. The impaired TNF-alpha transcription in cells from ID subjects indicates that the quality of the immune response is linked to the Fe status of mononuclear cells.

Effects of dietary menhaden oil, soy, and a cyclooxygenase inhibitor on human breast cancer cell growth and metastasis in nude mice

The purpose of Study 1 was to examine the effect of dietary soy on the progression of MDA-MB-435 human breast cancer cell solid tumors in nude mice. When toasted soy chips were fed at levels of 5%, 10%, or 20% (wt/wt) in a high-fat, linoleic acid-rich diet for 12 weeks, there was a trend for larger mammary fat pad tumors to occur with increasing soy intake. However, compared with the controls the severity of macroscopic lung metastasis was reduced significantly in the groups fed 10% and 20% soy. Study 2 compared the effects of diets containing 23% corn oil (CO), 18% menhaden oil (MO) + 5% CO, 18% MO + 5% CO + 10% soy chips, and MO or soy-supplemented diets + indomethacin treatment in the same animal model. Feeding the 18% MO diet without soy or indomethacin reduced primary tumor growth; statistically significant effects were not observed in any of the other groups. All three of the groups with MO supplementation showed a reduction in the occurrence and severity of macroscopic lung metastases, together with the expected decreases in tumor prostaglandin E levels. These effects were most pronounced when MO was combined with indomethacin treatment. When indomethacin was given with dietary soy, the previously reported suppressive effect of the cyclooxygenase inhibitor on MDA-MB-435 cell tumor progression was lost, despite reductions in tumor prostaglandin E concentrations.

Endotoxin induced production of interleukin-6 is enhanced by vitamin E deficiency and reduced by black tea extract

Studies were performed to investigate the effect of a polyphenol rich extract from black tea and vitamin E on bacterial lipopolysaccharide (endotoxin) induced IL-6 production, alterations in liver glutathione and antioxidant acute phase protein (caeruloplasmin) concentration, in rats fed on a synthetic diet for 21 days. In the vitamin E sufficient group a significantly lower IL-6 concentration than in vitamin E deficient animals was observed. Addition of tea extract to the diet produced a similar reduction in IL-6, but no synergism occurred in the presence of both vitamin E and tea extract. However, a significantly lower caeruloplasmin and a significantly higher liver glutathione concentration was observed in rats fed both substances. It is suggested that consideration of dietary components which alter antioxidant/oxidant status may contribute towards treatment of inflammatory/autoimmune diseases.

Free fatty acid profiles in the non-obese diabetic (NOD) mouse: basal serum levels and effects of endocrine manipulation

The non-obese diabetic mouse (NOD) is one of the few available models of spontaneous autoimmune insulin-dependent diabetes mellitus (IDDM). The authors determined the free fatty acid (FFA) levels and the concentrations and relative percentages of the various classes of FFA before the onset of diabetes in both sexes at 2 and 4 months of age and in diabetic females. A circadian rhythm of FFA concentrations was found in prediabetic mice, with lower values in the evening. Moreover, there was a sex difference in FFA concentrations in the morning, with 2-month-old females having higher concentrations than males. Sex and age-related differences were also observed in the concentrations of the various classes of FFA, with higher polyunsaturated fatty acid concentrations in 2-month-old females and increases in di- and tri-unsaturated fatty acids concentrations in both sexes with age. Hormonal manipulation such as adrenalectomy and/or castration modulated total FFA and the concentrations of the various classes of FFA in 2-month-old mice. These FFA differences between males and females should be taken into account in the onset of type I diabetes.

Cytokine control of nutrition and metabolism in critical illness

During the last two decades, major advances in technology and in our fundamental understanding of the biologic aspects of sepsis and cancer cachexia have dramatically affected the therapeutic strategies available to the surgeon to care for critically ill patients. It is clear, however, that cytokines affect whole body nutrition and metabolism and are responsible for many of the clinically observed nutritional effects of injury, infection, and cancer, including fever, hypermetabolism, anorexia, protein catabolism, cachexia, and altered fat, glucose, and trace mineral metabolism. These metabolic and nutritional effects of cytokines are influenced by the nutritional status of the host, which is generally altered during the course of the critical illness. In the future, the use of specialized diets and the use of selective cytokine blockade are likely to be important components of the overall care of the catabolic patient.

Long‐term intake of a low‐casein diet is associated with higher relative NK cell cytotoxic activity in F344 rats

Earlier studies in our laboratory showed that animals exposed to aflatoxin B1 (AFB1) develop fewer gamma-glutamyl transpeptidase-positive preneoplastic foci and tumors when fed 6% dietary casein than when fed 22% casein during promotion; mechanisms underlying this effect have not been elucidated. We examined natural killer (NK) cell activity, mitogenic responses, and lymphocyte surface antigen profiles in male Fischer 344 rats dosed with AFB1 or dosing vehicle alone and then fed 6% or 22% casein isocaloric diets for one year. Mean body weights and food intake did not differ significantly among the groups during the study. NK cells purified from peripheral blood of rats fed 6% casein mediated higher specific lysis (p < 0.0001) against YAC-1 target cells than cells obtained from animals fed 22% casein. Mitogenic responses of splenic lymphocytes to concanavalin A and lymphocyte subpopulations, identified by flow cytometry, did not differ significantly among dietary groups. Hepatic tumors were detected in 27% of the 22% casein AFB1-treated group and in 6% of animals in the 6% casein AFB1-treated group. The association between long-term intake of a 6% casein diet and higher relative NK cell cytotoxic activity suggests a potentially important mechanism that may help protect against the development of hepatocellular tumors. Further study of this mechanism as a causal factor in limiting tumor development is required.

Purified dietary n-3 polyunsaturated fatty acids alter diacylglycerol mass and molecular species composition in concanavalin A-stimulated murine splenocytes

A low-dose, short-term dietary supplementation with highly purified (n-3) fatty acid ethyl esters was studied in mice to determine the effect on splenic cell membrane diacylglycerol mass and composition. Mice were fed diets containing either 3% safflower oil (SAF) ethyl esters, 2% SAF plus 1% eicosapentaenoic acid ethyl ester (EPA), or 2% SAF plus 1% docosahexaenoic acid ethyl ester (DHA). Following a 10-day feeding period, pathogen-free mice were sacrificed and splenic cells isolated and stimulated with concanavalin A (Con A) at 10 micrograms/ml. After 0 min (basal), 5 min, and 180 min, 1,2-diacyl, 1-O-alkyl-2-acyl, and 1-O-alkenyl-2-acyl-sn-glycerol subclasses were isolated and quantitated by HPLC. Diacylglycerol (DAG) was found to be the major diradylglycerol (DG) component in murine splenocytes. DHA-fed mice had significantly (P < 0.05) higher levels of DAG at all stimulation time points relative to EPA and SAF animals. Significant effects (P < 0.05) of diet, time, and a diet x time interaction (P < 0.05) were noted for various DAG molecular species. In general, a significantly higher (n-3) polyunsaturated fatty acid (PUFA) content in the EPA and DHA groups, and a significantly higher (n-6) PUFA content in the SAF group was noted. 18:0-22:5(n-3), 18:1-22:5(n-3) and 16:1-20:5(n-3) species were present only in EPA and DHA-DAG, confirming the incorporation of (n-3) fatty acids into splenocyte DAG. The data indicate that the molecular species composition of murine splenocyte DAG is significantly modulated by low-dose, short-term EPA and DHA feeding. In addition, substitution of SAF with DHA results in an increase in DAG mass. These alterations could potentially influence signal transduction pathways regulating lymphocyte function.

Effect of dietary fish oil on renal function and rejection in cyclosporine-treated recipients of renal transplants

BACKGROUND

Dietary fish oil exerts effects on renal hemodynamics and the immune response that may benefit renal-transplant recipients treated with cyclosporine. To evaluate this possibility, we studied the effect of fish oil on renal function, blood pressure, and the incidence of acute rejection episodes in cyclosporine-treated recipients of renal transplants.

METHODS

In a randomized, double-blind trial, 33 recipients of first cadaveric kidney transplants who were treated with cyclosporine and prednisolone ingested 6 g of fish oil daily during the first postoperative year (the fish-oil group), whereas another 33 renal-graft recipients treated with cyclosporine and prednisolone ingested 6 g of coconut oil daily for three months after which time it was stopped (the control group).

RESULTS

One year after transplantation, the fish-oil group had higher median values than the controls for glomerular filtration rate (53 vs. 40 ml per minute per 1.73 m2, P = 0.038) and effective renal plasma flow (214 vs. 178 ml per minute per 1.73 m2, P = 0.023) and lower mean arterial pressure (103 vs. 118 mm Hg, P = 0.0011). The cyclosporine doses in the two groups were similar. The cumulative number of rejection episodes was 20 in the controls, as compared with 8 in the fish-oil group (P = 0.029). One-year graft survival also tended to be better in the fish-oil group, (97 vs. 84 percent, P = 0.097).

CONCLUSIONS

The daily administration of 6 g of fish oil during the first postoperative year has a beneficial effect on renal hemodynamics and blood pressure in renal-transplant recipients treated with cyclosporine. Although the fish-oil group had significantly fewer rejection episodes than the control group, graft survival at one year was not significantly better in the fish-oil group.

Adjuvant dietary fat intake reduction in postmenopausal breast cancer patient management. The Women's Intervention Nutrition Study (WINS)

Management of localized breast cancer now commonly involves a breast-sparing approach combined with systemic adjuvant therapy resulting in improved cosmetic results and patient survival. Reducing dietary fat intake represents a conceptually new approach to further improve outcome of patients with resected breast cancer. The rationale supporting evaluation of dietary fat reduction in the management of patients with localized breast cancer is based on: (1) epidemiologic observations (along with biochemical and hormonal correlates) of major differences in stage-by-stage survival of patients with localized breast cancer comparing outcome in countries with low fat (Japan) versus high fat (U.S.A.) dietary intakes; (2) relationships between dietary fat intake and factors prognostic of clinical outcome in patients with established breast cancer; (3) effects of weight gain (especially that associated with adjuvant chemotherapy) on breast cancer clinical outcome; (4) in vivo animal studies demonstrating adverse influence of increased dietary fat intake (especially linoleic acid) on growth and metastatic spread of mammary cancer; (5) direct adverse effects of increased linoleic acid on human breast cancer growth in vitro; (6) plausible mechanisms which could mediate the effects of dietary fat intake reduction on breast cancer growth and metastatic spread; (7) demonstration of adherence to dietary fat reduction regimens in ongoing clinical feasibility studies including those involving postmenopausal patients with resected breast cancer; and (8) favorable sample size requirements for definitive assessment of dietary fat intake reduction influence on breast cancer growth and metastases (using as endpoints relapse-free survival and overall survival) in postmenopausal breast cancer patients with localized disease.