Plasma levels of beta-carotene are inversely correlated with circulating neutrophil counts in young male cigarette smokers

Mechanistic aspects of carotenoid health benefits - where are we now?

Dietary intake and tissue levels of carotenoids have been associated with a reduced risk of several chronic diseases, including cardiovascular diseases, type 2 diabetes, obesity, brain-related diseases and some types of cancer. However, intervention trials with isolated carotenoid supplements have mostly failed to confirm the postulated health benefits. It has thereby been speculated that dosing, matrix and synergistic effects, as well as underlying health and the individual nutritional status plus genetic background do play a role. It appears that our knowledge on carotenoid-mediated health benefits may still be incomplete, as the underlying mechanisms of action are poorly understood in relation to human relevance. Antioxidant mechanisms - direct or via transcription factors such as NRF2 and NF-κB - and activation of nuclear hormone receptor pathways such as of RAR, RXR or also PPARs, via carotenoid metabolites, are the basic principles which we try to connect with carotenoid-transmitted health benefits as exemplified with described common diseases including obesity/diabetes and cancer. Depending on the targeted diseases, single or multiple mechanisms of actions may play a role. In this review and position paper, we try to highlight our present knowledge on carotenoid metabolism and mechanisms translatable into health benefits related to several chronic diseases.

Thykamine Extracts from Spinach Reduce Acute Inflammation In Vivo and Downregulate Phlogogenic Functions of Human Blood Neutrophils In Vitro

The anti-inflammatory and antioxidant role of Thykamine, a botanical extract of thylakoides obtained from spinach leaves, has been investigated in animal and cellular models. The oxidative properties have been proven by inhibiting NO production (>98%) in J774A.1 cells and by protecting a linoelic acid emulsion subjected to lipid peroxidation caused by AAPH. Thykamine injected intraperitoneally to rats reduced the inflammatory process of (TNBS)-induced colitis and carrageenan-induced paw edema. As neutrophils are the first cells to migrate to inflammatory sites, the influence of Thykamine on the primary neutrophil functions were studied. Thykamine dose-dependent reduced neutrophil chemiotaxis, phagocytosis, and degranulation. No change in the release of LDH by neutrophils on Thykamine was recorded. Thykamine inhibited by 85% the neutrophil production of O₂⁻. A superoxide recovery activity was observed on a zymography demonstrating a SOD-like enzyme on Thykamine extracts. Spontaneous fluorescence provided by carotenoid and chlorophyll pigments (488/675 nm) detected Thykamine on the surface, in the cytoplasm (mainly central where Golgi are present) and weakly in the nucleus of neutrophils. The results argue that SOD and pigments found in Thykamine are part of its antioxidant and anti-inflammatory properties shown in in vivo and in vitro models of inflammation.

Sour Cherries but Not Apples Added to the Regular Diet Decrease Resting and fMLP-Stimulated Chemiluminescence of Fasting Whole Blood in Healthy Subjects

OBJECTIVE

Berry fruits rich in anthocyanins have antioxidant and anti-inflammatory properties. Blood phagocytes are an important source of oxidants that contribute to inflammatory response and oxidative stress. We examined the effect of sour cherry consumption on luminol-enhanced whole blood chemiluminescence (LBCL) reflecting oxidants generation by circulating phagocytes in healthy subjects.

METHODS

Thirty-four and 29 healthy subjects (on a regular diet) consumed 500 g of sour cherries containing 346.5 mg of total anthocyanins or 500 g of anthocyanin-free apples everyday (between 1100 and 1400 hours) for 30 days. Twenty-four volunteers without any dietary intervention served as the control with respect to LBCL changes over the study period. Fasting blood and spot morning urine samples were collected before and after the fruit courses and after the 10-day wash-out period to measure resting and agonist (fMLP)-induced LBCL, blood cell count, concentration of various phenolics, and plasma antioxidant activity.

RESULTS

Sour cherries inhibited (p < 0.05) median resting LBCL (by 29.5% and 33.7%) and fMLP-LBCL (by 24.7% and 32.3%) after 30-day consumption and after 10-day wash-out, respectively. No changes in LBCL were noted in the apple consumers and controls. Increased urinary levels of chlorogenic, 4-hydroxyhippuric, and 3-hydroxyhippuric acids occasionally correlated negatively with resting and fMLP-LBCL in sour cherry consumers. Other measured variables did not change in all groups over the study period.

CONCLUSIONS

The inhibition of resting and agonist-induced LBCL suggests that regular sour cherry consumption may suppress the formation of reactive oxygen species by circulating phagocytes and decrease the risk of systemic imbalance between oxidants and antioxidants. This may be attributed to the anthocyanins in sour cherry and be one of mechanisms of the health-promoting effects of consumption of anthocyanin-rich fruits.

Lipid peroxidation and antioxidants in plasma and red blood cells from patients with pemphigus vulgaris

In pemphigus vulgaris, the increased production of reactive oxygen species from activated neutrophils decreases concentrations of antioxidant vitamins and enzymes in plasma and red blood cells (RBC), resulting in oxidative stress. We compared lipid peroxidation, a measure of reactive oxygen species production, antioxidant vitamins, reduced glutathione (GSH), glutathione peroxide (GSH-Px), and catalase enzyme activity in blood samples obtained from 18 nonsmoking pemphigus vulgaris patients and an equal number of age- and gender-matched, healthy control subjects. Plasma and RBC lipid peroxidation levels (malonyl dialdehyde) were significantly higher (p < 0.05) in pemphigus vulgaris patients than in control subjects. Significantly lower concentrations of plasma antioxidant vitamins (vitamin E and beta-carotene) and vitamin A (p < 0.001), antioxidant enzymes (catalase in RBC and plasma, GSH-Px in RBC [p < 0.05]), and respective GSH activities in both RBC and plasma (p < 0.05 and p < 0.01) were found in pemphigus vulgaris patients than in control subjects. GSH-Px in plasma did not change significantly. The results provide evidence for a potential role of increased lipid peroxidation and peroxidation and decreased antioxidants in pemphigus vulgaris by its inflammatory character.

Reference values and predictors of white blood cell subset counts: a cross-sectional study among HIV seronegative pregnant women in Zimbabwe

OBJECTIVE

To identify predictors and develop reference values of white blood cell subset counts for pregnant black women in Zimbabwe.

STUDY DESIGN

In this cross-sectional study, multiple linear regression (MLR) analysis was employed to assess the relationship of WBC subset counts with age, gestational age, gravidity, season, serum retinol, beta-carotene, ferritin, folate and alpha-1 antichymotrypsin among 998 women 22-35 weeks pregnant attending antenatal care (ANC) in Harare, Zimbabwe.

RESULTS

Mean age was 24.0 (95% CI; 23.6-24.4), range 14-45 years. The mean gestational age was 29.2 (95% CI; 29.0-29.4), range 22-35 weeks. Median gravidity was 2, range 1-9. Predictors of neutrophil counts were gestational age, season and serum ferritin, the latter in interaction with gravidity (interaction, p = 0.016). Mean lymphocyte count was 0.13 x 10(9)cells/l higher in gravida >4 than gravida 1-3, and 0.35 x 10(9)cells/l higher in the late rainy than other seasons. Predictors of monocyte counts were gestational age, serum folate and season, while eosinophil counts declined with advancing gestation. Reference values adjusted or unadjusted for identified predictors were different from those of pregnant and non-pregnant white women reported in the literature.

CONCLUSIONS

Gravidity, season and micronutrient status influence WBC counts during pregnancy and therefore are of physiological and clinical importance. WBC reference values in the literature were not applicable obviating the need for local reference values.

The effect of vitamin E and vitamin C supplementation on LDL oxidizability and neutrophil respiratory burst in young smokers

OBJECTIVE

The purpose of this study was to determine the effect of vitamin E and/or vitamin C supplementation on low-density lipoprotein (LDL) oxidizability and neutrophil (PMN) superoxide anion production in young smokers.

METHODS

Thirty smokers with a <5 pack-year history were randomly assigned to take placebo; vitamin C (1 g/day); vitamin E (400 IU/day), or both vitamins in a double-blind fashion. Subjects took the supplements for 8 weeks. At weeks 0 and 8, blood was collected for isolation of LDL and PMN, and for antioxidant vitamin analysis. LDL was oxidized with a copper (Cu) catalyst, and oxidation was measured by formation of conjugated dienes over a 5-hour time course. Lag times and maximum oxidation rates were calculated from the time course data. PMN superoxide anion release was assessed by respiratory burst after stimulation with phorbol ester and opsonized zymosan, and their ability to oxidize autologous LDL following treatment with the above stimuli was measured with the conjugated diene assay.

RESULTS

Subjects who received vitamin E alone had a significant increase in the lag phase of Cu-catalyzed LDL oxidation (week 0, 118+/-31 min vs. week 8, 193+/-80 min, mean +/- SD, p < 0.05), whereas the vitamin C and placebo groups had no changes in LDL oxidation kinetics. The group receiving both vitamins E and C had a significant reduction in oxidation rate (week 0. 7.4+/-2.3 vs. week 8, 5.1+/-2.1, p < 0.05). There were no significant changes for any group in PMN superoxide anion production or PMN LDL oxidation after stimulation with either phorbol ester or opsonized zymosan. Plasma and LDL vitamin E concentrations were significantly increased in both groups that received vitamin E. The subjects who received vitamin C alone had no significant change in plasma vitamin C concentrations; however, when data were pooled from both groups who received vitamin C, the increases were significant.

CONCLUSION

Vitamin E supplementation of young smokers was effective in reducing Cu-catalyzed LDL oxidizability; however, vitamin E and/or C supplementation showed few significant effects on the more physiologically relevant PMN function. This casts doubt on the ability of antioxidant supplementation to reduce oxidative stress in smokers in vivo. Therefore, smoking cessation remains the only means by which young smokers can prevent premature coronary heart disease.

Vitamins E plus C and interacting conutrients required for optimal health. A critical and constructive review of epidemiology and supplementation data regarding cardiovascular disease and cancer

Antioxidants are crucial components of fruit/vegetable rich diets preventing cardiovascular disease (CVD) and cancer: plasma vitamins C, E, carotenoids from diet correlate prevalence of CVD and cancer inversely, low levels predict an increased risk of individuals which is potentiated by combined inadequacy (e.g., vitamins C + E, C + carotene, A + carotene); self-prescribed rectification of vitamins C and E at adequacy of other micronutrients reduce forthcoming CVD, of vitamins A, C, E, carotene and conutrients also cancer; randomized exclusive supplementation of beta-carotene +/- vitamin A or E lack benefits except prostate cancer reduction by vitamin E, and overall cancer reduction by selenium; randomized intervention with synchronous rectification of vitamins A + C + E + B + minerals reduces CVD and counteracts precancerous lesions; high vitamin E supplements reveal potentials in secondary CVD prevention. Plasma values desirable for primary prevention: > or = 30 mumol/l lipid-standardized vitamin E (alpha-tocopherol/cholesterol > or = 5.0 mumol/mmol); > or = 50 mumol/l vitamin C aiming at vitamin C/vitamin E ratio > 1.3-1.5; > or = 0.4 mumol/l beta- (> or = 0.5 mumol/l alpha+ beta-) carotene.

CONCLUSIONS

In CVD vitamin E acts as first risk discriminator, vitamin C as second one; optimal health requires synchronously optimized vitamins C + E, A, carotenoids and vegetable conutrients.

Changes in antioxidant enzyme levels and DNA damage during aging

Multiple mechanisms underlie the human aging process, but interest continues in the role that free radicals and antioxidants may play. The concentrations of lymphocyte free radical generation (O(2) (-)& H(2)O(2)), DNA damage and antioxidant enzyme levels (glutathione Stransferase, superoxide dismutase and catalase) were evaluated in 110 healthy individuals with an age range of 20-80 years. The antioxidant enzyme levels were significantly less in very old age when compared to young. Moreover, the levels of free radical concentration and DNA damage were increased in the same age group with respect to younger group. Cigarette smoking had a positive relation with free radicals and DNA damage, and inverse relation with antioxidants. On the other hand, body mass was found to have positive relation with free radical generation only. The data indicate that depletion of antioxidant enzyme levels would render the older people more susceptible to free radical stress and DNA damage.

Changes in the polymorphonuclear leukocyte function of blood samples induced by storage time, temperature and agitation

We have investigated changes in polymorphonuclear leukocyte (PMN) functions of blood samples caused by such typical elements of laboratory handling as storage time, temperature and agitation. The blood of five healthy subjects was stored upright in test tubes at 4, 22 and 37 degrees C over periods of 20 min, one, two, six and 24 h. Controlled agitation was performed on a shaker. The following PMN functional parameters were measured: the white blood cell count (WBC), migration, elastase (EL) release, reactive oxygen species (ROS) production and lipid peroxidation. Migration was determined in a whole-blood membrane filter assay; ROS production by latex-stimulated, luminol-enhanced chemiluminescence (CL) in a whole-blood assay; EL as EL alpha 1-antitrypsin complex; and lipid peroxidation by malondialdehyde (MDA) generation. The reactions after handling were compared with the values measured immediately after blood withdrawal which served as reference values of 'genuine' PMN reactivity. The outstanding result was the marked scatter between the individual reactions. Overall, the proportion of migrating PMNs in the blood total decreased, while CL, correlating positively with MDA, increased with the time of storage. EL increased considerably in some of the samples. Agitation raised CL and MDA. The effect of temperature was apparent only after 24 h at 37 degrees C. There was evidence that inhomogeneities in the blood samples were another interfering factor, since resuspension of sedimented blood after storage can be incomplete. In order to obtain reliable results from PMN functional tests, whole-blood assays and processing of blood samples within 20 min after blood withdrawal are recommended.