Lesley M Stevenson

Bovine lactoferrin supplementation supports immune and antioxidant status in healthy human males

Dietary supplements of bovine lactoferrin are purported in consumer literature to enhance and support the immune system response through their antioxidant, antibacterial, and antiviral properties. Our aim was to investigate more fully the potential immune modulating properties and antioxidant activity of an oral supplementation of bovine lactoferrin in humans. Using an intraindividual repeated measure design, 8 healthy males aged 30 to 55 years, self-administered daily for 21 days, one capsule of placebo for 7 days, followed by 100 mg of lactoferrin for 7 days, followed by 200 mg of lactoferrin for 7 days. Peripheral blood lymphocyte subset counts, T-cell activation, natural killer (NK) cell cytotoxicity, serum cytokine levels (tumor necrosis factor [TNF]-alpha, interferon [IFN]-gamma, interleukin [IL]-2, IL-4, IL-6, and IL-10), and serum hydrophilic, lipophilic, and total antioxidant capacity were repeatedly measured before and after each progressive supplementation. Statistically significant increases were found between presupplementation levels and levels after 200 mg of supplementation in total T-cell activation (as measure by CD3(+)) (P < .001), helper T-cell activation (as measure by CD4(+)) (P < .001), cytotoxic T-cell activation (as measured by CD8(+)) (P < .001), and hydrophilic antioxidant capacity (P < .05). No significant changes were seen in the other parameters measured. These results support the proposal that oral supplements of bovine lactoferrin may be a useful adjunct toward modulation of immune activity, in particular T-cell activation and antioxidant status.

Alkylamides from echinacea modulate induced immune responses in macrophages.

The ability of Echinacea and its components to alter the immune response was examined in vitro in a macrophage cell line under either basal or immunostimulated conditions. Potential immunostimulatory and inflammatory activity was determined using a nuclear transcription factor (NFκB) expression, tumour necrosis factor α (TNFα) and nitric oxide (NO) production as biomarkers. In the absence of alternate stimulation, the only significant effects seen were a decrease in NFκB expression by a 2-ene alkylamide ((2E)-N-isobutylundeca-2-ene-8,10-diynamide (1)) and a decrease in TNFα levels by cichoric acid and an Echinacea alkylamide fraction (EPL AA). When the cells were stimulated by lipopolysaccharide (LPS), inhibition of the increased NFκB expression levels was caused by cichoric acid, an Echinacea preparation (EPL), EPL AA and a 2,4-diene ((2E,4E,8Z,10Z)-N-isobutyldodeca-2,4,8,10-tetraenamide (2)). Increases in TNFα levels were inhibited by cichoric acid, EPL and EPL AA but enhanced by 1 in the presence of LPS, while only EPL AA was able to inhibit the stimulated increases in NO. When using phorbol myristate acetate to stimulate the cells, NFκB and NO levels were unaffected by Echinacea or its components while only cichoric acid and 2 inhibited TNFα levels. Although cichoric acid was found to have an effect, it is probably not an important contributor to the Echinacea modulation of the immune response in vivo, as it is not bioavailable. Echinacea appears to attenuate the response of macrophages to an immune stimulus and its combination of phytochemicals exhibits different pharmacological properties to one or more of the isolated major individual components.

Bovine colostrum supplementation and exercise performance: potential mechanisms

Bovine colostrum (BC) is rich in immune, growth and antimicrobial factors, which promote tissue growth and the development of the digestive tract and immune function in neonatal calves. Although the value of BC to human adults is not well understood, supplementation with BC is becoming increasingly popular in trained athletes to promote exercise performance. The combined presence of insulin-like growth factors (IGF), transforming growth factors, immunoglobulins, cytokines, lactoferrin and lysozyme, in addition to hormones such as growth hormone, gonadotrophin-releasing hormone, luteinizing hormone-releasing hormone and glucocorticoids, would suggest that BC might improve immune function, gastrointestinal integrity and the neuroendocrine system, parameters that may be compromised as a result of intensive training. A review of studies investigating the influence of BC supplementation on exercise performance suggests that BC supplementation is most effective during periods of high-intensity training and recovery from high-intensity training, possibly as a result of increased plasma IGF-1, improved intramuscular buffering capacity, increases in lean body mass and increases in salivary IgA. However, there are contradicting data for most parameters that have been considered to date, suggesting that small improvements across a range of parameters might contribute to improved performance and recovery, although this cannot be concluded with certainty because the various doses and length of supplementation with BC in different studies prevent direct comparison of results. Future research on the influence of BC on sports performance will only be of value if the dose and length of supplementation of a well-defined BC product is standardized across studies, and the bioavailability of the active constituents in BC is determined.

The influence of bovine colostrum supplementation on exercise performance in highly trained cyclists

Purpose: The aim of this experiment was to investigate the influence of low dose bovine colostrum supplementation on exercise performance in cyclists over a 10 week period that included 5 days of high intensity training (HIT). Methods: Over 7 days of preliminary testing, 29 highly trained male road cyclists completed a VO2max test (in which their ventilatory threshold was estimated), a time to fatigue test at 110% of ventilatory threshold, and a 40 km time trial (TT40). Cyclists were then assigned to either a supplement (n = 14, 10 g/day bovine colostrum protein concentrate (CPC)) or a placebo group (n = 15, 10 g/day whey protein) and resumed their normal training. Following 5 weeks of supplementation, the cyclists returned to the laboratory to complete a second series of performance testing (week 7). They then underwent five consecutive days of HIT (week 8) followed by a further series of performance tests (week 9). Results: The influence of bovine CPC on TT40 performance during normal training was unclear (week 7: 1±3.1%, week 9: 0.1±2.1%; mean±90% confidence limits). However, at the end of the HIT period, bovine CPC supplementation, compared to the placebo, elicited a 1.9±2.2% improvement from baseline in TT40 performance and a 2.3±6.0% increase in time trial intensity (% VO2max), and maintained TT40 heart rate (2.5±3.7%). In addition, bovine CPC supplementation prevented a decrease in ventilatory threshold following the HIT period (4.6±4.6%). Conclusion: Low dose bovine CPC supplementation elicited improvements in TT40 performance during an HIT period and maintained ventilatory threshold following five consecutive days of HIT.

Modulation of macrophage immune responses by Echinacea

Echinacea preparations are widely used herbal medicines for the prevention and treatment of colds and minor infections. There is little evidence for the individual components in Echinacea that contribute to immune regulatory activity. Activity of an ethanolic Echinacea extract and several constituents, including cichoric acid, have been examined using three in vitro measures of macrophage immune function – NF-κB, TNF- α and nitric oxide (NO). In cultured macrophages, all components except the monoene alkylamide (AA1) decreased lipopolysaccharide (LPS) stimulated NF-κB levels. 0.2 µg/ml cichoric acid and 2.0µg/mL Echinacea Premium Liquid (EPL) and EPL alkylamide fraction (EPL AA) were found to significantly decrease TNF-α production under LPS stimulated conditions in macrophages. In macrophages, only the alkylamide mixture isolated from the ethanolic Echinacea extract decreased LPS stimulated NO production. In this study, the mixture of alkylamides in the Echinacea ethanolic liquid extract did not respond in the same manner in the assays as the individual alkylamides investigated. While cichoric acid has been shown to affect NF-κB, TNF-α and NO levels, it is unlikely to be relevant in the Echinacea alterations of the immune response in vivo due to its non- bioavailability – i.e. no demonstrated absorption across the intestinal barrier and no detectable levels in plasma. These results demonstrate that Echinacea is an effective modulator of macrophage immune responses in vitro.

Feeding ZESPRI™ GOLD Kiwifruit puree to mice enhances serum immunoglobulins specific for ovalbumin and stimulates ovalbumin-specific mesenteric lymph node cell proliferation in response to orally administered ovalbumin

The health benefits of fruits have been recognized for some time, but only recently have their effects on the immune system been investigated. Kiwifruit contains vitamins, minerals, and phytochemicals that are known to be important for normal functioning of the immune system. In this work, the influence of feeding 2 ZESPRI GOLD Kiwifruit processed products (Tauranga, New Zealand) on immune function in mice was investigated. Using a model to demonstrate adaptive immune responses in the gut, mice were fed either ZESPRI GOLD Kiwifruit puree or ZESPRI GOLD Kiwifruit 40 degrees Brix Juice concentrate for 20 days, during which time they were immunized via the oral route with ovalbumin and subsequently given a suboptimal dose of the mucosal adjuvant cholera toxin. ZESPRI GOLD Kiwifruit puree enhanced the response to ovalbumin by significantly increasing the levels of total immunoglobulins and immunoglobulin G specific for ovalbumin and enhanced the antigen-specific proliferation of cells from the draining mesenteric lymph nodes compared with mice fed a 20% sugar control. These results indicate that ZESPRI GOLD Kiwifruit can modulate an antigen-specific immune response and suggest that ZESPRI GOLD Kiwifruit may represent a new type of functional food ingredient.

A forced titration study of the antioxidant and immunomodulatory effects of Ambrotose AO supplement

BackgroundOxidative stress plays a role in acute and chronic inflammatory disease and antioxidant supplementation has demonstrated beneficial effects in the treatment of these conditions. This study was designed to determine the optimal dose of an antioxidant supplement in healthy volunteers to inform a Phase 3 clinical trial.MethodsThe study was designed as a combined Phase 1 and 2 open label, forced titration dose response study in healthy volunteers (n = 21) to determine both acute safety and efficacy. Participants received a dietary supplement in a forced titration over five weeks commencing with a no treatment baseline through 1, 2, 4 and 8 capsules. The primary outcome measurement was ex vivo changes in serum oxygen radical absorbance capacity (ORAC). The secondary outcome measures were undertaken as an exploratory investigation of immune function.ResultsA significant increase in antioxidant activity (serum ORAC) was observed between baseline (no capsules) and the highest dose of 8 capsules per day (p = 0.040) representing a change of 36.6%. A quadratic function for dose levels was fitted in order to estimate a dose response curve for estimating the optimal dose. The quadratic component of the curve was significant (p = 0.047), with predicted serum ORAC scores increasing from the zero dose to a maximum at a predicted dose of 4.7 capsules per day and decreasing for higher doses. Among the secondary outcome measures, a significant dose effect was observed on phagocytosis of granulocytes, and a significant increase was also observed on Cox 2 expression.ConclusionThis study suggests that Ambrotose AO® capsules appear to be safe and most effective at a dosage of 4 capsules/day. It is important that this study is not over interpreted; it aimed to find an optimal dose to assess the dietary supplement using a more rigorous clinical trial design. The study achieved this aim and demonstrated that the dietary supplement has the potential to increase antioxidant activity. The most significant limitation of this study was that it was open label Phase 1/Phase 2 trial and is subject to potential bias that is reduced with the use of randomization and blinding. To confirm the benefits of this dietary supplement these effects now need to be demonstrated in a Phase 3 randomised controlled trial (RCT).Trial RegistrationAustralian and New Zealand Clinical Trials Register: ACTRN12605000258651

A new highly oxygenated pseudoguaianolide with 5-LOX inhibitory activity from Rudbeckia hirta L. flowers

A new highly oxygenated pseudoguaianolide, rudbeckolide (1), was isolated from Rudbeckia hirta L. flowers. The structure of this terpenoid lactone was established on the basis of extensive 1D and 2D NMR spectroscopic analyses. The compound exhibited strong 5-lipoxygenase inhibitory activity (84.9% inhibition at 10 μg/mL) in vitro and the result provided partial evidence for the usage of the plant as traditional medicine.

Evidence-based medicinal value of Rudbeckia hirta L. flowers

A phytochemical investigation on the 5-lipoxygenase (5-LOX) inhibitory methanolic extract of Rudbeckia hirta L. flowers yielded 10 phenolic metabolites, including three phenolic acids, two phenolic acid esters, four flavonol glycosides and a trimethylated flavonol. The structures of the isolated metabolites were determined on the basis of spectroscopic analyses and by comparison with the literature data. Seven of these metabolites were isolated for the first time from the genus Rudbeckia. The in vitro 5-LOX inhibitory, immunomodulatory and antioxidant (oxygen radical absorbance capacity) activities of the isolated compounds were evaluated, and the results provided a new scientific evidence for the ethnopharmacological use of the herb in inflammatory conditions.