Sissi Wachtel-Galor

Ganoderma lucidum (‘Lingzhi’), a Chinese medicinal mushroom : biomarker responses in a controlled human supplementation study

Lingzhi (Ganoderma lucidum) is a woody mushroom highly regarded in traditional medicine and is widely consumed in the belief that it promotes health and longevity, lowers the risk of cancer and heart disease and boosts the immune system. However, objective scientific validation of the putative health benefits of Lingzhi in human subjects is lacking, and issues of possible toxicity must be addressed. The present double-blinded, placebo-controlled, cross-over intervention study investigated the effects of 4 weeks Lingzhi supplementation on a range of biomarkers for antioxidant status, CHD risk, DNA damage, immune status, and inflammation, as well as markers of liver and renal toxicity. It was performed as a follow-up to a study that showed that antioxidant power in plasma increased after Lingzhi ingestion, and that 10 d supplementation was associated with a trend towards an improved CHD biomarker profile. In the present study, fasting blood and urine from healthy, consenting adults (n 18; aged 22-52 years) was collected before and after 4 weeks supplementation with a commercially available encapsulated Lingzhi preparation (1.44 g Lingzhi/d; equivalent to 13.2 g fresh mushroom/d) or placebo. No significant change in any of the variables was found, although a slight trend toward lower lipids was again seen, and antioxidant capacity in urine increased. The results showed no evidence of liver, renal or DNA toxicity with Lingzhi intake, and this is reassuring. The present study of the effects in healthy, well-nourished subjects provides useful, new scientific data that will support controlled intervention trials using at-risk subjects in order to assess the therapeutic effect of Lingzhi in the promotion of healthy ageing.

Ganoderma lucidum ('Lingzhi'); acute and short-term biomarker response to supplementation

Ganoderma lucidum (Lingzhi) is a popular Chinese herb with an impressive array of reputed health benefits, including antioxidant properties. However, these require scientific validation. The aim of this study was to investigate in vitro antioxidant capacity of Lingzhi, absorption and systemic distribution of Lingzhi antioxidants, and effects of short-term (10 days) supplementation on biomarkers of antioxidant status, coronary heart disease (CHD) risk and DNA damage. In this double-blinded, placebo-controlled, cross-over intervention study, blood and urine samples were collected from 10 healthy volunteers at 0 (fasting) and 45, 90, 135 and 180 min post-ingestion of a single dose (1.1g) of Lingzhi. Repeat fasting samples were collected after 10 days’ supplementation with 0.72g/d Lingzhi. The acute response (up to 3 hours) was also investigated with a larger dose (3.3g) of Lingzhi (n=7). Results showed that the total antioxidant capacity (as the FRAP value) of an aqueous suspension of Lingzhi was 360 μmol/g. Ingestion of Lingzhi caused a significant post-ingestion increase (mean±SEM 23±3 μmol/L; P<0.05) in plasma antioxidant capacity, with peak response at 90min. Average increase of 29±11% (P<0.05) in urine antioxidant capacity was seen within 3 hours of ingestion. After 10 days’ supplementation with 0.72g per day of Lingzhi, fasting plasma lipid standardised α-tocopherol concentration and urine antioxidant capacity increased (P<0.05). Fasting plasma ascorbic acid and total α-tocopherol concentrations and erythrocyte SOD and GPx activities increased slightly but non-significantly with supplementation. Plasma lipids and uric acid tended to decrease, but changes were not statistically significant. No discernable differences were seen in other variables measured. Results indicate that Lingzhi intake causes an acute increase in plasma antioxidant capacity. No deleterious effects on measured variables were seen. The pattern of biomarker response after supplementation indicated possible benefit in terms of antioxidant status and CHD risk, but further study is needed to elucidate the nature and longer-term effects of the absorbable antioxidants from Lingzhi.

Vegetarian Diets and Public Health: Biomarker and Redox Connections

Vegetarian diets are rich in antioxidant phytochemicals. However, they may not act as antioxidants in vivo, and yet still have important signaling and regulatory functions. Some may act as pro-oxidants, modulating cellular redox tone and oxidizing redox sensitive sites. In this review, evidence for health benefits of vegetarian diets is presented from different perspectives: epidemiological, biomarker, evolutionary, and public health, as well as antioxidant. From the perspective of molecular connections between diet and health, evidence of a role for plasma ascorbic acid as a biomarker for future disease risk is presented. Basic concepts of redox-based cell signaling are presented, and effects of antioxidant phytochemicals on signaling, especially via redox tone, sulfur switches and the Antioxidant Response Element (ARE), are explored. Sufficient scientific evidence exists for public health policy to promote a plant-rich diet for health promotion. This does not need to wait for science to provide all the answers as to why and how. However, action and interplay of dietary antioxidants in the nonequilibrium systems that control redox balance, cell signaling, and cell function provide rich ground for research to advance understanding of orthomolecular nutrition and provide science-based evidence to advance public health in our aging population.

Effect of Ganoderma lucidum on human DNA is dose dependent and mediated by hydrogen peroxide

Abstract Ganoderma lucidum, an oriental fungus, is widely used for the promotion of health and longevity and is reported to have antioxidant and genoprotective properties. The aim of this study was to investigate the effect of G. lucidum on human lymphocytic DNA ex vivo using the comet assay, and to explore the mechanism of action and the effect of dose. Results showed that G. lucidum has a genoprotective effect at low concentration (0.0001% w/v), but damaged DNA at higher concentrations. The mechanism of damage appeared to be mediated by hydrogen peroxide, which was generated in vitro by G. lucidum, as the effect was ameliorated by the presence of catalase. At concentrations at which no damage was induced, G. lucidum appeared to confer protection against subsequent oxidant challenge to cells. The production of hydrogen peroxide by G. lucidum and its cytotoxic effects should be considered as a factor in future studies. However, the protective effect of G. lucidum at low concentration may explain, in part, some of the reported health benefits of this herb.

Increasing the antioxidant content of food: a personal view on whether this is possible or desirable.

A commonly held belief is that higher intake of antioxidants will promote better health through enhanced antioxidant status and lowered oxidative stress. However, the benefits of antioxidant-rich foods have not been reproduced in supplementation trials with pure antioxidants. This has driven research and commercial interest in foods, including traditional foods and their components, with enhanced antioxidant content and improved antioxidant bioavailability, which in many cases is very low. In this paper, evidence for the health benefits of antioxidant-rich foods and methods to increase the antioxidant content and bioavailability of food antioxidants are reviewed briefly, and the concept that increased food antioxidant content/intake per se is beneficial is examined from a cautionary perspective, considering issues of low bioavailability, rapid catabolism, biotransformation and the paradoxical pro-oxidant effects of dietary antioxidants.

Biomarkers in long-term vegetarian diets.

Publisher Summary The chapter explains biochemical markers in body fluids or cells that reflect body status in terms of nutrition, antioxidant balance, physiological function, and pathological change. The chapter presents the four aspects of the effects of a long-term vegetarian diet on health and on biomarkers. These four aspects are biomarkers that reflect possible nutritional deficiency in association with long-term vegetarian diets, biomarkers that reflect improved oxidant/antioxidant balance in association with vegetarian diets, biomarkers that reflect lower risk of disease in long-term vegetarians, and biomarkers that can differentiate the vegetarian from the nonvegetarian. It should be noted that it is not only the long-term vegetarian who can develop nutritional deficiency of key micronutrients. With the ageing of the global population and the increased awareness of dietary influences and oxidative stress on health, it is timely for clinical chemistry to advance more rapidly into the arena of nutritional and oxidant/antioxidant assessment and to offer measurement of biomarkers that assess health, as opposed to solely focusing on those that aid diagnosis and management of established disease. More awareness of the direct and indirect influence of diet on biomarkers of health and disease is needed as well. Some recommendations are presented in regard to how the clinical chemistry laboratory can advance its contribution to health assessment, as an alternative or additional paradigm to the diagnosis and monitoring of established disease.

Antioxidants, Vegetarian Diets and Aging

Aging is a complex and almost universal biologic phenomenon that increases the risk of disease and death. Exact mechanisms of aging are unresolved, but oxidative stress is a common thread binding the various theories of aging, and is a suggested key underlying factor and driver of the deleterious consequences of human aging in terms of cancer, cardiovascular disease, diabetes, dementia, and other age-related diseases. Oxidative stress can be modulated or opposed by the antioxidant defenses of the body. Many antioxidants found in blood plasma are of dietary origin, and there is convincing evidence that people who habitually take an antioxidant-rich diet live longer, healthier lives. Here we present some of the evidence that oxidative stress is a key factor in aging and age-related disease, and that those who adhere to an antioxidant-rich vegetarian diet have lower oxidative stress and a longer healthspan. Finally, we discuss briefly the possible molecular mechanisms of action of diet-derived antioxidants, with a focus on redox balance and cytoprotective adaptations to pro-oxidant activity of antioxidant phytochemicals.