Instruct: Given a question, retrieve relevant passages that answer the question.
Query: homeopathy
Among medical researchers and clinicians the dominant view is that it is unethical to deceive patients by prescribing a placebo. This opinion is formalized in a recent policy issued by the American Medical Association (AMA [Chicago, IL]). Although placebos can be shown to be always safe, often effective, and sometimes necessary, doctors are now effectively prohibited from using them in clinical practice. I argue that the deceptive administration of placebos is not subject to the same moral objections that face other forms of deception in clinical practice and medical research. Although deception is normally objectionable on the grounds that it limits autonomy and breaches trust, these grounds do not apply to placebos when they are prescribed within appropriate ethical limits. Patients have reason to prefer that doctors can prescribe placebos in ethically responsible ways. Hence, the AMA has an obligation to endorse and to promote the responsible use of deceptive placebos in clinical practice.
Cui and associates show that healthy individuals have natural autoantibodies (NAAs) specific for myeloperoxidase, proteinase 3, and glomerular basement membrane (GBM) with the same specificity as anti-neutrophil cytoplasmic antibodies and anti-GBM antibodies that are pathogenic. Although Ehrlich proposed horror autotoxicus and Burnet envisioned elimination of forbidden clones, NAAs are present in all healthy individuals and play beneficial homeostatic roles. Pathogenic autoimmunity is dysregulation of natural homeostatic autoimmunity rather than onset of a previously absent self-recognition.
Emblica officinalis Gaertn. or Phyllanthus emblica Linn, commonly known as Indian gooseberry or amla, is arguably the most important medicinal plant in the Indian traditional system of medicine, the Ayurveda. Various parts of the plant are used to treat a range of diseases, but the most important is the fruit. The fruit is used either alone or in combination with other plants to treat many ailments such as common cold and fever; as a diuretic, laxative, liver tonic, refrigerant, stomachic, restorative, alterative, antipyretic, anti-inflammatory, hair tonic; to prevent peptic ulcer and dyspepsia, and as a digestive. Preclinical studies have shown that amla possesses antipyretic, analgesic, antitussive, antiatherogenic, adaptogenic, cardioprotective, gastroprotective, antianemia, antihypercholesterolemia, wound healing, antidiarrheal, antiatherosclerotic, hepatoprotective, nephroprotective, and neuroprotective properties. In addition, experimental studies have shown that amla and some of its phytochemicals such as gallic acid, ellagic acid, pyrogallol, some norsesquiterpenoids, corilagin, geraniin, elaeocarpusin, and prodelphinidins B1 and B2 also possess antineoplastic effects. Amla is also reported to possess radiomodulatory, chemomodulatory, chemopreventive effects, free radical scavenging, antioxidant, anti-inflammatory, antimutagenic and immunomodulatory activities, properties that are efficacious in the treatment and prevention of cancer. This review for the first time summarizes the results related to these properties and also emphasizes the aspects that warrant future research to establish its activity and utility as a cancer preventive and therapeutic drug in humans.
Ancient Egypt was one of the greatest civilizations to have arisen, becoming the cradle of scientific enquiry and social development over 3 millennia; undoubtedly its knowledge of medicine has been vastly underestimated. Few artefacts survive which describe the medical organization, but from the extent of the diseases afflicting that ancient populus there would have been much to study. Evidence from papyri, tomb bas reliefs and the writings of historians of antiquity tell of an intense interest in the sciences, humanities and medicine born of an educated society which had overcome the superstitions of its nomadic ancestors.
BACKGROUND/AIMS: Herbal agents are popular and perceived as safe because they are supposedly 'natural'. We report 10 cases of toxic hepatitis implicating Herbalife products. METHODS: To determine the prevalence and outcome of hepatotoxicity due to Herbalife products. A questionnaire was sent to all public Swiss hospitals. Reported cases were subjected to causality assessment using the CIOMS criteria. RESULTS: Twelve cases of toxic hepatitis implicating Herbalife preparations (1998-2004) were retrieved, 10 sufficiently documented to permit causality analysis. Median age of patients was 51 years (range 30-69) and latency to onset was 5 months (0.5-144). Liver biopsy (7/10) showed hepatic necrosis, marked lymphocytic/eosinophilic infiltration and cholestasis in five patients. One patient with fulminant liver failure was successfully transplanted; the explant showed giant cell hepatitis. Sinusoidal obstruction syndrome was observed in one case. Three patients without liver biopsy presented with hepatocellular (2) or mixed (1) liver injury. Causality assessment of adverse drug reaction was classified as certain in two, probable in seven and possible in one case(s), respectively. CONCLUSIONS: We present a case series of toxic hepatitis implicating Herbalife products. Liver toxicity may be severe. A more detailed declaration of components and pro-active role of regulatory agencies would be desirable.
Lycium barbarum has been traditionally used in combination with several herbs for medicinal properties, but systematic modern clinical evaluation as a single herb has not been reported. To examine the systematic effects of L. barbarum on immune function, general well-being, and safety, we tested the effects of a standardized L. barbarum fruit juice (GoChi, FreeLife International, Phoenix, AZ, USA) at 120 mL/day, equivalent to at least 150 g of fresh fruit, the amount traditionally used, or placebo for 30 days in a randomized, double-blind, placebo-controlled clinical study in 60 older healthy adults (55-72 years old). The GoChi group showed a statistically significant increase in the number of lymphocytes and levels of interleukin-2 and immunoglobulin G compared to pre-intervention and the placebo group, whereas the number of CD4, CD8, and natural killer cells or levels of interleukin-4 and immunoglobulin A were not significantly altered. The placebo group showed no significant changes in any immune measures. Whereas the GoChi group showed a significant increase in general feelings of well-being, such as fatigue and sleep, and showed a tendency for increased short-term memory and focus between pre- and post-intervention, the placebo group showed no significant positive changes in these measures. No adverse reactions, abnormal symptoms, or changes in body weight, blood pressure, pulse, visual acuity, urine, stool, or blood biochemistry were seen in either group. In conclusion, daily consumption of GoChi significantly increased several immunological responses and subjective feelings of general well-being without any adverse reactions.
Bach flower remedies continue to be popular and its proponents make a range of medicinal claims for them. The aim of this systematic review was to critically evaluate the evidence for these claims. Five electronic databases were searched without restrictions on time or language. All randomised clinical trials of flower remedies were included. Seven such studies were located. All but one were placebo-controlled. All placebo-controlled trials failed to demonstrate efficacy. It is concluded that the most reliable clinical trials do not show any differences between flower remedies and placebos.
Elevated plasma homocysteine levels are associated with an increased risk of atherosclerosis and thrombosis, as well as a variety of other pathologies such as birth defects, Alzheimer's disease and other dementias, osteoporosis, diabetes and renal disease. Homocysteine metabolism is catalyzed by a number of enzymes that require B-vitamins as cofactors, and homocysteine levels are particularly responsive to folate status. The predictive power of plasma homocysteine level as a risk factor for atherothrombotic orders raised the appealing hypothesis that reduction of homocysteine levels by vitamin supplementation might result in a commensurate reduction is the risk of atherothrombotic events. Unfortunately, most clinical trials failed to show a significant benefit of vitamin supplementation on cardiovascular events, in spite of significant lowering of plasma homocysteine levels. Thus, it is not clear whether homocysteine actually plays a causal role in many pathologies with which it is associated, or whether it is instead a marker for some other underlying mechanism. A large body of data links hyperhomocysteinemia and folate status with oxidant stress. In this article I review data that suggests that homocysteine not only promotes cellular and protein injury via oxidant mechanisms, but is also a marker for the presence of pathological oxidant stress. Thus, it is possible that hyperhomocysteinemia is not a common primary cause of atherothrombotic disorders in the general population, but rather a marker of systemic or endothelial oxidant stress that is a major mediator of these disorders. Published by Elsevier Ltd.
BACKGROUND: Plasma homocysteine levels have been directly associated with cardiac disease risk. Current research raises concerns as to whether comprehensive lifestyle approaches including a plant-based diet may interact with other known modulators of homocysteine levels. METHODS: We report our observations of homocysteine levels in 40 self-selected subjects who participated in a vegan diet-based lifestyle program. Each subject attended a residential lifestyle change program at the Lifestyle Center of America in Sulphur, Oklahoma and had fasting plasma total homocysteine measured on enrollment and then after 1 week of lifestyle intervention. The intervention included a vegan diet, moderate physical exercise, stress management and spirituality enhancement sessions, group support, and exclusion of tobacco, alcohol, and caffeine. B vitamin supplements known to reduce blood homocysteine levels were not provided. RESULTS: Subjects' mean homocysteine levels fell 13%: from 8.66 micromol/L (SD 2.7 micromol/L) to 7.53 micromol/L (SD 2.12 micromol/L; P < 0.0001). Subgroup analysis showed that homocysteine decreased across a range of demographic and diagnostic categories. Conclusions. Our results suggest that broad-based lifestyle interventions favorably impact homocysteine levels. Furthermore, analysis of Lifestyle Center of America program components suggests that other factors in addition to B vitamin intake may be involved in the observed homocysteine lowering.
CONTEXT: Lead, mercury, and arsenic intoxication have been associated with the use of Ayurvedic herbal medicine product (HMPs). OBJECTIVES: To determine the prevalence and concentration of heavy metals in Ayurvedic HMPs manufactured in South Asia and sold in Boston-area stores and to compare estimated daily metal ingestion with regulatory standards. DESIGN AND SETTING: Systematic search strategy to identify all stores 20 miles or less from Boston City Hall that sold Ayurvedic HMPs from South Asia by searching online Yellow Pages using the categories markets, supermarkets, and convenience stores, and business names containing the word India, Indian cities, and Indian words. An online national directory of Indian grocery stores, a South Asian community business directory, and a newspaper were also searched. We visited each store and purchased all unique Ayurvedic HMPs between April 25 and October 24, 2003. MAIN OUTCOME MEASURES: Concentrations (microg/g) of lead, mercury, and arsenic in each HMP as measured by x-ray fluorescence spectroscopy. Estimates of daily metal ingestion for adults and children estimated using manufacturers' dosage recommendations with comparisons to US Pharmacopeia and US Environmental Protection Agency regulatory standards. RESULTS: A total of 14 (20%) of 70 HMPs (95% confidence interval, 11%-31%) contained heavy metals: lead (n = 13; median concentration, 40 microg/g; range, 5-37,000), mercury (n = 6; median concentration, 20,225 microg/g; range, 28-104,000), and/or arsenic (n = 6; median concentration, 430 microg/g; range, 37-8130). If taken as recommended by the manufacturers, each of these 14 could result in heavy metal intakes above published regulatory standards. CONCLUSIONS: One of 5 Ayurvedic HMPs produced in South Asia and available in Boston South Asian grocery stores contains potentially harmful levels of lead, mercury, and/or arsenic. Users of Ayurvedic medicine may be at risk for heavy metal toxicity, and testing of Ayurvedic HMPs for toxic heavy metals should be mandatory.
An evidence-based systematic review of acai (Euterpe oleracea) by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.
The aqueous seed extract of Persea americana Mill (Lauraceae) is used by herbalists in Nigeria for the management of hypertension. As part of our on-going scientific evaluation of the extract, we designed the present study to assess its acute and sub-acute toxicity profiles in rats. Experiments were conducted to determine the oral median lethal dose (LD50) and other gross toxicological manifestations on acute basis. In the sub-acute experiments, the animals were administered 2.5 g/kg (p.o) per day of the extract for 28 consecutive days. Animal weight and fluid intake were recorded during the 28 days period. Terminally, kidneys, hearts, blood/sera were obtained for weight, haematological and biochemical markers of toxicity. Results show that the LD50 could not be determined after a maximum dose of 10 g/kg. Sub-acute treatment with the extract neither affected whole body weight nor organ-to-body weight ratios but significantly increased the fluid intake (P < 0.0001). Haematological parameters and the levels of ALT, AST, albumin and creatinine were not significantly altered. However, the concentration of total proteins was significantly increased in the treated group. In conclusion, the aqueous seed extract of P. americana is safe on sub-acute basis but extremely high doses may not be advisable.
Linaclotide (Linzess) for irritable bowel syndrome with constipation and for chronic idiopathic constipation.
Objective To describe the attitudes and behaviours regarding placebo treatments, defined as a treatment whose benefits derive from positive patient expectations and not from the physiological mechanism of the treatment itself. Design Cross sectional mailed survey. Setting Physicians’ clinical practices. Participants 1200 practising internists and rheumatologists in the United States. Main outcome measures Investigators measured physicians’ self reported behaviours and attitudes concerning the use of placebo treatments, including measures of whether they would use or had recommended a “placebo treatment,” their ethical judgments about the practice, what they recommended as placebo treatments, and how they typically communicate with patients about the practice. Results 679 physicians (57%) responded to the survey. About half of the surveyed internists and rheumatologists reported prescribing placebo treatments on a regular basis (46-58%, depending on how the question was phrased). Most physicians (399, 62%) believed the practice to be ethically permissible. Few reported using saline (18, 3%) or sugar pills (12, 2%) as placebo treatments, while large proportions reported using over the counter analgesics (267, 41%) and vitamins (243, 38%) as placebo treatments within the past year. A small but notable proportion of physicians reported using antibiotics (86, 13%) and sedatives (86, 13%) as placebo treatments during the same period. Furthermore, physicians who use placebo treatments most commonly describe them to patients as a potentially beneficial medicine or treatment not typically used for their condition (241, 68%); only rarely do they explicitly describe them as placebos (18, 5%). Conclusions Prescribing placebo treatments seems to be common and is viewed as ethically permissible among the surveyed US internists and rheumatologists. Vitamins and over the counter analgesics are the most commonly used treatments. Physicians might not be fully transparent with their patients about the use of placebos and might have mixed motivations for recommending such treatments.
The intestinal flora is considered to have an impact on the development of the immune system. In the anthroposophic lifestyle, a diet comprising vegetables spontaneously fermented by lactobacilli, and a restrictive use of antibiotics, anti-pyretics and vaccinations, is typical. The aim of this study was to assess the gut flora in infants in relation to certain lifestyle characteristics associated with anthroposophy. Sixty-nine children < 2 years of age with an anthroposophic lifestyle, and 59 infants of a similar age with a traditional lifestyle, were clinically examined and questionnaire replies assessed. Fecal samples were analyzed by bacterial enumeration, bacterial typing through biochemical fingerprinting and by measuring microflora-associated characteristics (MACs). The numbers of colony-forming units (CFU)/g of feces were significantly higher for enterococci and lactic acid bacteria in children who had never been exposed to antibiotics (5.5 x 107 vs. 2.1 x 107; p < 0.001 and 10 x 107 vs. 4.1 x 107; p < 0.01, respectively). Furthermore, the number of enterococci was significantly higher in breastfed and vegetarian infants (p < 0.01). The diversity (Simpson's diversity index) of lactobacilli, as determined by biochemical fingerprinting, was higher in infants born at home than in those born in hospital (p < 0.01). Several MACs were related to specific lifestyle features, and infants with an anthroposophic lifestyle had a higher proportion of acetic acid and a lower proportion of propionic acid in their stool as compared to the control children. In conclusion, lifestyle factors related to the anthroposophic way of life influenced the composition of the gut flora in the infants. These differences may contribute to the lower prevalence of atopic disease previously observed in children in anthroposophic families.
OBJECTIVE: To investigate if standardised powder made from rose-hip (Rosa canina) can reduce the symptom score in patients with rheumatoid arthritis. METHODS: In a double-blind placebo-controlled trial, patients with rheumatoid arthritis (RA) according to ARA/ACR criteria were randomised to treatment with capsulated rose-hip powder 5g daily or matching placebo for 6 months at two outpatient clinics in Berlin and Copenhagen. Primary outcome variable was Health Assessment Questionnaire (HAQ) at 6 months, secondary outcome included DAS-28, physician's global evaluation of disease activity, RAQoL, SF-12 and concomitant pain medication. RESULTS: In a total of 89 patients (90% female, mean age 56.6+11.3 years, mean disease duration 12.8+9.6 years) HAQ-DI in the rose-hip group improved by 0.105+/-0.346, whereas in the placebo group it worsened by 0.039+/-0.253 (p adjusted=0.032). In the HAQ Patient Pain Scale no significant differences were observed between both groups. In the HAQ Patient Global Scale a trend was seen favouring rose-hip (p=0.078). The DAS-28 score yielded improvement in the rose-hip group of 0.89+/-1.32 and in the placebo group of 0.34+/-1.27 (p=0.056) indicating moderate clinical relevance. The Physicians Global Scale demonstrated more improvement in the rose-hip compared to the placebo group (p=0.012). RAQoL and SF-12 physical score improved significantly in the rose-hip group compared to placebo, whereas SF-12 mental score remained unchanged. Intake of pain medication was not different between the groups. Per-protocol analysis confirmed these results. CONCLUSION: The results indicate that patients with RA may benefit from additional treatment with rose hip powder. Copyright 2009 Elsevier GmbH. All rights reserved.
Is it ever right to prescribe placebos to patients in clinical practice? The General Medical Council is ambivalent about the issue; the American Medical Association asserts that placebos can be administered only if the patient is (somehow) 'informed'. The potential problem with placebos is that they may involve deception: indeed, if this is the case, an ethical tension arises over the patient's autonomy and the physician's requirement to be open and honest, and the notion that medical care should be the primary concern. This paper examines the case of depression as an entry point for understanding the complexities of the prescription of placebos. Recent important meta-analyses of antidepressants claim that they are not significantly more effective in a clinical setting than placebos. Given that antidepressants have numerous adverse side effects and are hugely expensive, this provocative research has serious potential ethical and practical implications for patients and medical providers. Should placebos be prescribed in place of antidepressants? The case of depression highlights another important issue which medical ethical codes have hitherto overlooked: well-being is not synonymous with being realistic about oneself, one's circumstances and the future. While severely depressed individuals are unduly pessimistic about themselves and the world around them, treatment of depressed individuals can be deemed successful when patients have successfully attained those positive illusions that are indicative of psychological health. This is exactly what successful psychological treatments of depression seem to achieve. It is therefore possible that there may be a limited unavoidable role for deception in medicine.
OBJECTIVE: Meta-analysis of randomized controlled trials (RCTs)--of a hip powder of Rosa canina (rosehip) preparation for symptomatic treatment of osteoarthritis (OA), in order to estimate the empirical efficacy as a pain reducing compound. METHOD: RCTs from systematic searches were included if they explicitly stated that OA patients were randomized to either rosehip or placebo. The primary outcome was reduction in pain calculated as effect size (ES), defined as the standardized mean difference (SMD). As secondary analysis the number of responders to therapy was analyzed as Odds Ratios (OR), and expressed as the Number Needed to Treat (NNT). Restricted Maximum Likelihood (REML) methods were applied for the meta-analyses using mixed effects models. RESULTS: The three studies (287 patients and a median trial-duration of 3 months)--all supported by the manufacturer (Hyben-Vital International)--showed a reduction in pain scores by rosehip powder (145 patients) compared to placebo (142 patients): ES of 0.37 [95% confidence interval (CI): 0.13-0.60], P=0.002. Test for homogeneity seemed to support that the efficacy was consistent across trials (I(2)=0%). Thus it seems reasonable to assume that the three studies were measuring the same overall effect. It seemed twice as likely that a patient allocated to rosehip powder would respond to therapy, compared to placebo (OR=2.19; P=0.0009); corresponding to a NNT of six (95% CI: 4-13) patients. CONCLUSIONS: Although based on a sparse amount of data, the results of the present meta-analysis indicate that rosehip powder does reduce pain; accordingly it may be of interest as a nutraceutical, although its efficacy and safety need evaluation and independent replication in a future large-scale/long-term trial.
In tissue cultures of normal adult and malignant mammalian cells, homocystine has been substituted for methionine in a medium rich in folic acid and cyanocobalamin. Normal adult cells thrive. Three highly malignant cell types from three different species, including man, die.
Hibiscus sabdariffa Linne is a traditional Chinese rose tea and has been effectively used in folk medicines for treatment of hypertension, inflammatory conditions. H. sabdariffa aqueous extracts (HSE) were prepared from the dried flowers of H. sabdariffa L., which are rich in phenolic acids, flavonoids and anthocyanins. In this review, we discuss the chemopreventive properties and possible mechanisms of various H. sabdariffa extracts. It has been demonstrated that HSE, H. sabdariffa polyphenol-rich extracts (HPE), H. sabdariffa anthocyanins (HAs), and H. sabdariffa protocatechuic acid (PCA) exert many biologic effects. PCA and HAs protected against oxidative damage induced by tert-butyl droperoxide (t-BHP) in rat primary hepatocytes. In rabbits fed cholesterol and human experimental studies, these studies imply HSE could be pursued as atherosclerosis chemopreventive agents as they inhibit LDL oxidation, foam cell formation, as well as smooth muscle cell migration and proliferation. The extracts also offer hepatoprotection by influencing the levels of lipid peroxidation products and liver marker enzymes in experimental hyperammonemia. PCA has also been shown to inhibit the carcinogenic action of various chemicals in different tissues of the rat. HAs and HPE were demonstrated to cause cancer cell apoptosis, especially in leukemia and gastric cancer. More recent studies investigated the protective effect of HSE and HPE in streptozotocin induced diabetic nephropathy. From all these studies, it is clear that various H. sabdariffa extracts exhibit activities against atherosclerosis, liver disease, cancer, diabetes and other metabolic syndromes. These results indicate that naturally occurring agents such as the bioactive compounds in H. sabdariffa could be developed as potent chemopreventive agents and natural healthy foods.
Background An increased rate of brain atrophy is often observed in older subjects, in particular those who suffer from cognitive decline. Homocysteine is a risk factor for brain atrophy, cognitive impairment and dementia. Plasma concentrations of homocysteine can be lowered by dietary administration of B vitamins. Objective To determine whether supplementation with B vitamins that lower levels of plasma total homocysteine can slow the rate of brain atrophy in subjects with mild cognitive impairment in a randomised controlled trial (VITACOG, ISRCTN 94410159). Methods and Findings Single-center, randomized, double-blind controlled trial of high-dose folic acid, vitamins B6 and B12 in 271 individuals (of 646 screened) over 70 y old with mild cognitive impairment. A subset (187) volunteered to have cranial MRI scans at the start and finish of the study. Participants were randomly assigned to two groups of equal size, one treated with folic acid (0.8 mg/d), vitamin B12 (0.5 mg/d) and vitamin B6 (20 mg/d), the other with placebo; treatment was for 24 months. The main outcome measure was the change in the rate of atrophy of the whole brain assessed by serial volumetric MRI scans. Results A total of 168 participants (85 in active treatment group; 83 receiving placebo) completed the MRI section of the trial. The mean rate of brain atrophy per year was 0.76% [95% CI, 0.63–0.90] in the active treatment group and 1.08% [0.94–1.22] in the placebo group (P = 0.001). The treatment response was related to baseline homocysteine levels: the rate of atrophy in participants with homocysteine >13 µmol/L was 53% lower in the active treatment group (P = 0.001). A greater rate of atrophy was associated with a lower final cognitive test scores. There was no difference in serious adverse events according to treatment category. Conclusions and Significance The accelerated rate of brain atrophy in elderly with mild cognitive impairment can be slowed by treatment with homocysteine-lowering B vitamins. Sixteen percent of those over 70 y old have mild cognitive impairment and half of these develop Alzheimer's disease. Since accelerated brain atrophy is a characteristic of subjects with mild cognitive impairment who convert to Alzheimer's disease, trials are needed to see if the same treatment will delay the development of Alzheimer's disease. Trial Registration Controlled-Trials.com ISRCTN94410159
The effectiveness of Hibiscus sabdariffa L. (HS) in the treatment of risk factors associated with cardiovascular disease is assessed in this review by taking a comprehensive approach to interpreting the randomized clinical trial (RCT) results in the context of the available ethnomedical, phytochemical, pharmacological, and safety and toxicity information. HS decoctions and infusions of calyxes, and on occasion leaves, are used in at least 10 countries worldwide in the treatment of hypertension and hyperlipidemia with no reported adverse events or side effects. HS extracts have a low degree of toxicity with a LD50 ranging from 2,000 to over 5,000 mg/kg/day. There is no evidence of hepatic or renal toxicity as the result of HS extract consumption, except for possible adverse hepatic effects at high doses. There is evidence that HS acts as a diuretic, however in most cases the extract did not significantly influence electrolyte levels. Animal studies have consistently shown that consumption of HS extract reduces blood pressure in a dose dependent manner. In RCTs, the daily consumption of a tea or extract produced from HS calyxes significantly lowered systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults with pre to moderate essential hypertension and type 2 diabetes. In addition, HS tea was as effective at lowering blood pressure as the commonly used blood pressure medication Captropril, but less effective than Lisinopril. Total cholesterol, low-density lipoprotein cholesterol (LDL-C), and triglycerides were lowered in the majority of normolipidemic, hypolipidemic, and diabetic animal models, whereas high-density lipoprotein cholesterol (HDL-C) was generally not affected by the consumption of HS extract. Over half of the RCTs showed that daily consumption of HS tea or extracts had favorable influence on lipid profiles including reduced total cholesterol, LDL-C, triglycerides, as well as increased HDL-C. Anthocyanins found in abundance in HS calyxes are generally considered the phytochemicals responsible for the antihypertensive and hypocholesterolemic effects, however evidence has also been provided for the role of polyphenols and hibiscus acid. A number of potential mechanisms have been proposed to explain the hypotensive and anticholesterol effects, but the most common explanation is the antioxidant effects of the anthocyanins inhibition of LDL-C oxidation, which impedes atherosclerosis, an important cardiovascular risk factor. This comprehensive body of evidence suggests that extracts of HS are promising as a treatment of hypertension and hyperlipidemia, however more high quality animal and human studies informed by actual therapeutic practices are needed to provide recommendations for use that have the potential for widespread public health benefit.
Mild to moderate hyperhomocysteinemia is a risk factor for neurodegenerative diseases. Human studies suggest that homocysteine (Hcy) plays a role in brain damage, cognitive and memory decline. Numerous studies in recent years investigated the role of Hcy as a cause of brain damage. Hcy itself or folate and vitamin B12 deficiency can cause disturbed methylation and/or redox potentials, thus promoting calcium influx, amyloid and tau protein accumulation, apoptosis, and neuronal death. The Hcy effect may also be mediated by activating the N-methyl-D-aspartate receptor subtype. Numerous neurotoxic effects of Hcy can be blocked by folate, glutamate receptor antagonists, or various antioxidants. This review describes the most important mechanisms of Hcy neurotoxicity and pharmacological agents known to reverse Hcy effects.
Longevity, lifespan, cancer, cellular transformation, energy, calorie restriction, diabetes--what can tie together such a diversity of hot topics in biomedical research? Emerging findings suggest that the answer lies in understanding the functions of the recently discovered family of proteins known as Sirtuins. Barcelona hosted the first scientific meeting completely focused on these evolutionary conserved protein deacetylases, bringing together experts in the biochemistry to cellular biology, mice models, drug targeting and pathophysiology of these molecules. Their work, summarized here, establishes the Sirtuins as major players in cellular homeostasis and human diseases that act through a whole range of biochemical substrates and physiological processes. Undoubtedly, this is an increasingly expanding field that it is here to stay and growth.
Alzheimer’s disease (AD) is the most common form of neurodegenerative disease. The vast majority cases of AD are sporadic, without clear cause, and a combination of environmental and genetic factors have been implicated. The hypothesis that homocysteine (Hcy) is a risk factor for AD was initially prompted by the observation that patients with histologically confirmed AD had higher plasma levels of Hcy, also called hyperhomocysteinemia (HHcy), than age-matched controls. Most evidence accumulated so far implicates HHcy as a risk factor for AD onset, but conflicting results also exist. In this review, we summarize reports on the relationship between HHCy and AD from epidemiological investigations, including observational studies and randomized controlled clinical trials. We also examine recent in vivo and in vitro studies of potential mechanisms whereby HHcy may influence AD development. Finally, we discuss possible reasons for the existing conflicting data, and provide suggestions for future studies.