Herbs and the kidney

Metabonomic study of aristolochic acid-induced nephrotoxicity in rats

This paper describes a metabonomic study characterizing the nephrotoxicity induced by aristolochic acid (AA), a suspected kidney toxicant. For these studies, we examined the biochemical compositions of AA-treated rat urine using LC-MS and pattern recognition methods. The biochemical and histological patterns of rat groups treated with different AA sources showed distinct differences from those of the control group. Certain metabolic pathways, such as homocysteine formation and the folate cycle were significantly accelerated, while others, including arachidonic acid biosynthesis, were decreased. A subset-validation procedure using linear discriminant analysis (LDA) and selected predictive variables indicated that approximately 95% of the treated and nontreated rat urine samples were classified correctly into their respective treatment groups. The results suggested that this metabonomic approach is a promising methodology for the rapid in vivo screening of nephrotoxicity associated with ingesting multi-ingredient medicinal herb supplements, and provides a valid method for comprehending the chemical-induced perturbations in the metabolic network and the networked lesions.

Herbs or natural substances as complementary therapies for chronic kidney disease: ideas for future studies

Chronic kidney disease (CKD) is an increasingly common condition with limited treatment options that is placing a major financial and emotional burden on the community. The use of complementary and alternative medicines (CAMS) has increased many-fold over the past decade. Although several compelling studies show renal toxicities and an adverse outcome from use of some CAMS, there is also emerging evidence in the literature that some may be renoprotective. Many nephrologists are unaware of these potential therapeutic benefits in treating CKD, or they are reluctant to consider them in research trials for fear of adverse effects (including nephrotoxicity) or deleterious interaction with co-prescribed, conventional medicines. The increased use of self-prescribed CAMS by their patients suggests that practitioners and researchers should keep abreast of the current information on these agents. A primary goal of this article was to review the available scientific evidence for the use of herbs or natural substances as a complementary treatment for patients with CKD. A further goal was to report the literature on herbs that have been reported to cause kidney failure.

Fanconi's syndrome, interstitial fibrosis and renal failure by aristolochic acid in Chinese herbs

Aristolochic acid-associated nephropathy (AAN) has been identified as a separate entity of progressive tubulo-interstitial nephropathy. Its characteristic pathological findings, including hypocellular interstitial fibrosis, intimal thickening of interlobular and afferent arterioles with glomeruli sparing or mild sclerosis, have been identified. Many cases of AAN in adults have been reported in Taiwan as well as throughout the world, but it has seldom been described in children. We report on a 10-year-old boy who presented with severe anemia, Fanconi's syndrome, and progressive renal failure. Renal biopsy revealed typical findings of AAN. Aristolochic acids I and II were identified from a Chinese herb mixture ingested by the boy. AAN was diagnosed after other etiologies had been excluded. The case demonstrates the hazards of Chinese herbs with regard to children's health in Taiwan and suggests that more attention should be paid to this issue.

Study on separation of aristolochic acid I and II by micellar electrokinetic capillary chromatography and competition mechanism between SDS and β-cyclodextrin

In this study, a rapid MEKC method using 40 mM sodium borate buffer containing 50 mM SDS as surfactant was developed for the analysis of aristolochic acid (AA) in Aristolochia plants. Baseline separation of AA-I and AA-II was achieved within 3 min with high separation efficiency, satisfactory sensitivity, repeatability, and recovery. Resolution between AA-I and AA-II is above 5 and great performance with higher than 200,000 theoretical plate numbers was obtained. The detection limits (based on 3 S/N) were both 1.0 microg/mL. Two kinds of AA in 35 herbal samples of Aristolochia plants were successfully determined. The competition mechanism between beta-CD and SDS was also investigated by changing the content ratio of beta-CD and SDS.

The potential impact of the use of homeopathic and herbal remedies on monitoring the safety of prescription products

The purpose of this paper is to explore the possibility that adverse reactions and drug interactions arising from the use of homeopathic and herbal medicines could lead to confusion when adverse reactions to conventional medicines are reported. An extensive literature review was conducted on the occurrence of adverse reactions and drug interactions following the use of homeopathic or herbal remedies, and the potential for these to confound adverse event reporting to conventional medicines considered. The survey demonstrates the potential for herbal remedies and homeopathic products, to produce adverse drug reactions or drug interactions, and shows the scope for potential for confusion with those arising from conventional medicines. There is a need for greater awareness that adverse reactions apparently due to a conventional medicine, might in reality be due to a herbal medicine or a drug interaction between a herbal medicine and a conventional drug, particularly when a health professional is unaware of the extent of a patient's self-medication with alternative therapies.

An Unusual Cause of Hypokalemic Paralysis: Aristolochic Acid Nephropathy with Fanconi Syndrome

Aristolochic acid nephropathy (AAN) with Fanconi syndrome presenting as hypokalemic paralysis is extraordinarily rare and may be unrecognized. We describe a 41-year-old man who presented with the inability to ambulate upon awakening in the morning. Physical examination revealed symmetric paralysis of bilateral lower limbs. Laboratory studies showed profound hypokalemia with renal potassium (K) wasting, hyperchloremic metabolic acidosis, hypophosphatemia with hyperphosphaturia, hypouricemia with hyperuricosuria, and glycosuria, consistent with Fanconi syndrome. Mild renal insufficiency was also observed. A meticulous search for underlying causes of Fanconi syndrome was unrevealing. However, a significant amount of aristolochic acid (AA) was detected in the consumed Chinese herb mixture (AA-I, 7 microg/g) for the treatment of his leg edema for the past 2 months. His hypokalemia, renal insufficiency, and Fanconi syndrome completely resolved 2 months after the withdrawal of Chinese herb mixture and the supplementation of potassium citrate and active vitamin D3. AAN with Fanconi syndrome should be considered as a cause of hypokalemia in any patient administered undefined Chinese herbs.

Kidney injury from alternative medicines

In the developing world, up to 80% of the population uses traditional medicine for primary health care. In industrialized countries, adaptations of traditional medicine, termed "complementary" or "alternative" medicine (CAM), are used by a growing number of patients for preventive or palliative care. However, alternative medicine (AM) may be an important risk for the development of acute and chronic kidney injury because of several factors: nonconventional preparations rarely meet the required essential standards of consistency in composition and biological activity; many of these products contain undisclosed over-the-counter or prescription drugs or can be adulterated with hormones and glandular extracts; herbal preparations can be contaminated by pesticides and heavy metals; and because of errors in plant identification and confusing terminology, opportunities for mistakes and deliberate substitution can occur. Furthermore, there is a lack of reports of adverse events and drug interactions because of a lack of professional surveillance, and specific data on systemic and kidney toxicity are not easily available. Kidney injury/kidney syndromes caused by AM consist of acute tubular necrosis/toxicity (eg, Fanconi's syndrome), acute interstitial nephritis, papillary necrosis, hypertension, kidney stones, urinary retention, chronic tubulointerstitial nephritis with fibrosis, urinary tract carcinoma, and acute rejection of the kidney transplant. To improve the care for patients using AM, extension of physicians' knowledge about its possible hazards and toxicity is essential. This review deals with acute and chronic kidney toxicity caused by animal-, plant-, and mineral-based, nonconventional medicine and kidney failure caused by drug interactions with AM.

Legal issues in caring for patients with kidney disease by selectively integrating complementary therapies

Clinical integration of complementary and alternative medical (CAM) therapies, such as acupuncture and traditional oriental medicine, chiropractic, herbal medicine, massage therapy, and "mind-body" therapies, into conventional health care raises important legal and risk management issues. Understanding which CAM therapies patients use is legally prudent, as conventional treatment advice may interact with patients' own efforts toward self-care. In addition, nephrologists may limit potential liability for medical malpractice by classifying any given therapy as follows: (1) the medical evidence supports both safety and efficacy--recommend; (2) the medical evidence supports safety, but evidence regarding efficacy is inconclusive-accept but monitor; (3) the medical evidence supports efficacy, but evidence regarding safety is inconclusive-accept but monitor; and (4) the medical evidence indicates either serious risk or inefficacy--avoid and discourage. Applying this framework whether a therapy is labeled "conventional" or "CAM" is consistent with the key recommendation of the recent report by the Institute of Medicine at the National Academy of Sciences on Complementary and Alternative Medicine, namely, to apply the same principles and standards of evidence of treatment effectiveness to all treatments. Liability risk management also includes going beyond legal and ethical informed consent requirements by engaging the patient in shared decision making concerning all material treatment options, including CAM therapies, if supported by evidence. Physicians further should familiarize themselves with documentation standards suggested by the Federation of State Medical Board Guidelines and whether these are applicable in their state or home institution. These steps aim to enable nephrologists to respond to patient interest in CAM therapies in a way that is clinically responsible, ethically appropriate, and legally defensible.