Assessment of herbal medicinal products: challenges, and opportunities to increase the knowledge base for safety assessment

Herbal products in pregnancy: experimental studies and clinical reports

The aim of this work is to provide an update from an overview of the literature of the most frequently consumed herbal remedies during pregnancy, both alone and concomitantly with prescribed medications and particularly on their side effects to the mother and fetus. We have also analyzed some of the adverse interactions that may occur due to concomitant use of herbal and pharmaceutical products during pregnancy. Herbal remedies are not evaluated according to the same standards as pharmaceuticals, and in the USA some of it are not licensed but sold as food supplements. There is a lack of basic knowledge on the part of both clinicians and patients as to the indications for use and safety of herbal medicines used in pregnancy and lactation. If 'traditional use' is the only available information, the pregnant woman should be made aware of this to enable her to make an informed decision concerning potential use.

Single-dose oral toxicity of fermented scutellariae radix extract in rats and dogs

The aim of this study was to investigate the acute oral toxicity of fermented Scutellariae Radix (JKTMHGu- 100) in rats and dogs. JKTM-HGu-100 was orally administered at a dose of 2,000 mg/kg in Sprague-Dawley rats. An escalating single-dose oral toxicity test in beagle dogs was performed at doses of 500, 1000, and 2000 mg/kg with 4-day intervals. Clinical signs, changes in body weight, mortality, and necropsy findings were examined for 2 weeks following oral administration. No toxicological changes related to the test substance nor mortality was observed after administration of a single oral dose of JKTM-HGu-100 in rats or dogs. Therefore, the approximate lethal dose (LD) for oral administration of JKTMHGu-100 in rats was considered to be over 2,000 mg/kg, and the maximum tolerance doses (MTDs) in rats and dogs were also estimated to be over 2,000 mg/kg. These results indicate that JKTM-HGu-100 shows no toxicity in rodents or non-rodents at doses of 2,000 mg/kg or less.

Molecular identification and cytotoxicity study of herbal medicinal materials that are confused by Aristolochia herbs

Herbal materials derived from Aristolochia species contain carcinogenic aristolochic acids (AAs) and have been used as traditional Chinese medicines (TCMs) or adulterants of other TCMs. The purpose of this study is to identify the TCMs Stephaniae Tetrandrae Radix, Akebiae Caulis, Aucklandia Radix and Aristolochiae Fructus by sequencing the matK, rbcL, trnH-psbA and trnL-trnF DNA regions. The cytotoxicities of AAs and these TCMs were also studied in COS-7 and HEK-293 cells. Diagnostic polymorphic sites were identified in all the four DNA loci for the differentiation of genuine herbs from their adulterants/substitute. The 48 h IC50 of AAI were 78 μM (COS-7) and 70 μM (HEK-293) while the IC50 of AAII were higher than 100 μM in both cell lines. Except Aucklandia Radix, cytotoxicity study also showed that AA-containing herbs were more toxic than their corresponding genuine herbs and substitute.

Underestimating the toxicological challenges associated with the use of herbal medicinal products in developing countries

Various reports suggest a high contemporaneous prevalence of herb-drug use in both developed and developing countries. The World Health Organisation indicates that 80% of the Asian and African populations rely on traditional medicine as the primary method for their health care needs. Since time immemorial and despite the beneficial and traditional roles of herbs in different communities, the toxicity and herb-drug interactions that emanate from this practice have led to severe adverse effects and fatalities. As a result of the perception that herbal medicinal products have low risk, consumers usually disregard any association between their use and any adverse reactions hence leading to underreporting of adverse reactions. This is particularly common in developing countries and has led to a paucity of scientific data regarding the toxicity and interactions of locally used traditional herbal medicine. Other factors like general lack of compositional and toxicological information of herbs and poor quality of adverse reaction case reports present hurdles which are highly underestimated by the population in the developing world. This review paper addresses these toxicological challenges and calls for natural health product regulations as well as for protocols and guidance documents on safety and toxicity testing of herbal medicinal products.

Toxicity assessment of Leonuri Herba aqueous extract orally administered to rats for 13 consecutive weeks

ETHNOPHARMACOLOGICAL RELEVANCE

The Leonuri Herba has been traditionally used for women's disease in Asian countries.

AIM OF THE STUDY

The objective of the present study was to evaluate the subchronic toxicity of Leonuri Herba aqueous extract in male and female F344 rats.

MATERIAL AND METHODS

Leonuri Herba aqueous extract was administered orally once daily at dose levels of 0, 125, 250, 500, 1000 and 2000 mg/kg/day for 13 weeks. Toxicological assessment was performed including mortality, clinical signs, body and organ weights, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings and histopathologic examination.

RESULTS

There were no treatment related differences in clinical signs, urinalysis, hematology and serum chemistry, except for a histopathologic examination. The squamous cell hyperplasia in the forestomach was observed in both sexes of rats given 2000 mg/kg/day of Leonuri Herba aqueous extract.

CONCLUSION

In conclusion, the NOAEL (No Observed Adverse Effect Level) for Leonuri Herba aqueous extract was determined as 1000 mg/kg/day in both sexes of rats under the present experimental conditions. And the acceptable daily intake value for Leonuri Herba aqueous extract was calculated to be 10mg/kg body weight per day using a safety factor of 100 to the NOAEL.

Multimechanistic antifibrotic effect of biochanin a in rats: implications of proinflammatory and profibrogenic mediators

OBJECTIVE

Biochanin A (BCA) is an isoflavone found in red clover and peanuts. Recently, it drew much attention as a promising anticancer and antioxidant. Due to its diversity in pharmacological actions, we were encouraged to investigate its potential as an antifibrotic, elucidating the different molecular mechanisms involved.

DESIGN

Rats were pretreated with BCA, then injected with carbon tetrachloride (CCl4) for 6 weeks. Changes in liver weight and histology were examined and levels of aspartate and alanine aminotransferases, cholesterol, triglycerides, alkaline phosphatase and total bilirubin measured. To assess hepatic efficiency, indocyanine green was injected and its clearance calculated and albumin, total proteins and insulin-like growth factor-1 expression were measured. Cytochrome P4502E1 activity, cytochrome P4501A1 expression, in addition to sulfotransferase1A1 expression were determined to deduce the effect of BCA on hepatic metabolism. As oxidative stress markers, lipid peroxides levels, reduced glutathione, superoxide dismutase and catalase activities, as well as the total antioxidant capacity, were assessed. Nitric oxide, inducible nitric oxide synthase and cyclooxygenase-2 were used as indicators of the inflammatory response. Signaling pathways involving tumor necrosis factor-alpha, nuclear factor-kappa B, transforming growth factor-beta1, matrix metalloproteinase-9 and alpha-smooth muscle actin were investigated accordingly. Extent of fibrosis was examined by Masson's stain and measuring hydroxyproline levels.

RESULTS

BCA pretreatment significantly protected against the chronic damage of CCl4. Liver injury, oxidative stress, inflammation and fibrosis markers decreased, while hepatic efficiency improved.

CONCLUSION

Our findings suggested that BCA administration protects against fibrotic complications, a property that can be contributed to the multimechanistic approach of the drug.

Vietnamese traditional medicine from a pharmacist's perspective

Traditional medicine plays an important role in the healthcare system of Vietnam. Vietnamese traditional medicine (VTM) is underpinned by the oriental philosophy and theory of healing. VTM is largely influenced by traditional Chinese medicine, but differs to a certain extent. VTM is largely not evidence-based from a clinical perspective but subclinical research data from the past decades support the traditional use of many herbal VTM drugs. For safe use, knowledge of the occurrence of adverse reactions and herb-drug interactions is necessary. The Vietnamese government supports further development of VTM in a scientific way and integration of VTM with Western medicine. This article first gives an overview of the general aspects of VTM (historical perspective, regulatory aspects, comparison with traditional Chinese medicine, philosophical background, the Vietnamese market situation, quality assurance and formulations), and subsequently focuses on its safe and effective use in Vietnamese clinical pharmacy and medical practice.

In vitro antioxidant properties of mangosteen peel extract

The growing interest in the replacement of synthetic food antioxidants by natural ones has fostered research on the screening of plant-derived raw materials for identifying new antioxidants. The special attention of research today is focused on inexpensive or residual sources from agricultural industries. Fruit peels as sources of powerful natural antioxidants are often the waste parts of various fruits from consumption and food industry. Among the fruit peels, mangosteen peel is an important source of natural phenolic antioxidants. The mangosteen peel contains various bioactive substances, i.e., phenolic acids and flavonoids, which possess biological and medicinal properties, especially antioxidant properties. The aim of this review, after presenting analytical techniques for determining in vitro antioxidant activity of mangosteen peel extract, is to summarize available data on the factors affecting antioxidant activity of mangosteen peel extract. In addition, the potential antioxidant activity of mangosteen peel extract, the bioactive compounds identified from mangosteen peel extract and their antioxidant activity are presented. Potential applications of the mangosteen peel extract in food, pharmaceutical and cosmetic products are also discussed.

Legal regulations of complementary and alternative medicines in different countries

Traditional medicines that formed the basis of health care throughout the world since the earliest days of mankind are still widely used and have considerable importance in international trade. Recognition of their clinical, pharmaceutical, and economic value is still growing, although this varies widely between countries and therefore regulation of exploitation and exportation is essential, together with international cooperation and coordination for their conservation so as to ensure their availability for the future. World Health Organization and European Union issued the guidelines defined the basic criteria for the evaluation of quality, safety, and efficacy of herbal medicines with the goal of assisting national regulatory authorities, scientific organizations, and manufacturers in assessing documentation, submissions, and dossiers in respect of such products. Legislative controls in respect of medicinal plants have not evolved around a structured control model. There are different ways in which countries define medicinal plants or herbs or products derived from them. The present review highlights the status of different countries adopted various approaches to licensing, dispensing, manufacturing, and trading to ensure their safety, quality, and efficacy.

Typical toxic components in traditional Chinese medicine

INTRODUCTION

Traditional Chinese medicine (TCM) is widely used around the world. However, with its wide use has been the identification of a number of toxicological issues that have severely restricted its use in clinical treatment. The identification of these toxic substances within TCM has become somewhat of a hot topic in recent years.

AREAS COVERED

This article reviews literature published on professional authoritative journals in the last 10 years on the toxic constituents and toxicology of TCM, including chemical structures, absorption and metabolism. The literature search for this article was based, but not limited to, toxic constituents including: alkaloids, glycosides, toxic proteins, polypeptide, amino acids, phenols or organic acids, terpenes and lactones. The authors discuss the toxic substances referring to their toxicity on organs, tissues and systems.

EXPERT OPINION

More and more toxic constituents from different TCMs have been identified, in addition to information on how they act in the body at a molecular level. However, the toxicology of TCMs is very complex, and although some progress has been made, a lot work is still needed in order to put an end to toxic incidents.

Phytotherapy: emerging therapeutic option in urologic disease

Phytotherapy belongs to the area of complementary and alternative medicine (CAM) and the definition of phytotherapy is the use of plants or plant extracts for medicinal uses. Interest in phytotherapy is growing in both Asian and western countries for its use in the prevention and management of disease, improvement of general health and anti-aging. And also, there are several studies about the efficacy of phytotherapy in urologic diseases like benign prostatic hyperplasia (BPH), erectile dysfunction (ED), late-onset hypogonadism (LOH) and infertility in males. Phytotherapy for BPH including saw palmetto, pygeum, and nettles, is under vigorous research for the therapeutic effect. No solid evidence showing better effective treatment modality for ED than placebo has been found yet for phytotherapy. Recently, a potent NO donor, L-arginine is under research with promising results. Phytotherapy is used by a number of patients with urological disease, and urologists need to have accurate knowledge about phytotherapy as well as keep a cautious approach. The possible effects and side effects should be defined and related to urologic patients by urologists.

Evaluation of subchronic toxicity of the hydroethanolic extract of Tropaeolum majus in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

The use of medicinal plants for the treatment of diseases usually comes from the belief that they present low toxicity due their natural origin. However, it is necessary a toxicological and pharmacological evaluation for these plants. Tropaeolum majus is a medicinal plant used in popular medicine to treat several diseases, including cardiovascular disorders, urinary tract infections and asthma. Even though several studies proved its therapeutic effects, there are few toxicological studies with this species.

AIM OF THE STUDY

The present study was carried out to evaluate the subchronic toxicity of the hydroethanolic extract obtained from leaves of T. majus (HETM) in Wistar rats.

MATERIAL AND METHODS

Male and female Wistar rats received three doses of HETM (75, 375 and 750 mg/kg) for 28 days. After the treatments biochemical, hematological and histopathological parameters were analyzed.

RESULTS

No significant alterations in the animal's body weight gain, relative organs weight, serum biochemical analysis, hematological or histopathological analyses of liver, kidneys and spleen were observed.

CONCLUSIONS

These results demonstrate the absence of subchronic toxicity due to oral treatment with HETM for 28 days in Wistar rats. However, other toxicological studies are necessary to evaluate the total safety of this plant.

Review of current and "omics" methods for assessing the toxicity (genotoxicity, teratogenicity and nephrotoxicity) of herbal medicines and mushrooms

ETHNOPHARMACOLOGICAL RELEVANCE

The increasing use of traditional herbal medicines around the world requires more scientific evidence for their putative harmlessness. To this end, a plethora of methods exist, more or less satisfying. In this post-genome era, recent reviews are however scarce, not only on the use of new "omics" methods (transcriptomics, proteomics, metabonomics) for genotoxicity, teratogenicity, and nephrotoxicity assessment, but also on conventional ones.

METHODS

The present work aims (i) to review conventional methods used to assess genotoxicity, teratogenicity and nephrotoxicity of medicinal plants and mushrooms; (ii) to report recent progress in the use of "omics" technologies in this field; (iii) to underline advantages and limitations of promising methods; and lastly (iv) to suggest ways whereby the genotoxicity, teratogenicity, and nephrotoxicity assessment of traditional herbal medicines could be more predictive.

RESULTS

Literature and safety reports show that structural alerts, in silico and classical in vitro and in vivo predictive methods are often used. The current trend to develop "omics" technologies to assess genotoxicity, teratogenicity and nephrotoxicity is promising but most often relies on methods that are still not standardized and validated.

CONCLUSION

Hence, it is critical that toxicologists in industry, regulatory agencies and academic institutions develop a consensus, based on rigorous methods, about the reliability and interpretation of endpoints. It will also be important to regulate the integration of conventional methods for toxicity assessments with new "omics" technologies.

Evaluation of the liver protection and toxicity of Da-Huang-Zhe-Chong pill in rats

CONTEXT

Da-Huang-Zhe-Chong pill (DHZCP), a classical traditional Chinese formula, consists of 12 crude drugs which have been widely used with significant therapeutic effects. Some drugs in this formula have toxicities that might result in some adverse effects of DHZCP.

OBJECTIVE

The liver protection and toxicity of DHZCP were first evaluated against chronic carbon tetrachloride (CCl(4))-induced liver injury in rats.

MATERIALS AND METHODS

The rats were treated by intraperitoneal injection of 10% CCl(4) for 12 weeks. At the end of week 4, DHZCP at doses of 44 g/kg (high-dose group) and 22 g/kg (low-dose group) was intragastrically administered to CCl(4)-treated rats, once a day for four weeks. At the end of weeks 8 and 12, the general status of the rats, histopathology of liver, serum alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), alkaline phosphatase (ALP) and total bilirubin (TBIL) levels were observed or determined and recorded. By correspondence analysis (CA) on biochemical markers and liver histopathological score (HS), the "dose-time-response" relationship of DHZCP on the hepatic injury rats was evaluated.

RESULTS

The results showed that DHZCP exhibited a significant protective effect on liver injury by reversing the biochemical parameters and histopathological changes. However, this hepatoprotective effect may be weakened, or even be transferred to toxicity with the increase of the administration dose (44 g·kg(-1)·d(-1)) and time (more than 2 months) of this formula. These results were consistent with the histopathological observation and the serum levels.

DISCUSSION AND CONCLUSION

Administration of proper dose and time of DHZCP could well play its hepatoprotective effect and even treat hepatitis, but the safety on liver should be considered when large-dose (44 g·kg(-1)·d(-1)) DHZCP is used for long time (more than 2 months). We suggest that the administration dose and time of DHZCP in clinical use should not be increased and prolonged, and simultaneously liver function should be regularly monitored.

Herbal medicine for depression, anxiety and insomnia: a review of psychopharmacology and clinical evidence

Research in the area of herbal psychopharmacology has increased markedly over the past decades. To date however, a comprehensive review of herbal antidepressant, anxiolytic and hypnotic psychopharmacology and applications in depression, anxiety and insomnia has been absent. A search of MEDLINE (PubMed), CINAHL, PsycINFO, and the Cochrane Library databases was conducted (up to February 21st 2011) on commonly used psychotropic herbal medicines. A review of the literature was conducted to ascertain mechanisms of action of these botanicals, in addition to a systematic review of controlled clinical trials for treatment of mood, anxiety and sleep disorders, which are common comorbid psychiatric disorders. Specific emphasis was given to emerging phytomedicines. Analysis of evidence levels was conducted, as were effect sizes (Cohen's d) where data were available. Results provided evidence of a range of neurochemical, endocrinological, and epigenetic effects for 21 individual phytomedicines, which are detailed in this paper. Sixty six controlled studies were located involving eleven phytomedicines. Several of these provide a high level of evidence, such as Hypericum perforatum for major depression, and Piper methysticum for anxiety disorders. Several human clinical trials provide preliminary positive evidence of antidepressant effects (Echium amoenum, Crocus sativus, and Rhodiola rosea) and anxiolytic activity (Matricaria recutita, Ginkgo biloba, Passiflora incanata, E. amoenum, and Scutellaria lateriflora). Caution should however be taken when interpreting the results as many studies have not been replicated. Several herbal medicines with in vitro and in vivo evidence are currently unexplored in human studies, and along with use of emerging genetic technologies "herbomics", are areas of potential future research.

Pharmacovigilance of herbal products in India

Herbal formulations being widely accepted therapeutic agents as antidiabetics, antiarthritics, hepatoprotectives, cough remedies, memory enhancers, and adaptogens. The commonest myth regarding herbal medicines is that these medicines are completely safe, and can therefore be safely consumed by the patient on his/her own, without a physician's prescription. This belief has led to large-scale self-medication by people all over the world, often leading to disappointing end-results, side-effects, or unwanted after-effects. There is an increasing awareness at several levels of the need to develop pharmacovigilance practices for herbal medicines. The current model of pharmacovigilance and its associated tools have been developed in relation to synthetic drugs, and applying these methods to monitoring the safety of herbal medicines presents unique challenges in addition to those described for conventional medicines. Several problems relate to the ways in which herbal medicines are named, perceived, sourced, and utilized. This may be because of differences in the use of nonorthodox drugs (e.g., herbal remedies) which may pose special toxicological problems, when used alone or in combination with other drugs. The purpose of pharmacovigilance is to detect, assess, and understand, and to prevent the adverse effects or any other possible drug-related problems, related to herbal, traditional, and complementary medicines.

Antifertility effects of herbs: Need for responsible reporting

Evaluation of herbs for antifertility effects has been in progress worldwide for several decades to identify effective and safe substances for control of population explosion. Inspite of availability of internationally accepted guidelines for the assessment of reproductive toxicity/antifertility potential of test substances, many published articles, on critical review, seem to lack reproducibility and are thus likely to mislead both the scientific community and the general public. This paper, while emphasizing the importance of generating authentic toxicity/safety information on acclaimed medicinal herbs, spells out existing pitfalls in such studies, and explores some control measures worth considering in times to come.

Adjunctive nutraceuticals with standard pharmacotherapies in bipolar disorder: a systematic review of clinical trials

OBJECTIVE

  Studies using augmentation of pharmacotherapies with nutraceuticals in bipolar disorder (BD) have been conducted and preliminary evidence in many cases appears positive. To date, however, no specialized systematic review of this area has been conducted. We present the first systematic review of clinical trials using nutrient-based nutraceuticals in combination with standard pharmacotherapies to treat BD. A subsequent aim of this report was to discuss posited underlying mechanisms of action.

METHODS

  PubMed, CINAHL, Web of Science, and Cochrane Library databases, and grey literature were searched during mid-2010 for human clinical trials in English using nutraceuticals such as omega-3, N-acetyl cysteine (NAC), inositol, and vitamins and minerals, in combination with pharmacotherapies to treat bipolar mania and bipolar depression. A review of the results including an effect size analysis (Cohen's d) was subsequently conducted.

RESULTS

  In treating bipolar depression, positive evidence with large effect sizes were found for NAC (d=1.04) and a chelated mineral and vitamin formula (d=1.70). On the outcome of bipolar mania, several nutraceuticals reduced mania with strong clinical effects: a chelated mineral formula (d=0.83), L-tryptophan (d=1.47), magnesium (d=1.44), folic acid (d=0.40), and branched-chain amino acids (d=1.60). Mixed, but mainly positive, evidence was found for omega-3 for bipolar depression, while no evidentiary support was found for use in mania. No significant effect on BD outcome scales was found for inositol (possibly due to small samples).

CONCLUSIONS

  BD treatment outcomes may potentially be improved by additional use of certain nutraceuticals with conventional pharmacotherapies. However, caution should be extended in interpreting the large effects of several isolated studies, as they have not yet been replicated in larger trials.

Authentication of the medicinal plant Senna angustifolia by RAPD profiling

In this study "RAPD" molecular marker was employed for the identification of Senna angustifolia, Senna acutifolia, Senna tora and Senna sophera. Total 32 decamer primers were screened in amplification with genomic DNA extracted from all species, of which 6 primers yielded species-specific reproducible bands. Out of 42 loci detected, the polymorphic, monomorphic and unique loci were 24, 2 and 16, respectively. Based on dendrogram and similarity matrix, 4 species were differentiated from each other and showed more divergence. Thus, this technique may prove and to contribute the identification of these species of Senna having similar morphology sold in the local markets.

Genotoxicity assessment of a herbal formula, Ojeok-san

ETHNOPHARMACOLOGICAL RELEVANCE

Ojeok-san (OJS, wuji powder, goshaku-san), a widely used herbal formula in traditional Korean medicine, is used to treat illnesses such as the common cold, fatigue and gastrointestinal disorders; however there is insufficient background information about its safety. To establish safety information for OJS, we evaluated its genotoxicity.

MATERIALS AND METHODS

The ability of OJS to induce reverse mutations was evaluated in Salmonella typhimurium (TA100, TA1535, TA98 and TA1537) and Escherichia coli (WP2uvrA) in the presence or absence of the metabolic activation system (S-9 mix). Chromosomal aberrations were evaluated in response to OJS, and viability and metaphase were analyzed in Chinese hamster lung (CHL) cells in the presence or absence of S-9 mix. A micronucleus test was performed using bone marrow cells from male ICR mice. OJS was orally administered twice at a 24h interval at a dose of 500, 1000 and 2000 mg/kg in mice.

RESULTS

There were no increases in the number of revertant colonies at any concentrations of OJS regardless of S-9 mix in all tester strains compared to the vehicle control. OJS did not significantly increase the number of structural aberration in CHL cells in the presence or absence of S-9 mix. The oral administration of OJS at doses up to 2000 mg/kg caused no significant increase in the number of micronucleated polychromatic erythrocytes (MNPCEs) and in the mean value for the ratio of PCE to total erythrocytes (PCE/(PCE+NCE)). NCE is normochromatic erythrocyte. OJS did not increase the incidence of MNPCEs in bone marrow.

CONCLUSIONS

These results suggest that OJS is toxicologically safe on genotoxicity studies.

Investigation of the "dose-time-response" relationships of rhubarb on carbon tetrachloride-induced liver injury in rats

AIM OF THE STUDY

The present study investigated the liver protection and toxicity of rhubarb against carbon tetrachloride (CCl4)-induced chronic liver injury in rats.

MATERIALS AND METHODS

The rats were treated by intraperitoneal injection of 10% CCl4 for 12 weeks. At the end of week 4, rhubarb at doses of 40 g kg(-1) (high-dose group), 20 g kg(-1) (medium-dose group) and 10 g kg(-1) (low-dose group) was intragastrically administered to CCl4-treated rats once a day for three weeks. At the end of week 16, all rats were maintained for 1 month without any administration. At the end of weeks 8, 12, 16 and 20, the general status of rats, histopathology of liver, serum alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), total bilirubin (TBIL) and hyaluronic acid (HA) levels were observed, respectively. Combined with clustering analysis and correspondence analysis, the "dose-time-response" relationships of rhubarb on the liver injury rats were synthetically investigated.

RESULTS

High dose (40 g kg(-1)) of rhubarb exhibited a significant protective effect on injured liver by reversing the biochemical parameters and histopathological changes. But, this hepatoprotective effect will be weakened, even be transferred to toxicity with increasing the administration dose and time of rhubarb. These results were consistent with the histopathological observation and the determination of serum levels.

CONCLUSIONS

The safety should be considered simultaneously in the long-term and high dose use of rhubarb, the liver function and change should be regularly detected. This study provided some useful references for the clinical rational use of rhubarb and other herbal medicinal products.

Comparative study of hops-containing products on human cytochrome P450-mediated metabolism

The potential for 15 different ales (6), ciders (2 apple and 1 pear), and porters (6) and 2 non-alcoholic products to affect cytochrome P450 (CYP)-mediated biotransformation and P-glycoprotein-mediated efflux of rhodamine was examined. As in our previous study, a wide range of recovered nonvolatile suspended solids dry weights were noted. Aliquots were also found to have varying effects on biotransformation and efflux. Distinct differences in product ability to affect the safety and efficacy of therapeutic products confirmed our initial findings that some porters (stouts) have a potential to affect the safety and efficacy of health products metabolized by CYP2D6 and CYP3A4 isozymes. Most products, except 2 of the ciders and the 2 non-alcoholic products, also have the potential to affect the safety of CYP2C9 metabolized medications and supplements. Further studies are required to determine the clinical significance of these findings.

Lead content in pot marigold (Calendula officinalis L.) inflorescences and leaves: impact of precipitations and vicinity of motorway

Trace metal contamination is a major environmental and health problem virtually in all countries. The present study was aimed to estimate the lead content of pot marigold (Calendula officinalis L.) inflorescences and leaves collected from a nonpolluted test field. The lead content in dry pot marigold inflorescences was 9.34 ± 0.79 µg/g, in dry leaves 11.57 ± 0.47 µg/g, and in soil 0.649 ± 0.012 µg/g. The distance of pot marigold collection beds (30-220 m from the motorway) had no effect on lead content. There was a strong positive correlation between the amount of precipitations and lead content of pot marigold leaves but not inflorescences indicating the soil as primarily the source of increased lead content. In conclusion, no effect of motorway vicinity was found for pot marigold inflorescences or leaves lead content; however, as a precaution, it is not recommended to collect the plants during or just after showers.

Herbal bioactivation, molecular targets and the toxicity relevance

There have been increasing reports on the adverse reactions associated with herbal consumption. For many of these adverse reactions, the underlying biochemical mechanisms are unknown, but bioactivation of herbal compounds to generate reactive intermediates have been implicated. This minireview updates our knowledge on metabolic activation of herbal compounds, molecular targets and the toxicity relevance. A number of studies have documented that some herbal compounds can be converted to toxic or even carcinogenic metabolites by Phase I [e.g. cytochrome P450s (CYPs)] and less frequently by Phase II enzymes. For example, aristolochic acids (AAs) in Aristolochia spp, which undergo reduction of the nitro group by hepatic CYP1A1/2 or peroxidases in extrahepatic tissues to generate highly reactive cyclic nitrenium ions. The latter can react with macromolecules (DNA and protein), resulting in activation of H-ras and myc oncogenes and gene mutation in renal cells and finally carcinogenesis of the kidneys. Teucrin A and teuchamaedryn A, two diterpenoids found in germander (Teuchrium chamaedrys) used as an adjuvant to slimming herbal supplements that caused severe hepatotoxicity, are converted by CYP3A4 to reactive epoxide which reacts with proteins such as CYP3A and epoxide hydrolase and inactivate them. Some naturally occurring alkenylbenzenes (e.g. safrole, methyleugenol and estragole) and flavonoids (e.g. quercetin) can undergo bioactivation by sequential 1-hydroxylation and sulfation, resulting in reactive intermediates capable of forming DNA adducts. Extensive pulegone metabolism generated p-cresol that is a glutathione depletory. The hepatotoxicity of kava is possibly due to intracellular glutathione depletion and/or quinone formation. Moreover, several herbal compounds including capsaicin from chili peppers, dially sulfone in garlic, methysticin and dihydromethysticin in kava, oleuropein in olive oil, and resveratrol found in grape seeds are mechanism-based (suicide) inhibitors of various CYPs. Together with advances of proteomics, metabolomics and toxicogenomics, an integrated systems toxicological approach may provide deep insights into mechanistic aspects of herb-induced toxicities, and contribute to bridging the relationships between herbal bioactivation, protein/DNA adduct formation and the toxicological consequences.

Qualitative and quantitative determination of polyacetylenes in different Bupleurum species by high performance liquid chromatography with diode array detector and mass spectrometry

Polyacetylenes are main toxic ingredients in Bupleurum longiradiatum, a poisonous plant that has ever been misused as substitutes for Chaihu (Bupleuri Radix). For the first time, a high-performance liquid chromatography method coupled with diode array detector and mass spectrometry (HPLC-DAD-MS) was developed for qualitative and quantitative analysis of nine polyacetylenes in Bupleurum species. All references, including two new polyacetylenes, were isolated from B. longiradiatum and purified using a semi-preparation HPLC chromatography. The analysis was performed on a TSKgel ODS-100V C18 column (3 μm, 150 mm x 4.6 mm i.d.) using a gradient system of acetonitrile and water, with diode array detection (254 nm). The method was validated for linearity, precision, accuracy, limit of detection and quantification. A total of 27 Bupleurum samples were examined with this method, which showed a great variety in the distribution and contents of the polyacetylenes. It was found that polyacetylenes (1-8) were the main ingredients in B. longiradiatum, while a few kinds of polyacetylenes (5-8) were also identified in B. smithii, B. smithii var. parvifolium, B. bicaule and B. angustissimum. However, no polyacetylenes (1-9) were detected in the authentic Chaihu samples and the other Bupleurum species. The results indicated that the toxic B. longiradiatum could readily be distinguished from other medicinal Bupleurum species based on the polyacetylene profiles, and the guidelines and quality control of polyacetylenes for Chaihu are useful. The acute toxicity of the ethanol extract of B. longiradiatum and its fractions was also investigated.

Safety of botanical ingredients in personal care products/cosmetics

The key issue of the safety assessment of botanical ingredients in personal care products (PCP) is the phytochemical characterisation of the plant source, data on contamination, adulteration and hazardous residues. The comparative approach used in the safety assessment of GM-plants may be applied to novel botanical PCP ingredients. Comparator(s) are the parent plant or varieties of the same species. Chemical grouping includes definition of chemical groups suitable for a read-across approach; it allows the estimation of toxicological endpoints on the basis of data from related substances (congeneric groups) with physical/chemical properties producing similar toxicities. The Threshold of Toxicological Concern (TTC) and Dermal Sensitisation Threshold (DST) are tools for the assessment of trace substances or minor ingredients. The evaluation of skin penetration of substances present in human food is unnecessary, whereas mixtures may be assessed on the basis of physical/chemical properties of individual substances. Adverse dermal effects of botanicals include irritation, sensitisation, phototoxicity and immediate-type allergy. The experience from dietary supplements or herbal medicines showed that being natural is not equivalent to being safe. Pragmatic approaches for quality and safety standards of botanical ingredients are needed; consumer safety should be the first objective of conventional and botanical PCP ingredients.

Evaluation of safety of the herbal formula Ojeok-san: acute and sub-chronic toxicity studies in rats

AIM OF THE STUDY

Ojeok-san (OJS; wuji powder in China and goshaku-san in Japan), a widely used herbal formula in traditional Korean medicine and Japanese herbal medicine (Kampo medicine), has been used to treat common cold and illnesses including fatigue and gastrointestinal disorders, but there is very little information on its safety. To provide information on the safety of OJS, we evaluated its acute and sub-chronic toxicity in rats.

MATERIALS AND METHODS

The single and sub-chronic toxicity of OJS was examined using male and female Sprague-Dawley rats. The rats were treated with the OJS extract orally at the highest dose level of 2000 mg/kg/day body weight. After single administration, signs of toxicity were observed every hour for the first 6h and every day for two weeks. In the sub-chronic toxicity study, OJS was administered for 13 weeks. Mortality, clinical signs, body weight changes, food and water consumption, ophthalmologic findings, urinalysis, hematological and biochemical parameters, gross findings, organ weights and histological markers were monitored during the study period.

RESULTS

We found no mortality and no abnormality in clinical signs, body weight, and necropsy findings for any of the animals in the acute and sub-chronic toxicity study following oral administration of OJS.

CONCLUSION

OJS may not have any single dose toxicity. The lethal dose with a 50% mortality rate (LD(50)) was over 2000 mg/kg. The no-observed adverse effects level (NOAEL) was considered to be 2000 and 1000 mg/kg/day for male and female rats, respectively.