Structure-mutagenicity relationship of kaurenoic acid from Xylopia sericeae (Annonaceae)

Safety of the proposed amendment of the specifications of the food additive E960c(i) or E960c(ii)

The EFSA Panel on Food Additives and Flavourings (FAF Panel) provides a scientific opinion on the safety of the proposed amendment of the EU specifications of Rebaudioside M produced via enzyme-catalysed bioconversion (E960c(i) or E 960c(ii)), to include a different microorganism strain in the definition. Rebaudioside M is produced via enzymatic bioconversion from Stevia leaf extract, using the genetically modified yeast strain K. phaffii CGMCC 7539. The final product is composed mostly of rebaudioside M (> 97%) and a mixture of rebaudiosides A, B and D at various concentrations. The Panel considered that the proposed amendment of the specifications is justified with respect to the inclusion of a new microorganism strain, taking into account that the manufacturing process and the submitted analytical data are already covered by the parameters listed in the existing EU specifications for E 960c(i) and E 960c(ii). The Panel considered that it is in the remit of the risk managers to decide whether the proposed changes in the specifications should result in an amendment of the already existing EU specifications of E960c(i) or E960c(ii). Viable cells and DNA from the production strain are not present in the final product; hence, the manufacturing process does not raise a safety concern. The Panel considered that the proposed food additive has the same physicochemical characteristics of E 960c(i) or E 960c(ii); therefore, the biological and toxicological data considered in previous evaluations will also apply to the safety assessment of Rebaudioside M produced from K. phaffii CGMCC 7539. The Panel concluded that there is no safety concern with respect to the proposed amendment to the EU specifications of E 960c(i) or E 960c(ii) related to the use of the new genetically modified strain K. phaffii CGMCC 7539 in the manufacturing process of the food additive Rebaudioside M produced via enzyme-catalysed bioconversion.

Synthetic Derivatives of Natural ent-Kaurane Atractyligenin Disclose Anticancer Properties in Colon Cancer Cells, Triggering Apoptotic Cell Demise

The antitumor activity of different ent-kaurane diterpenes has been extensively studied. Several investigations have demonstrated the excellent antitumor activity of synthetic derivatives of the diterpene atractyligenin. In this research, a series of new synthetic amides and their 15,19-di-oxo analogues obtained from atractyligenin by modifying the C-2, C-15, and C-19 positions were designed in order to dispose of a set of derivatives with different substitutions at the amidic nitrogen. Using different concentrations of the obtained compounds (10-300 μM) a reduction in cell viability of HCT116 colon cancer cells was observed at 48 h of treatment. All the di-oxidized compounds were more effective than their alcoholic precursors. The di-oxidized compounds had already reduced the viability of two colon cancer cells (HCT116 and Caco-2) at 24 h when used at low doses (2.5-15 μM), while they turned out to be poorly effective in differentiated Caco-2 cells, a model of polarized enterocytes. The data reported here provide evidence that di-oxidized compounds induced apoptotic cell death, as demonstrated by the appearance of condensed and fragmented DNA in treated cells, as well as the activation of caspase-3 and fragmentation of its target PARP-1.

Hellebrigenin triggers death of promyelocytic leukemia cells by non-genotoxic ways

Bufadienolides are digitalis-like aglycones mainly found in skin secretions of toads. Among their biological properties, the mechanisms of antiproliferative action on tumor cells remain unclear for many compounds, including against leukemia cells. Herein, it was evaluated the mechanisms involved in the antiproliferative and genotoxic actions of hellebrigenin on tumor cell lines and in silico capacity to inhibit the human topoisomerase IIa enzyme. Firstly, its cytotoxic action was investigated by colorimetric assays in human tumor and peripheral blood mononuclear cells (PBMC). Next, biochemical and morphological studies were detailed by light microscopy (trypan blue dye exclusion), immunocytochemistry (BrdU uptake), flow cytometry and DNA/chromosomal damages (Cometa and aberrations). Finally, computational modelling was used to search for topoisomerase inhibition. Hellebrigenin reduced proliferation, BrdU incorporation, viability, and membrane integrity of HL-60 leukemia cells. Additionally, it increased G2/M arrest, internucleosomal DNA fragmentation, mitochondrial depolarization, and phosphatidylserine externalization in a concentration-dependent manner. In contrast to doxorubicin, hellebrigenin did not cause DNA strand breaks in HL-60 cell line and lymphocytes, and it interacts with ATPase domain residues of human topoisomerase IIa, generating a complex of hydrophobic and van der Waals interactions and hydrogen bonds. So, hellebrigenin presented potent anti-leukemic activity at concentrations as low as 0.06 μM, a value comparable to the clinical anticancer agent doxorubicin, and caused biochemical changes suggestive of apoptosis without genotoxic/clastogenic-related action, but it probably triggers catalytic inhibition of topoisomerase II. These findings also emphasize toad steroid toxins as promising lead antineoplasic compounds with relatively low cytotoxic action on human normal cells.

Safety evaluation of the food additive steviol glycosides, predominantly Rebaudioside M, produced by fermentation using Yarrowia lipolyticaVRM

The EFSA Panel on Food Additive and Flavourings (FAF Panel) provides a scientific opinion on the safety of a new process to produce steviol glycosides by fermentation of simple sugars using a genetically modified strain of Yarrowia lipolytica (named Y. lipolytica VRM). The manufacturing process may result in impurities different from those that may be present in the other steviol glycosides E 960a-d, therefore the Panel concluded that separate specifications are required for the food additive produced as described in the current application. Viable cells and DNA from the production strain are not present in the final product. The Panel considered that the demonstration of the absence of kaurenoic acid in the proposed food additive, using a method with a limit of detection (LOD) of 0.3 mg/kg, is adequate to dispel the concerns for potential genotoxicity. Given that all steviol glycosides follow the same metabolic pathways, the Panel considered that the current steviol glycosides would fall within the same group of substances. Therefore, the Panel considered that the already existing data on rebaudioside M and structurally related steviol glycosides are sufficient, and a similar metabolic fate and toxicity is expected for the food additive. The results from the bacterial reverse mutation assay and the in vitro micronucleus assay were negative and indicated absence of genotoxicity from the food additive. The existing acceptable daily intake (ADI) of 4 mg/kg body weight (bw) per day, expressed as steviol equivalents, was considered to be applicable to the proposed food additive. The Panel concluded that there is no safety concern for steviol glycosides, predominantly Rebaudioside M, produced by fermentation using Y. lipolytica VRM, to be used as a food additive at the proposed uses and use levels.

Ent-kaurane diterpenoids from the Annonaceae family: a review of research progress and call for further research

The Annonaceae is one of the plant families with members that are credited with numerous pharmacological functions. Among the group of compounds responsible for these bioactivities are the ent-kaurane diterpenoids. The ent-kauranes are a group of 20-Carbon, tetracyclic diterpenoids that are widely distributed in other plant families including the Annonaceae family. This mini-review focuses mainly on the ent-kaurane diterpenoids isolated from the Annonaceae family, delineates the various biological activities of these compounds, and highlights the research gaps that exist for further scientific scrutiny.

Sphagneticola trilobata (L.) Pruski-derived kaurenoic acid prevents ovalbumin-induced asthma in mice: Effect on Th2 cytokines, STAT6/GATA-3 signaling, NFκB/Nrf2 redox sensitive pathways, and regulatory T cell phenotype markers

ETHNOPHARMACOLOGICAL RELEVANCE

Sphagneticola trilobata (L.) Pruski is used in traditional medicine in Brazil for inflammatory diseases treatment including asthma. The diterpene kaurenoic acid (KA) is one of its active compounds, but whether KA activity could explain the traditional use of S. trilobata in asthma is unknown.

AIM

Investigate KA effect and mechanisms in asthma.

METHODS

Experimental asthma was induced by ovalbumin immunization and challenge in male Swiss mice. KA (0.1-10 mg/kg, gavage) was administered 1 h before the ovalbumin challenge. Total leukocytes, eosinophil, and mast cell were counted in bronchoalveolar lavage fluid (BALF), and lung histopathology was performed. Lung mRNA expression of Th2 and regulatory T cells markers, and BALF type 2 cytokine production were quantitated. NFκB activation and oxidative stress-related components in pulmonary tissue were measured.

RESULTS

KA inhibited the migration of total leukocytes and eosinophils to BALF, reduced lung histopathology (inflammatory cells and mast cells), mRNA expression of IL-33/ST2, STAT6/GATA-3 and NFκB activation in the lung, and reduced IL-33, IL-4, IL-5 production in the BALF. KA also reduced the mRNA expression of iNOS and gp91^phox, and superoxide anion production accompanied by the induction of Nrf2, HO-1 and NQO1 mRNA expression, thus, exerting an antioxidant effect. Finally, KA induced nTreg-like and Tr1-like, but not Th3-like markers of suppressive T cell phenotypes in the lung tissue.

CONCLUSION

KA prevents antigen-induced asthma by down-regulating Th2 and NFκB/cytokine-related pathways, and up-regulating Nrf2 and regulatory T cells' markers. Thus, explaining the ethnopharmacological use of S. trilobata for the treatment of lung inflammatory diseases.

Evidence of an antidepressant-like effect of xylopic acid mediated by serotonergic mechanisms

BACKGROUND

Depression causes significant debilitating symptoms and economic burden. Current management is challenged by slow onset of action and modest efficacies of antidepressants; thus, the search for newer antidepressants remains relevant. We evaluated the antidepressant effects of a kaurene diterpene, xylopic acid (XA), in zebrafish and mouse models.

METHODS

The chronic unpredictable stress (CUS) protocol in zebrafish and the tail suspension test (TST), forced swim test (FST), lipopolysaccharide-induced depression-like behaviour test (LID) and repeated open space swimming test (OSST) in mice were used. We further examined the impact of depleting monoamines on XA's antidepressant effects. The contribution of glutamatergic and nitrergic pathways on the antidepressant effect of XA in mice and XA's effects on 5-HT receptors and monoamine oxidase (MAO) enzymes were also evaluated. Finally, XA's influence on neuroprotection was evaluated by measuring BDNF and oxidative stress enzymes in whole brain. XA doses (1-10 μM) in zebrafish and (10, 30, 100 mg kg-1) in mice exerted potent antidepressant-like potential in FST, TST, LID and showed fast-onset antidepressant-like property in the OSST.

RESULTS

The antidepressant-like properties in mice were reversed by blocking synthesis/release of serotonin but not noradrenaline using p-chlorophenylalanine and α-methyl-p-tyrosine, respectively. This antidepressant-like effect was potentiated by D-cycloserine and Nω-Nitro-L-arginine methyl ester (L-NAME) but not by D-serine and L-arginine. XA also evoked partial agonist-like effects on 5-hydroxytrptamine receptors on the rat fundus but it did not have MAO inhibition effect. It also increased BDNF, glutathione and antioxidant enzymes.

CONCLUSION

Therefore, xylopic acid possesses antidepressant-like effects largely mediated by serotonergic and neuroprotective mechanisms.

The diterpene from Sphagneticola trilobata (L.) Pruski, kaurenoic acid, reduces lipopolysaccharide-induced peritonitis and pain in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Sphagneticola trilobata (L.) Pruski is a plant species belonging to the Asteraceae family. Kaurenoid acid (KA) is a diterpene metabolite and one of the active ingredients of Sphagneticola trilobata (L.) Pruski. Extracts containing KA are used in traditional medicine to treat pain, inflammation, and infection.

AIM

The goal of the present study was to investigate the in vivo effects of KA (1-10 mg/kg, per oral gavage) upon LPS inoculation in mice by intraperitoneal (i.p.) or intraplantar (i.pl.; subcutaneous plantar injection) routes at the dose of 200 ng (200 μL or 25 μL, respectively).

METHODS

In LPS paw inflammation, mechanical and thermal hyperalgesia MPO activity and oxidative imbalance (TBARS, GSH, ABTS and FRAP assays) were evaluated. In LPS peritonitis we evaluated leukocyte migration, cytokine production, oxidative stress, and NF-κB activation.

RESULTS

KA inhibited LPS-induced mechanical and thermal hyperalgesia, MPO activity and modulated redox status in the mice paw. Pre- and post-treatment with KA inhibited migration of neutrophils and monocytes in LPS peritonitis. KA inhibited the pro-inflammatory/hyperalgesic cytokine (e.g., TNF-α, IL-1β and IL-33) production while enhanced anti-inflammatory/analgesic cytokine IL-10 in peritoneal cavity. In agreement with the effect of KA over pro-inflammatory cytokines it inhibited oxidative stress (total ROS, superoxide production and superoxide positive cells) and NF-κB activation during peritonitis.

CONCLUSION

KA efficiently dampens LPS-induced peritonitis and hyperalgesia in vivo, suggesting it as a suitable candidate to control excessive inflammation and pain during gram-negative bacterial infections and bringing mechanistic explanation to the ethnopharmacological application of Sphagneticola trilobata (L.) Pruski in inflammation and infection.

Chemopreventive effect of troxerutin against hydrogen peroxide-induced oxidative stress in human leukocytes through modulation of glutathione-dependent enzymes

Troxerutin is a natural flavonoid present abundantly in tea, coffee, olives, wheat, and a variety of fruits and vegetables. Due to its diverse pharmacological properties, this flavonoid has aroused interest for treatment of various diseases, and consequently prompted investigation into its toxicological characteristics. The aim of this study was to evaluate the genotoxic and mutagenic effects and chemoprotective activity attributed to troxerutin using human peripheral blood leukocytes (PBLs) through several well-established experimental protocols based upon different parameters. Data demonstrated that troxerutin (100 to 1000 µM) induced no marked cytotoxic effect on PBLs after 24 hr, and did not produce strand breaks and mutagenicity. Regarding chemoprevention, this flavonoid attenuated cytotoxicity, genotoxicity, and mutagenicity initiated by hydrogen peroxide (H₂O₂) in human PBLs. Further, troxerutin demonstrated no marked cytotoxic effect on PBLs and exerted a protective effect against oxidative stress induced by H₂O₂ through modulation of GSH-dependent enzymes.

A male germ cell assay and supporting somatic cells: its application for the detection of phase specificity of genotoxins in vitro

Male germ stem cells are responsible for transmission of genetic information to the next generation. Some chemicals exert a negative impact on male germ cells, either directly, or indirectly affecting them through their action on somatic cells. Ultimately, these effects might inhibit fertility, and may exhibit negative consequences on future offspring. Genotoxic anticancer agents may interact with DNA in germ cells potentially leading to a heritable germline mutation. Experimental information in support of this theory has not always been reproducible and suitable in vivo studies remain limited. Thus, alternative male germ cell tests, which are now able to detect phase specificity of such agents, might be used by regulatory agencies to help evaluate the potential risk of mutation. However, there is an urgent need for such approaches for identification of male reproductive genotoxins since this area has until recently been dependent on in vivo studies. Many factors drive alternative approaches, including the (1) commitment to the principles of the 3R's (Replacement, Reduction, and Refinement), (2) time-consuming nature and high cost of animal experiments, and (3) new opportunities presented by new molecular analytical assays. There is as yet currently no apparent appropriate model of full mammalian spermatogenesis in vitro, under the REACH initiative, where new tests introduced to assess genotoxicity and mutagenicity need to avoid unnecessary testing on animals. Accordingly, a battery of tests used in conjunction with the high throughput STAPUT gravity sedimentation was recently developed for purification of male germ cells to investigate genotoxicity for phase specificity in germ cells. This system might be valuable for the examination of phases previously only available in mammals with large-scale studies of germ cell genotoxicity in vivo. The aim of this review was to focus on this alternative approach and its applications as well as on chemicals of known in vivo phase specificities used during this test system development.

Extracts of Bridelia ovata and Croton oblongifolius induce apoptosis in human MDA‑MB‑231 breast cancer cells via oxidative stress and mitochondrial pathways

Breast cancer is the most common type of cancer and is also the second leading cause of cancer‑associated death in women worldwide. Thus, there is an urgent requirement for the development of effective treatments for this disease. Bridelia ovata and Croton oblongifolius are herbs used in Thai traditional medicine that have been used to treat various health problems; B. ovata has traditionally been used as a purgative, an antipyretic, a leukorrhea treatment and as a birth control herb. C. oblongifolius has been used to increase breast milk production, for post‑partum care (where it is used as a hot bath herb), and as a treatment for flat worms and dysmenorrhea. However, there is little research investigating the anticancer properties of these herbs. The present study aimed to investigate the anticancer properties of crude ethyl acetate extracts of B. ovata (BEA) and C. oblongifolius (CEA) in order to explore their underlying mechanisms in breast cancer cell death. The phytoconstituents of the crude extracts of BEA and CEA were studied using gas chromatography‑mass spectrometry (GC‑MS). GC‑MS analysis showed that the primary compound in BEA is friedelan‑3‑one, and kaur‑16‑en‑18‑oic acid in CEA. Cytotoxicity was investigated using an MTT assay, both BEA and CEA showed greater toxicity against MDA‑MB‑231 breast cancer cells compared with their effect on MCF10A normal epithelial mammary cells. BEA and CEA exerted various effects, including inducing apoptotic cell death, reducing mitochondrial transmembrane potential, increasing the levels of intracellular ROS, activating caspases, upregulating pro‑apoptotic and downregulating anti‑apoptotic genes and proteins. BEA and CEA were shown to have anticancer activity against breast cancer cells and induce apoptosis in these cells via a mitochondrial pathway and oxidative stress.

Pharmacokinetic Profile of Kaurenoic Acid after Oral Administration of Araliae Continentalis Radix Extract Powder to Humans

The objective of this study was to characterize pharmacokinetics (PKs) of kaurenoic acid (KAU) after administration of the clinical usual dose of Araliae Continentalis Radix extract powder to Korean subjects for the first time and evaluate the mechanism of its absorption in vitro. A simple, sensitive, and selective analytical method was developed for the detection of KAU in human plasma. Concentrations of KAU were quantified by ultra-performance liquid chromatography tandem mass spectrometry after simple liquid–liquid extraction. This pharmacokinetic model of KAU was best described by a two-compartment model with first-order absorption. To identify efflux transporters involved in the absorption of KAU, a Caco-2 monolayer model was used. Estimated PK parameters were: systemic clearance, 23.89 L/h; inter-compartmental clearance, 15.55 L/h; rate constant for absorption, 1.72 h⁻¹; volume of distribution of the central compartment, 24.44 L; and volume of distribution of the peripheral compartment, 64.05 L. Results from Caco-2 bidirectional transport study suggested that KAU was a potential substrate of efflux transporters. In summary, PKs of KAU were successfully characterized after administration of a usual dose of Araliae continentalis Radix extract powder in human with the newly developed bioanalytical method and the mechanism of absorption of KAU was identified clearly.

Essential oil from fruit of Xylopia langsdorffiana: antitumour activity and toxicity

CONTEXT

The genus Xylopia L. (Annonaceae) includes aromatic plants that have both nutritional and medicinal uses. Essential oils of Xylopia species have antitumour effects. However, the efficacy of the essential oil from the fruit of Xylopia langsdorffiana St. Hil & Tul. (EOX) has not been examined.

OBJECTIVE

EOX was evaluated to determine its chemical composition, antitumour activity and toxicity.

MATERIALS AND METHODS

EOX was obtained from fresh fruits of X. langsdorffiana subjected to hydrodistillation, and gas chromatography-mass spectrometry was used to characterize the chemical composition of EOX. The toxicity of EOX was evaluated using haemolysis, acute toxicity and micronucleus assays. The in vitro antitumour activity of EOX was investigated using the sulforhodamine B assay. The sarcoma 180 murine tumour model was used to evaluate the in vivo antitumour activity and toxicity of EOX (50 and 100 mg/kg) after 7 d of treatment.

RESULTS

The major components of EOX were α-pinene (34.57%) and limonene (31.75%). The HC₅₀ (concentration producing 50% haemolysis) was 293.6 μg/ml. EOX showed greater selectivity for the leukaemia cell line K562, with total growth inhibition (TGI) (concentration producing TGI) of 1.8 μg/ml, and for multidrug-resistant ovarian tumour cell line NCI/ADR-RES (TGI of 45.4 μg/ml). The LD₅₀ was approximately 351.09 mg/kg. At doses of 50 and 100 mg/kg, EOX inhibited the in vivo growth of sarcoma 180 by 38.67 and 54.32%, respectively. EOX displayed minor hepatic alterations characteristic of acute hepatitis and induced no genotoxicity.

CONCLUSION

EOX showed in vitro and in vivo antitumour activity and low toxicity, which warrants further pharmacological studies.

Mutagenic assessment of three synthetic pyridine-diaryl ketone derivatives

Nowadays, there are increasing numbers of studies about synthetic chemicals according to the supply demands of bioactive chemicals. The current study aims to investigate genotoxic potential of bioactive synthetic pyridine compounds, phenyl-3-pyridinylmethanone (1), p-tolyl-3-pyridinylmethanone (2), and 4-methoxyphenyl-3-pyridinylmethanone (3), using Ames/ Salmonella and Escherichia coli WP2 bacterial reversion mutagenicity test systems. The mutant bacterial tester strains sodium azide-sensitive Salmonella typhimurium TA1535, 9-aminoacridine-sensitive S. typhimurium TA1537, and N-methyl- N′ -nitro- N-nitrosoguanidine-sensitive E. coli WP2 uvrA were used to detect the mutagenic potential of the test compounds. The results indicated that none of the test substances showed significant mutagenic activity on S. typhimurium TA1535, TA1537, and E. coli WP2 uvrA bacterial strains up to 1 µg/plate concentrations.

Chemical composition, antitumor activity, and toxicity of essential oil from the leaves of Lippia microphylla

The chemical composition, antitumor activity and toxicity of the essential oil from Lippia microphylla leaves (OEL) were investigated. The major constituents were thymol (46.5%), carvacrol (31.7%), p-cymene (9%), and γ-terpinene (2.9%). To evaluate the toxicity of OEL in non-tumor cells, the hemolytic assay with Swiss mice erythrocytes was performed. The concentration producing 50% hemolysis (HC50) was 300 μg/mL. Sarcoma 180 tumor growth was inhibited in vivo 38% at 50 mg/kg, and 60% at 100 mg/kg, whereas 5-FU at 50 mg/kg caused 86% inhibition. OEL displays moderate gastrointestinal and hematological toxicity along with causing some alteration in liver function and morphology. However, the changes were considered reversible and negligible in comparison to the effects of several anticancer drugs. In summary, OEL displays in vivo antitumor activity and a moderate toxicity, which suggests further pharmacological study.

A kinetic study of the main guaco metabolites using syrup formulation and the identification of an alternative route of coumarin metabolism in humans

For decades guaco species have been empirically used for the treatment of respiratory diseases. However, studies have shown that the toxic and therapeutic effects of the main guaco metabolites are dose-dependent, and none clinical study was done to evaluate the behavior of these substances in humans. In this work, a pilot study measuring the kinetic profile of the main guaco metabolites was performed leading to the knowledge of an alternative route of coumarin metabolism in humans. Initial screenings demonstrated that the administration of 60 mL of guaco syrup (single dose) did not provide sufficient levels of coumarin (COU), 7-hydroxycoumarin (7-HCOU), o-coumaric acid (OCA) and kaurenoic acid (KAU). The pharmacokinetic parameters were calculated by orally administering 60 mL of guaco syrup spiked with 1500 mg of COU. The kinetic study demonstrated that the plasmatic levels of 7-HCOU (considered the main metabolite of COU) were 10 times lower than the levels of COU, and the kinetic profile of 7-HCOU suggests sequential metabolism in the liver with low access of 7-HCOU to the systemic circulation. The study also demonstrated that OCA is one of the main bioavailable metabolites of COU. Therefore, the hydrolysis of the lactone ring forming a carboxylated compound is one of the possible routes of COU metabolism in humans. The half-lives of COU, 7-HCOU and OCA were approximately 4.0, 1.0 and 3.0 h, respectively and there was evidence that the recommended dosage of guaco syrup did not provide sufficient levels of COU, 7-HCOU or OCA to obtain a bronchodilation effect. Clinical studies are necessary to prove the efficacy and safety of products based on guaco.

Assessment of genotoxic and mutagenic potential of hexavalent chromium in the freshwater fish Labeo rohita (Hamilton, 1822)

The present study was undertaken to investigate the genotoxicity and mutagenicity of sublethal concentrations of hexavalent chromium (potassium dichromate) in the Indian major carp, Labeo rohita. The 96 h LC50 value of potassium dichromate estimated was 118 mg L(-1) by probit analysis using SPSS (version 16.0) software. Based on 96 h LC50 value, three sublethal test concentrations of potassium dichromate (29.5, 59.0 and 88.5 mg L(-)(1)) were selected and specimens were exposed in vivo to these test concentrations for 96 h. The mutagenic and genotoxic effects of potassium dichromate were evaluated in gill and blood cells using micronucleus (MN) test and comet assay. In general, significant (p < 0.05) effects due to the concentrations and the exposure durations were observed in exposed specimens. The MN induction was highest at 96 h at all the test concentrations in the peripheral blood. A similar trend was observed for the DNA damage, measured in terms of percentage of tail DNA, in erythrocyte and gill cells. The study indicated hazardous effect of the hexavalent chromium to fish and other aquatic organisms and indirectly to human beings.

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.