Assessment of the potential genotoxic risk of Phyllantus orbicularis HBK aqueous extract using in vitro and in vivo assays

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.

Usefulness of the SOS Chromotest in the study of medicinal plants as radioprotectors

PURPOSE

The aim of this work is to investigate the usefulness of a modified protocol of the SOS Chromotest to detect antigenotoxicity activities against gamma-rays of plant extracts with proven antioxidant activity, and to elucidate the antigenotoxic mechanisms involved in radioprotection using this system.

MATERIALS AND METHODS

The methodology developed was assayed with amifostine, the most studied radioprotector, and with Phyllanthus orbicularis HBK, Cymbopogon citratus (DC) Stapf and Pinus caribaea Morelet extracts, using pre- and post-treatment procedures.

RESULTS

The P. caribaea and C. citratus extracts were antigenotoxic against gamma-rays when the cells were pre-treated with both extracts, suggesting a possible antigenotoxic action through a free radical scavenging mechanisms. Amifostine and the P. orbicularis extract were also antigenotoxic under pre- and post-treatment conditions, indicating that several antimutagenic components of this plant extract may also operate by some intracellular mechanism, unlike its antioxidant activity.

CONCLUSIONS

The results have demonstrated the usefulness of the modified SOS Chromotest assay in the screening of phytochemical radioprotectors as well as in the study of their antimutagenic mechanisms.