RESUMO
Objective To evaluate the toxic effects of different concentrations of Coptidis Rhizoma extract on Caenorhabditis elegans. Methods Coptidis Rhizoma was extracted by water, and then selected some indicators to evaluate the toxic effects of Coptidis Rhizoma by using C. elegans as model organism. The effects of different concentrations of water extracts of Coptidis Rhizoma on lethality, maximum lifespan and median lethal time, individual development, spawning number and locomotion behavior were measured to evaluate the toxic effects on C. elegans. Results Compared with the control group, the lethality of C. elegans was significantly increased by water extracts of Coptidis Rhizoma at 0.5, 1.0, and 2.5 mg/mL (P < 0.01), and maximum lifespan and median lethal time were significantly decreased (P < 0.01). In the aspect of individual development, Coptidis Rhizoma extract at 1.0 and 2.5 mg/mL significantly inhibited the growth of C. elegans (P < 0.01). Three concentration extracts could significantly reduce the number of spawning in a certain dose-dependent manner in the aspect of reproductive behavior (P < 0.001), and the head swing frequency of C. elegans (P < 0.01) in the aspect of locomotion behavior, respectively. There was no significant difference in body bending frequency between the 0.5 and 1.0 mg/mL exposed group, of which the lowest bending frequency was 2.5 mg/mL exposed group (P < 0.01). There was no significant difference in the frequency of forward swing, backward swing and Omega/U swing of three exposed groups. Conclusion The water extracts of Coptidis Rhizoma had obvious toxic effects on C. elegans, which provided the basis for the biological evaluation of the toxicity of different processed products of Coptidis Rhizoma by using C. elegans as a model organism, and provided new ideas and methods for the biological assessment of toxicity of Chinese medicinal materials.
RESUMO
Amostram-se grilos de serapilheira com armadilhas enterradas (pitfall). No entanto, algumas espécies são sub-amostradas, por que alguns indivíduos conseguem fugir da armadilha. Neste trabalho sugerimos a substituição da solução aquosa de detergente, por uma solução de formol-glicerina-álcool, para aumentar a eficiência da amostragem. Testamos se: (i) formol reduz a fuga de grilos; (ii) formol é repelente para os grilos. Foram instaladas 80 armadilhas, formando pares formol-detergente e detergente-detergente, com 20 cm entre armadilhas dentro do par, e 3 m entre pares. Foram coletados 105 indivíduos, sendo 29 adultos, de nove espécies, em três grupos taxonômicos: Phalangopsinae, Trigonidiinae e Brachytrupinae. Tanto o número de adultos quanto de ninfas capturados nas armadilhas com detergente não foi afetado pela proximidade de armadilha com formol. Nos pares formol-detergente, o número de adultos em formol foi maior que em detergente, enquanto o número de ninfas não foi diferente. Assim, formol não foi repelente nem para adultos nem para ninfas de grilos. As armadilhas com formol foram mais eficientes, por reterem mais adultos do que as com detergente, devido ao efeito de knock-down. As ninfas não foram afetadas porque sua fuga do detergente já é reduzida, devido a seu tamanho reduzido e menor esclerotização. Tamanho menor implica saltos menores, insuficientes para o escape. Esclerotização menor implica maior permeabilidade, de forma que uma vez que a ninfa cai na armadilha, ela não consegue mais fugir.
Pitfall traps are used to sample litter inhabiting crickets, but some species are underestimated, because captured individuals escape from the trap. Here we suggest the substitution of aqueous detergent killing solution by formol-glicerin-alcohool solution, to increase sampling efficiency. We tested two hypotheses: (i) formol solution reduces the escape of crickets from the traps; (ii) formol solution is repellent. We arranged 80 traps in pairs of traps formol/detergent and detergent/detergent, 20 cm between traps within pairs, and 3 m between pairs. We collected 105 cricket individuals, being 29 adults, from nine species, in three taxonomic groups: Phalangopsinae, Trigonidiinae, and Brachytrupinae. Capture of both adults and nymphs was not affected by proximity of formol solution traps. In formol-detergent pairs, formol traps captured more adult individuals than detergent traps, but the number of nymphs did not differ. Therefore, formol was not repellent neither for adults nor nymphs. Traps with formol were more eficient, because they retained more adults than those with detergent, because of knock-down effect. Nymphs were not affected by the killing solution because their escape frequency is already low, due to their tiny size and reduced sclerotization. Tiny size implies short jumps, insuficient to escape. Reduced sclerotization implies greater permeability, so that once fallen into the trap, nymphs cannot escape any more.