Objective

2

To explore the acute toxicities and hepatotoxicities of aqueous extracts of Taxilli Herba from

Morus alba

，

Toxicodendron

trichocarpum

，

Camellia oleifera

，

Salix babylonica

，

Melia azedarach

， and

Nerium indicum

against zebrafish model and the effect of different hosts on the toxicity of Taxilli Herba， hoping to provide a theoretical basis for the safe use of Taxilli Herba.

Method

2

The normally developed AB zebrafish at 3-day post fertilization was selected for acute toxicity study. According to the results of preliminary toxicity experiments， the zebrafishes were treated with aqueous extracts of Taxilli Herba from different hosts at six doses， and their mortality was calculated 72 h later. GraphPad Prism 6.0 was used for plotting the dose-toxicity curve， followed by the calculation of their median lethal concentration （LC

50

） and 10% lethal concentration （LC

10

）. The gz15Tg/+（AB） liver fluorescent protein transgenic zebrafish with normal development at 4-day post fertilization was applied for the hepatotoxicity study. The zebrafishes were divided into the low-， medium-， and high-dose groups of aqueous extracts of Taxilli Herba from six hosts， the positive control （acetaminophen） group， and the blank （embryo amniotic fluid） group， and then treated with the corresponding drugs. Seventy-two hours later， the liver morphology and fluorescent area changes in zebrafish were observed. And the activities of alanine aminotransferase （ALT） and aspartate aminotransferase （AST） were detected.

Result

2

The results of acute toxicity test demonstrated that the LC

50

values of water extracts of Taxilli Herba from

M. alba

，

T.

trichocarpum

，

C. oleifera

，

S. babylonica

，

M. azedarach

， and

N. indicum

were 1.24， 0.94， 0.51， 0.38， 0.11， 0.09 g·L

-1

， respectively， and the LC

10

values were 0.70， 0.60， 0.35， 0.28， 0.08， 0.07 g·L

-1

， respectively. As revealed by hepatotoxicity test， compared with the blank group， the positive control group exhibited liver morphological changes， decreased fluorescent area （

P

<

0.01）， and elevated ALT and AST activities （

P

<

0.01）， suggesting that acetaminophen was hepatotoxic to zebrafish. However， there was no change in the liver morphology or fluorescent area of zebrafish in the low-， medium-， and high-dose groups of water extracts of Taxilli Herba from

M. alba

， and the ALT and AST activities were decreased. By contrast， the liver morphology and fluorescent areas in the medium- and high-dose groups of water extracts of Taxilli Herba from

T.

trichocarpum

，

C. oleifera

，

S. babylonica

，

M. azedarach

， and

N. indicum

changed to varying degrees （

P

<

0.05，

P

<

0.01）. Besides， the activities of both ALT and AST were also enhanced. These indicated that Taxilli Herba from

M. alba

had no hepatotoxicity to zebrafish， while that from

T.

trichocarpum

，

C. oleifera

，

S. babylonica

，

M. azedarach

， and

N. indicum

showed varying degrees of hepatotoxicity to zebrafish.

Conclusion

2

The toxicity of Taxilli Herba is host-dependent. Taxilli Herba from

M. alba

has no hepatotoxicity， but that from the other five hosts shows varying degrees of hepatotoxicity. Standardizing the host source may be an important measure to realize the medication safety of Taxilli Herba.