ABSTRACT
Objective The aim of this study is to explore the hypoglycemic effect of active components of Anoectochilus roxburghii on zebrafish models. Methods Anoectochilus roxburghii components were extracted and separated into three groups: the alcohol extraction group, macromolecular polysaccharide group (≥ 5 ×103) and small molecular polysaccharide group (＜5×103). Zebrafish embryos were exposed to 2% glucose solution (2% Glu) at 24 h to imitate acute hyperglycemia phenotype, and then treated with the three Anoectochilus roxburghii components. Based on this high-glucose model, the zebrafish embryos at 72 h were collected to detect the whole tissue glucose value. Furthermore, semi-quantitative PCR and whole mount in situ hybridization were performed to detect the expression of mRNA levels of glycometabolism-related genes. Results An acute diabetic zebrafish model was induced by high glucose stress. In this model, some key factors during glycometabolism such as insulin, pck-1 and pdx-1 were significantly affected, while the alcohol extracts of Anoectochilus roxburghii obviously reversed these abnormalities induced by high glucose stress, even to normal levels. Conclusions The alcohol extracts of Anoectochilus roxburghii has obvious hypoglycemic effect on diabetic zebrafish model. Our result suggest that Anoectochilus roxburghii has a potential application in the hypoglycemic drug screening.
ABSTRACT
Objective The aim of this study was to explore the inhibitory effect of alcohol extracts of Narcissus bulb on melanogenesis in zebrafish embryos.Methods Zebrafish embryos were exposed to different concentrations of alcohol extracts of Narcissus (0, 50, 100, 200, and 500 μg/mL), and then the formation of melanin was observed.Furthermore, we measured the enzyme activity of tyrosinase (TYR), which plays a pivotal role in melanogenesis.Meanwhile, the spatial and temporal pattern of melanin-specific marker genes were detected.Arbutin (Ar) was used as a positive control in all these experiments.Results The treatment of alcohol extracts of Narcissus bulb inhibited melanogenesis in the zebrafish embryos in a dose-dependent manner.Furthermore, the mRNA expression levels of melanin-related genes such as tyrosinase (TYR), silver (SILV) and Mitfa were significantly reduced after treatment with different concentrations of Narcissus extracts by in-situ and semi-quantitative PCR.Finally, the enzyme activity of tyrosinase was also gradually decreased with increasing concentrations of the alcohol extracts.Conclusions Narcissus alcohol extracts can effectively inhibit the production of melanin in zebrafish embryos.This study provides potential evidence and approaches for the screening of natural whitening compounds using zebrafish models.