Bioluminescence is a widespread phenomenon in nature, and luminescent organisms can be found both on land and in the ocean. Among them, luciferase based bioluminescence systems have been widely studied, inspiring the exploration of genetic and epigenetic aspects and the development of a series of related assays for in vivo and in vitro studies. This paper summarizes the recent developments of luciferase based bioluminescence assays in terms of bioluminescence systems, types of luciferases, and the development and application of luciferase bioluminescence assays.

OBJECTIVE To explore the effects of Citrus medica before and after being steamed on blood metabolism and dryness indexes in rats. METHODS Twenty-four SD rats were randomly divided into blank group， C. medica group （2.4 g/kg）， processed C. medica group （2.4 g/kg）， Citrus aurantium group （positive control， 1.2 g/kg）， with 6 rats in each group. After 5 weeks of continuous administration， the body weight， food intake， water intake and urine volume were observed dynamically. The content of aquaporin 3 （AQP3） in serum was detected. The metabolic profile of rat serum samples was analyzed by liquid chromatography-mass spectrometry. Principal component analysis （PCA） and orthogonal partial least squares-discriminant analysis （OPLS-DA） were used to screen differential metabolites， and screened differential metabolites were mapped to the KEGG database for pathway analysis. RESULTS The body weight of rats in each group increased slowly； the food intake and water intake of processed C. medica group tended to be higher than those in C. medica group and C. aurantium group， but there was no significant difference among those groups （P＞0.05）. On the 21st day of administration， compared with C. aurantium group， the urine volume of processed C. medica group was significantly increased （P＜0.05）， the serum AQP3 content of processed C. medica group was significantly decreased （P＜0.05）， and were close to those of blank group. According to the metabonomic study， C. medica mainly affected the lipids metabolism， and processed C. medica mainly affected the amino acid metabolism. The differential metabolites pathway between C. medica and processed C. medica involved the metabolism of cysteine and methionine， metabolism of glycine， serine and threonine， and metabolism of taurine and hypotaurine. CONCLUSIONS Processed C. medica might relieve the dryness of C. medica by affecting adenosine phosphate-protein kinase A. The content of AQP3 in serum can be used as the 52 evaluation index for the dryness of C. medica before and after processing. The effects of C. medica and processed C. medica on endogenous metabolites in rat serum are quite different，especially in the aspect of lipid metabolism.