Activation of neurons in the insular cortex and lateral hypothalamus during food anticipatory period caused by food restriction in mice.

Mice fed a single meal daily at a fixed time display food anticipatory activity (FAA). It has been reported that the insular cortex (IC) plays an essential role in food anticipation, and lateral hypothalamus (LH) regulates the expression of FAA. However, how these areas contribute to FAA production is still unclear. Thus, we examined the temporal and spatial activation pattern of neurons in the IC and LH during the food anticipation period to determine their role in FAA establishment. We observed an increase of c-Fos-positive neurons in the IC and LH, including orexin neurons of male adult C57BL/6 mice. These neurons were gradually activated from the 1st day to 15th day of restricted feeding. The activation of these brain regions, however, peaked at a distinct point in the food restriction procedure. These results suggest that the IC and LH are differently involved in the neural network for FAA production.

Spectrum-effect relationship between HPLC fingerprint and antioxidant of "San-Bai Decoction" extracts.

"San-Bai Decoction" (SBD) has been a traditional Chinese medicine compound preparation for replenishing Qi and promoting blood circulation, whitening skin, and removing blemishes since ancient times. However, its chemical composition and antioxidant activity are not clear thus far, which limits the in-depth study on its pharmacodynamic material basis and efficacy. The objective of this study was to establish the fingerprint profile of SBD, assess its antioxidant activity by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, and find the spectrum-effect relationship of SBD by Grey Relation Analysis (GRA) and Partial Least Squares Regression (PLS). In this study, the fingerprint of SBD was established by high performance liquid chromatography (HPLC), and 20 common peaks were found, among which 6 peaks were designated. The similarities between the fingerprints of 12 batches of SBD and the reference fingerprint (R) were all greater than 0.900. Meanwhile, the antioxidant activities of all batches were concentration-dependent in their linear regression equation. The result of GRA showed that the correlation order of 20 common peaks for DPPH radical scavenging was X13 > X7 > X3 > X6 > X10 > X11 > X4 > X12 > X2 > X18 > X9 > X5 > X19 > X1 > X20 > X16 > X17 > X15 > X8 > X14. At the same time, PLS study demonstrated that the contribution of six identified characteristic peaks to DPPH radical scavenging ability was X1 = X7 > X6 > X19 > X20 > X16. In this study, the spectrum-effect relationship of SBD between its HPLC fingerprint and the antioxidant activity can be used to screen the pharmacodynamic substance basis of its antioxidant action and lay the foundation for establishing quality standards and product development.