Effect of DMHF (2,5-dimethyl-4-hydroxy-3(2H)-furanone) inhalation on gene expression in Rat brain

Background: 2,5-Dimethyl-4-hydroxy-3(2H)-furanone (DMHF) is one of the major odor compounds generated by the Maillard reaction. We previously reported that the inhalation of DMHF decreased systolic blood pressure via the autonomic nervous system in rats. The autonomic nervous system is also closely related to appetite regulation. The present study investigated the effects of DMHF on dietary intake and gene expression. Results: The inhalation of DMHF increased the dietary intake of rats during the feeding period. However, body weight gain was suppressed after six weeks of feeding. A DNA microarray analysis showed that DMHF altered gene expression associated with feeding behavior and neurotransmission in the rat brain. Conclusion: DMHF inhalation promotes appetite and changes gene expression in rats. Furthermore, phenotypic changes may regulate neurotransmission and appetite at the mRNA level in addition to controlling the autonomic nervous system. Six-week-old Wistar rats were purchased from CLEA Japan Inc. (Tokyo, Japan). Rats were housed in plastic cages in an animal room at 22 ± 2℃ and 50 ± 10% humidity under an artificial lightning system of 12-h light and 12-h darkness (lights on from 08:00 to 20:00). Rats were housed for a week to acclimate to the environment, and were able to access water and chow diets ad libitum during the experimental period. Rat brains were obtained for the DNA microarray analysis after the inhalation of DMHF. A 5-mL aliquot of distilled water (control) or DMHF was deposited into a two-neck flask; air was pumped into one neck and the vapor phase from the flask was ejected from the other. After 5 min of DMHF inhalation, rats were left to stand for 10 min and then sacrificed. The inhalation of DMHF was performed before the circadian rhythm dark period.