Effect of LV, HS, and MetA on energy expenditure and thermogenesis-related gene expression in HFD-induced obese mice. Rectal temperature (A), UCP-1 mRNA expression in subcutaneous fat (B), and UCP-2 mRNA expression in EWAT (C) of NFD and DIO mice after 9 weeks of 60% HFD feeding. Rectal temperature was measured at regular intervals (30, 60, 90, 120, and 180 min) after sample administration when the mice were exposed to 10 °C ambient temperature in a cold room at 8 weeks on HFD (at 18 weeks of age). Gene-expression levels were analyzed using qPCR. HFD, 60% high-fat-diet control group; HFD + GC_245, HFD contains Garcinia cambogia extract (245 mg/kg)-fed group; HFD + LV_100, HFD contains lemon verbena extract (100 mg/kg)-fed group; HFD + HS_100, HFD contains Hibiscus flower extract (100 mg/kg)-fed group; HFD + MetA_50, HFD contains the MetA-mixed extract of lemon verbena plus Hibiscus flower (50 mg/kg)-fed group; HFD + MetA_100, HFD contains the MetA-mixed extract of lemon verbena plus Hibiscus flower (100 mg/kg)-fed group. Values are expressed as means ± SEM (n = 10). a–d Values within arrow with different letters are significantly different from each other at p < 0.05 as determined by Turkey’s multiple-range test.