Stress resistance promoting potentials of turmeric oil and curcuminoids in mice

Curcuma longa rhizomes (turmeric) are used as tonic in traditionally known Indian systems of medicine. Aim of this study was to compare stress response suppressing efficacies of a Curcuma longa extract (CLE) enriched in curcuminoids with those of curcumin and turmeric oil (TO). Effects of daily oral treatments with curcumin (5 mg/kg/day) or CLE (5, 20, and 80 mg/kg/day) or TO (1, 3, 10, 30 and 100 mg/kg/day) to male mice on their body weight and core temperature and in stress induced hyperthermia, tail suspension, and pentobarbital sleep tests were quantified. Although their single doses had no significant effects in foot shock stress induced hyperthermia test, curcumin like and dose dependant suppressing effects of CLE were observed after its repeated daily doses. Such effects of TO in the test was also observed after its higher tested daily doses only. Occasional foot shock stress triggered body weight losses and elevated basal core temperatures were also dose dependently antagonized by CLE and TO. Unlike for curcumin or CLE no effects of TO in tail suspension and pentobarbital sleep test were observed after its lower tested 11 daily doses. These observations reveal that volatile bioactive constituents of turmeric other than curcuminoids also possess stress resistance promoting properties and suggest that such efficacy of turmeric powder do not depend on their curcumin or curcuminoids contents only. Mouse bioassay procedure used in this study is well suited for pharmacological standardization of turmeric extracts and also for identifying their bioactive constituents.