Objective: To establish an objective method to estimate the disparity between the cold and hot natures on the basis of an intrinsic correlation between temperature tropism of mice and the cold and hot natures of Chinese medicines.
Methods: Male KM mice were randomly divided into 7 groups of 6 each, namely the normal group (NM), the weak model group (WM), the strong model group (SM), the weak model plus Radix ginseng rubra group (WM + RG), the weak model plus Panax quinquefolius L. group (WM + PQ), the strong model plus Radix ginseng rubra group (SM + RG) and the strong model plus Panax quinquefolius L. group (SM +PQ). The specific herbal drugs were administered intragastricly. To induce the weak model, mice were fed with a limited supply of feed and forced to swim in cold water until almost drowning while the strong model induced by feeding a high-protein diet with an unlimited feed access. The doses of Radix ginseng rubra and Panax quinquefolius L. were 35 mg/g of body weight per day (counted by the quantity of crude material) and lasting for seven days. The NM and model groups without dosing were intragastricly administered with physiological saline of the same volume to the dosing groups. The percentage of the remaining time of mouse on a high temperature (40 degrees C) pad to the total monitoring time was recorded by a self-designed intelligent animal behavior monitoring system. Meanwhile, the drinking volume of mice in each group was measured. Immediately after experiment, the activities of Na(+)K(+)-ATPase and superoxide dismutase (SOD) in liver tissue were measured by assay kits of phosphorus and xanthine oxidase methods respectively.
Results: The features of deficient and cold symptom, such as fatigue, stagnant weight growth, decreased water intake, cold limbs and tail etc, were observed in WM group. And the features of heat symptom, such as increased weight and water intake, hyperactivity etc, were observed in SM group. The percentage of time that the mouse remained on 40 degrees C pad of the WM group within the seven days experiment was significantly higher than that of the normal group (70.6% +/- 21.3% vs 52.1% +/- 6.5%, P < 0.05). While the value of SM group (45.7% +/- 4.6% ) was significantly lower than that of the normal group (P < 0.05); the value of WM + RG group and WM + PQ group were 65.6% +/- 7.8% and 75.3% +/- 13.0% respectively (both P < 0.05 compared with WM group); the values of SM + RG group and SM + PQ group were 36.1% +/- 15.5% and 55.5% +/- 7.7% respectively (both P < 0.05 compared with SM group). The activities of Na(+)K(+)-ATPase and SOD of WM mice treated with either Radix ginseng rubra or Panax quinquefolius L. were found to have a significant up-regulation (P < 0.05) as compared with untreated WM mice. But only the Panax quinquefolius L. showed an up-regulating effect upon Na(+)K(+) ATPase and SOD in SM mice.
Conclusions: The external cold and hot natures of Radix ginseng rubra and Panax quinquefolius L. can be represented in an ethological way by the changes of animal's temperature tropism. And such a tropism may be internally regulated by body's energy metabolism.