RESUMO
OBJECTIVE: To observe the effect of electroacupuncture (EA) of auricular concha region (ACR), "Zusanli" (ST 36) and "Sanyinjiao"(SP 6) on abnormal skin barrier and color in streptozotocin (STZ)-induced type 2 diabetes mellitus (T 2 DM) rats so as to find a better therapeutic method. METHODS: Fifty male Sprague Dawley (SD) rats were randomized into control (n = 10), model (n = 13), EA-ST 36-SP 6 (n = 14) and EA-ACR (n = 13) groups. T 2 DM model was established by intraperitoneal injection of 1% STZ (50 mg/kg) and by feeding the animals with high-fat diet for 30 days. EA (15 Hz, 1 mA) was applied to bilateral "Zusanli" (ST 36), "Sanyinjiao" (SP 6) and ACR respectively for 30 min, once daily for 14 days. Multi Probe Adapter 9 skin measurement system (MPA 9) was used to measure the stratum corneum hydration (SCH), transepidermal water loss (TEWL), erythema index (El), melanin index (MI) and chromatic aberration values (L. a. b.) of the abdomenal and back (L1 - L6) skin, respectively. RESULTS: In comparison with the control group and pre-modeling, blood glucose contents of the model, EA-ST 36-SP 6 and EA-ACR groups were increased significantly (P < 0.01) after modeling. Compared with the model group, blood glucose levels of both EA-ST 36-SP 6 and EA-ACR groups were down-regulated apparently (P < 0.01) after treatment. Thirty days after modeling, the SCH, TEWL, EI, MI, L. and a. levels of the back skin, and the SCH and L. levels of the abdominal skin were decreased significantly (P < 0.05), while the level of b. in the back skin, and those of TEWL, EL, a. and b. of the abdominal skin increased considerably in the model group (P < 0.05). After EA, the levels of SCH, TEWL MI, L. a. and b. in the EA-ST 36-SP 6 group, SCH, TEWL, L. and b. in the EA-ACR group of the back skin, and SCH, L. and b. of both EAST 36-SP 6 and EA-ACR groups, as well as EI and a. of the EA-ST 36-SP 6 group of the abdominal skin were reversed remarkably (P < 0.05). No significant differences were found between the EA-ST 36-SP 6 and model groups in the levels of El of the back skin, TEWL and MI of the abdominal skin, and between the EA-ACR and model groups in the levels of SCH, EI, MI and a. of the back skin, and TEWL, EI, MI and a. of the abdominal skin (P > 0.05). In spite of a mildly better therapeutic effect of EA-ST 36-SP 6 in regulating some of the abovementioned indexes, no significant differences were found between the two EA groups in all the indexes (P > 0.05). CONCLUSION: EA of both ST 36-SP 6 and ACR can effectively down-regulate blood glucose level, suppress DM-induced decrease of SCH, TEWL, L. and a. of the back skin, and SCH of the abdominal skin, and down-regulate b. levels of the back and abdominal skin in T 2 DM rats, showing an improvement of the impaired skin barrier and color changes following EA intervention.