*4.2. Extract Preparation*

The dry herb pieces of SR (1.0 kg), CR (1.0 kg) and SC (1:1, 3 kg) were extracted with boiling water (1:8) twice, 2 h each time, filtered through gauze and concentrated to 1.0 g/mL, respectively.

#### *4.3. Animals and Induction of T2DM Rats*

Pathogen-free male Sprague-Dawley rats (200 ± 20 g) were supplied by the Zhejiang Province Experimental Animal Center. All animals were maintained in cages at 22–26 ◦C with 55%–65% relative humidity, under a 12 h dark/light cycle, with water and respective diet available ad libitum. The experiments were performed following the principles of the Care and Use of Laboratory Animal and approved by the Animal Ethics Committee of Nanjing University of Chinese Medicine.

After acclimatization for one week, animals were randomly separated into seven groups (6 rats/group): normal group (N), model group (M), metformin group (P), Scutellaria Radix group (SR), Coptidis Rhizome group (CR), Low dose of combined extracts group (LSC), and High dose of combined extracts group (HSC). The normal rats were fed with common pellet diets during the experiment and rats in other groups were fed by a high-fat diet (including 67.5% standard laboratory chow, 20% sucrose, 10% lard oil, and 2.5% egg yolk powder(*w*/*w*)). After one month of dietary intervention, a dose of 30 mg/kg STZ (dissolved using 0.1 M citrate buffer, pH 4.2) was given to all the groups except the normal group. The normal rats were given the same dose of sodium buffer. Three days later, all rats were fasted 12 h (free access to water). Fasting blood glucose (FBG) was measured by ONE TOUCH II type blood sugar apparatus. Rats were considered to be T2DM model when their FBG levels exceeded 16.7 mmol/L.

#### *4.4. Drug Administration, Biological Sample Collection, and Preparation*

The P group rats were intragastrically given metformin at a dose of 0.09 g/kg (0.09 g metformin per 1 kg rat body weight) for one month. The SR and CR group rats were intragastrically given SR, CR extracts at a dose of 6.3 g/kg (6.3 g crude herbs per 1 kg rat body weight) for one month, respectively. The LSC and HSC group rats were intragastrically given SC extracts at a dose of 6.3 g/kg, 12.6 g/kg (6.3 g crude herbs per 1 kg rat body weight, 12.6 g crude herbs per 1 kg rat body weight) for one month, respectively. All experiments and animal care were approved by the Animal Ethics Committee of Nanjing University of Chinese Medicine.

The rats were fixed in supine position and anesthetized with 10% chloral hydrate by intraperitoneal injection, blood samples were collected in heparinized tubes and no anticoagulant tubes on the 30th day after treatment from abdominal aorta. They were then centrifuged at 3000 r/min for 10 min to obtain the plasma and serum samples stored at −80 ◦C. The levels of pro-inflammatory cytokines and biochemical indexes in serum were measured using Elisa kits.

Liver tissues were quickly removed, placed on ice, and homogenized in 9 vol. (*w*/*v*) of phosphate buffer saline. The homogenate was centrifuged at 4 ◦C, 13,000 rpm for 10 min and supernatant liquor was then stored at −80 ◦C until detection of PEPCK, FBPase, G6Pase, GP, GK, PFK, PK, and GS by using Elisa kits according to the instructions of the manufacturer.

One hundred microliters of plasma were added to 300 μL of acetonitrile and two hundred microliters of urine were added to 200 μL of acetonitrile. These mixtures were vortexed for 1 min and centrifuged at 13,000 r/min for 10 min to obtain the supernatant. A 2 μL aliquot of each plasma or urine sample was injected for LC/MS analysis.

#### *4.5. Histological Analysis*

Each liver, pancreas, skeletal muscle, adipose tissue was fixed in 4% (*w*/*v*) paraformaldehyde over 24 h. With graded ethanol dehydration, specimens were embedded in paraffin. Sequentially, 3 mm sections were rehydrated and stained with hematoxylin and eosin. The program of staining was obtained with the IX51 microscope (Olympus Corporation, Tokyo, Japan).
