*2.3. Experimental Animal Grouping*

We used 3-month-old male and female SAMP8 mice as our experimental animals, and we randomly divided them into one control group and three experimental groups (low, medium, and high doses) with 10 mice in each group (n = 10), and 80 mice in total. For both male and female animals, Group A was the control group, Group B was the low-dose SPE group (61.5 mg/kg BW/day), Group C was the medium-dose SPE group (123 mg/kg BW/day), and Group D was the high-dose SPE group (184.5 mg/kg BW/day). We obtained approval for our animal experiment procedures from the Institutional Animal Care and Use Committee (IACUC) of Providence University (Approval No: 20201218 A008).

At the end of the treatment, we euthanized all mice using 95% CO2. We then collected blood and separated serum using centrifugation. This was then stored at −80 ◦C. We collected and weighed organs such as the liver, lung, heart, kidney, adipose tissue, and skeletal muscles, and stored them at −80 ◦C. We stored small portions of vital organ tissue sections in formalin for histological analysis. We used brain tissue to estimate LPO, catalase activities, and SOD activities.

#### *2.4. Aging Index*

We included behavioral aspects in the evaluation items of the aging index. For 30 s, we observed the reactivity of mice (reactivity) and also their escape response (passivity) following pinching of the skin on the nape of the neck. We also noted appearance aspects such as the glossiness of the skin (glossiness) and its roughness (coarseness), as well as any loss of hair (hair loss). We also sought to identify any skin ulceration (ulcer). With regard to animal eyes (eyes), we looked for mucositis around the eyes or edema of the eyelid (periophthalmic lesion). We also inspected animals using touch to assess any changes in spine lordokyphosis (lordokyphosis). We assessed each evaluation item by means of 5 grades, namely, 0, 1, 2, 3, and 4. The higher the score, the more serious the aging phenomenon observed.
