## 3 Results and Analysis
### Plasma + TwHF Treatment Ameliorated IMQ-Induced Psoriatic Skin Lesion  
To confirm whether LTP + TwHF can efficiently ameliorate skin lesions in psoriasis, we used the IMQ-induced psoriasis-like mice with LTP treatment alone, TwHF treatment alone, and LTP + TwHF treatment. Mice in our animal experiment were randomly assigned into five groups: the Control, IMQ, LTP, TwHF, and LTP + TwHF groups. Figure 7 suggests that the dorsal skin treated with IMQ generated typical psoriasis-like inflammatory responses on the back, such as thickening, scaling, and erythema after 3 days, and lesions gradually increased with extended IMQ administration. The LTP treatment aggravated the psoriatic lesions. The PASI score shown in Figure 7c suggests that the PASI scores of the LTP group were about 10% higher than that of the IMQ group. The main reason is the damage to the SC caused by plasma (as shown in Figure 6) and the subsequent enhancement in the transdermal delivery of IMQ. TwHF notably alleviated the skin lesion throughout the treatment period (TwHF group in Figure 7b,c). The extracts from the root of TwHF inhibit the expression of proinflammatory-tory cytokines, proinflammatory mediators, adhesion molecules, and matrix metalloproteinases. TwHF possesses potent anti-inflammatory and immunosuppressive properties in vitro and in different animal models in numerous preclinical studies [15, 42, 43]. Figure 6: The HE (hematoxylin-eosin) staining of the mice skin before/after LTP treatment: (**a**) The HE staining of normal mice skin before plasma treatment. (**b**) The HE staining of normal skin after 5 min plasma treatment. The SC is damaged after Plasma treatment for 5 min. (**c**) SC is totally removed by the 10 min plasma treatment. Unlike the plasma scanning treatment for IMQ-induced psoriasis, the position of LTP treatment was fixed during SC damage treatment. Figure 7: LTP + TwHF ameliorates psoriatic symptoms and skin inflammation in IMQ-induced psoriatic mice. (**a**) Flow chart of the experiment. (**b**) The back skin photos of mice were taken on the 3 rd, 5 th 7 th day after IMQ painting. (**c**) PASI scores in all groups of mice were evaluated daily and the statistical difference between all groups was indicated. Data are expressed as mean \(\pm\) SD (\(n\) = 5 mice/group, * \(p<0.05\)). One representative of three separate experiments is shown while all results were similar among these three experiments. Because the LTP treatment enhanced the transdermal delivery of IMQ, the psoriasisform dermatitis became more serious after the LTP treatment. TwHF group only alleviated mild symptoms of the IMQ model. The comparison between the red dash line and green dash line suggests that the LTP + TwHF psoriasisform dermatitis is more efficient at suppressing epidermal thickening and inhibiting systemic inflammation. LTP + TwHF also significantly alleviated the severity of the IMQ-induced psoriasis. The scores for erythema and thickness, along with the cumulative score of four groups are compared in Figure 7c. The decrease in the LTP group scores compared to the LTP + TwHF group is \(-\)40% more than the decrease from the IMQ group to the TwHF group, which indicates that the LTP + TwHF treatment can reduce psoriasis symptoms more efficiently than TwHF treatment alone. The application of TwHF right after LTP treatment is expected to substantially enhance the transdermal delivery of TwHF. Therefore, the combination of LTP and TwHF realized the more efficient treatment on psoriatic lesions. The H&E staining shown in Figure 8b captured the IMQ-induced psoriatic lesions, including the presence of epidermal parakeratosis, acanthosis cell layer thickening, and the downward epidermal extension of in-depth dermis. However, the LTP group (Figure 8c) had a more severe downward epidermal extension of in-depth dermis. Meanwhile, the administration of TwHF (Figure 8d) alleviated the severity of the skin lesion, and the administration of LTP + TwHF (Figure 8e) achieved a similar effect.