## 3 Results and Discussion
### Determination of Collagen-Related Proteins in the Dorsal Skin of Nude Mice  
The dermis includes collagen types I, II, III, and IV, with type I accounting for approximately 90% of the connective tissue protein, followed by type III, both of which are associated with elasticity. During skin aging, the amount of type I collagen decreases while the amount of type III collagen increases. Furthermore, the ratio of type III to type I collagen in the skin increases with UVB irradiation [40]. In addition, increased type III collagen levels may be a response to skin damage caused by UV irradiation, similar to the increased levels observed in scar tissue [7]. Therefore, controlling the ratio of type III to type I collagen can effectively promote anti-aging effects [14]. Collagen, of which type I collagen is the predominant type, is synthesized in the form of procollagen precursors secreted outside the dermis cells to form regularly arranged fibrous structures [32,41]. The following findings related to procollagen content were observed at week 13 of UVB and LPTWK10 treatments. The type I procollagen content in the UVB group was significantly lower than that in the NC group by approximately 43.22% (Figure 5A), which significantly increased on treatment with a high dose of LPTWK10 or the spray-dried LPTWK10 supernatant by approximately 69.88 and 75.68%, respectively (\(p<0.05\)). The type III procollagen content in the UVB group was significantly higher than that in the NC group (90.81%), which significantly decreased by 43.07% on treatment with a high dose of LPTWK10 (\(p<0.05\)) (Figure 5B). The ratio of type III to type I procollagen in the skin was further compared, with a lower ratio indicating protective effects for the skin (Figure 5C). Figure 4: Effects of the administration of LPTWK10 or LPTWK10 spray-dried supernatant powders on dorsal (**A**) TNF-\(\alpha\), (**B**) IL-6, and (**C**) IL-1\(\beta\) levels in UVB-induced nude mice. Data are presented as mean \(\pm\) SD (\(n=7\) or 8). Values with different uppercase letters were significantly different by [PERSON]’s multiple range test (\(p<0.05\)). TNF-\(\alpha\): tumor necrosis factor-\(\alpha\); IL-6: interleukin-6; IL-1\(\beta\): interleukin-1\(\beta\); UVB: ultraviolet B; NC: normal control; PC: positive control; LPLD, LPLD and LPLD: administration of LPTWK10 viable cells at 2 \(\times\) 10\({}^{8}\) CFU/kg bw/day, 2 \(\times\) 10\({}^{9}\) CFU/kg bw/day and 2 \(\times\) 10\({}^{10}\) CFU/kg bw/day, respectively; SPLD, SPMD and SPHD: administration of LPTWK10 spray-dried supernatant powders at 0.30 g/kg bw/day, 0.60 g/kg bw/day, and 1.20 g/kg bw/day, respectively. The type III/type I pro-collagen ratio was significantly higher in the UVB group than in the NC group, at approximately 0.06, which significantly decreased by approximately 0.06 on treatment with a high dose of LPTWK10 (\(p<0.05\)). MMPs are zinc ion-dependent endopeptidase involved in the degradation of various extracellular matrix (ECM) components and function in wound repair [8]. MMPs can be subdivided into collagenases, gelatinases, stromelysins, and membrane types based on receptor specificity, domain structure, and cell surface binding properties [42]. MMP-1  
Figure 5: Effects of the administration of LPTWK10 or LPTWK10 spray-dried supernatant powders on dorsal (**A**) Type I procollagen, (**B**) Type III procollagen, (**C**) Type III procollagen/Type I procollagen, (**D**) MMP-1, (**E**) MMP-9 and (**F**) AP-1 levels in UVB-induced nude mice. Data are presented as mean \(\pm\) SD (\(n=7\) or 8). Values with different uppercase letters were significantly different by [PERSON]’s multiple range test (\(p<0.05\)).