## 3 Results and Discussion
### Skin Anti-Wrinkling Effects of SP  
UV-induced ROS production is associated with skin wrinkling and hyperpigmentation, leading to skin aging. Reduction in collagen levels and increased secretion of matrix-degrading enzymes such as MMPs in old skin compared with that in young skin are considered the major causes of human skin wrinkling [30]. Collagen comprises approximately 25% of all proteins in the human body and provides a foundation for connective tissues, including the skin. Many modern aesthetic methods aim to improve or stimulate the synthesis of collagen fibers in the skin [31]. UV irradiation is the main external factor that damages collagen fibers. It penetrates deep into the skin, affecting cells, collagen, elastic fibers, and other extracellular proteins. UV rays are absorbed more easily by hydrophobic amino acids, such as tryptophan, tyrosine, and phenylalanine, which are exposed during protein denaturation caused by sunburn, leading to collagen damage. In addition, UV rays impair the chaperone proteins responsible for proper collagen assembly, resulting in abnormal collagen formation [29]. In view of the results obtained for free radical scavenging and ROS production (Figures 3 and 4), we assessed the improvement in photoaging by evaluating the collagen levels in cells exposed to UV irradiation and treated with the extracts. As shown in Figure 5, 0.1 mg/mL SP (115.46 \(\pm\) 3.39, \(p\) < 0.001), 1 mg/mL WB (109.17 \(\pm\) 1.86, \(p\) < 0.001), and SPWB (138.52 \(\pm\) 1.77, \(p\) < 0.001) increased the collagen  
Figure 4: Comparison of intracellular ROS production in UVB-irradiated human skin fibroblasts treated with the different extracts. PCB, PCB standard; SP, the PCB extract from _Arthospira maxima_, prepared by water extraction using ultrasonication at room temperature followed by ethanolic extraction at 70 \({}^{\circ}\)C; WB, the wheat bran extract prepared by water extraction at 4 \({}^{\circ}\)C for eight hours; SPWB, a mixture of SP and WB containing the same amounts of PCB and SP. The mean \(\pm\) SD values for triplicate experiments are shown; error bars represent the SD. * \(p\) < 0.05, ** \(p\) < 0.01 and *** \(p\) < 0.001 compared with the control (UV+) group. levels in human skin fibroblasts compared with those in the UV(+) group (44.92 \(\pm\) 6.26). We considered the effects of the extracts on collagen levels in the UV-irradiated cells because of their high antioxidant activities associated with the inhibition of ROS production. In particular, the results of collagen production were similar to those of the antioxidant activities of SP and SPWB, as shown in Figure 3, and the enhanced effects of SPWB could be attributed to the synergism of components in SP and the protective effects of WB. Therefore, these findings suggest that PCB and SP, containing the same amount of PCB in the extract, could increase collagen synthesis in human skin fibroblasts and that the efficacy of SP was mostly due to PCB. UV irradiation increases the synthesis and expression of MMP-1 in dermal fibroblasts, a process driven by the excessive generation of ROS, which plays a critical role in photoaging [30]. The levels of MMP-1 in UVB-irradiated human skin fibroblast cells were determined (Figure 6) to confirm the skin anti-wrinkling effects of the PCB extracts from _A. maxima_. The MMP-1 levels were significantly decreased upon treatment with the extracts (PCB, 99.70 \(\pm\) 6.85; SP, 92.60% \(\pm\) 0.95; WB, 109.35 \(\pm\) 0.66) compared with that in the UV(+) group (148.94 \(\pm\) 8.68, \(p\) < 0.001). Notably, SPWB suppressed the MMP-1 levels to a greater extent (77.36% \(\pm\) 0.68) than the other samples. The composition of collagen fibers differs across organs based on their functions. In the skin, which endures mechanical stress, fibrillar collagens predominate, with higher amounts of type I collagen and smaller amounts of types III and V. Type I collagen is found in various tissues, including the skin, bone, cornea, sclera, and blood vessel walls.