## 3 Results and Discussion
### TPC, TFC, Antiaging Activity, and Antimicrobial Activity of Fermented CF Leaf Methanolic Extract  
Although some studies have evaluated the antioxidative activity of CF seeds, few have focused on the TPC, TFC, and antiaging activity (especially its IC\({}_{50}\) value) of CF leaves. Collagen and elastin constitute the major components of the extracellular matrix (ECM) of the dermis, which are broken down by collagenase and elastase activities, which are the characteristic biomarkers of skin aging [36]. MMPs can cleave the dermal ECM, thereby damaging skin integrity [3]. Therefore, inhibiting the activities of these degradation enzymes can prevent or retard skin aging. Table 1 presents the TPC, TFC, and antiaging activities of the methanolic extract of CF leaves fermented by _A. oryzae_. The results indicated that the TPC and TFC of the fermented leaf extract were 162.5 \(\pm\) 6.7 mg-GAE/g-DW and 87.1 \(\pm\) 2.8 mg-QE/g-DW, respectively. The TPC of the fermented leaf extract was higher than that in previous reports: 97.19 mg-GAE/g-DW (leaf extract), 26.11 mg-GAE/g-DW (seed extract), 3.24 mg-GAE/g-DW (seed extract), 11.861 mg-GAE/g-DW (seed extract), and 28.97 mg-GAE/g-DW (product of seed fermented by _L. plantarum_) [5; 8; 9; 15; 37]. The TPC of the fermented leaf extract was less than that of the 75% ethanolic leaf extract (156.15 mg-QE/g-DW) but higher than that of the seed extracts (2.55 and 3.52 mg-QE/g-DW) [5; 15; 37]. Moreover, collagenase, elastase, hyaluronidase, and MMP-1 activities (IC\({}_{50}\)) of the fermented leaf  
Figure 2: Physiological activities of unfermented and fermented methanolic extracts of _C. formosanum_ leaves and unhulled seeds. (**A**) ABTS scavenging activity and (**B**) antityrosinase activity. Data are expressed as the means and standard deviations of three independent experiments. extract were 113.5 \(\pm\) 9.2, 137.4 \(\pm\) 16.2, 106 \(\pm\) 7.6, and 176.4 \(\pm\) 13.8 mg/L, respectively. As a result of the high correlation between aging and oxidative stress, antioxidants may help retard aging [38]. [PERSON] et al. (2016) indicated that CF can inhibit MMP-1 expression in cellular/animal models [3]. [PERSON] et al. (2021) reported that CF water extracts (0.5%) exhibited high antiaging activity by regulating the expression of skin-related and collagen-related genes [12]. Our study is the first to report the antiaging activity (i.e., anti-collagenase, anti-elastase, anti-hyaluronidase, and anti-MMP-1) of the fermented CF leaf extract, and even a low concentration (100-200 mg/L) was highly effective (Table 1), which may be because of its high TPC, as supported by previous reports [39]. Excessive antibiotic use has markedly increased antibiotic resistance and adverse effects, compelling researchers to explore safe and effective remedies [40]. Plant-derived products have unmatched chemical diversity and provide abundant opportunities for new antimicrobial drug development [41]. Table 2 lists the antimicrobial activity of the _A. oryzae_-fermented methanolic extract of CF leaves. To apply the fermented CF leaf extract in the cosmetic industry, its antimicrobial activity against five strains (_S. aureus, E. coli, P. aeruginosa, C. albicans_, and _A. brasiliensis_) mandatorily used for a USP 51 antimicrobial effectiveness test as well as _C. acnes_ was evaluated. The results indicated that the MIC values of _E. coli, S. aureus, P. aeruginosa, C. acnes_ were 150 \(\pm\) 12, 180 \(\pm\) 14, 140 \(\pm\) 9, and 120 \(\pm\) 5 mg/L, respectively. The MFC values of _C. albicans_ and _A. brasiliensis_ were 230 \(\pm\) 26 and 280 \(\pm\) 21 mg/L, respectively. The fermented CF leaf extract was active against these tested strains. _A. brasiliensis_ was a less sensitive strain, possibly due to the use of the same fungal genus (_A. oryzae_) as the fermenting strain. _C. acnes_ was the most sensitive strain among tested bacterial strains, indicating that the fermented leaf extract was a potential ingredient for skin treatment.