# Antimicrobial Efficacy of Edible Mushroom Extracts: Assessment of Fungal Resistance
## 3 Results and Discussion
### Antifungal Activity of T. camphoratus Methanol Extract (TcM)
#### 3.2.2 Antifungal Activity Test of TcM on Apple or Grape JA (Complex Medium)
Antioxidant MAPK pathway mutants have also demonstrated tolerance under treatment of cell wall-disrupting agents. Efficacy of cell wall disrupting drugs required both the \"cell wall integrity\" and \"antioxidant\" MAPK systems to be intact, while mutations in the MAPK system resulted in drug resistance [61; 62; 63]. For instance, antioxidant MAPK system mutants of the baker's yeast _Saccharomyces cerevisiae, hog1_ (MAPK) or _pbs2_ (MAPK kinase; MAPK) exhibited tolerance to drugs targeting the cell wall [61; 62; 63]. Of note, mutants of the upstream sensors including transmembrane (_sho1_) or histidine kinase (_sln1_)  
Figure 2: Resistance of antioxidant signaling mutants of fungi to FLU and SA. (**a**) Response of _A. fumigatus_ wild type (AF293) and MAPK mutants (_sakA_, _mpkC\(\Delta\)_). (**b**) Response of _P. expansum_ wild type (W1) and antioxidant mutant (FR2). (**c**) Diagram describing the tolerance of fungal signaling mutants to FLU or the mushroom extract T\(\mathrm{c}\)M. The round circle at the lower half of each plate indicates a membrane filter where SA or DMSO (no treatment control) was applied. Fungal radial growth is shown at the upper half of each plate; note that _A. fumigatus_ fully covered the control (no treatment) plates, reflecting rapid growth. osmo-sensors in the antioxidant MAPK signaling system were also partially tolerant to the cell wall-inhibitory agent, calcofluor white [61; 62; 63]. It is also worth noting that, among the benzo analogs examined thus far, the development of fungal tolerance seemed specific to SA. In our previous study, application of other benzo derivatives such as cinnamaldehyde, 2-hydroxy-5-methoxybenzaldehyde, 2,3- or 2,5-dihydroxybenzoic acid, 2-acetoxybenzoic acid, etc., did not result in tolerance by fungal MAPK mutants to the treatments [41; 64]. In fact, MAPK mutants, rather, exhibited increased susceptibility to other benzo derivatives when compared to the wild type. We initially speculated that the sensitivity was due to the high redox-activity of benzo derivatives that make the antioxidant MAPK mutants more susceptible to the treatments [57; 58; 59]. However, the mechanism of differential antifungal activity (\"tolerant\" versus \"sensitive\" response) between SA and other benzo derivatives during the targeting of fungal MAPK mutants remains to be elucidated. A previous study with methanol and water extracts from Shitiake mushroom (_Lentituna edodes_ ([PERSON] [PERSON]) revealed that the water extract from _L. edodes_ possessed the most potent radical scavenging activity [43]. Hence, it is thought that TcW mostly possesses radical scavenging activity and low antifungal activity, while TcM possesses molecules exerting potent antifungal activity. Types of bioactive components of _T. camploratus_ and their bioactivities have recently been reviewed [20] (see also Table 4). The chemical components of _T. camploratus_ mainly include: (a) Polysaccharides such as sulfated polysaccharides (SPS) exhibiting anticancer activity via the downregulation of epidermal growth factor receptor (EGFR) signaling, galactomannan (ACP) possessing immunostimulatory effect, which degrades transforming growth factor \(\beta\) (TGF\(\beta\)) and TGF\(\beta\) receptors (TGFR), etc. ; (b) terpenoids such as triterpenes inhibiting diabetes or increasing wound healing, antcin-H exhibiting anticancer activity via the inhibition of ERK1/2-AP-1/c-Fos and C/EBP-\(\beta\) signaling system, antcin-K inducing apoptosis through the increased generation of reactive oxygen species (ROS) and reduction in ATP levels (thus, suited for liver cancer therapy); (c) maleic and succinic acid derivatives such as antrodin C lowering high glucose-triggered cellular toxicity/senescence while it upregulates antioxidant genes; and (d) other compounds such as antrodan, antrolone, or 2,3,5-trimethoxy-4-cresol exhibiting anti-prostate hyperplasia, anti-inflammatory, or anticancer activity, respectively [20].