# Fungal Pigments and Their Roles Associated with Human Health
## 7 Conclusions and Further Prospects  
Fungal pigments have primarily been known for their extensive application as colorants in the food, cosmetic and textiles industries for the past several decades. However, their applications other than as colorants are very broad, including as cholesterol-lowering drugs, exemplified by monacolin K, a clinically used drug also called lovastatin [217], and various anti-microbial and antitumor agents. Unexpected functions of new pigments as well as known ones are continuously being revealed. Fungal pigments have attracted significant interests from the pharmaceutical industry as sources of potential drugs to fight many life-threatening diseases such as cardiovascular disorders, Alzheimer's disease, human carcinomas (hepatoma, breast, lung, colorectal, gastric, pancreatic, leukemia, hematopoietic, renal cell, and other cancers), infectious diseases, and parasitic diseases such as malaria. Since many fungal pigments have shown potential relevance to human health, there is increasing interest in understanding their mechanisms of action to pave the way for the future development of therapeutics against both acute and chronic diseases. Among the fungal pigments, melanin stands out for two reasons: (i) melanin confers excellent protection from such stressors as radiation, thermal fluctuations and drought, thereby giving an insight into the development of radiation-protective agents and devices for the human exploration into the outer space; (ii) melanin is known to contribute to pathogenesis and drug resistance in pathogenic fungi, and consequently represents an important target for the treatment of recalcitrant fungal infection in humans.  
Thanks to advancements in microbiological, biochemical, genetic and genomics technologies and the development of high-throughput bioassay systems as well as the bioinformatics analyses, there are several potentially fruitful areas of research on fungal pigments. First, there is a diversity of fungal pigments produced by evolutionarily distant fungi. At present, the origins for the genes and the regulatory pathways governing their synthesis are largely unknown. Phylogenomic and transcriptomic studies should provide novel insights in this area. Second, a standardized test system and/or protocol should be established for screening the bioactivity of fungal pigments for both in vitro and in vivo assays, including appropriate positive and negative controls. Third, the structure-activity relationships are unknown for most fungal pigments. Finally, while the focus of our review is on colored fungal pigments, fungal metabolites that impact pigment productionunpub in both fungi and other organisms, including precursors and regulators for and metabolic products of pigments but they themselves are not colored, represent an additional source of fungal metabolites that have also been explored for human health benefits. One such metabolite in this category is kojic acid, a compound obtained from the filamentous fungus _Aspergillus oryzae_[218]. While colorless itself, kojic acid can inhibit tyrosinase which is essential for the synthesis of melanin in human skin and, consequently, it has been broadly used in dermatological applications [219]. With the increasing demand from the pharmaceutical industry, fungal pigments and their related products are expected to be an excellent resource for the design and development of novel therapeutic molecules in the future.  
[PERSON] and [PERSON] conceived and delineated manuscript organization; [PERSON] wrote the original draft; [PERSON] revised the manuscript. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the Natural Science and Engineering Research Council of Canada (2020-531998) and McMaster University (to [PERSON]), and by a China Scholarship Council fellowship (to [PERSON]).  
We thank [PERSON] for helpful suggestion and proofreading.  
The authors declare no conflict of interest.