# Potential Possibilities of Using Peat, Humic Substances, and Sulfurous Waters in Cosmetology
## 3 Peat
### Pharmacological and Biological Activity of Peat and Humic Substances  
Medical and hygienic uses of peat date back to the 18 th century. Peat has long been used in many fields of medicine, such as rheumatology, physiotherapy, and sports medicine, and increasingly in dermatology and cosmetology [24]. In traditional folk medicine, peat was used to treat skin diseases, cold stress, rheumatic pain, diabetes, kidney stones, heart ailments, leprosy, and immune system diseases [22; 39]. Examples of historical and contemporary uses of peat for internal use in the treatment of various ailments include radioprotective [40], hepatoprotective [41], neuroprotective [42], and antihypoxic [43; 44] uses as well as renal ischemia [45] and cardiovascular diseases [46]. In Poland, peloids are the second most frequently used natural resource after medicinal waters [47]. The peat preparation patented in 1991 by Professor [PERSON] enjoyed great fame [48]. It has been attributed to many medical uses, including anti-cancer properties, but no medical (internal) benefits have ever been confirmed by reliable scientific research. In the 1900s, Polish scientists conducted intensive research on the Tolpa peat preparation, aimed at confirming its effectiveness, including antioxidant, anti-cancer, and hepatotoxicity properties; uses against gastric and duodenal ulcers, against respiratory tract infections, and on sinusitis and cervicitis; as well as in immunology, allergy, hematology, and angiology [49; 50; 51]. The immunomodulatory effect of peat has been demonstrated by influencing the activation of neutrophils and macrophages, inducing the production of interferon and tumor necrosis factor in human peripheral blood leukocytes, as well as NK cells [52; 53]. In the study by [PERSON] et al. [54], they demonstrated a beneficial effect of humic acids administered systemically on the condition of periodontal tissues in rats with induced periodontitis. The influence of these compounds on the level of interleukin (IL)-1\(\beta\) and IL-10 in serum and gingival homogenates, the number of osteoclasts, and osteoblastic activity were observed. Additionally, the influence of humic acids on the healing of aphthous ulcers in the oral cavity has also been demonstrated. The influence of fulvic acids on the pathogenesis of atopic dermatitis has also been demonstrated. The local action of these compounds involves the downregulation of CCL17 and CCL22, inhibition of P38 MAPK, and JNK phosphorylation [55]. In the study by [PERSON] et al. [56], the anti-inflammatoryactivity of humic acids was evaluated on HaCaT cells. A decrease in the gene expression of the cytokines IL-6 and IL-1\(\beta\) was observed. The anti-inflammatory and immunomodulatory effects of peat are primarily related to its antioxidant and anti-free radical properties [24; 25; 26; 27; 57]. The anti-free radical effect of humic substances results from the presence of phenolic groups and non-phenolic groups in their structure, including carbohydrate fragments [58]. [PERSON] et al. [59] demonstrated also the presence of phenolic acids in peat extracts and confirmed their antioxidant effect. Phenolic acids may originate directly from biomass or from the breakdown of humic substances or are a product of the Maillard reaction. Humic acids also have the ability to chelate heavy metals, e.g., cadmium, from the body. The potential impact of radioisotopes as active substances responsible for the effects of peat was also examined [60]. Both peat extracts and humic and fulvic acids isolated from them exert antimicrobial activity in vitro. Antibacterial activities have been shown against many bacteria including _Staphylococcus aureus_, _Pseudomonas aeruginosa_, _Escherichia coli_, _Klebsiella pneumoniae_ as well as against _Candida albicans_[13; 16]. Humic acids and poly(OH)carboxylates isolated from peat are also selective inhibitors of the replication of the _Herpes simplex_ virus and _Cytomegalovirusovirus_[17; 61]. [PERSON] et al.