title: Fulvic acid promotes extracellular anti-cancer mediators from RAW 264.7 cells, causing to cancer cell death in vitro.
abstract: Fulvic acid (FA) is known to promote electrochemical balance as a donor or a receptor possessing many biomedical functions. Nevertheless, the effect of FA on the anti-cancer activity has not been elucidated. In the current study, we first isolated FA from humus and investigated whether FA regulates immune-stimulating functions, such as production of nitric oxide (NO), in RAW 264.7 cells. Our data showed that FA slightly enhances cell viability in a dose-dependent manner and secretion of NO from RAW 264.7 cells. It upregulated the protein and mRNA expression of inducible NO synthesis (iNOS). In addition, FA enhanced the DNA-binding activity of nuclear factor-κB (NF-κB) in RAW 264.7 cells; the NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC) effectively attenuated the expression of FA-stimulated iNOS, suggesting that FA stimulates NF-κB to promote iNOS and NO production. Finally, FA-stimulated culture media (FA-CM) from RAW 264.7 cells were collected and MCA-102 fibrosarcoma cells were cultured in this media. The FA-CM augmented MCA-102 fibrosarcoma cell apoptosis; however, an NO inhibitor N(G)-monomethyl-l-arginine (NMMA) slightly inhibited the FA-CM-mediated MCA-102 fibrosarcoma cell apoptosis, which was accompanied by low levels of NO. In the present study, we found that FA induces the generation of NO and iNOS in RAW 264.7 cells by inducing NF-κB activation; however, NO did not significantly stimulate MCA-102 fibrosarcoma cell apoptosis in the current study. In addition, FA-CM enhanced cell death in various human cancer cells such as Hep3B, LNCaP, and HL60. Taken together, FA most likely stimulates immune-modulating molecules such as NO and induces cancer cell apoptosis.
authors.affiliation: Department of Marine Life Sciences, Jeju National University, Jeju-si 63243, Republic of Korea.
authors.forename: Rajapaksha Gedara Prasad Tharanga
authors.initials: RGPT
authors.lastname: Jayasooriya
authors.affiliation: Department of Marine Life Sciences, Jeju National University, Jeju-si 63243, Republic of Korea.
authors.forename: Matharage Gayani
authors.initials: MG
authors.lastname: Dilshara
authors.affiliation: Department of Marine Life Sciences, Jeju National University, Jeju-si 63243, Republic of Korea; Nakdonggang National Institute of Biological Resource, Sangju-si, Gyeongsangbuk-do 37242, Republic of Korea.
authors.forename: Chang-Hee
authors.initials: CH
authors.lastname: Kang
authors.affiliation: Department of Marine Life Sciences, Jeju National University, Jeju-si 63243, Republic of Korea.
authors.forename: Seungheon
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Biochemistry, College of Oriental Medicine, Dong-Eui University, Busan 47340, Republic of Korea.
authors.forename: Yung Hyun
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Department of Biotechnology, Dong-A University, Busan 49315, Republic of Korea.
authors.forename: Yong Kee
authors.initials: YK
authors.lastname: Jeong
authors.affiliation: Department of Marine Life Sciences, Jeju National University, Jeju-si 63243, Republic of Korea. Electronic address: immunkim@jejunu.ac.kr.
authors.forename: Gi-Young
authors.initials: GY
authors.lastname: Kim
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis; D001578:Benzopyrans / Q000737:chemistry / Q000494:pharmacology*; D005354:Fibrosarcoma / Q000188:drug therapy* / Q000473:pathology; D018922:HL-60 Cells; D006801:Humans; D008264:Macrophages / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D011392:Proline / Q000031:analogs & derivatives / Q000494:pharmacology; D000067996:RAW 264.7 Cells; D012987:Soil / Q000737:chemistry; D013859:Thiocarbamates / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D001578:Benzopyrans; D016328:NF-kappa B; D012987:Soil; D013859:Thiocarbamates; C066229:prolinedithiocarbamate; D009569:Nitric Oxide; D011392:Proline; D052247:Nitric Oxide Synthase Type II; C005023:fulvic acid
keywords: Apoptosis; Fulvic acid; Nitric oxide; Nuclear factor-κB