pigmented

Pentoxifylline (PTX) modulates immunologic activity by stimulating cytokine production. Pentoxifylline is a methylxanthine derivative that inhibits phosphodiesterase and affects blood rheology. It also inhibits platelet aggregation and improves blood flow by increasing erythrocyte and leukocyte flexibility.

2-Fluorodeoxyarbutin is a derivative of Deoxyarbutin and acts as an inhibitor of tyrosine hydroxylase and dopa oxidase. It suppresses melanin synthesis in intact melanocytes and can be utilized in the study of skin lightening or the treatment of pigmented lesions.

Hederacolchiside A1 (Raddeanoside R13) shows anti-leishmanial activity, it exhibits a strong antiproliferative activity on all stages of development of the parasite by altering membrane integrity and potential. Hederacolchiside A1 shows antiproliferation activities in three cancer cell lines with the IC50 value of 2.4 uM, it exhibits a preferential cytotoxicity on a pigmented melanoma cell line. It suppresses proliferation of tumor cells by inducing apoptosis through modulating PI3K/Akt/mTOR signaling pathway.

Globotetraosylceramides are bioactive neutral glycosphingolipids. They are the major glycolipids in human erythrocytes. They act as receptors for the Shiga toxins Stx1, Stx2, and Stx2e, the cytotoxic protein pierisin-1, and parvovirus B19. Globotetraosylceramides increase the expression of proteins responsible for enamel deposition, including ameloblastin, amelogenin, and enamelin, in dental epithelial cells and activate the ERK and p38 MAPK signaling pathways. Levels of globotetraosylceramides are elevated in fibroblasts from patients with salt and pepper syndrome, a neurocutaneous condition characterized by intellectual disability and hyper- and hypo-pigmented skin. Globotetraosylceramides (porcine RBC) contains a mixture of globotetraosylceramides with variable fatty acyl chain lengths isolated from porcine red blood cells.

TDRL-X80 is a potent inhibitor of the pigmented dry skin protein (XPA), inhibiting the DNA binding activity of XPA. It acts on single, double, and cisplatin-damaged DNA with IC50 values of 18, 20, and 29 μM in fluorescence polarization (FP) assays and 21, 39, and 28 μM in ELISA assays.

Protorubradirin is an antibiotic that can be isolated from the non-pigmented Streptomyces achromogenes var. rubradiris alongside Rubradirin. It exhibits inhibitory activity against HIV reverse transcriptase. In vitro studies show that Protorubradirin also inhibits strains of Staphylococcus aureus and Streptococcus. In infected mice, subcutaneous administration of Protorubradirin demonstrates in vivo efficacy against antibiotic-resistant Staphylococcus aureus strains. However, oral administration may significantly reduce its activity compared to Rubradirin, possibly due to its C-nitroso sugar decomposing more rapidly in acidic gastric conditions.

Haginin A is an effective inhibitor of hyperpigmentation caused by UV irradiation or by pigmented skin disorders through downregulation via ERK and Akt/PKB activation, MITF, and also by the subsequent downregulation of tyrosinase and TRP-1 production. Hag