Inhibitory Effects of Dutasteride on TLR4: An In vitro Pain Study

Dutasteride was potentially proposed to control chronic pain by Toll-Like Receptor 4 (TLR4) inhibition through its effect on TLR4 expression, Myeloid differentiation primary response 88 (MyD88), Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), secretory Interleukin-1β (IL-1β), and nitric oxide (NO) in the Lipopolysaccharides (LPS)-stimulated U-87 MG cell line. Human astrocytoma U-87 MG cell line was cultured and incubated with 10 μg/mL of LPS for 24 hours to create a neuro-inflammation model, using two different treatment approaches. The first approach included LPS treatment for 24 hours, followed by dutasteride (20 μg/mL) incubation for the next 72 hours. In the second treatment approach, the cells were co-incubated with LPS and dutasteride for 72 hours. Expression of TLR4, MyD88, NF-κBp65, and secretory IL-1 was evaluated by Western blotting while expression of NO was assessed by NO assay. TLR4, MyD88, NF-κBp65, and secretory IL-1β levels increased in LPS-treated cells after 24 hours. Dutasteride significantly decreased the secretion of NO and also, the levels of TLR4, MyD88, and NF-κBp65 in both treatment approaches. No difference in IL-1β level was seen with the second treatment approach. Dutasteride has anti-inflammatory properties and probably analgesic effects, by mechanisms different from conventional analgesics.