Dr Sohère Roked is a GP in the UK with a specialist interest in integrative medicine. She prescribes 5-HTP to patients with anxiety and depression, alongside vitamins and other natural supplements, and sees no problem with it being used for mild conditions. "With the patients I see, generally I've seen good results with it. Antidepressants do work for some people, so I'm not against them completely, but others don't want to go down that path straight away. This gives them another option."
Mouse bone marrow macrophage (BMMs) of 5-week-old female ICR mice (Charles River Laboratories, Seoul, South Korea) were used as previously described . Animals were maintained in accordance with the National Institute of Toxicological Research of the Korea Food and Drug Administration guideline for the humane care and use of laboratory animals Institutional Animal Care and Use Committee (IACUC) approval was obtained from Kyung Hee University (Seoul, Korea). Briefly, bone marrow of tibiae and femurs of mice were flushed with α-MEM. After removing erythrocytes with hypotonic buffer, cells were cultured in α-MEM containing 10% FBS for 24 h and adherent cells were discarded. Non-adherent bone marrow cells were transferred onto 100-mm non-coated petri dishes at 5×106 cells per dish and cultured in the presence of M-CSF (30 ng/ml) for 3 days. Condition medium (CM) was obtained from HPDLCs treated with 200 μM H2O2 or Tβ4 (0.5, 1 and 5 μg/mL) for 2 days. To evaluate the osteoclastogenic activity of CM from HPDLCs, we added the CM mixture (60% CM plus 40% fresh α-MEM without M-CSF or RANKL) or rh-Tβ4 to pre-osteoclast-stage cells and further cultured the cells for up to 5 days to achieve mature osteoclast differentiation BMMs (1.5 × 105 cells/well) and PDLCs (1.5 × 104 cells/well) were co-cultured for 7 days in the presence of M-CSF (30 ng/ml), RANKL (100 ng/mL), H2O2 (200 μM) or Tβ4 (0.5, 1 and 5 μg/mL) in α-MEM, supplemented with10% in 48-well plates under 5% CO2 atmosphere.
The short half-life (<2h) of 5-HTP may inherently limit the therapeutic potential of 5-HTP, as the systemic 5-HTP exposure levels will fluctuate substantially, even with relatively frequent dosing. Such exposure fluctuations are usually associated with increased adverse event burden, resulting from Cmax drug spikes, and decreased clinical efficacy resulting from sub-therapeutic exposure for large parts of the day. It has been proposed that 5-HTP dosage forms achieving prolonged delivery would be more effective, as is generally the situation with short-acting active pharmaceutical ingredients.