Cell lines

HBL-38 and HPB-ALL cells

Preparation method

The solubility of this compound in DMSO is >10 mM. General tips for obtaining a higher concentration: Please warm the tube at 37 ℃ for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below - 20 ℃ for several months.

Reacting condition

0 ~ 1000 ng/mL; for 24 hrs

Applications

In HBL-38 cells, Indirubin (10 ng/mL) strongly inhibited interferon-γ production without any influence on cell proliferation. The IC50 value of Indirubin was 0.15 ng/mL. However, in HPB-ALL cells, Indirubin did not affect interleukin-4 production stimulated by phytohemaggulutinin, as well as cell proliferation.

Animal models

TNCB-induced delayed-type hypersensitivity mouse model

Dosage form

20 mg/day; i.p.; 4 days before sensitization to 4 days after sensitization

Applications

In the single elicitation experiment, Indirubin significantly inhibited ear swelling of the TNCB-induced delayed-type hypersensitivity mouse model at the 24th hr after treatment. In the experiment with repeated epicutaneous applications, Indirubin also inhibited ear swelling but these effects gradually reduced. Meanwhile, Indirubin did not cause any body weight loss.

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.

Interferon-γ is thought to be a member of the inflammatory cytokine family. Because of its augmentation of inflammatory reactions through biological activities. Indirubin, the active ingredient of Danggui Longhui Wan, has inhibitory effects on the production of interferon-γ.

In vitro: Indirubin exerted its inhibitory effects not only on interferon-γ production by human myelomonocytic HBL-38 cells but also on interferon-γ and interleukin-σ production by murine splenocytes with no influence on the proliferation of either cells [1].

In vivo: Because of Indirubin’s inhibitory activity on interferon-γ production, the authors further investigated the effects of indirubin on 2,4,6-trinitro-l-chlorobenzene-induced delayed-type hypersensitivity. When injected intraperitoneally, indirubin significantly inhibited the ear swelling of TNCB-elicited mice. Moreover,the amount of interferon-γ in the culture supernatants of elicited mouse lymphocytes was inhibited by indirubin treatment [1].

Clinical trials: Several clnical trials have been conducted to study the efficacy of indirubin for the treatments of psoriasis and Acute Promyeloid Leukemia .

Reference:
[1] Kunikata T, Tatefuji T, Aga H, Iwaki K, Ikeda M, Kurimoto M.   Indirubin inhibits inflammatory reactions in delayed-type hypersensitivity. Eur J Pharmacol. 2000 Dec 20;410(1):93-100.