Guanine

Guanine is one of the fundamental components of nucleic acids (DNA and RNA). Guanine is a purine derivative, consisting of a fused pyrimidine-imidazole ring system with conjugated double bonds. Guanine has the potential to serve as a large-capacity N pool. Guanine has cytotoxic, antinociceptive and neuroprotective effects^[1][2][3][4]. In Vitro:Guanine (1 h) inhibits Shigella dysenteriae type 1 Shiga toxin A subunit in African green monkey Vero cells, with IC₅₀ of 11.5 μM^[2].
Guanine (24 h) shows cytotoxicity against African green monkey Vero cells, with CC₅₀ of 136.5 μM^[2].
Guanine (10 μM, 16-40 h) partially antagonizes the cytostatic effect of Mycophenolic acid (HY-B0421) on LAN5 cells^[3].
In Vivo:Guanine (600 nmol; i.t.) inhibits spinal glutamate- and AMPA-induced biting behaviour in mice^[4].
Guanine (200-600 nmol; i.t.) produces A1 adenosine receptor-mediated antinociception against intraplantar glutamate-, Capsaicin (HY-10448)-, and Acetic acid (HY-Y0319)-induced pain in mice, with ID50 values of 107, 84, and 48 nmol and maximal inhibitions of 48%, 58%, and 56%, respectively^[4].
Guanine (200-600 nmol; i.t.) produces dose-dependent antinociception against tail-flick test thermal nociception in mice, with peak efficacy at 400 nmol yielding ~78% MPE^[4].
Guanine (200-600 nmol; i.t.) dose-dependently increases CSF levels of inosine, xanthine, and uric acid, with a significant increase in AMP at the highest dose^[4].