Table 2

%Human tumor cell lines: carbidopa sensitivity and maximal AAAD activitya

Human tumor cell lineCell survival on carbidopa exposureMaximal AAAD activity (nmol/min/mg protein)
NCI-H146SCLC0% (IC50 = 12± 1 μm)b2.329 ± 0.086c
NCI-H209SCLC0% (IC50 = 22± 5 μm)b0.83 ± 0.048c
NCI-H727Carcinoid0% (IC50 = 29± 2 μm)b0.342 ± 0.085c
SK-N-SHNeuroblastoma 27%d0.658 ± 0.083c
A204Rhabdomyosarcoma 42%dNone detectedc
MCF7Breast carcinoma100%dNone detectedc
NCI-H460Large cell lung carcinoma100%dNone detectede
Du 145Prostate carcinoma100%dNone detectede
  • a Carbidopa (≤100μ m; 72 h exposure) cytotoxicity was determined by trypan blue exclusion and AAAD activity levels by the AAAD assay of cellular homogenates.

  • b Average ± SE; n = 3.

  • c Average ± SE; n ≥ 3.

  • d Carbidopa concentration, 100μ m; n = 2; percentage survival = no. of viable treated cells/no. of viable control cells.

  • e n ≥ 2.