BioMed Research International / 2010 / Article / Tab 3

Research Article

Genotoxic and Cytotoxic Safety Evaluation of Papain (Carica papaya L.) Using In Vitro Assays

Table 3

Mutoxitest—Number of Trp+ revertants/plate (mean ± SD). Aliquots (100  𝜇 L) of exponentially growing cultures were mixed with 100  𝜇 L of different concentrations of the papain or 0.9% NaCl, as negative control, and mixed with 2.5 mL molten top agar at 45 C and plated on minimal glucose agar plates supplemented with 0.5 mg tryptophan/litre. The mutagenic responses were expressed as the absolute number of Trp+ revertants/plate, after incubation at 37 C, for 48 hours. Values are the mean of 3 independent experiments with standard deviations not exceeding 15%.

Number of Trp+ revertants/plate (mean ± SD)
Agent ( 𝜇 g/plate)E. coli IC203 uvrA oxyRE. coli IC204 uvrA umuDC

Papain 5158 ± 26.015 ± 3.0
Papain 25162 ± 16.017 ± 3.0
Papain 50154 ± 26.012 ± 3.0
Papain 100129 ± 24.014 ± 3.0
Papain 125178 ± 10.016 ± 3.0
Papain 250162 ± 25.017 ± 3.0
Papain 500149 ± 24.018 ± 3.0
Positive control H2O2 (300)853* ± 70.215a ± 1.9

Negative control 0.9% NaCl (50  𝜇 L/plate)141 ± 28.016 ± 4.0

a Number of H2O2-induced revertants equivalent to that found with other genotoxic agents used by Blanco et al. in 1998.
𝑝 < 0 . 0 0 1 when compared to negative control (0.9% NaCl).