BioMed Research International / 2010 / Article / Tab 1

Research Article

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

Table 1

(a) Effect of different papain concentrations on the survival of E. coli strains. Exponentially growing cultures were centrifuged, washed with 0.9% NaCl sterile solution, and suspended in the same solution. Aliquots (1 mL) of these suspensions were incubated with different papain concentrations or 0.9% NaCl for 60 minutes, at 37 C, with shaking. Afterwards, aliquots (100  𝜇 L) were taken, diluted and plated onto LB medium for determining surviving fractions ( S F = 𝑁 6 0 / 𝑁 0 ) for each strain at different papain concentrations. Values are the mean of 3 independent experiments (6 determinations) with standard deviations not exceeding 15% (mean ± SD). 5% Significance level was adopted to compare data.

E. coli strains ( S F = 𝑁 6 0 / 𝑁 0 )

Papain concentrations ( 𝜇 g/mL)AB1157 (WT)BW9091 (xthA)BH20 (fpg)PQ65 (rfa)

500.81 ± 0.041.00 ± 0.061.10 ± 0.050.98 ± 0.04
2501.24 ± 0.081.40 ± 0.040.80 ± 0.021.04 ± 0.01
5000.80 ± 0.061.10 ± 0.030.90 ± 0.040.93 ± 0.02

Negative control 0.9% NaCl (50  𝜇 L)1.00 ± 0.021.00 ± 0.050.90 ± 0.031.10 ± 0.04

Positive control H2O2 (10 mM)0.20* ± 0.010.003* ± 0.000040.17* ± 0.0070.19* ± 0.01

The results are not significantly different ( 𝑝 > 0 . 0 5 ) when compared to negative control.
* The results are significantly different ( 𝑝 < 0 . 0 5 ) when compared to negative control.
(b) Effect of papain associated with talc on the survival of E. coli strains. Exponentially growing cultures were centrifuged, washed with 0.9% NaCl, and suspended in the same solution. Aliquots (1 mL) of these suspensions were incubated with different papain concentrations (associated or not with talc) or 0.9% NaCl for 60 minutes, at 37 C, with shaking. Afterwards, aliquots (100  𝜇 L) were taken, diluted and plated onto LB medium for determining surviving fractions ( S F = 𝑁 6 0 / 𝑁 0 ) for each strain. Values are the mean of 3 independent experiments (6 determinations) with standard deviations not exceeding 15% (mean ± SD). 5% significance level was adopted to compare data.

E. coli strains ( S F = 𝑁 6 0 / 𝑁 0 )
AgentsAB1157 (WT)BW9091 (xthA)

0.9% NaCl (negative control)1.00 ± 0.021.00 ± 0.04
Papain (500  𝜇 g/mL)1.00 ± 0.030.93 ± 0.03
Papain associated with talc (500  𝜇 g/mL)0.80 ± 0.010.96 ± 0.03
Talc (500  𝜇 g/mL)0.90 ± 0.010.87 ± 0.02
H2O2 (10 Mm) (positive control)0.20* ± 0.0040.003* ± 0.00004

The results are not significantly different ( 𝑝 > 0 . 0 5 ) when compared to negative control.
* The results are significantly different ( 𝑝 < 0 . 0 5 ) when compared to negative control.