Peeling Away Problems

The Antioxidating, Antimicrobial, and Antimutagenic Effects of Tree Bark

Results for the Folin-Ciocalteau Assay.

Results for the FRAP Assay.

Results for the Bacterial Susceptibility Tests.

Results

     In the Ames Test, sodium azide (NaN₃) was used as a positive control (mutagen) for bacteria strain Salmonella typhimurium TA 1535. At 0.5 µg/plate, NaN₃ was quite mutagenic for TA1535 (600 colonies compared to 40 colonies background control). While at a 1:60 dilution (1.6% extract), all four extract showed nonmutagenic for TA1535 (similar colony numbers as background control) and were not toxic to the bacteria cells. However, when mixed together (0.5 µg NaN₃ + 1:60 diluted extract), the sodium azide-induced bacterial mutation was reduced by approximately 30% (Fig. 4).

Figure 4: The antimutagenic effects of the tree bark extracts on Sodium Azide (NaN₃). The number of bacterial colonies was recorded after NaN₃ or NaN₃ plus extracts was added into the bacteria culture. All four of the extracts, at a 1:60 dilution, showed antimutagenic effects by decreasing revertant colony numbers by ~30%.

    The white spruce bark extract was also selected to do a dose dependent test (Fig.5). The White Spruce extracts were at 1%, 3%, 10%, 33%, and 100% extract. The bacteria with only NaN₃ had an average of ~425 colonies, however when NaN₃ mixed with  the extract (at different dilutions), the colony numbers decreased. The 1%, 3%, 10%, 33% extracts decreased colony numbers by ~25% and the 100% extract decreased colony numbers by ~40%.

Figure 5: The dose dependant antimutagenic effects of the white spruce tree bark extract on Sodium Azide (SA) The number of bacterial colonies was recorded after SA or SA plus different percentages of the white spruce extract were added to the bacterial culture (    ). The extract itself had a similar effect on bacteria as the background (    ). All of the white spruce extracts showed antimutagenic effects.

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