## 4 Discussion
For more precise results, it would be necessary to repeat the measurements with techniques such as electronic paramagnetic resonance, which can almost eliminate the effect of plant pigments on the measurements [15,16]. The most significant interferences in the results of DPPH tests are caused by plant pigments and therefore the focus was on them. The results obtained with the Folin-Ciocalteu method were similar to those obtained using the DPPH method. Antioxidant activity was detected in the initial extracts and the values were higher in the lipophilic extracts. Folin-Ciocalteu reagent itself is sensitive not only to the presence of phenols, but also to the presence of other reducing substances (vitamin C and other antioxidants), so it is expected for the first extracts to have higher absorbance values [17]. The obtained absorbances for the first extracts are generally low and indicate low antioxidant activity. Absorbance, though low, was observed in both the second and third extracts and most likely caused by the presence of polyphenols from the plant extracts. Since the presence of antioxidants was only detected in the first extracts using these two methods, for practical reasons further measurements were carried out only in the first extracts. The FRAP method showed that the antioxidant capacity of the samples to reduce the ferro (III) ion to the ferro (II) ion was very low for both the hydrophilic and lipophilic extracts for approximately all the samples and both types of extracts. This is due to factors such as the reactivity of ferro ions, which is lower compared to more sensitive DPPH and ABTS radicals. Other reasons may be an acidic medium that reduces the reactivity of some compounds, particularly thiols, and a possible chelation of ferro ions produced in reaction with some antioxidants [18,19] and with other compounds found in creams. The influence of plant pigments on the results can be excluded because the measurement was carried out in the part of the spectrum in which the pigments do not absorb. Based on all this, more sensitive methods should be chosen to test the antioxidant capacity of these samples. The results for both types of extracts obtained using the ABTS method show that the lipophilic extracts had a higher antioxidant capacity. Therefore, it was necessary to modify the method as the discoloration of the samples occurred almost immediately and it was impossible to measure the absorbances after 10 min. ABTS is fast, simple, sensitive and suitable for the determination of the antioxidant activity in both lipophilic and hydrophilic extracts [20]. Therefore, measurements of this type of samples in both types of extracts could be performed quickly and with distinction between individual preparations. The chelation capacity for heavy metals is also one of the ways in which antioxidant activity can be expressed. Heavy metals such as iron and copper are known to stimulate oxidative processes and contribute to the formation of free radicals. Antioxidants prevent these processes and contribute to the protection of the organism by binding metals at physiologically acceptable levels. The chelatione capacity for metals is expressed as the chelatione capacity for ferro ions with ferrosine. Measurements could only be made for the hydrophilic extracts. The results were low with the exception of those for the cream sample 7. For the lipophilic extracts, the positive blank containing hexane alone had a much lower absorbance than the lipophilic samples, which is paradoxical considering that antioxidants present in the lipophilic phase should reduce the amount of iron available for complexation with ferrosine. A possible reason for this phenomenon in the samples may be the presence of plant pigments that absorb in the same region in which the measurement was carried out; these pigments are also present in the hydrophilic phase, so it can be said that they also had an effect on the absorbance values of the hydrophilic extracts.