## 4 Discussion
### Investigation of Interaction of LIN with Selected Antifungal Agents
In the case of the combination of LIN with FLC, two types of interactions were demonstrated: synergism (FICI = 0.134) and addition (FICI = 0.57) towards these strains. Their MIC values were reduced from 500 \(\mu\)g/mL and 0.975 \(\mu\)g/mL to 2.02 \(\mu\)g/mL and 0.065 \(\mu\)g/mL, respectively. The synergistic effect of LIN with geraniol (FICI = 0.3905) against _C. neoformans_ was also observed. In the case of LIN in combination with FLC, their MIC values were also 4-fold reduced and addition was shown (FICI = 0.5077). It is worth noting that the concentrations of the two components necessary to eliminate these fungi together were very low [16]. Studies involving the assessment of the interaction of LIN with FLC were also conducted by other authors. In accordance with the results of [PERSON] et. al. [50], the combination of LIN with this azole showed that terpenes exhibit excellent synergistic activity against _C. albicans_ with FICI = 0.140. The authors suggested that LIN (at 0.008% (\(v/v\)) concentration) could reduce the MIC of FLZ by 64-folds (from 64 \(\mu\)g/mL to 1 \(\mu\)g/mL). Moreover, similar studies were conducted by [PERSON] et al. [9]. These research works also showed a synergistic effect for the combination of LIN with FLZ. LIN acted with this azole against planktonic as well as developing biofilm forms of reference _C. albicans_ ATCC 90028 strain with FICI = 0.156 and FICI = 0.3, respectively. The MIC values of both components decreased significantly. In turn, in relation to the clinical isolate of _C. albicans_, addition (FICI = 0.6) or synergism (FICI = 0.312) was indicated for these forms, respectively. The next data [28] presented the effect of a combination of LIN with FLC against isolates of _C. Krusei_. FICI values of terpene with azole were in the range 0.19-0.63. The addition and synergy were exhibited in twelve (57.1%) and nine (42.9%) isolates. LIN decreased MIC values of FLZ from 74.66 \(\mu\)g/mL even to 9.81 \(\mu\)g/mL in the case of these strains. In turn, other studies [70] showed that LIN and \(\alpha\)-longipinene synergistically reduce the biofilm formation. To sum up the results of our own research and that of other authors, the combination of LIN with selected compounds can significantly increase their antifungal effectiveness using their synergistic and additive effects. LIN in the right concentration and combinations may be useful to control fungal infections and can provide an alternative or complementary therapy in the treatment of candidiasis [71]. These results may suggest the possibility of including LIN as an ingredient in several mouthwash and gargle products used to relieve the symptoms of sore throats, sensitive gums, and mouth ulcers, as well as to eliminate fungal infections [18]. Moreover, due to its protective effects and low toxicity, LIN can be used as an adjuvant of antifungals or antiseptics. Therefore, it has a great potential to be applied as a natural and safe alternative form of therapy [71]. The antifungal properties of the mixture of LIN with selected antifungals may be used for creating new products. These findings are very promising for the development of new therapeutic options for candidial infections.