Determination of the phenolic content of different extracts of myrtle (Myrtus Communis l.) and investigation of its antioxidants and anti-inflammatory effects in cell culture

Myrtus (Myrtus communis L.) is a red berry plant, having strong antioxidant and anti-inflammatory properties due to its phenolic compounds and anthocyanidin components. The aim of this study was to determine the antioxidant and anti-inflammatory effects of different extracts of myrtle and to investigate the invitro antiinflammatory effect of myrtle extract which has the highest ferulic acid content being a well known anti-inflammatory molecule. In this study, myrtle leaf, dried, dried shredded, raw myrtle fruit, myrtle seed and myrtle fruit were used. The extracts were obtained by brewing and boiling techniques at different time periods (1 min, 3 min, 5 min, 10 min). The amounts of phenolic compounds such as catechin, ethyl ferrulate, genticic acid, p-coumaric acid, syringic acid, kaempferol, epicatechin, routine, caffeic acid and ferulic acid were determined by LC-MS/MS. In-vitro antioxidant (FRAP, TEAC and DPPH) and anti-inflammatory activities (hyaluronidase inhibition assay and WST-1 test) were determined by spectrophotometric methods. The effects of myrtle plant extracts, which have the highest ferulic acid content and antioxidant and anti-inflammatory activities, on the cytokine levels (IL-1𝛼, IL-1𝛽, NF-κB, IL-6, IL-10, TNF-𝛼 ve IFN-𝛾) in macrophage cell culture (human monocytic cell line, THP-1) were investigated. This is the first study to evaluate the anti-inflammatory potential of brewing and boiling extracts of myrtle plant in the THP-1 cell line. In the first stage of the study, it was found that the highest concentrations at the 5th minute in LC-MS / MS analysis of the myrtle plant extracts which have been obtained in the brewing technique. After this minute the concentrations depleted. It was shown that the highest concentrations of ferulic acid and kaempferol reached at these time. For this reason, 5 minutes were chosen as suitable time for the study. It was found that the concentrations of phenolic compounds in the boiled dried shredded fruit were higher than other extracts. The TEAC, FRAP and DHPP activities of these extracts were observed to be varied in regard to brewing and boiling time. The antioxidant activities were in parallel with LC-MS / MS results, and it was determined that there was an increase in antioxidant activity with increasing brewing time. The highest antioxidant activity of myrtle fraction ( TEAC (10,90 ± 0,36 - 18,53 ± 2,78), FRAP (0,67 ±0,05 - 3,45 ± 0,41) ve DHPP (22,32 ± 1,21 - 109,86 ± 0,52 ) was reached in dried shredded fruit extract. It was demonstrated that the inhibition of hyaluronidase activity have positive correlation with results of LC-MS/MS analysis and antioxidant activities in samples prepared by brewing and boiling extracts. The maximum correlation was observed at the 5th minute extract of dried shredded fruit. Inhibition percentages of WST-8 of brewing and boiling extracts were found to be correlated with LC-MS/MS analysis, antioxidant activity results and the highest inhibitions were observed at 5th and 10th minute. In the third stage of the study, the effects of boiling and brewing extract, which have the highest in vitro antioxidant and anti-inflammatory effects, and the effect of ferulic acid on the inflammation in lymphocyte cell culture were determined. While IL-1𝛽, TNF-𝛼 and IFN-𝛾 levels showed a statistically significant decrease with myrtle and ferrulic acid, depletion in NF-κB, IL-6, and IL-1𝛼 levels and increase in IL-10 levels were not found statistically significant. The data obtained from this project indicate that myrtle plant extracts have antioxidant and antiinflammatory activity and may be used as protective agents against some cancer and autoimmune diseases.