TY - JOUR N2 - The free-living Acanthamoeba sp. causes various diseases. Treatment of them is very difficult and not always effective because of encystation, making it highly resistant to antiamoebic drugs. Gram-positive bacteria Staphylococcus aureus, Gram-negative bacteria Escherichia coli, and an yeast Candida albicans also exhibit outstanding resistance to antimicrobial substances. The search for new natural amoebicidal and antimicrobial agents of plant origin is still of current interest. The aim of the study was to investigate the amoebicidal activity of the extracts obtained from tissue culture and a field-grown plant of Chaenomeles japonica against pathogenic trophozoites of Acanthamoeba spp. and antimicrobial effect against S. aureus, E. coli, and C. albicans. The extracts of C. japonica had an inhibitory effect on the proliferation of Acanthamoeba trophozoites as compared to the non-treated control. Among the crude extracts tested, the extract of leaves, from both shoot culture and the field-grown plant had remarkable amoebicidal action against the trophozoites but also antibacterial activity against Gram-positive bacteria Staphylococcus aureus. The extract from leaves from shoot culture, already on the second and third days of treatment, showed an antiamoebicidal effect at a concentration of 1 mg mL-1 (inhibition of trophozoites 87.5% and 91.8%, respectively). In addition to leaves from shoot culture (a conc. 5 mg mL-1, 2nd day inhibition of trophozoites 85.7% and 3rd day 97.2%), leaves from a field-grown plant (a conc. 5 mg mL-1, 2nd day 91.0% and 3rd day 94.4%) and callus (a conc. 5 mg mL-1, 2nd day 90.0% and 3rd day – 95.4%) also exhibited a good antiamoebicidal activity. Out of the four extracts, the extracts from leaves from both shoot culture and a field-grown plant were reported to be the most active against Gram-positive S. aureus, which was determined by the values of MIC = 5.0 mg mL-1 and MIC = 2.5 mg mL-1, respectively. The inhibitory potential depends on the yield and composition of mainly bioactive compounds: pentacyclic terpenoids (mainly betulinic, ursolic, and oleanolic acids) and polyphenols (mainly chlorogenic acid and its isomers, epicatechin, dimeric, and trimeric proanthocyanidins, quercetin and kaempferol derivatives). L1 - http://czasopisma.pan.pl/Content/111464/PDF/ABC%20Bot.%202-19%205-M.Kikowska%20i%20in.pdf L2 - http://czasopisma.pan.pl/Content/111464 PY - 2019 IS - No 2 EP - 58 DO - 10.24425/abcsb.2019.127747 KW - Acanthamoeba spp. KW - Chaenomeles japonica KW - pentacyclic terpenoids KW - plant extracts KW - plant in vitro cultures KW - polyphenols KW - Staphylococcus aureus A1 - Kikowska, Małgorzata A1 - Derda, Monika A1 - Thiem, Barbara A1 - Włodarczyk, Agata A1 - Długaszewska, Jolanta A1 - Stochmal, Anna A1 - Żuchowski, Jerzy A1 - Hadaś, Edward PB - Biological Commission of the Polish Academy of Sciences – Cracow Branch VL - vol. 61 DA - 2019.12.28 T1 - Evaluation of antiamoebic and antimicrobial activities in vitro of Chaenomeles japonica (Thunb.) Lindl. ex Spach extracts SP - 47 UR - http://czasopisma.pan.pl/dlibra/publication/edition/111464 T2 - Acta Biologica Cracoviensia s. Botanica ER -