Antimicrobial activity, ergosterol content and phytochemical screening of Rorippa Islandica (Oeder ex Murr.) and...

The purpose of this study was to identify non-polluting medicinal plant alternatives. Two medicinal plants, Rorippa islandica and Carrichtera annua (family Brassicaceae), collected from the NorthWestern Coastal region (Marsa Matrouh, Egypt), were investigated to determine their bioactive constituents in ethanol crude extracts using GC-MS and HPLC techniques, and to evaluate their in vitro antifungal activity against five pathogenic fungi. GC-MS analysis revealed the presence of 50 and 54 compounds in R. islandica and C. annua, respectively. The primary compound in R. islandica was 13-Docosenamide (20.54%), while in C. annua it was 2-Hydroxy-1-(hydroxymethyl) ethyl stearate (9.74%). HPLC identified 19 and 18 phenolic compounds in R. islandica and C. annua, respectively, with gallic acid as the predominant compound in both plants (3417.72 µg/g and 3733.98 µg/g, respectively). Both plant extracts exhibited promising antifungal activity. For R. islandica, the most potent effect at 10 mg/ml was observed with the 70% ethanol successive extract against Colletotrichum gloeosporioides (inhibition zone 29 ± 0.3 mm; MIC 7.8 µg/ml; MFC 15.62 µg/ml). For C. annua, the most potent effect at 10 mg/ml was from the total extract against Curvularia lunata (inhibition zone 35 ± 0.1 mm; MIC 1.97 µg/ml; MFC 3.9 µg/ml). A significant reduction in ergosterol content was observed in the total and successive ethanol (96% and 70%) fractions of both plants, with the highest reduction in C. lunata and C. gloeosporioides treated with C. annua extract (49.93% and 47.7%, respectively), and in P. glabrum and C. gloeosporioides treated with R. islandica extract (47.2% and 42.58%, respectively). Morphological changes induced by the total and ethanol (96% and 70%) extracts of both plants were examined using AFM.