Antifungal and Antioxidant Potential of Methanolic Extracts from <i>Acorus calamus</i> L., <i>Chlorella vulgaris</i> Beijerinck, <i>Lemna minuta</i> Kunth and <i>Scenedesmus dimorphus</i> (Turpin) Kützing

• Main Authors: Toncho Dinev, Milena Tzanova, Katya Velichkova, Diyana Dermendzhieva, Georgi Beev
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Applied Sciences
• Subjects: antifungal; antioxidant; methanolic plant extracts
• Online Access: https://www.mdpi.com/2076-3417/11/11/4745

Plant extracts are an important alternative to antibiotics, which are ever more restricted because of their developing microbial resistance and some adverse effects that have been observed following frequent application. The aim of the present study was to determine the antifungal and antioxidant activity of the methanolic extracts of <i>Acorus calamus</i>, <i>Chlorella vulgaris</i>, <i>Lemna minuta</i> and <i>Scenedesmus dimorphus</i>. The antifungal activity of the extracts against strains of <i>Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Aspergillus niger, Aspergillus carbonarius, Fusarium graminearum</i>, <i>Fusarium oxysporum</i>, <i>Penicillium chrysogenum</i> and <i>Alternaria alternata</i> was evaluated via the agar well diffusion method. The antioxidant activity of the extracts was measured through the determination of three parameters—total phenolic content, total flavonoid content and radical scavenging potential (determined through UV/Vis analysis). <i>A. calamus</i> extracts had the highest antimicrobial activity against eight fungal strains, followed by the <i>C. vulgaris</i>, <i>L. minuta</i> and <i>S. dimorphus</i> extracts, which were inhibitory against two to three strains. Among the extracts from the species studied, the extract from <i>S. dimorphus</i> showed the highest antioxidant potential, as determined via the DPPH (1,1’-diphenyl-2-picrylhydrazil-radical) method. This correlated to its high total phenolic and flavonoid content. From <i>A. calamus</i> and <i>L. minuta</i>, methanolic extracts were obtained that exhibited similar values of the aforementioned parameters, followed by <i>C. vulgaris</i> extracts, which showed the lowest antioxidant activity. Based on the Pearson correlation coefficients, the impacts of the total phenolic content and the total flavonoid content on radical scavenging capacity are similar, and flavonoids were a significant part of the total phenolic compounds extracted from the plant materials studied.