Promising Endophytic Alternaria alternata from Leaves of Ziziphus spina-christi: Phytochemical Analyses, Antimicrobial and Antioxidant Activities

Abstract

Fungal endophytes are considered one of the most important reservoirs of bioactive compounds which defeat resistant microbes. In our study, endophytic Alternaria alternata was isolated from Ziziphus spina-christi and identified morphologically and genetically with accession number OM 331,682. Preliminary phytochemical screening of ethyl acetate (EA) crude extract of A. alternata revealed that this extract contains alkaloids, tannins, flavonoids, glycosides, phenols, and terpenoids. Moreover, the extract was analyzed using gas chromatography-mass spectrometry (GC–MS) which verified the presence of numerous bioactive compounds. Antimicrobial results illustrated that EA crude extract exhibited promising antimicrobial activity against Gram-negative bacteria (Escherichia coli ATCC 11229, Proteus vulgaris RCMB 004, Pseudomonas aeruginosa ATCC 27853, and Klebsiella pneumonia RCMB 003), Gram-positive bacteria (Bacillus subtilis RCMB 015, Staphylococcus aureus ATCC 25923, and Staphylococcus epidermidis ATCC 14990), and unicellular fungi (Candida albicans ATCC 90028). Ultrastructure study of treated K. pneumonia showed remarkably elucidated destruction of the cell wall and cell membrane and leakage of cytoplasmic materials. Furthermore, the extract has potential antioxidant activity where IC50 was 409 µg/mL. Moreover, this extract did not show any toxicity on Vero normal cell line. These findings confirmed that the endophytic A. alternata from Z. spina-christi is a promising source of bioactive compounds which can be used in different biological applications.

Antioxidant Properties of Nine Commonly Used Medicinal Plants in Arabs Region

“…The recorded scavenging activity of the aqueous methanolic extracts of T. ammi, F. assa-foetida, E.cardamomum1, S. alexandrina, A. obesum, E.cardamomum2, T. when ascorbic acid is used as standard [31]. Alternaria alternata that had been isolated from Ziziphus spina-christi reported to have as potential antioxidant activity against DPPH as the IC 50 reached 409µg/ml [32]. Our finding that T. ammi seed extract has a strong ABTS scavenging activity as the IC 50 reached 100.035 ± 19.38µg is in full agreement with the report that studied 24 commonly used medicinal plants from Nepal and Japan and stated that T. ammi seed showed a strong activity against DPPH as the recorded % of inhibition was 90.67 ± 0.58 [33].…”

The effects of Ziziphus Spina leaves’ Hydro-Alcoholic Extract Vaginal Cream and Clotrimazole on Candida albicans in Wistar Rats

“… 33 Additionally, Zizyphus Spina has endophytic A. Alternaria, which has potent antioxidant activity that can cause cell membrane disruption. 34 Finally, the tannins in Zizyphus Spina, by eliminating Iron, reduce the pathogen growth and proliferation. 35 …”

“…33 Additionally, Zizyphus Spina has endophytic A. Alternaria, which has potent antioxidant activity that can cause cell membrane disruption. 34 Finally, the tannins in Zizyphus Spina, by eliminating Iron, reduce the pathogen growth and proliferation. In a study by Butassi et al 36 it was reported that Phytolacca tetramera from Argentina has antifungal activity against Candida albicans and Candida glabrata.…”

Cultivable endophytic fungal community associated with the karst endemic plant Nervilia fordii and their antimicrobial activity

“…Increasing evidence is showing that plants with antimicrobial activities may provide the most viable opportunity to screen out novel fungal endophytes with bioactive compounds ( Strobel et al, 2004 ; Lv et al, 2010 ; Cui et al, 2015 ; Malhadas et al, 2017 ). For example, the endophytic A. alternata isolated from the leaves of the medicinal plant Ziziphus spina-christi displayed positive inhibition activity against several pathogenic bacteria and fungi ( Elghaffar et al, 2022 ). Similarly, endophytic fungi isolated from many plants, i.e., Dysosma versipellis , Saussurea involucrate , and Rhododendron tomentosum ( Lv et al, 2010 ; Tejesvi et al, 2011 ; Tan et al, 2018 ), with high antimicrobial efficiency also potentially represent new antibacterial compounds.…”

“…with antibacterial, antifungal, and anticancer activities ( Hashem et al, 2022 ; Salem et al, 2022b ; Shehabeldine et al, 2022a ). Therefore, endophytic fungi provide the possibility of discovering valuable natural drugs with novel structures and biological activities ( Elghaffar et al, 2022 ).…”