This study aimed to investigate and compare the total phenolic (TPC) and flavonoid (TFC) contents and antioxidant and antibacterial activities of different extracts recovered from Date Palm Pollen collected from Tunisian cultivars of Kerkennah (DPP-K) and Tozeur (DPP-T) using various solvents, including hexane, chloroform, ethyl acetate, acetone, ethanol and water. The results revealed that DPP-T had higher TPC than DPP-K for all solvent extracts, except for hexane, with a value of 237.74 ± 9.58 mg GAE/g for the water extract. The highest level of TFC (75.10 ± 4.37 mg QE/g) was recorded in the acetone DPP-T extract, which was about twice as high as that of DPP-K. A total of eight phenolic compounds were identified and quantified in both extracts by HPLC, namely gallic acid, catechin, caffeic acid, epicatechin, vanillic acid, coumarin, quercitin and rutin. The antioxidant activities of the extracts were screened using DPPH and β-carotene bleaching assays. The results indicated that the DPP-T acetone extract showed the best DPPH scavenging activity (IC 50 = 46.56 ± 0.28 µg/ml), with no activity being recorded for DPP-K. The DPP-T extract also showed significant effects in terms of the β-carotene test (28.12 ± 0.04 µg/ml) when compared to BHT as a reference standard. The extracts were screened for antimicrobial activity against 10 bacterial and 7 fungal strains, and the results showed that ethyl acetate DPP-K extract exhibited the strongest activity against L. monocytogenes and that the S. aureus strain was most sensitive to DPP-T, with MIC and MBC values of 0.98 mg/ml and 1.95 mg/ml, respectively. Both DPP-T and DPP-K showed strong inhibition effects on the growth of F. oxysporum. Further time kill assays demonstrated the potency of DPP-K and DPP-T ethyl acetate extracts to inhibit the growth of L. monocytogenes and S. aureus, respectively.Overall, the findings suggest that DPP could be considered a promising source of new natural antioxidant and antimicrobial agents for use in various food and pharmaceutical products and formulations. This suggested that the DPP extract is a good potential inhibitor of food 3 spoiling microbial growth and could be a highly effective therapeutic choice for human and plant infections.

Ecballium elaterium is a perennial herb with multiple medicinal properties. It was widely used in folk medicine as cathartic, anti-inflammatory and analgesic agents. The present study was devoted to investigate the effect of diethyl ether, acetone, and methanol solvent on the extraction, phytochemicals profiles, antioxidant and antimicrobial activities of Ecballium elaterium seeds and peels fruits. The total phenolic, flavonoid, flavonol, condensed tannins and carotenoids contents were estimated. Maximum phenolic (107 ± 4 mg GAE/g) and flavonoid (18 ± 0 mg QE/g) contents were also found in the methanol peels fruits extract. Results showed that methanol peels fruits extract have the highest antioxidant activity with IC 50 values of 1.2 ± 0.1 and 1 ± 0 mg/mL for DPPH and ABTS, respectively, and EC 50 value of 1040 ± 5 mg/mL for reducing power assays. Acetone and diethyl ether peels fruits extracts showed the best antibacterial agents especially against Micrococcus luteus, however no antifungal activity was observed. Spectral data of FT-IR analysis of Ecballium elaterium seeds and peels fruits extracts revealed the presence of functional groups such as ─DH, C─H, C─D and C=D. Due to their high antioxidant and antibacterial activities, E. elaterium seeds and peels fruits extracts have promising potential as future natural antioxidant and antibacterial agents in food industry.Keywords: Ecballium elaterium; solvent effects; phytochemical contents; antioxidant and antimicrobial properties; FT-IR analysis.Practical Application: Ecballium elaterium seeds and peels fruits can be potentially used as natural antioxidant and antibacterial inhibitor.

BackgroundIn order to validate its antiseptic and anticancer properties with respect to traditional uses, we have screened for the first time the antimicrobial activity of aerial parts of M. vulgare L. essential oil against different pathogenic microorganisms and the cytotoxic activity against HeLa cell lines.MethodsThe agar disk diffusion method was used to study the antibacterial activity of M. vulgare essential oil against 12 bacterial and 4 fungi strains. The disc diameters of zone of inhibition (DD), the minimum inhibitory concentrations (MIC) and the concentration inhibiting 50% (IC50) were investigated to characterize the antimicrobial activities of this essential oil. The in vitro cytotoxicity of M. vulgare essential oil was examined using a modified MTT assay; the viability and the IC50 were used to evaluate this test.ResultsThe antimicrobial activity of the essential oil was investigated in order to evaluate its efficacy against the different tested microorganisms. The present results results showed a significant activity against microorganisms especially Gram (+) bacteria with inhibition zones and minimal inhibitory concentration values in the range of 6.6-25.2 mm and 1120-2600 μg/ml, respectively, whereas Gram (-) bacteria exhibited a higher resistance. As far as the antifungal activity, among four strains tested, Botrytis cinerea exhibited the strongest activity with inhibition zones of 12.6 mm. However, Fusarium solani, Penicillium digitatum and Aspergillus niger were less sensitive to M. vulgare essential oil. About the citotoxicity assay, this finding indicate the capability of this essential oil to inhibited the proliferation of HeLa cell lines under some conditions with IC50 value of 0.258 μg/ml.ConclusionThis investigation showed that the M. vulgare essential oil has a potent antimicrobial activity against some Gram (+) pathogenic bacteria and Botrytis cinerea fungi. The present studies confirm the use of this essential oil as anticancer agent. Further research is required to evaluate the practical values of therapeutic applications.

In this study, we aimed to explore and compare the composition, metabolic diversity and antimicrobial potential of endophytic fungi colonizing internal tissues of healthy and brittle leaf diseased (BLD) date palm trees (Phoenix dactylifera L.) widely cultivated in arid zones of Tunisia. A total of 52 endophytic fungi were isolated from healthy and BLD roots of date palm trees, identified based on internal transcribed spacer-rDNA sequence analysis and shown to represent 13 species belonging to five genera. About 36.8% of isolates were shared between healthy and diseased root fungal microbiomes, whereas 18.4 and 44.7% of isolates were specific to healthy and BLD root fungal microbiomes, respectively. All isolates were able to produce at least two of the screened enzymes including amylase, cellulase, chitinase, pectinase, protease, laccase and lipase. A preliminary screening of the isolates using disk diffusion method for antibacterial activity against four Gram-positive and three Gram-negative bacteria and antifungal activities against three phytopathogenic fungi indicated that healthy and BLD root fungal microbiomes displayed interesting bioactivities against examined bacteria and broad spectrum bioactivity against fungal pathogens. Some of these endophytic fungi (17 isolates) were fermented and their extracts were evaluated for antimicrobial potential against bacterial and fungal isolates. Results revealed that fungal extracts exhibited antibacterial activities and were responsible for approximately half of antifungal activities against living fungi. These results suggest a strong link between fungal bioactivities and their secondary metabolite arsenal. EtOAc extracts of Geotrichum candidum and Thielaviopsis punctulata originating from BLD microbiome gave best results against Micrococcus luteus and Bacillus subtilis with minimum inhibitory concentration (MIC, 0.78 mg/mL) and minimum bactericidal concentration (6.25 mg/mL). G. candidum gave the best result against Rhizoctonia solani with MIC 0.78 mg/mL and minimum fungicidal concentration (MFC, 6.25 mg/mL). In conclusion, using plant microbiomes subjected to biotic stresses offers new endophytes with different bioactivities than those of healthy plants. Therefore, date palm endophytic fungi represent a hidden untapped arsenal of antibacterial and broad spectrum antifungal secondary metabolites and could be considered promising source of bioactive compounds with industrial and pharmaceutical applications.

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This research study examines academic self-perceptions and course satisfaction among university students and associated factors during virtual classes. A cross-sectional online survey of (n = 328) undergraduate and postgraduate Saudi students who took virtual classes during the second semester of the academic year 2019–2020 and the first semester of the academic year 2020–2021 during the coronavirus disease 2019 (COVID-19) pandemic. The findings demonstrated students’ scores on negative academic self-perceptions (mean (M) = 9.84; standard deviation (S.D.) = 3.09) are significantly higher in comparison to positive academic self-perceptions (M = 7.71; S.D. = 2.46) and the difference was statistically significant, t(327) = 3.69, p < 0.001. The analysis demonstrated that mean differences were significant across ‘year of study’, ‘field of study’, ‘CGPA’ (cumulative grade points average), ‘employment status’, ‘on-site work’ and ‘being a parent of young child’ (p < 0.01). Correlation analysis shows a linear positive association between perceptions of workload and low technical support with negative academic self-perceptions (p < 0.001) and an inverse relationship with positive academic self-perceptions (p < 0.001). The multiple regression analysis demonstrated that the predictor variables in the model (perceptions of workload and technical support) explain 62% variance in negative academic self-perceptions and 41% variance in positive academic self-perceptions. Furthermore, the analysis demonstrated that positive academic self-perceptions bring a 32% variance in course satisfaction. These findings underscore the importance of balancing workload during online studies in higher education and provision of adequate technical support to reduce the negative academic self-perceptions which are associated with lower levels of course satisfaction. Students’ academic self-perceptions and course satisfaction during virtual studies are important factors to retain students’ motivation in learning and academic performance.