The increasing antimicrobial resistance requires continuous investigation of new antimicrobial agents preferably derived from natural sources. New powerful antibacterial agents can be produced by simply combining oils that are known for their antibacterial activities. In this study, apricot seed oil (ASO), date seed oil (DSO), grape seed oil (GSO), and black seed oil (BSO) alone and in binary mixtures were assessed. Fatty acid profiles of individual oils and oil mixtures showed linoleic acid, oleic acid, palmitic acid, stearic acid, and linolenic acid contents. Linoleic acid was the most abundant fatty acid in all samples except for ASO, where oleic acid was the dominant one. GSO showed the highest total phenolic content while ASO showed the lowest one. Antibacterial screening was performed against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Staphylococcus aureus. Results showed antibacterial activity in all oils against tested strains except for ASO against S. aureus. Highest antibacterial activity recorded was for ASO against P. mirabilis. ASO-GSO mixture (AG) was the best mixture where it showed synergistic interactions against all strains except P. aeruginosa. In conclusion, seed oil mixtures are likely to show promising antibacterial activities against specific strains.
Date seeds, which are the main by-products of date fruit consumption, were shown to possess promising biological activities and health benefits with minimal human use. The present investigation analyzed and compared the phenolic content of six date seed varieties from four different origins (Khudari, Sakai, and Safawi from Saudi Arabia, Majdool from Jordan, Zahdi from Iraq, and Kabkab from Iran). The aqueous extracts were examined for possible antioxidant, antibacterial, and anti-tumor potential. Date seed oil was extracted, and fatty acid profiles were compared. The results revealed that date seeds are a rich source of polyphenols, which have been linked to biological activities. Furthermore, the phenolic content seemed highly dependent on the variety, where Kabkab had the highest TPC value (271.2 mg GAE/g DM) while Majdool had the lowest value (63.2 mg GAE/g DM). Antioxidant activities of all varieties were highly correlated with the total phenolic content. The antibacterial investigation demonstrated that the Sakai variety possessed the dominant activity, whereas Majdool showed no activity. The results further indicated the sensitivity of both Staphylococcus aureus and Bacillus cereus, with a stronger effect against B. cereus, while no effect was observed against Gram-negative strains (Salmonella Typhi and Escherichia coli). All varieties were able to decrease colon and lung cancer cell viability, especially Khudari and Sakai, with stronger effects against colon cancer cells. Analysis of date seed oil showed high oleic acid content, especially in Sakai. The findings suggest that date seeds are promising candidates for future pharmaceutical applications as nutraceuticals to help combat certain illnesses, as well as functional foods and natural additives that boost the nutritional value of food products, increase their shelf lives, and improve the overall health of consumers.
29 May 2023 in International Journal of Microbiology
Carbapenem-resistant Enterobacterales (CRE) pathogens have been increasingly isolated and reported in Lebanon. Several studies have been published over the last two decades about the CRE situation in the country. However, compared to the worldwide data, those studies are scarce and mostly restricted to single center studies. In this review, we aim to present a comprehensive and reliable report illustrating the current situation regarding CRE in Lebanon. Variable studies have shown an increasing pattern of carbapenem resistance in Enterobacterales since the first reports of CRE isolates in 2007 and 2008. Escherichia coli and Klebsiella pneumoniae were the most detected ones. The OXA-48 class D carbapenemases were the most prevalent carbapenemases among CRE isolates. Moreover, the emergence of other carbapenemases like the NDM class B carbapenemase has been noticed. Strict infection control measures in hospitals, including the identification of CRE carriers, are needed in Lebanese hospitals since carriage is a potential risk for the spread of CRE in healthcare settings. The dissemination of CRE in the community is noticed and attributed to multiple causes, such as the refugee crisis, water contamination, and antimicrobial misuse. In conclusion, strict infection control measures in healthcare settings, in addition to accurate antimicrobial stewardship program implementation, are urgently needed.
Tea, one of the most popular beverages worldwide, generates a substantial amount of spent leaves, often directly discarded although they may still contain valuable compounds. This study aims to optimize the extraction of polyphenols from spent black tea (SBT) and spent green tea (SGT) leaves while also exploring their antioxidant and antibacterial properties. Response surface methodology was utilized to determine the optimal experimental conditions for extracting polyphenols from SBT and SGT. The total phenolic content (TPC) was quantified using the Folin–Ciocalteu method, while antioxidant activity was evaluated through the DPPH assay. Antibacterial activity was assessed using the disk diffusion method. Additionally, high-performance liquid chromatography (HPLC) was employed to analyze the phytochemical profiles of the SBT and SGT extracts. Optimal extraction for SBT achieved 404 mg GAE/g DM TPC and 51.5% DPPH inhibition at 93.64 °C, 79.9 min, and 59.4% ethanol–water. For SGT, conditions of 93.63 °C, 81.7 min, and 53.2% ethanol–water yielded 452 mg GAE/g DM TPC and 78.3% DPPH inhibition. Both tea extracts exhibited antibacterial activity against Gram-positive bacteria, with SGT showing greater efficacy against S. aureus and slightly better inhibition of B. subtilis compared to SBT. No activity was observed against the Gram-negative bacteria E. coli and S. typhimurium. HPLC analysis revealed hydroxybenzoic acid as the main phenolic compound in SBT (360.7 mg/L), while rutin was predominant in SGT (42.73 mg/L). The optimized phenolic-rich extracts of SBT and SGT demonstrated promising antioxidant and antibacterial potential, making them strong candidates for use as natural health boosters in food products.
(1) Background: Kiwifruit is a globally valued fruit. Its industrial processing produces a substantial amount of waste, particularly peels, which present an appealing potential source of bioactive compounds. This study focuses on optimizing the extraction of phenolics from kiwi peels using a water bath (WB) and infrared irradiation (IR) and assessing their biological activities. (2) Methods: Optimal conditions for polyphenol extraction from kiwifruit peels, in terms of temperature and time, were determined using Response Surface Methodology. Total phenolic content (TPC) was measured by the Folin–Ciocalteu method, and antioxidant activity was assessed utilizing the DPPH method. Antibacterial activities against Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella Typhimurium were determined using the minimum inhibitory concentration (MIC). The lyophilized extract was tested for its anticancer effect on A549 lung cancer cell lines. The phytochemical profiles of the WB and IR extracts were analyzed through High-Performance Liquid Chromatography (HPLC). (3) Results: The optimal extraction conditions for the WB method were found to be 75 °C for 35 min, and 90 °C for 5 min for IR. The corresponding TPC obtained by IR was 21 mg GAE/g DM, which was 4.4 times higher than that obtained by WB (4.8 mg GAE/g DM). This indicates that IR was more efficient in extracting phenolics from kiwi peels. The antioxidant activity under the optimum conditions of WB and IR was 14 mg TE/g DM and 16 mg TE/g DM, respectively. Both the WB and IR extracts demonstrated antibacterial activity against B. cereus with an MIC value of 25 mg/mL. Additionally, the IR extract displayed an antibacterial effect against S. aureus, with an MIC value of 50 mg/mL. The WB and IR kiwi peel extracts were effective in significantly reducing A549 cell viability at 50 µg/mL and 100 µg/mL, respectively. Caffeic acid (0.54 ppm) and catechin (5.44 ppm) were the major polyphenols identified in WB and IR extracts, as determined by HPLC. (4) Conclusions: IR was more efficient in extracting phenolics from kiwi peels than WB. The findings also suggest that kiwi peel can be effectively utilized as an antioxidant, antibacterial, and anticancer agent.