Awad Yousef Shala

Pseudomonas aeruginosa is a harmful pathogen that causes a variety of acute and chronic infections through quorum sensing (QS) mechanisms. The increasing resistance of this bacterium to numerous antibiotics has created a demand for new medications that specifically target QS. Endophytes can be the source of compounds with antibacterial properties. This research is the first to examine tannic acid (TA) produced by endophytic fungus as a potential biotherapeutic agent. A novel endophytic fungal isolate identified as Penicillium oxalicum was derived from the cladodes of Opuntia ficus-indica (L.). The species identification for this isolate was confirmed through sequencing of the internal transcribed spacer region. The metabolites from the culture of this isolate were extracted using ethyl acetate, then separated and characterized using chromatographic methods. This led to the acquisition of TA, a compound that shows strong anti-QS and excellent antibacterial effects against extensively drug-resistant P. aeruginosa strains. Furthermore, it was shown that treating P. aeruginosa with the obtained TA reduced the secretion of virulence factors controlled by QS in a dose-dependent manner, indicating that TA inhibited the QS characteristics of P. aeruginosa. Simultaneously, TA significantly inhibited the expression of genes associated with QS, including rhlR/I, lasR/I, and pqsR. In addition, in silico virtual molecular docking showed that TA could efficiently bind to QS receptor proteins. Our results showed that P. oxalicum could be a new source of TA for the treatment of infections caused by extensively drug-resistant P. aeruginosa.

Essential oils have been considered as an efficient approach and environmentally safe as natural plant stimulants. The current research evaluated the effect of foliar spray of essential oils of French lavender and citronella grass and their mixture (0, 2.5, 5 and 7.5 ml/l) on strawberry plants under greenhouse conditions during the two consecutive seasons of 2022 and 2023. Chromatographic analysis of essential oil constituents identified 1,8-cineole (43.95%) and linalool (26.27%) were dominant in lavender essential oil while citronellal (27.64%) and geraniol (24.51%) were the most abundant compounds in citronella grass essential oil. Foliar application of essential oils significantly increased plant height, number of leaves, leaf area, fruit length, fruit diameter, fruit firmness, early yield, total yield and fruit quality, the highest content of phenolics, anthocyanins, ascorbic acid and total soluble solids especially after application of French lavender essential oil at high concentration as compared to the control. This study suggests the application of French lavender essential oil at 7.5 ml/l as a promising eco-friendly approach to improve strawberry plant growth and productivity towards a better fruit quality.

Saline water has been proposed as a solution to partially supply plants with their water requirements due to a lack of fresh water for cultivation in arid and semi-arid sites. Gamma-aminobutyric acid (GABA) is a non-protein amino acid participating in numerous metabolic processes to mitigate the undesirable effects of salinity. A pot experiment was carried out during 2021 and 2022 at Sakha Horticulture Research Station to investigate the effect of foliar application of GABA at 20 and 40 mM on vegetative growth and biochemical changes in French lavender under increasing levels of sea water salinity irrigation treatments (0, 1000, 2000, and 3000 ppm). Results indicated that increasing salinity concentration noticeably decreased plant height, number of branches, herb fresh and dry weight, root length, root fresh and dry weights, photosynthetic pigments, relative water content, and essential oil percentage. On the other hand, accumulation of proline and antioxidant enzymes was increased under increasing salinity concentrations. We conclude that foliar application of GABA acid at 40 mM can alleviate the adverse effects of salinity on the abovementioned French lavender plant characteristics by improving vegetative growth and root characteristics, as well as diminishing chlorophyll degradation, maintaining high leaf relative water content, increasing proline accumulation and antioxidant activity.

Wound infections became a great challenge, especially after the emergence of bacterial resistance to commonly used antibiotics. Medicinal plants can be the source of alternative antibacterial agents effective against multi drug resistant (MDR) bacteria. This research aimed to evaluate the effectiveness of different Silybum marianum seed extracts in fighting MDR bacteria that infect wounds. First, thirty purified bacterial cultures obtained from superficial, infected wounds were subjected to antibiotic sensitivity tests. The selected MDR isolates were then used to test the antimicrobial effects of different S. marianum seed extracts. The most potent extract was evaluated for its impact on the ultrastructure of the cells of sensitive bacterial isolates using transmission electron microscopy (TEM). The bioactive ingredients of this extract were analyzed by means of gas chromatography–mass spectroscopy (GC–MS). Then, in-silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties were predicted for the main components. The results indicated that four out of 30 bacterial isolates were considered MDR bacteria. Primary morphological features of colonies, secondary (automatic) identification using the Biomerieux Vitek 2 System, and 16S rRNA sequencing of the four isolates confirmed that they represent Staphylococcus aureus, Stenotrophomonas maltophilia, Klebsiella pneumoniae, and Escherichia coli. Among different extracts of S. marianum seeds, ethanol extract showed the strongest inhibitory effect on both Gram-positive and Gram-negative bacteria, with minimum inhibitory concentration (MIC) values between 9.375 and 1.172 mg/mL. However, at concentrations four times higher, this extract was unable to kill bacterial cells, indicating that it had a bacteriostatic effect on the tested MDR strains. TEM revealed denaturation and distorted cell ultrastructure in S. aureus and S. maltophilia after exposure to ethanol extract. In addition, GC–MS analysis of the ethanol extract identified nine compounds known to have important biological activities, and ADMET analysis showed good drug-likeness for two of these compounds. Consequently, S. marianum seeds could be a good source of alternative bacteriostatic agents effective against MDR bacterial strains that cause wound infections.

The obtained results from evaluation the reaction of twenty-five sugar beet cultivars ( 100 day old) to the disease, explained that, the disease severity of the disease (powdery mildew) was high in the first tested season, while, it was low in the second season. The information of climatic conditions showed that, high differences in maximum and minimum temperature centigrade and relative humidity (RH) % between two tested seasons during the months which were the disease development within them (December, January, February and March),), therefore, the maximum and minimum temperature centigrade were high and the relative humidity % was low and suitable for disease distribution during first season comparing with the second season. Overall, the obtained results indicated that, FD17B4010, MK4199 and Alanya-KWS cultivars, were recorded the least disease severity % (high resistant) against infection with the fungus E. betae and could be recommended in future cultivation. In the contrast, Carma, Dipendra-KWS, Frappina-KWS, SV-2173 and Hammond cultivars, were the most susceptible cultivars(recorded the highest disease severity % ) which can be recommended eliminated and not be planted under Egyptian climatic condition. Moreover, efficacy of foliar spraying of treatments which tested included the essential oils Pelargonium graveolens at 10ml/L and Cymbopogon nardus at 10ml/L and natural substances of Frankincense at 2500 ppm and Chitosan nanoparticles at 500ppm, fungicide Topas 100, EC 1 mL \L , or sprayed with water (control) against powdery mildew disease was tested under field conditions.

The development of bacterial resistance to conventional treatments (chiefly antibiotics) has led to the complication of wound infections, thus rendering the search for novel alternative infection-fighting techniques even more urgent. Historically, medicinal plants have been widely used to obtain natural health products, thus, they constitute sources for very promising alternative antibacterial agents against multidrug-resistant (MDR) bacteria. Thus, this study aimed to evaluate the in vitro antibacterial activity of different seed extracts of Silybum marianum against antibiotic-resistant wound infection–causing bacteria (Staphylococcus aureus strain NBRC 100910, Stenotrophomonas maltophilia strain IAM 12423, Klebsiella pneumoniae strain DSM 30104, and Escherichia coli strain NBRC 102203). The most effective extract was selected to investigate its antioxidant potency, assess its effects on the bacterial cell ultrastructure using transmission electron microscopy (TEM), and screen its bioactive components using gas chromatography–mass spectroscopy (GC–MS) analysis. The results indicated that most antibiotics were ineffective against the bacterial isolates; hence, the bacterial isolates were considered to be MDR bacteria. Ethanol extract exhibited the highest inhibition activity against gram-positive and -negative bacteria alongside high antioxidant and antibacterial activities, as revealed by the denaturation and deformation of the ultrastructure of methicillin-resistant S. aureus and S. maltophilia observed via TEM. The GC–MS analysis of ethanol extract revealed the presence of diverse active components with numerous biological activities. Therefore, S. marianum seeds might be promising antioxidant and antibacterial agents against MDR wound infection–causing bacterial strains.

Chrysanthemum is a flowering plant grown worldwide and is one of the most popular ornamental plants. Chrysanthemums are usually cultivated using root suckers and shoot cuttings. This conventional technique is relatively slow. In addition, as cuttings are gained regularly from mother plants, there is a chance of viral infection and degeneration, which raises the production cost. The hurdles mentioned above have been managed by applying in vitro propagation techniques, which can enhance reproduction rates through in vitro culture and use very small explants, which are impossible with the conventional approach. Usually, it is difficult to get true-to-type plants as the parents with good quality, but clonal propagation of a designated elite species makes it possible. Hence, this review highlights recent studies of the in vitro propagation of Chrysanthemum included; the appropriate explant sources, medium compositions, alternative disinfection of culture media, plant growth regulators (PGRs), different mutagenesis applications, acclimatization efficiency, and alternative light sources to overcome the shortcomings of conventional propagation techniques.

: Candida albicans is one of the main agents responsible for opportunistic pathogenic infections. The progressive emergence of fungal resistance to conventional antibiotics and its side effects, as well as treatment costs, are considered major limitations for antifungal drugs. It has drawn scientists' attention to the search for potential substitution and reliable therapeutic alternatives for the antifungal compounds from sources like medicinal plants, which contain numerous bioactive compounds such as essential oils. Essential oils (EO), apart from having lower toxicity and better biodegradability, are eco-friendly in nature as compared with conventional antibiotics. Furthermore, extracted essential oils have been reported to possess potent antimicrobial, antiinflammatory, and antioxidant properties that nominate them as promising natural candidates to combat numerous fungal ailments. Thus, the determination of antifungal efficacy of essential oil-bearing plants on Candida spp. will provide miscellaneous knowledge for future clinical studies that are required for the development of new formulations as alternative therapeutic agents to control the growth of Candida species. Therefore, this review summarizes the gist of major essential oils that have been investigated for their anti- Candida potential with some recommendations for further study.

Eucalyptus globulus Labill. is one of the most widely utilized medicinal plants throughout the world due to its wide spectrum of interesting biological activities that are mainly attributed to the diversity of phytochemical constituents in the plant parts. The emerging crisis of pathogen resistance for conventional antibiotics is considered a global concern for the diminishing effectiveness of antibiotics; hence, there is an urgent need to explore new antimicrobial ingredients from botanical sources, among which the most promising sources are medicinal plants. Moreover, the growing limitation toward synthetic antioxidants motivated the scientific community all over the world to identify plant-acquired antioxidants and antimicrobials. This is a huge global challenge, because of the increasing public health awareness and reliance on natural compounds, as these compounds are safer alternatives. Moreover, the undesirable impacts of synthetic pharmaceuticals can be avoided. Furthermore, plant extracts and their oil could be used as eco-friendly plant-based products for insects, weeds, and plant pathogen control, which will diminish the dependence on synthetic chemicals. Thus, this review is to highlight the richness of the E. globulus plant, with precious bioactive constituents, antioxidants, antimicrobials, and phytoremediation, and herbicidal activities, which will pave the way to the development of new pharmaceuticals and agrochemicals, as well as food preservatives. They may also provide potential commercial applications to counteract the limitations of synthetic antioxidants.

Now-a-days, the novel coronavirus pandemic has projected millions of deaths around the globe. An effective popular medicinal plant identified during this pandemic is Withania somnifera (L.) Dunal, locally called Ashwagandha or Indian Ginseng. The antiviral activity of this plant is well established in the fight against serious virus infections. This review mainly focuses on the antiviral and immuno-booster efficacy of the plant for combating various virus diseases. The bioactive principles of the plant, withanaloids, has been effectively used for human health. W. somnifera has distinct effects on the viral RBD (receptor-binding domain) and host ACE2 (angiotensin-converting enzyme 2) receptor complex. This may be useful in curing COVID-19 and other virus infection because of its tremendous immuno boosting properties.