The medicinal administration of Aloe vera gel has become promising in pharmaceutical and cosmetic applications particularly with the development of the nanotechnology concept. Nowadays, effective H. pylori treatment is a global problem; therefore, the development of natural products with nanopolymers such as chitosan nanoparticles (CSNPs) could represent a novel strategy for the treatment of gastric infection of H. pylori. HPLC analysis of A. vera gel indicated the presence of chlorogenic acid as the main constituent (1637.09 µg/mL) with other compounds pyrocatechol (1637.09 µg/mL), catechin (1552.92 µg/mL), naringenin (528.78 µg/mL), rutin (194.39 µg/mL), quercetin (295.25 µg/mL), and cinnamic acid (37.50 µg/mL). CSNPs and A. vera gel incorporated with CSNPs were examined via TEM, indicating mean sizes of 83.46 nm and 36.54 nm, respectively. FTIR spectra showed various and different functional groups in CSNPs, A. vera gel, and A. vera gel incorporated with CSNPs. Two strains of H. pylori were inhibited using A. vera gel with inhibition zones of 16 and 16.5 mm, while A. vera gel incorporated with CSNPs exhibited the highest inhibition zones of 28 and 30 nm with resistant and sensitive strains, respectively. The minimal inhibitory concentration (MIC) was 15.62 and 3.9 µg/mL, while the minimal bactericidal concentration (MBC) was 15.60 and 7.8 µg/mL with MBC/MIC 1 and 2 indexes using A. vera gel and A. vera gel incorporated with CSNPs, respectively, against the resistance strain. DPPH Scavenging (%) of the antioxidant activity exhibited an IC50 of 138.82 μg/mL using A.vera gel extract, and 81.7 μg/mL when A.vera gel was incorporated with CSNPs. A.vera gel incorporated with CSNPs enhanced the hemolysis inhibition (%) compared to using A.vera gel alone. Molecular docking studies through the interaction of chlorogenic acid and pyrocatechol as the main components of A. vera gel and CSNPs with the crystal structure of the H. pylori (4HI0) protein supported the results of anti-H. pylori activity.

Silver nanoparticles (Ag-NPs) exhibit vast potential in numerous applications, such as wastewater treatment and catalysis. In this study, we report the green synthesis of Ag-NPs using Acacia ehrenbergiana plant cortex extract to reduce cationic Rhodamine B (RhB) dye and for antibacterial and antifungal applications. The green synthesis of Ag-NPs involves three main phases: activation, growth, and termination. The shape and morphologies of the prepared Ag-NPs were studied through different analytical techniques. The results confirmed the successful preparation of Ag-NPs with a particle size distribution ranging from 1 to 40 nm. The Ag-NPs were used as a heterogeneous catalyst to reduce RhB dye from aqueous solutions in the presence of sodium borohydride (NaBH4). The results showed that 96% of catalytic reduction can be accomplished within 32 min using 20 μL of 0.05% Ag-NPs aqueous suspension in 100 μL of 1 mM RhB solution, 2 mL of deionized water, and 1 mL of 10 mM NaBH4 solution. The results followed a zero-order chemical kinetic (R 2 = 0.98) with reaction rate constant k as 0.059 mol L–1 s–1. Furthermore, the Ag-NPs were used as antibacterial and antifungal agents against 16 Gram-positive and Gram-negative bacteria as well as 1 fungus. The green synthesis of Ag-NPs is environmentally friendly and inexpensive, as well as yields highly stabilized nanoparticles by phytochemicals. The substantial results of catalytic reductions and antimicrobial activity reflect the novelty of the prepared Ag-NPs. These nanoparticles entrench the dye and effectively remove the microorganisms from polluted water.

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The aim of this work was to study the effects of hydrogen peroxide (H 2 O 2) application against cucumber green mottle mosaic virus (CGMMV) infection in watermelon (Citrullus lanatus) plants. From the obtained results, the induced resistance using H 2 O 2 treatments caused a delay in the appearance of CGMMV symptoms in watermelon plants. The viral infection showed abnormal morphological symptoms such as mosaics, yellow blisters and reduction in size. Pretreatment with H 2 O 2 before infection was beneficial in increasing the contents of pigments, total proteins, total free amino acids and proline. Consequently, plants appeared morphologically similar to healthy controls. Signaling the effect of the H 2 O 2 treatment could induce partial resistance or delay the appearance of symptoms and decreased virus concentration. The induced mechanism of resistance was suggested to be through alterations of plant antioxidant status-both enzymatic and non-enzymatic. All analyzed antioxidant enzymes were induced in response to H 2 O 2 ±CGMMV. due to the H 2 O 2 application prior to infection, malondialdehyde (MdA) content was reduced, indicating a lowering in lipid peroxidation caused by virus infection. On the other hand, internal H 2 O 2 and phenolics contents were induced in H 2 O 2 + CGMMV-treated leaves. To confirm: total antioxidant activity was increased to be double the value (80.67%) of that recorded in healthy plants (47.18%), indicating changes in antioxidant status as a response to H 2 O 2 and/or CGMMV infection. This work provided evidence of the signaling role of exogenous H 2 O 2 , which led to systemic acquired resistance (SAR) induction acting against CGMMV infection in watermelon plants. From the present findings, a suggestion of spraying of H 2 O 2 might be helpful in avoiding the appearance of CGMMV severe symptoms throughout the plants' life.

The present study evaluated the potential antibacterial activity of Artemisia absinthium L. and Artemisia herba-alba Asso. extracts through different organic and aqueous solvents. The tested bacteria were pathogenic types; Listeriamonocytogenes, Pseudomonas aeruginosa, Salmonella enterica and Staphylococcus aureus. There were different affinities for the studied organic solvents besides aqueous one. The comparative study was accomplished with comparing to the morphological, anatomical and palynological characters. The similarity parameter is obtained. ANOVA test analyzed MIC values for both plant extracts. Pearson Correlation Coefficients were determined for all both plant traits. MIC and MBC values were confirmed on using butanol and diethyl ether extracts besides butanol and chloroform extracts for Artemisia absinthium L. and Artemisia hera alba Asso against tested pathogenic bacteria respectively as an alternative natural antibacterial inhibitor agent.

Plant extracts have always been used as an alternative source of antimicrobial compounds. The recent spread of multi-drug-resistant bacteria and their increased treatment costs necessitated the study of alternative, cheap sources. The family Euphorbiaceae has over 300 genera and is widely used in traditional medicine. Euphorbia triaculeata, E. fractiflexa, and E. inarticulata were selected to study the antibacterial activity of the methanolic extract against 13 Gram-positive Staphylococcus aureus strains (including methicillin-resistant S. aureus) and 2 Gram-negative isolates, Escherichia coli and Klebsiella pneumoniae, by the Kirby Bauer Disc diffusion test. Paper discs with different concentrations of the extracts (100, 50, and 25 µg mL−1) were prepared, along with the methanol control and standard antibiotic control. A gas chromatography-mass spectrometry (GC/MS) analysis was done to study the phytochemical components present in the plant methanolic extracts. A total of 50 different phytochemical compounds with antibacterial activity were detected by GC/MS analysis of the plants. Twenty-five compounds were detected in E. inarticulata, 24 in E. triaculeata, and 21 in E. fractiflexa. Out of 37 compounds found in E. inarticulata and E. triaculeata, 12 (32.43%) were common to both. Eleven (22%) compounds were unique to E. inarticulata, while 9 (18%) compounds were unique to E. triaculeata, and 13 (26%) compounds were unique to E. fractiflexa. E. fractiflexa showed the best antibacterial activity against MRSA and Gram-negative bacteria. It also showed higher unique compounds with antibacterial activity (26%), followed by E. inarticulata (11, 22%). This is the first GC/MS analysis and antimicrobial activity report of E. triaculeata and E. fractiflexa.

Antibiotics are critical in the management of a variety of bacterial infections, however, repeated infections produced by relentless bacteria are obstructing effective infection treatment and it is the most significant and vexing problem at the moment. Medicinal chemists face a difficult problem in developing appropriate lead compounds for various diseases, isatin and its hybrids would be one of them due to its versatility in many medications and its derivatives exhibit an extensive variety of structural and mechanistic properties. This review looks at the isatin hybrids that have probable antibacterial action. The structure-activity relationship (SAR) and the way of producing action are also examined in order to locate the course for the intent and expansion of isatin hybrids by means of increased efficacy, reduced toxicity and good pharmacokinetic profiles. Based on the findings, it can be inferred that 3-hydrazone, imine, spiro, oxindole, guanidino and N-alkyl, aryl, acyl substituted isatin hybrids with electronegative groups on other heterocycles have improved bactericidal activity. Furthermore, the antibacterial activity of isatin is dependent on the binding linkage, such as amide (NHCO), carbonyl (CO) or other hetero atom-containing linkers that have improved antibacterial activity. This review gives an idea and scope for the synthesis of novel isatin-containing heterocyclics with the goal of having potent bactericidal activity.

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