Diversity of Citrullus colocynthis (L.) Schrad Seeds Extracts: Detailed Chemical Profiling and Evaluation of Their Medicinal Properties.

Seeds and fruits of Citrullus colocynthis have been reported to possess huge potential for the development of phytopharmaceuticals with a wide range of biological activities. Thus, in the current study, we are reporting the potential antimicrobial and anticancer properties of C. colocynthis seeds extracted with solvents of different polarities, including methanol (M.E.), hexane (H.E.), and chloroform (C.E.). Antimicrobial properties of C. colocynthis seeds extracts were evaluated on Gram-positive and Gram-negative bacteria, whereas, anticancer properties were tested on four different cell lines, including HepG2, DU145, Hela, and A549. All the extracts have demonstrated noteworthy antimicrobial activities with a minimum inhibitory concentration (MIC) ranging from 0.9-62.5 µg/mL against Klebsiella planticola and Staphylococcus aureus; meanwhile, they were found to be moderately active (MIC 62.5-250 µg/mL) against Escherichia coli and Micrococcus luteus strains. Hexane extracts have demonstrated the highest antimicrobial activity against K. planticola with an MIC value of 0.9 µg/mL, equivalent to that of the standard drug ciprofloxacin used as positive control in this study. For anticancer activity, all the extracts of C. colocynthis seeds were found to be active against all the tested cell lines (IC50 48.49-197.96 µg/mL) except for the chloroform extracts, which were found to be inactive against the HepG2 cell line. The hexane extract was found to possess the most prominent anticancer activity when compared to other extracts and has demonstrated the highest anticancer activity against the DU145 cell line with an IC50 value of 48.49 µg/mL. Furthermore, a detailed phytoconstituents analysis of all the extracts of C. colocynthis seeds were performed using GC-MS and GC-FID techniques. Altogether, 43 phytoconstituents were identified from the extracts of C. colocynthis seeds, among which 21, 12, and 16 components were identified from the H.E., C.E., and M.E. extracts, respectively. Monoterpenes (40.4%) and oxygenated monoterpenes (41.1%) were the most dominating chemical class of compounds from the hexane and chloroform extracts, respectively; whereas, in the methanolic extract, oxygenated aliphatic hydrocarbons (77.2%) were found to be the most dominating chemical class of compounds. To the best of our knowledge, all the phytoconstituents identified in this study are being reported for the first time from the C. colocynthis.

Comprehensive Phytochemical Analysis of Various Solvent Extracts of Artemisia judaica and Their Potential Anticancer and Antimicrobial Activities.

Solvents play an important role in the extraction process by considerably affecting the amount and nature of secondary metabolites of medicinal plants. Thus, the effect of solvents must be investigated to obtain desired biological properties of plant extracts. In the current study, we extracted aerial parts of Artemisia judaica, native to Saudi Arabia, in three different solvents, including methanol (MeOH), hexane (Hex), and chloroform (Chl). Obtained extracts from the aerial parts of A. judaica were analysed by GC-MS and GC-FID techniques, which resulted in the identification of 46, 18, and 17 phytoconstituents from the Hex, Chl, and MeOH extracts, respectively. All the extracts contain oxygenated terpenes, aliphatic hydrocarbons, and aromatics as major classes of compounds in varying amounts. Among the various phytoconstituents identified, piperitone was the dominant compound and was found in all the extracts in different amounts, specifically, 28.8, 26.1, and 20.1% in the Chl, MeOH, and Hex extracts, respectively. Moreover, all these extracts (Chl, MeOH, and Hex) were tested for the antimicrobial properties on both Gram-positive and negative bacteria as well as for their anticancer properties on four different cell lines including HepG2, DU145, Hela, and A549. Among the different extracts, the Hex and Chl extracts demonstrated identical antimicrobial properties, while the Chl extract showed superior anticancer properties when compare to the other extracts. The higher biological properties of Chl extracts including both antimicrobial and anticancer activities may be attributed to the presence of large amounts of piperitone and/or santonin, which are distinctly present in excess amounts in the Chl extract.

Pulicaria undulata Extract-Mediated Eco-Friendly Preparation of TiO2 Nanoparticles for Photocatalytic Degradation of Methylene Blue and Methyl Orange.

Eco-friendly approaches for the preparation of nanomaterials have recently attracted considerable attention of scientific community due to rising environmental distresses. The aim of the current study is to prepare titanium dioxide (TiO2) nanoparticles (NPs) using an eco-friendly approach and investigate their performance for the photocatalytic degradation of hazardous organic dyes. For this, TiO2 NPs were prepared by using the aqueous extract of the Pulicaria undulata (L.) plant in a single step at room temperature. Energy-dispersive X-ray spectroscopy established the presence of both titanium and oxygen in the sample. X-ray diffraction revealed the formation of crystalline, anatase-phase TiO2 NPs. On the other hand, transmission election microscopy confirmed the formation of spherical shaped NPs. The presence of residual phytomolecules as capping/stabilization agents is confirmed by UV-vis analysis and Fourier-transform Infrared spectroscopy. Indeed, in the presence of P. undulata, the anatase phase of TiO2 is stabilized at a significantly lower temperature (100 °C) without using any external stabilizing agent. The green synthesized TiO2 NPs were used to investigate their potential for the photocatalytic degradation of hazardous organic dyes including methylene blue and methyl orange under UV-visible light irradiation. Due to the small size and high dispersion of NPs, almost complete degradation (∼95%) was achieved in a short period of time (between 1 and 2 h). No significant difference in the photocatalytic activity of the TiO2 NPs was observed even after repeated use (three times) of the photocatalyst. Overall, the green synthesized TiO2 NPs exhibited considerable potential for fast and eco-friendly removal of harmful organic dyes.

Synthesis of Au, Ag, and Au-Ag Bimetallic Nanoparticles Using Pulicaria undulata Extract and Their Catalytic Activity for the Reduction of 4-Nitrophenol.

Plant extract of Pulicaria undulata (L.) was used as both reducing agent and stabilizing ligand for the rapid and green synthesis of gold (Au), silver (Ag), and gold-silver (Au-Ag) bimetallic (phase segregated/alloy) nanoparticles (NPs). These nanoparticles with different morphologies were prepared in two hours by stirring corresponding metal precursors in the aqueous solution of the plant extracts at ambient temperature. To infer the role of concentration of plant extract on the composition and morphology of NPs, we designed two different sets of experiments, namely (i) low concentration (LC) and (ii) high concentration (HC) of plant extract. In the case of using low concentration of the plant extract, irregular shaped Au, Ag, or phase segregated Au-Ag bimetallic NPs were obtained, whereas the use of higher concentrations of the plant extract resulted in the formation of spherical Au, Ag, and Au-Ag alloy NPs. The as-prepared Au, Ag, and Au-Ag bimetallic NPs showed morphology and composition dependent catalytic activity for the reduction of 4-nitrophenol (4-NPh) to 4-aminophenol (4-APh) in the presence of NaBH4. The bimetallic Au-Ag alloy NPs showed the highest catalytic activity compared to all other NPs.