In vitro antioxidant potential of methanolic and aqueous extracts of Ardisia solanacea Roxb. leaf

Quality characteristics, phytochemical analysis, and antioxidant of extract Cuscuta reflexa (Roxb.)

Cuscuta reflexa is an extensive leafless, parasitic climber that has been used since ancient times for various purposes and as a therapeutic plant in different areas of Pakistan. The phytochemical, antibacterial, antioxidant, and fatty acid investigations were carried out on the leaves, stems, and fruit extracts of C. reflexa. Preliminary phytochemical screening has shown the presence of various phytochemicals such as carbohydrates, protein, amino acids, alkaloids, flavonoids, phenols, glycosides, saponins, tannins, terpenoids, steroids, and phenolic compounds. The percentage variation of some components fluctuated like moisture (6.85-10.34%), ash (5.38-7.83%), acid insoluble ash (0.28-0.71%), water-soluble ash (0.78-0.96%), hexane extractives (1.23-1.91%), alcohol extractives (10.39-12.23%), water extractives (25.34-30.35%), loss on drying (1.16-1.47%) and crude fiber (15.04-18.26%) for leaves, stems, and fruits respectively. The level of free fatty acid was different as follows: leaves (2.37%), stems (2.16%), and fruits (2.94%); a high value of peroxide was observed in stems, followed by leaves and fruits. The iodine and saponification values in leaves, stems, and fruits were found in the range of 105-116 g I2/100 g, and 165-175 mg KOH/g. The antibacterial activity was carried out by the disc diffusion method against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria. It was found that all extracts of the selected plant were most active against E. coli with a zone of inhibition of 4, 4, and 6 at MIC 250 as compared to S. aureus, which showed a zone of inhibition of 3, 4, and 5 at MIC 250 µg/ml. The antioxidant potential of the leaves, stems, and fruit extracts, examined on the basis of their scavenging activity of free radicals, was found to be good. The result of the gas chromatography-mass spectroscopy (GC-MS) analysis reveals that linoleic acid (38.10–40.53%) is the most abundant fatty acid of C. reflexa and the smallest amount was found in tricosanoic acid (0.12-0.19%). In general, the isolated compounds were reported to possess anticarcinogenic, antitumor, antimicrobial, and anti-inflammatory properties. It was concluded that C. reflexa has a markedly therapeutic potential to heal wounds and may provide the pharmacological basis for its folk uses.

Anti-biofilm and Antibacterial Activities of Silver Nanoparticles Synthesized by the Reducing Activity of Phytoconstituents Present in the Indian Medicinal Plants

Biofilm forming from a variety of microbial pathogens can pose a serious health hazard that is difficult to combat. Nanotechnology, however, represents a new approach to fighting and eradicating biofilm-forming microorganisms. In the present study, the sustainable synthesis and characterization of biocompatible silver nanoparticles (AgNPs) from leaf extracts of Semecarpus anacardium, Glochidion lanceolarium, and Bridelia retusa was explored. Continuous synthesis was observed in a UV–vis spectroscopic analysis and the participating phytoconstituents, flavonoids, phenolic compounds, phytosterols, and glycosides, were characterized by Attenuated total reflectance-Fourier transform infrared spectroscopy. The size and surface charge of the particles were also measured by dynamic light scattering spectroscopy. Scanning electron microscopy study was employed to examine the morphology of the nanoparticles. The spectroscopic and microscopic study confirmed the successful synthesis of AgNPs by plant extracts acting as strong reducing agents. The synthesized AgNPs were screened for antibacterial and anti-biofilm activity against human pathogens Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. Results of the study demonstrate the potential of phyto-synthesized AgNPs to act as anti-biofilm agents and for other biomedical applications.

Biosynthesis of Silver Nanoparticles from Protium serratum and Investigation of their Potential Impacts on Food Safety and Control

Silver nanoparticles play an integral part in the evolution of new antimicrobials against the broad ranges of pathogenic microorganisms. Recently, biological synthesis of metal nanoparticles using plant extracts has been successfully consummated. In the present study, the biosynthesis of silver nanoparticles (AgNPs) was conducted using the leaf extract of plant Protium serratum, having novel ethnomedicinal. The synthesized AgNPs were characterized using UV-Visible spectroscopy, dynamic light scattering spectroscopy (DLS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy. The DLS study revealed the surface charge of the resulted nanoparticles that was highly negative, i.e., −25.0 ± 7.84 mV and the size was 74.56 ± 0.46 nm. The phytochemical and FTIR analysis confirmed the role of water-soluble phyto-compounds for the reduction of silver ions to silver nanoparticles. The potential antibacterial activity of AgNPs was studied against the food borne pathogens viz. Pseudomonas aeruginosa (IC₅₀ = 74.26 ± 0.14 μg/ml), Escherichia coli (IC₅₀ = 84.28 ± 0.36 μg/ml), Bacillus subtilis (IC₅₀ = 94.43 ± 0.4236 μg/ml). The in vitro antioxidant potential of AgNPs was evaluated using 1, 1-diphenyl-2-picryl-hydrazil (IC₅₀ = 6.78 ± 0.15 μg/ml) and hydroxyl radical assay (IC₅₀ = 89.58 ± 1.15 μg/ml). In addition, the cytotoxicity of AgNPs was performed against fibroblast cell line L-929 to evaluate their biocompatibility. The overall results of the present investigation displayed the potential use of P. serratum leaf extract as a good bio-resource for the biosynthesis of AgNPs and their implementation in diverse applications, specifically as antibacterial agent in food packaging and preservation to combat against various food borne pathogenic bacteria along with its pharmaceutical and biomedical applications.

In vitro α-glucosidase inhibition, antioxidant, anticancer, and antimycobacterial properties of ethyl acetate extract of Aegle tamilnadensis Abdul Kader (Rutaceae) leaf

The present study was aimed to investigate in vitro α-glucosidase inhibition, antioxidant, anticancer, and antimycobacterial activities of the ethyl acetate extract of A. tamilnadensis leaves. The extract recorded strong α-glucosidase inhibition with an IC50 value of 100 μg/ml. The antioxidant potential of the extract was evaluated by nitric oxide radical inhibition, lipid peroxidation inhibition, ferric thiocyanate, and ABTS radical scavenging assay, and the extract recorded significant antioxidant activity. The ferric thiocyanate activity of extract was superior to butylated hydroxyl anisol (BHA), the standard antioxidant agent. The anticancer activity of the extract was evaluated against (1) breast cancer cell lines (MDAM B-231), (2) cervical cancer cell lines (HeLa), and (3) lung cancer cell line (A 549) using MTT assay, and significant activity was recorded against A 549 with an IC50 value of 64 μg/ml. Further studies on the morphology, acridine orange/ethidium bromide staining, and cell cycle analysis by flow cytometry confirm the extract-induced apoptosis in A 549. This extract also recorded significant anti-tuberculosis activity against Mycobacterium smegmatis. The current study suggests that the ethyl acetate extract of A. tamilnadensis is a potential source of natural α-glucosidase inhibitor and antioxidant for protection as well as prevention of life-threatening diseases like cancer.