Improved anti-diabetic and anticancer activities of green synthesized CuO nanoparticles derived from Tabernaemontana divaricate leaf extract

Hydrothermal synthesis and photocatalytic application of ZnS-Ag composites based on biomass-derived carbon aerogel for the visible light degradation of methylene blue

A facile and cost-effective hydrothermal followed by precipitation method is employed to synthesize visible light-driven ZnS-Ag ternary composites supported on carbon aerogel (CA). Extensive studies were conducted on the structural, morphological, and optical properties, confirming the successful formation of ternary nanocomposites. The obtained results evidently demonstrate the successful loading of ZnS and Ag onto the surface of the CA. High-resolution transmission electron microscopy analysis revealed that ZnS and Ag nanoparticles (AgNPs) were uniformly distributed on the surface of the CA with an average diameter of 18 nm. The biomass-derived CA, containing a hierarchical porous nano-architecture and an abundant number of -NH2 functional groups on the surface, can greatly prevent the agglomeration, stability and reduce particle size. Brunauer-Emmett-Teller analysis results indicated specific surface areas of 4.62 m2 g-1 for the CA, 48.50 m2 g-1 for the CA/ZnS composite, and 62.62 m2 g-1 for the CA/ZnS-Ag composite. These values demonstrate an increase in surface area upon the incorporation of ZnS and Ag into the CA matrix. Under visible light irradiation, the synthesized CA/ZnS-Ag composites displayed remarkably improved photodegradation efficiency of methylene blue (MB). Among the tested samples, the CA/ZnS-Ag composites exhibited the highest percentage of photodegradation efficiency, surpassing ZnS, CA, and CA/ZnS. The obtained percentages of degradation efficiency for CA, ZnS, CA/ZnS, and CA/ZnS-Ag composites were determined as 26.60%, 52.12%, 68.39%, and 98.64%, respectively. These results highlight the superior photocatalytic performance of the CA/ZnS-Ag composites in the degradation of MB under visible light conditions. The superior efficiency of the CA/ZnS-Ag composite can be attributed to multiple factors, including its elevated specific surface area, inhibition of electron-hole pair recombination, and enhanced photon absorption within the visible light spectrum. The CA/ZnS-Ag composites displayed consistent efficiency over multiple cycles, confirming their stable performance, reusability, and enduring durability, thereby showcasing the robust nature of this composite material.

Dandelion flower-fabricated Ag nanoparticles versus synthetic ones with characterization and determination of photocatalytic, antioxidant, antibacterial, and α-glucosidase inhibitory activities

In the present work, Silver nanoparticles (AgNPs) were fabricated through the dandelion flower hydroalcoholic extract, and their properties were characterized by FTIR, XRD, UV visible, SEM, and EDX. The results demonstrated that the average diameter of the green fabricated AgNPs is 45-55 nm (G-AgNPs). The antioxidant, antimicrobial, antidiabetic, and photocatalytic properties of G-AgNPs were compared with two commercially available different diameter sizes (20 and 80-100 nm) of AgNPs (C-AgNPs1- and C-AgNPs2, respectively). The sample's capacity for antioxidants was evaluated by DPPH free radical scavenging method. The consequences showed that G-AgNPs have higher radical scavenging activity (47.8%) than C-AgNPs2 (39.49%) and C-AgNPs1 (33.91%). To investigate the photocatalytic property, methylene blue dye was used. The results displayed that G-AgNPs is an effective photo-catalyst compared to C-AgNPs2 and C-AgNPs1, which respectively have an inhibition potential of 75.22, 51.94, and 56.65%. Also, the antimicrobial capacity of nanoparticles was assayed against, the gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria. The results indicated that G-AgNPs could effectively inhibit the growth of both bacteria, compared to C-AgNPs1 and C-AgNPs2. Finally, G-AgNPs exhibited a considerable α-glucosidase enzyme inhibitory effect (88.37%) in comparison with C-AgNPs1 (61.7%) and C-AgNPs2 (50.5%).

Anticariogenic potential of tabernaemontana divaricata

Context

Many parts of Tabernaemontana divaricata (T. divaricata) including its leaf is used for the analgesic and antibacterial purpose by Adivasis of Kerala.

Aims

To evaluate the antibacterial potential of T. divaricata against common caries pathogens like S. mutans and L. acidophilus.

Settings and Design

Research is done in Biogenix Research Lab, Thiruvananthapuram.

Methods and Material

Ethyl alcoholic extract of T. divaricata leaves is tested for its antibacterial action against common caries pathogens at various levels. It includes assessing the leaves' antibacterial activity, acid production of bacteria in the presence of the study sample, Minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC) and colony forming units (CFU) levels in the presence of the leaf extract.

Statistical Analysis Used

In descriptive statistics, mean and standard deviation is used. Mann-Whitney U test, Independent Students T-test, Student Paired T-test, and One-way ANOVA followed by Turkeys Post hoc analysis are the tests used in inferential statistics.

Results

It is found that T. divaricata has substantial antibacterial action against S. mutans and L. acidophilus.

Conclusions

Our indigenous plants have a lot of medicinal properties. T. divaricata is no exception to this, though it is commonly considered as a garden plant. In the current study, it has been proven that its leaves have antibacterial action against oral pathogens. So, the research has to be taken to a further level for its medicinal application.