Mentha piperita silver nanoparticle-loaded hydrocolloid film for enhanced diabetic wound healing in rats.

OBJECTIVE: To investigate the role of Mentha piperita silver nanoparticle-loaded carbopol gel for enhanced wound healing in a diabetic rat model. This research further aims to explore bioactive compounds derived from Mentha piperita obtained from high altitude. METHOD: Methanolic extracts of Mentha piperita (MP), Mentha spicata (MS) and Mentha longifolia (ML) were used to synthesise silver nanoparticles (AgNP). AgNP synthesis was confirmed by ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The antioxidant activity was assessed by 2, 2-diphenyl-1-picrylhydrazyl (DDPH) assay. Antiglycation potential was determined by measuring the fluorescent advanced glycation end products. The bioactive compound identified in the Mentha piperita methanolic (MPM) fraction through electrospray ionisation tandem mass spectrometric analysis (ESI-MS) was responsible for the highest antiglycation. The effects of MPM and MPM.AgNP-loaded Carbopol (Sanare Lab, India) on wound healing were compared in male, alloxan-induced, diabetic albino rats (200-250g), divided into control and treated groups. Effects on wound healing were assessed via histopathology. RESULTS: UV-Vis and FTIR confirmed NP synthesis with peaks for flavonoids and polyphenols. SEM and XRD explored the cubical, 30-63nm crystalline NP. The maximum antioxidant and antiglycation potential was observed in order of; MP.AgNP>MS.AgNP>ML.AgNP. The highest antioxidant activity was observed by methanolic and aqueous MP.AgNPs (88.55% and 83.63%, respectively) at 2mg.ml-1, and (75.16% and 69.73%, respectively) at 1mg.ml-1, compared to ascorbic acid (acting as a positive control, 90.01%). MPM.AgNPs demonstrated the best antiglycation potential of 75.2% and 83.3% at 1mg.ml-1 and 2mg.ml-1, respectively, comparable to positive control (rutin: 88.1%) at 14 days post-incubation. A similar trend was observed for antimicrobial activity against Bacillus subtilis, Micrococcus luteus and Escherichia coli with an inhibition zone of 21mm, 21.6mm and 24.6mm. Rosmarinic acid was the active compound present in Mentha piperita, as identified by ESI-MS. MPM.AgNP-loaded Carbopol resulted in 100% wound closure compared with control at 20 days post-wounding. In the treatment group, re-epithelialisation was achieved by day 18, compared with 25 days for the positive control group. CONCLUSION: MPM.AgNP-loaded Carbopol demonstrated safer and more effective biological properties, hence accelerating the diabetic excision wound healing process in alloxan-induced diabetic rats.

GC-MS metabolomics profile of methanol extract of Acacia modesta gum and gum-assisted fabrication and characterization of gold nanoparticles through green synthesis approach.

Hereunder, for the first time, we reported phytocompounds in the methanolic extract of Acacia modesta (AM) gum through Gas chromatography-mass spectrometry (GS-MS). Further, the AM gum aqueous solution was used for gold nanoparticles (AuNPs) synthesis through a simple, swift, eco-friendly, and less costly green synthesis approach. A total of 108 phytocompounds (63 with nonpolar, 45 with polar column) were identified in the gum extract, which includes fatty acids, alcohols, sterols, aldehyde/ketones, furans, aromatic compounds, esters, phenols, terpenes, sugar derivatives, alkaloids, and flavones. From three used concentrations (5, 10, and 15 mg/mL) of the AM gum aqueous solution, the 15 mg/mL gum solution resulted in more successful AuNP synthesis with a smaller size, which was visualized by a rusty red color appearance. UV-Visible absorption spectroscopy revealed the characteristic surface plasmon resonance (SPR) of AuNPs in aqueous solution at 540 nm. Dynamic light scattering (DLS) measurement of NPs solution revealed a hydrodynamic diameter of 162 ± 02 nm with the highest gum concentration where core AuNPs diameter was 22 ± 03 nm, recorded by Transmission electron microscopy. Zeta potential revealed fair stability of AuNPs that was not decreased with time. Catalytic activity experiments revealed that AM gum-based AuNPs can increase the rate of the reduction of methylene blue 10 times in comparison with AM gum extract alone. Results from this study showed that a diverse array of phytocompounds in AM gum can successfully reduce gold ions into gold nanoparticles, which can be used further in different pharmaceutical and industrial applications.

Biosynthesis of silver nanoparticles from leaf extract of Litchi chinensis and its dynamic biological impact on microbial cells and human cancer cell lines.

Green synthesis of metallic nanoparticles has attracted a great deal of attention from scientific community due to its biocompatibility and environment friendly nature. In the present study, silver nanoparticles were biologically synthesized using leave extracts of Litchi chinensis. Biosynthesized silver nanoparticles were characterized and their applications were observed by different methodologies. Bio-reduction reaction was confirmed by the surface plasmon resonance of silver nanoparticles at 417 nm through UV-VIS spectrophotometer. FTIR analysis revealed that the amine groups present in the leaf extracts were responsible for the reduction of silver ions to silver nanoparticles. X-ray diffraction analysis was used to determine the crystalline nature of silver nanoparticles and their diameter was noted in the range of 41-55 nm by scanning electron microscopy. Antibacterial activity was observed against gram positive and gram negative strains of bacteria. Furthermore, human epithelial type 2 cancer cells (HEp-2) and Human breast adenocarcinoma cells lines (MCF-7) were treated with the biosynthesized silver nanoparticles using MTT assay. The resulting cell death rate was noted up to 40.91+1.99%. This study concludes that plant mediated biosynthesis of nanoparticles is the superior alternative compared to chemical and physical approaches, to utilize them as drug delivery tool and need to conjugate apoptosis inducing biological agents with silver nanoparticles to suppress the uncontrolled division of cancer cells.