Green Synthesis of Copper Oxide Nanoparticles Synthesized by Terminalia chebula Dried Fruit Extract: Characterization and Antibacterial Action

Nanomaterial in controlling biofilms and virulence of microbial pathogens

The escalating threat of antimicrobial resistance (AMR) poses a grave concern to global public health, exacerbated by the alarming shortage of effective antibiotics in the pipeline. Biofilms, intricate populations of bacteria encased in self-produced matrices, pose a significant challenge to treatment, as they enhance resistance to antibiotics and contribute to the persistence of organisms. Amid these challenges, nanotechnology emerges as a promising domain in the fight against biofilms. Nanomaterials, with their unique properties at the nanoscale, offer innovative antibacterial modalities not present in traditional defensive mechanisms. This comprehensive review focuses on the potential of nanotechnology in combating biofilms, focusing on green-synthesized nanoparticles and their associated anti-biofilm potential. The review encompasses various aspects of nanoparticle-mediated biofilm inhibition, including mechanisms of action. The diverse mechanisms of action of green-synthesized nanoparticles offer valuable insights into their potential applications in addressing AMR and improving treatment outcomes, highlighting novel strategies in the ongoing battle against infectious diseases.

Anticariogenic, Antidiabetic, and Toxicology Evaluation of the Ethanolic Extract of Croton bonplandianum: An In Vitro Study

Background Herbal medicine has gathered increasing attention in contemporary healthcare practices, offering natural remedies for a wide range of ailments such as skin diseases, liver disorders, bronchitis, and asthma. Among the plethora of medicinal plants, Croton bonplandianum, commonly known as "Ban Tulsi," holds significant medicinal value owing to its diverse pharmacological properties. This study investigated the cytotoxicity, embryotoxicity, antidiabetic, and anticariogenic effects of an ethanolic extract derived from C. bonplandianum. The research objectives were to explore the preparation of an ethanolic extract of C. bonplandianum and employ a multifaceted approach by evaluating its cytotoxicity, embryotoxicity, anticariogenic, and antidiabetic potentials. Materials and methods In this study, the β-glucosidase inhibitory and the α-amylase inhibitory assays were utilized to evaluate the antidiabetic activity of the C. bonplandianum ethanolic extract. The in vitro cytotoxicity activity was assessed by using the brine shrimp lethality assay (BSLA), and embryotoxicity was evaluated using zebrafish embryos and larvae. Through the agar well diffusion method and the time-kill curve analysis, the anticariogenic activity was evaluated. Results In α-amylase and β-glucosidase inhibitory assays, the ethanolic extract of C. bonplandianum showed potent antidiabetic properties, near those of standard acarbose. The cytotoxicity evaluation using the BSLA showed less toxicity. The anticariogenic activity of the ethanolic extract of C. bonplandianum was assessed by comparing the standard (Amoxyrite) in terms of its zone of inhibition against oral pathogens such as Streptococcus mutans and Lactobacillus species (spp.). The antibacterial efficiency was validated using a time-kill curve assay in which the study depends on the concentration of the bacterial pathogenic organisms, namely, Lactobacillus spp. and S. mutans. In embryotoxicity evaluation, there were no morphological malformations in zebrafish larvae or embryos when exposed to high concentrations of C. bonplandianum ethanolic extract. Conclusion The ethanolic extract of C. bonplandianum exhibited promising antidiabetic and anticariogenic effects, supporting its conventional usage in alternative medicine. The outcomes of these research analyses suggest the plant potential as a natural source of compounds with bioactive qualities and can be utilized in the healthcare and pharmaceutical industries.

Green Synthesis of Copper and Copper Oxide Nanoparticles From Brown Algae Turbinaria Species' Aqueous Extract and Its Antibacterial Properties

Background Copper and copper oxide nanoparticles synthesized by green methods have attracted considerable attention due to their environmentally friendly properties and potential applications. Green synthesis involves non-hazardous and sustainable techniques used in the production of a wide range of substances, including nanoparticles, pharmaceuticals, and chemicals. These methods often use different organisms, including bacteria, fungi, algae, and plants, each offering different advantages in terms of simplicity, cost-effectiveness, and environmental sustainability. The environmentally friendly nature of these green synthesis methods responds to the growing need for sustainable nanotechnologies. Brown algae have gained popularity due to their distinct morphological characteristics and diverse biochemical composition. This research focuses on the process of synthesizing copper and copper oxide nanoparticles from the brown algae Turbinaria. It emphasizes the natural ability of the bioactive compounds contained in the algae extract to reduce and stabilize the nanoparticles. The green synthesis of copper and copper oxide nanoparticles from brown algae has demonstrated a wide range of applications, including antibacterial activity. Materials and methods Fresh Turbinaria algae were collected from marine environments to ensure that they were free of contaminants. The algae underwent a purification process to remove impurities and were dried. An aqueous extract was prepared by pulverizing the dried algae and mixing them with distilled water. A copper salt solution utilizing copper nitrate was prepared. The algae extract was mixed with the copper salt solution. There are bioactive compounds in the algae extract that help reduce copper ions, which makes copper and copper oxide nanoparticles come together. The reaction mixture was incubated in a controlled environment to facilitate the growth and enhance the stability of the nanoparticles. To separate the nanoparticles from the reaction mixture, centrifugation was employed, or filtration was done with Whatman filter paper (Merck, Burlington, MA). The nanoparticles were dried to yield a stable powder. Results Copper and copper oxide nanoparticles derived from brown algae extract showed antibacterial effects against Streptococcus mutans, Klebsiella sp., and Staphylococcus mutans. The scanning electron microscopy (SEM) analysis verified the irregular shape and elemental content of the synthesized copper and copper oxide nanoparticles. The X-ray diffraction (XRD) analysis indicated that the synthesized nanoparticles exhibited a crystallinity nature and were composed of a mixture of copper and copper oxide species, namely face-centered cubic and monoclinic structures. The transmission electron microscopy (TEM) images showed copper and copper oxide nanoparticles that were evenly distributed and had a rectangular shape. They exhibited substantial antimicrobial activity against both Gram-positive and Gram-negative bacteria. Conclusions This study enhances the field of green synthesis techniques by showcasing the adaptability of Turbinaria brown algae to synthesize copper and copper oxide nanoparticles. It underscores the potential advantages of these nanoparticles in terms of their antibacterial properties.

Free Radical Scavenging, Anti-inflammatory and Antibacterial Activity of Acorus calamus Leaves Extract Against Pseudomonas aeruginosa and Staphylococcus aureus

Background Herbal medicine, or phytotherapy, has been used for centuries in traditional healing practices to harness the therapeutic properties of different plant-derived elements. Acorus calamus, a perennial herbaceous plant, has significant historical importance in traditional medicine, specifically in Ayurveda, where it is referred to as "Vacha." This study investigates the antioxidant, anti-inflammatory, and antimicrobial characteristics of the A. calamus dimethyl sulfoxide (DMSO) extract. The objectives of the research are to provide valuable knowledge about the preparation of A. calamus DMSO extract and to explore its potential anti-inflammatory, antioxidant, and antimicrobial effects. Materials and methods The A. calamus DMSO extract was derived from leaves, and its antioxidant activity was evaluated through the use of the 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay, hydroxyl radical scavenging assay (H2O2 assay), and ferric reducing antioxidant power (FRAP) assay. The anti-inflammatory activity was assessed using the Bovine serum albumin (BSA) denaturation assay, egg albumin (EA) denaturation assay, and membrane stabilization assays. The antimicrobial activity was analyzed using the agar well diffusion technique and the time-kill curve assay. Results In DPPH and H2O2 tests, the DMSO extract of A. calamus showed significant antioxidant activity, near that of standard ascorbic acid. The FRAP assay demonstrated a correlation between the dose and the activity of reducing ferric ions. The A. calamus DMSO extract exhibited significant anti-inflammatory properties in BSA and EA denaturation assays, similar to the standard diclofenac sodium. The anti-inflammatory potential of the A. calamus DMSO extract was further confirmed through the membrane stabilization assay. The DMSO extract of A. calamus exhibited a significant inhibition zone against the pathogens Streptococcus mutans and Pseudomonas aeruginosa during the antimicrobial evaluation, surpassing the efficacy of the standard antibiotic. The time-kill curve assay validated the antibacterial efficacy, which was dependent on the concentration. Conclusion The A. calamus DMSO extract exhibited promising antioxidant, anti-inflammatory, and antimicrobial properties, supporting its traditional use in alternative medicine. The findings suggest its potential as a natural resource of compounds with bioactive properties for use in pharmaceutical and nutraceutical applications.

Evaluation of Free Radical Scavenging and Antimicrobial Activity of Coleus amboinicus-Mediated Iron Oxide Nanoparticles

Background In this research, iron oxide nanoparticles were synthesized using Coleus amboinicus stem extract, which is used for various diseases such as throat infection, cough, fever, nasal congestion, and digestive problems.  Aim This study aimed to formulate a green synthesis of iron oxide nanoparticles mediated by Coleus amboinicus (known as karpuravalli in Tamil) and assess its antimicrobial and antioxidant properties.  Materials and methods Iron oxide nanoparticles were synthesized, and then their antimicrobial properties were tested against two specific pathogens, i.e., Streptococcus mutans and Candida albicans, using the agar well diffusion technique. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, hydroxyl radical scavenging (H2O2) assay, and ferric ion reducing antioxidant power (FRAP) assay were conducted to check the free radical scavenging activity.  Result The results obtained showed that these iron oxide nanoparticles showed better antimicrobial activity against Streptococcus mutans when compared to Candida albicans, and the antioxidant activity showed a very close efficacy when compared to the standard.  Conclusion The research has demonstrated the high antioxidant activity and high antibacterial activity of iron oxide nanoparticles using Coleus amboinicus stem, a natural and cheaper antimicrobial drug compared to the drugs present on the market.