Toxicity potential evaluation of ethyl acetate extract of Cymodocea serrulata against the mosquito vectors vis-a-vis zebrafish embryos and Artemia salina cysts

Green Synthesis of Cymodocea serrulata Zinc Oxide Nanoparticles for Sustainable Antibacterial, and Mosquito Control and their Toxicity to non-target Organisms

Mosquito-borne diseases such as dengue, malaria, and filariasis have become serious global health concerns due to their contagious nature and widespread prevalence. In this study, ZnO NPs biosynthesized using the seagrass extract of Cymodocea serrulata (CS-ZnO NPs) were prepared from the leaf part and evaluated for their toxicity potential against the larvae, pupae, and adults of various mosquito species, including Aedes aegypti, Culex quinquefasciatus, and Anopheles stephensi. The CS-ZnO NPs were characterized using UV-Vis spectroscopy, XRD, FTIR, FE-SEM, EDX, and zeta potential analyses. The CS-ZnO NPs demonstrated significant antibacterial activity against tested bacterial strains: Pseudomonas otitidis (22 ± 0.81 mm), Enterococcus faecalis (18.66 ± 0.47 mm), Bacillus subtilis (14 ± 0.81 mm), and Serratia marcescens (9.66 ± 0.47 mm). Among the mosquito species tested, A. stephensi exhibited the most effective toxicity response. The ovicidal activity of CS-ZnO NPs against A. stephensi showed 12% egg hatchability at a concentration of 100 µg/mL. Furthermore, the larvicidal efficacy of CS-ZnO NPs against A. stephensi displayed strong lethal effects, with LC50 and LC90 values (in µg/mL) recorded as follows: 2.79 and 72.86 for the first instar, 5.89 and 209.93 for the second instar, 7.38 and 328.43 for the third instar, 9.56 and 435.36 for the fourth instar larvae; 8.18 and 357.68 for pupae; and 4.51 and 238.96 for adults. Biosafety assessments were conducted on Danio rerio embryos and Artemia salina nauplii to confirm the non-toxic nature of CS-ZnO NPs. Overall, C. serrulata-synthesized CS-ZnO NPs present a promising, eco-friendly alternative for controlling mosquitoes and eradicating deadly mosquito-borne diseases such as filariasis, dengue, and malaria.

Seagrass Meadows: Prospective Candidates for Bioactive Molecules

Seagrass meadows consist of angiosperms that thrive fully submerged in marine environments and form distinct ecosystems. They provide essential support for many organisms, acting as nursery grounds for species of economic importance. Beyond their ecological roles, seagrasses and their associated microbiomes are rich sources of bioactive compounds with the potential to address numerous human healthcare challenges. Seagrasses produce bioactive molecules responding to physical, chemical, and biological environmental changes. These activities can treat microbe-borne diseases, skin diseases, diabetes, muscle pain, helminthic diseases, and wounds. Seagrasses also offer potential secondary metabolites that can be used for societal benefits. Despite numerous results on their presence and bioactive derivatives, only a few studies have explored the functional and therapeutic properties of secondary metabolites from seagrass. With the increasing spread of epidemics and pandemics worldwide, the demand for alternative drug sources and drug discovery has become an indispensable area of research. Seagrasses present a reliable natural source, making this an opportune moment for further exploration of their pharmacological activities with minimal side effects. This review provides a comprehensive overview of the biochemical, phytochemical, and biomedical applications of seagrasses globally over the last two decades, highlighting the prospective areas of future research for identifying biomedical applications.

A Phytochemical Analysis and the Pharmacological Implications of the Seagrass Halodule uninervis: An Overview

Seagrasses are marine angiosperms that inhabit tropical and subtropical regions around the world. They play a vital role in marine biodiversity and the ecosystem by providing habitats and food for several marine organisms, stabilizing sediments, and improving water quality. Halodule uninervis from the family Cymodoceaceae has been used in traditional folk medicine for the treatment of many ailments. Additionally, several identified bioactive metabolites have been shown to contribute to its pharmacological activities, including anticancer, anti-inflammatory, and antioxidant. As such, H. uninervis could contribute to the development of novel drugs for various diseases. This review aims to compile the phytochemical composition and pharmacological activities of H. uninervis. Furthermore, details about its botanical characteristics and ecological significance are also discussed. By providing valuable insights into the role of H. uninervis in both the marine ecosystem and biomedicine, this review helps to highlight its potential as a therapeutic agent for future drug discovery and development.

Synthesis and characterization of marine seagrass (Cymodocea serrulata) mediated titanium dioxide nanoparticles for antibacterial, antibiofilm and antioxidant properties

Cymodocea serrulata mediated titanium dioxide nanoparticles (TiO2 NPs) were successfully synthesized. The XRD pattern and FTIR spectra demonstrated the crystalline structure of TiO2 NPs and the presence of phenols, flavonoids and alkaloids in the extract. Further SEM revealed that TiO2 NPs has uniform structure and spherical in shape with their size ranged from 58 to 117 nm. Antibacterial activity of TiO2 NPs against methicillin-resistant Staphylococcus aureus (MRSA) and Vibrio cholerae (V. cholerae), provided the zone of inhibition of 33.9 ± 1.7 and 36.3 ± 1.9 mm, respectively at 100 μg/mL concentration. MIC of TiO2 NPs against MRSA and V. cholerae showed 84% and 87% inhibition at 180 μg/mL and 160 μg/mL respectively. Subsequently, the sub-MIC of V. cholerae demonstrated minimal or no impact on bacterial growth at concentration of 42.5 μg/mL concentration. In addition, TiO2 NPs exhibited their ability to inhibit the biofilm forming V. cholerae which caused distinct morphological and intercellular damages analysed using CLSM and TEM. The antioxidant properties of TiO2 NPs were demonstrated through TAA and DPPH assays and exposed its scavenging activity with IC50 value of 36.42 and 68.85 μg/mL which denotes its valuable antioxidant properties with potential health benefits. Importantly, the brine shrimp based lethality experiment yielded a low cytotoxic effect with 13% mortality at 100 μg/mL. In conclusion, the multifaceted attributes of C. serrulata mediated TiO2 NPs encompassed the antibacterial, antioxidant and anti-biofilm inhibition effects with low cytotoxicity in nature were highlighted in this study and proved the bioderived TiO2 NPs could be used as a promising agent for biomedical applications.

Evaluation of Brown and red seaweeds-extracts as a novel larvicidal agent against the deadly human diseases-vectors, Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus

Infectious diseases such as malaria, dengue, and yellow fever are predominantly transmitted by insect vectors like Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus in tropical regions like India and Africa. In this study, we assessed the larvicidal activity of commonly found seaweeds, including Padina gymnospora, P. pavonica, Gracilaria crassa, Amphiroa fragilissima, and Spatoglossum marginatum, against these mosquito vectors. Our findings indicate that extracts from P. gymnospora Ethyl Acetate (PgEA), P. pavonica Hexane (PpH), and A. fragilissima Ethyl Acetate (AfEA) displayed the highest larval mortality rates for A. stephensi, with LC50 values of 10.51, 12.43, and 6.43 μg/mL, respectively. Additionally, the PgEA extract from P. gymnospora exhibited the highest mortality rate for A. aegypti, with an LC50 of 27.0 μg/mL, while the PgH extract from the same seaweed showed the highest mortality rate for C. quinquefasciatus, with an LC50 of 9.26 μg/mL. Phytochemical analysis of the seaweed extracts revealed the presence of 71 compounds in the solvent extracts. Fourier-transform infrared spectra of the selected seaweeds indicated the presence of functional groups such as alkanes, alcohols, and phenols. Gas chromatography-mass spectrometry analysis of the seaweeds identified major compounds, including hexadecanoic acid in PgEA, tetradecene (e)- in PpEA, octadecanoic acid in GcEA, and 7-hexadecene, (z)-, and trans-7-pentadecene in SmEA.