Chidambaram Jayaseelan

Natural products can serve as an alternative source of novel therapies that are required to address the problem of malarial infection resistance. Indian gooseberry (Phyllanthus emblica L.) leaves are often used in traditional medicine to treat fevers, but there isn't enough scientific proof that they contain antimalarial and effective phytochemicals. This study's primary goal was to investigate the antimalarial efficacy of P. emblica leaf ethyl acetate extract against Plasmodium falciparum (3D7) and its cytotoxicity against the HeLa cell line. The active compounds from P. emblica were isolated using a bioassay-guided fractionation of column chromatography technique, and NMR spectroscopy was employed to identify their structures. The drug's anti-malarial efficacy was assessed by estimating its growth-inhibitory activities employing the SYBR Green I asexual parasite drug assay. The cytotoxic effect was evaluated using the MTT assay. P. falciparum dihydroorotate dehydrogenase protein (Pf-DDP) was used as a drug target to investigate molecular docking. P. emblica crude extract and two fractions exhibited > 90% inhibition of 3D7 parasite proliferation, indicating good antimalarial activity at 100 and 10 µg/mL, respectively. Subsequently, the column chromatography study of each fraction, a targeted purification, contributed to the separation of six active compounds designated as 9-hydroxy isolongifolene (C1), Hexadecanoic acid (C2), Phenol, 2,6-Bis(1,1-Dimethylethyl) (C3), Furan, tetrahydro-3-methyl-4-methylene (C4), Octadecanoic acid (C5), and Beta-Sitosterol (C6). Compound C4 showed stronger bioactivity against P. falciparum (3D7) (IC₅₀ 4.32 µg/mL) parasites than other constituents, equivalent to the drug-sensitive strains (100 µg/mL). Considering the IC₅₀ levels of the two compounds, 90.56 and > 100 µg/mL, respectively, both demonstrated low cytotoxicity against HeLa cell lines. This research offers scientific support for the historical application of P. emblica in combating malaria. Building on existing knowledge, this study represents a groundbreaking effort to isolate and identify antimalarial compounds from P. emblica leaves for the first time. Moreover, our research underscores the potential of P. emblica in the development of antimalarial agents, encouraging further investigation of different species to suppress the growth of P. falciparum. This plant species could be a valuable source for developing new anti-malarial drugs.

The present work aimed to biofabricate copper oxide nanoparticles (CuO NPs) using Tinospora cordifolia leaf extract. The biofabricated CuO NPs were treated against the malarial parasite of chloroquine-resistant Plasmodium falciparum (INDO) and the antilarval efficacy was evaluated against the malaria vector Anopheles stephensi and dengue vector Aedes aegypti. The prominence at 285 nm in the UV–visible spectrum helped to identify the produced CuO NPs. Based on the XRD patterns, the concentric rings correspond to reflections at 38.26° (111), 44.11° (200), 64.58° (220), and 77.34° (311). These separations are indicative of CuO’s face-centered cubic (fcc) structure. The synthesized CuO NPs have FTIR spectra with band intensities of 3427, 2925, 1629, 1387, 1096, and 600 cm⁻¹. The absorbance band at 3427 cm⁻¹ is known to be associated with the stretching O-H due to the alcoholic group. FTIR proved that the presence of the -OH group is responsible for reducing and capping agents in the synthesis of nanoparticles (NPs). The synthesized CuO NPs were found to be polymorphic (oval, elongated, and roughly spherical) in form with a size range of 11–47 nm and an average size of 16 nm when the morphology was examined using FESEM and HRTEM. The highest antiplasmodial efficacy against the chloroquine-resistant strain of P. falciparum (INDO) was found in the synthesized CuO NPs, with LC₅₀ values of 19.82 µg/mL, whilst HEK293 cells are the least toxic, with a CC₅₀ value of 265.85 µg/mL, leading to a selectivity index of 13.41. However, the antiplasmodial activity of T. cordifolia leaf extract (TCLE) and copper sulfate (CS) solution showed moderate activity, with LC₅₀ values of 52.24 and 63.88 µg/mL, respectively. The green synthesized NPs demonstrated extremely high antilarval efficacy against the larvae of An. stephensi and Ae. aegypti, with LC₅₀ values of 4.06 and 3.69 mg/L, respectively.