Phytochemical screening, metabolite profiling and enhanced antimicrobial activities of microalgal crude extracts in co-application with silver nanoparticle

Abstract

Background: Microalgae is one of the major sources of natural compounds with antimicrobial activity. The metabolite profiling of the extracts could identify the bioactive compounds based on methanol (MET), ethanol (ETH), chloroform (CHL), hexane (HEX) and water (W) solvent systems. The microalgal crude extracts in co-application with silver nanoparticles (AgNPs) had enhanced antimicrobial activity with potential to overcome the global problem of microbial antibiotic resistance. Results: Chlorella sp. exhibited the highest lipid, N. oculata the highest total saturated fatty acids (TSFA), and T. suecica the highest mono-unsaturated (MUFA) and poly-unsaturated fatty acids (PUFA). The highest carbohydrate, protein and total phenolics contents (TPCs) were attained by N. oculata. The highest total flavonoids contents (TFCs), and chlorophyll a and b were in T. suecica, while comparable level of carotenoids were found in all species. For high-performance thin-layer chromatography (HPTLC) analyses, the eicosapentaenoic acid (EPA) with high peaks were detected in T. suecica-HEX and N. oculata-CHL; and β-carotene in Chlorella sp.-ETH. The gas chromatography-mass spectrometry (GC-MS) analyses showed high 13-docosenamide (Z)-in T. suecica-HEX; phytol in N. oculata-HEX; and neophytadiene in Chlorella sp.-ETH. The AgNPs-MCEs-MET and HEX at the 1.5:1 ratios exhibited strong activities against Bacillus subtilis, Streptococcus uberis, and Salmonella sp.; and the AgNPs-T. suecica-HEX and MET and AgNPs-Chlorella sp.-HEX at the 1.5:1 ratios exhibited activities against Klebsiella pneumoniae. Conclusion: Different bioactive components were detected in the MCEs based on the HPTLC and GC-MS analyses. Significant antimicrobial activities against the pathogenic microbes were demonstrated by the synergistic effects of the MCEs in co-application with the AgNPs. This could be beneficial in the fight against sensitive and multidrugresistant bacteria.

Nano/microparticles in conjunction with microalgae extract as novel insecticides against Mealworm beetles, Tenebrio molitor

“…Indeed, 1-nonadecene, 1-octadecene, 1-tetradecene, and diisooctyl phthalate have been shown to exert insecticidal or antibacterial activity across several species 35 . Although the mechanism of the C. reinhardtii extract was not addressed in detail here, the increased larvicidal activity of nanoparticles when mixed with its extract might be derived from the actions of bioactive compounds such as phenolic compounds and flavonoids 16 , 36 . Previous studies on the antimicrobial activity of ZnO nanoparticles hypothesized that reactive oxygen species (ROS) generated by the surface of ZnO NPs triggered irreversible damage to the microbial cell wall.…”

Formulasi Ekstrak Etanol Mikroalga Chroococcus turgidus untuk Sediaan Masker Peel-off sebagai Antibakteri

“…Berdasarkan tes dengan pereaksi FeCl3 5% senyawa fenol menunjukkan hasil positif yang dicirikan dengan perubahan warna ekstrak dari bening kehijauan menjadi warna biru kehitaman. Hussein et al 2020, menyatakan bahwa senyawa fenol yang diekstrak menggunakan pelarut polar dan semi polar pada Chlorella sp, Nannochloropsis oculata dan Tetraselmis suecica memiliki kemampuan menghambat pertumbuhan bakteri Gram positif dan negatif.…”

Cytotoxicity and 1H NMR metabolomics analyses of microalgal extracts for synergistic application with Tamoxifen on breast cancer cells with reduced toxicity against Vero cells

“…The new chemo-preventive drugs against breast cancer need to consider the safety and efficacy aspects to improve the therapeutics management and reduce the high cost and pain of patients ( Steward and Brown, 2013 ). There has been an increasing interest to develop novel therapeutic strategies against cancer using drugs or cytotoxic agents based on natural compounds ( Gurunathan et al., 2013 ; Hussein et al., 2020a , b , c , d ). Natural-based products including benzylpenicillin, didemnin B, girolline, lovastatin, bryostatin 1, dolastatin 10, cryptophycins, kahalalide F and bengamide derivative are utilized in clinical trials for cancer, cognitive diseases, analgesia and allergy ( Newman and Cragg, 2004 ).…”