RESUMEN
The incorporation of phytoactive compounds in the management of malarial vectors holds promise for the development of innovative and efficient alternatives. Nevertheless, the molecular and physiological responses that these bioactive substances induce remain underexplored. This present study investigated the toxicity of different concentrations of aqueous and methanol extracts of Ocimum tenuiflorum against larvae of Anopheles gambiae (sensu stricto) and unraveled the possible underlying molecular pathways responsible for the observed physiological effects. FTIR and GCMS analyses of phytoactive compounds in aqueous and methanol crude extracts of O. tenuiflorum showed the presence of OH stretching vibration, C = C stretching modes of aromatics and methylene rocking vibration; ring deformation mode with high levels of trans-ß-ocimene, 3,7-dimethyl-1,3,6-octatriene in aqueous extract and 4-methoxy-benzaldehyde, 1,3,5-trimethyl-cyclohexane and o-cymene in methanol extract. The percentage mortality upon exposure to methanol and aqueous extracts of O. tenuiflorum were 21.1% and 26.1% at 24 h, 27.8% and 36.1% at 48 h and 36.1% and 45% at 72 h respectively. Using reverse transcription quantitative polymerase chain reaction (RT-qPCR), down-regulation of ABC transporter, overexpression of CYP6M2, Hsp70, and α-esterase, coupled with significantly increased levels of SOD, CAT, and GSH, were observed in An. gambiae (s.s.) exposed to aqueous and methanol extracts of O. tenuiflorum as compared to the control. Findings from this study have significant implications for our understanding of how An. gambiae (s.s.) larvae detoxify phytoactive compounds.
Asunto(s)
Transportadoras de Casetes de Unión a ATP , Anopheles , Antioxidantes , Proteínas HSP70 de Choque Térmico , Ocimum , Extractos Vegetales , Animales , Anopheles/efectos de los fármacos , Anopheles/genética , Anopheles/metabolismo , Extractos Vegetales/farmacología , Antioxidantes/metabolismo , Transportadoras de Casetes de Unión a ATP/genética , Transportadoras de Casetes de Unión a ATP/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas HSP70 de Choque Térmico/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Larva/efectos de los fármacos , Larva/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Estrés Fisiológico/efectos de los fármacosRESUMEN
Control of mosquito vectors, which have caused a global disease burden, has employed various methods. However, the challenges posed by current physical and chemical methods have raised concerns about vector control programs, leading to the search for alternative methods that are less toxic, eco-friendly, and cost-effective. This study investigated the larvicidal potential of aqueous, methanol, and ethylacetate extracts of Guava (Psidium guajava) against Aedes aegypti and Culex quinquefasciatus larvae. Functional group and phytochemical characterization were performed using Fourier-Transform Infrared Spectroscopy (FTIR) and GC-MS analysis to identify the bioactive compounds in the extracts. Larval bioassays were conducted using WHO standard procedures at concentrations of 12.5, 25, 50, 125, and 250 mg/L, and mortality was recorded after 24, 48, and 72 h. Additionally, antioxidant enzyme profiles in the larvae were studied. All of the solvent extracts showed larvicidal activity, with the methanol extract exhibiting the highest mortality against Ae. aegypti and Cx. quinquefasciatus larvae, followed by aqueous and ethylacetate extracts. FTIR spectroscopic analysis revealed the presence of OH, C-H of methyl and methylene, CO and CC. The GC-MS analysis indicated that the methanol, aqueous, and ethylacetate extracts all had 27, 34, and 43 phytoactive compounds that were effective at causing larvicidal effects, respectively. Different concentrations of each extract significantly modulated the levels of superoxide dismutase, catalase, glutathione peroxidase, and reduced glutathione in larvae. This study's findings indicate the potential for developing environmentally friendly vector control products using the bioactive components of extracts from P. guajava leaves.
Asunto(s)
Aedes , Antioxidantes , Culex , Cromatografía de Gases y Espectrometría de Masas , Larva , Mosquitos Vectores , Extractos Vegetales , Psidium , Animales , Psidium/química , Aedes/efectos de los fármacos , Aedes/enzimología , Extractos Vegetales/farmacología , Extractos Vegetales/química , Larva/efectos de los fármacos , Culex/efectos de los fármacos , Culex/enzimología , Antioxidantes/farmacología , Antioxidantes/aislamiento & purificación , Antioxidantes/química , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/enzimología , Espectroscopía Infrarroja por Transformada de Fourier , Filariasis Linfática/prevención & control , Insecticidas/farmacología , Catalasa/metabolismo , Hojas de la Planta/química , Superóxido Dismutasa/metabolismo , Control de Mosquitos , Dengue/prevención & control , Dengue/transmisión , Bioensayo , Glutatión Peroxidasa/metabolismo , Insectos Vectores/efectos de los fármacosRESUMEN
This study investigated the phytostabilization and plant-promoting abilities of silver nanoparticles (AgNPs). Twelve Zea mays seeds were planted in water and AgNPs (10, 15 and 20 mg mL-1) irrigated soil for 21 days on soil containing 0.32 ± 0.01, 3.77 ± 0.03, 3.64 ± 0.02, 69.91 ± 9.44 and 13.17 ± 0.11 mg kg-1 of As, Cr, Pb, Mn and Cu, respectively. In soil treated with AgNPs, the metal contents were reduced by 75%, 69%, 62%, 86%, and 76%. The different AgNPs concentrations significantly reduced accumulation of As, Cr, Pb, Mn, and Cu in Z. mays roots by 80%, 40%, 79%, 57%, and 70%, respectively. There were also reductions in shoots by 100%, 76%, 85%, 64%, and 80%. Translocation factor, bio-extraction factor and bioconcentration factor demonstrated a phytoremediation mechanism based on phytostabilization. Shoots, roots, and vigor index improved by 4%, 16%, and 9%, respectively in Z. mays grown with AgNPs. Also, AgNPs increased antioxidant activity, carotenoids, chlorophyll a and chlorophyll b by 9%, 56%, 64%, and 63%, respectively, while decreasing malondialdehyde contents in Z. mays by 35.67%. This study discovered that AgNPs improved the phytostabilization of toxic metals while also contributing to Z. mays' health-promoting properties.
Enhanced phytoremediation strategies, which use nanoparticles to boost and facilitate the phytoremediation capacity of plants, are being recommended due to the limitations of traditional phytoremediation employing hyperaccumulating plants alone. Nanoparticles enhance phytoremediation potentials by directly reducing phytoavailable pollutants and promoting plant growth. Silver nanoparticles (AgNPs) are recognized as possessing the ability to enhance the phytoremediation of heavy metals HMs by converting them to a less toxic form and immobilizing the remaining phytoavailable HMs. This is in addition to their potential to modify plant biochemical and physiological properties to counteract HM toxicity.
Asunto(s)
Nanopartículas del Metal , Metales Pesados , Contaminantes del Suelo , Antioxidantes , Plata/toxicidad , Zea mays , Clorofila A , Nanopartículas del Metal/toxicidad , Plomo , Biodegradación Ambiental , Contaminantes del Suelo/toxicidad , Contaminantes del Suelo/análisis , Suelo , Raíces de Plantas/química , Plantas , Metales Pesados/análisisRESUMEN
The effects of a silver nanoparticles (AgNPs)-cow-dung combination on Abelmoschus esculentus physiology, enzyme activities, heavy metal bioaccumulation, and micronutrients were investigated. A. esculentus seedlings were nurtured with foliar application of water, 0.75 mg/L each of AgNPs, cow-dung and AgNPs-cow dung till maturity. AgNPs-cow dung inhibited root and shoot lengths by 12.9% and 24.8%, respectively as opposed to elongation recorded for individual application compared to the control. In contrast to the promotion of photosynthesis, enzyme and antioxidant activities by individual applications, AgNPs-cow dung suppressed more than 50% of these parameters. Implied toxicities of AgNPs-cow dung on A. esculentus manifested in increased malondialdehyde contents with concomitant higher bioaccumulation factor of heavy metals. Cow-dung and AgNPs each stimulated A. esculentus activities in different ways, but their combination was inhibitory, which may be ascribed to the transformed AgNPs in cow-dung and relative availability of toxic metals.
Asunto(s)
Abelmoschus , Nanopartículas del Metal , Metales Pesados , Animales , Bovinos , Plata/toxicidad , Nanopartículas del Metal/toxicidad , Estrés Oxidativo , Metales Pesados/toxicidadRESUMEN
Vector control strategies have focused on the development of effective and ecofriendly alternatives. In the present study, investigation of larvicidal and genotoxic effects of leaves of Hyptis suaveolens from four different extraction solvents (aqueous, hexane, methanol and acetone) on fourth instar larvae of Culex quinquefasciatus was carried out. Extraction was done using soxhlet apparatus and the characteristics functional group of active constituents were identified using Fourier Transform Infrared spectrophotometer. Larvicidal activities were screened using three different concentrations (50, 150 and 250 mg/mL) following WHO standard protocol and mortality was recorded after 24, 48 and 72 hr. Hexane extract showed the highest mortality (27.92, 38.75, 90.42 %; LC50: 272.5, 191.3, 114.8 mg/mL), followed by aqueous extract (20.83, 34.58, 59.58 %; LC50: 496.6, 392.9, 208.1 mg/mL) and acetone extract (20.83, 32.08, 59.58 %; LC50: 1111.2, 393.6, 266.1 mg/mL) and methanol extract (17.92, 29.17, 52.92 %; LC50: 466.0, 400.1, 272.3 mg/mL). Enzyme profile such as superoxide dismutase (SOD), glutathione-S-transferase (GST), catalase (CAT), glutathione (GSH) and alkaline phosphatase (ALP) were significantly altered in the larvae exposed to the four extracts. Phytochemical screening of all solvents extract revealed the presence of saponins, flavonoids, terpenoids and alkaloids as common constituents. Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) profile implied hexane and aqueous extracts altered the DNA of larvae. Furthermore, FTIR Spectroscopic analysis revealed phenols, alcohols, aliphatic primary amines and saponins as the major groups in the extracts. Conclusively, this study established the lethal potential of extracts of H. suaveolens as alternative plant-based and eco-friendly larvicide against Cx. quinquefasciatus.
Asunto(s)
Aedes , Anopheles , Culex , Hyptis , Insecticidas , Animales , Daño del ADN , Insecticidas/química , Insecticidas/farmacología , Larva , Mosquitos Vectores , Extractos Vegetales/química , Hojas de la Planta/química , Técnica del ADN Polimorfo Amplificado AleatorioRESUMEN
This study reports the implications of silver nanoparticles (AgNPs) and cow-dung contamination on water quality and oxidative perturbations in antioxidant biomarkers in the exposed Clarias gariepinus. Sixteen samples of C. gariepinus were exposed to fresh-water, 0.75 mg/mL each of AgNPs, cow-dung and a mixture of AgNPs-cow dung dosed water for 10 days. Cow-dung significantly (p < 0.05) depleted dissolved oxygen (DO) and increased biochemical oxygen demand (BOD) by 14% and 75% respectively. The trends of abundance and bioaccumulation of Ag in C. gariepinus exposed to different treatments followed kidney > muscle > gill > liver, implying the kidney was the worst affected organ. The AgNPs significantly (p < 0.05) perturbed vital organs in C. gariepinus by altering activities of antioxidant biomarkers, whereas AgNPs-cow dung had reduced perturbations implying organic matter bound Ag+ to reduce toxicity. These results conclude that AgNPs posed a challenging environment for C. gariepinus to thrive.