RESUMO
Spodoptera litura Fab. is a polyphagous pest causing damage to many agriculture crops leading to yield loss. Recurrent usage of synthetic pesticides to control this pest has resulted in resistance development. Plant-derived diterpenoid compound andrographolide was isolated from the leaves of Andrographis paniculata. It was analysed by gas chromatography-mass spectroscopy and quantified by HPLC. Nutritional indices and digestive enzymatic profile were evaluated. Third, fourth and fifth instar larvae were treated with different concentrations of andrographolide. At 3, 6 and 9 ppm-treated concentrations the larvae showed decreased RGR, RCR, ECI, ECD values with adverse increase in AD. The digestive enzymes were significantly inhibited when compared with control. Conspicuously, andrographolide showed pronounced mortality of S. litura by inhibition of enzyme secretion and intake of food. The binding ability of andrographolide with CYTP450 showed high affinity with low binding energy. Andrographolide has the potential to be exploited as a biocontrol agent against S. litura as an eco-friendly pesticide.
Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Diterpenos/farmacologia , Proteínas de Insetos/metabolismo , Inseticidas/farmacologia , Spodoptera/efeitos dos fármacos , Amilases/metabolismo , Andrographis/química , Animais , Diterpenos/isolamento & purificação , Diterpenos/metabolismo , Diterpenos/toxicidade , Relação Dose-Resposta a Droga , Inativação Metabólica/efeitos dos fármacos , Inseticidas/isolamento & purificação , Inseticidas/metabolismo , Inseticidas/toxicidade , Larva/efeitos dos fármacos , Lipase/metabolismo , Simulação de Acoplamento Molecular , Peptídeo Hidrolases/metabolismoRESUMO
Dental caries is a common cause for tooth loss and Streptococcus mutans is identified as the etiologic pathogen. This study evaluates the inhibitory potential of Epigallocatechin gallate (EGCG) on S.mutans glucansucrase enzyme and its biofilm. Glucansucrase binding and the inhibitory potential of EGCG was validated using AutoDock tool and enzyme inhibitory assay. Biofilm inhibitory potential was also confirmed using Scanning Electron Microscopic (SEM) analysis in human tooth samples. Molecular docking revealed that EGCG interacted with GLU 515 and TRP 517 amino acids and binds to glucansucrase. SEM analysis revealed inhibition of S.mutans biofilm by various concentrations of EGCG on surfaces of tooth samples. Bioinformatics and biological assays confirmed that EGCG potentially binds to the S. mutans glucansucrase and inhibits its enzymatic activity. Enzymatic inhibition of glucansucrase attenuated biofilm formation potential of S. mutans on tooth surface. Thus, we conclude that EGCG inhibitory potential of S. mutans biofilm on the tooth surface is a novel approach in prevention of dental caries.
Assuntos
Biofilmes/efeitos dos fármacos , Catequina/análogos & derivados , Cárie Dentária/prevenção & controle , Streptococcus mutans/efeitos dos fármacos , Catequina/farmacologia , Catequina/uso terapêutico , Cárie Dentária/microbiologia , Humanos , Microscopia Eletrônica de Varredura , Simulação de Acoplamento Molecular , Streptococcus mutans/ultraestrutura , Dente/microbiologiaRESUMO
Mosquito that accountable for dispersal of dengue fever is Aedes aegypti Linn. and considered to be a chief vector for dengue especially in South Asian countries. Aspergillus flavus is considered to be wild growing green yellow colonies and synthesis highly regulating aflatoxins (B1, B2, G1 and G2) as a secondary metabolite. Mycotoxins of A. flavus showed its efficacy against III and IV instars of Ae. aegypti with more than 90% mortality at the prominent dosage of 2â¯×â¯108 conidia/ml. The proximate lethal concentrations (LC50 and LC90) of mycotoxins against third and fourth instars was 2â¯×â¯105 and 2â¯×â¯107 respectively. Correspondingly, sub-lethal dosage of mycotoxin A. flavus significantly inhibited the level of α- ß-carboxylesterase and SOD activity and upregulated the level of major detoxifying enzymes GST and CYP450. Moreover, sub-lethal dosage also showed higher deterrent and fecundity effects. Gut-histological examination reveals that the A. flavus considerably affected the gut epithelial cells along with the inner gut lumen as compared to the control. The non-target screening of A. flavus against two aquatic predators (A. bouvieri and Tx. splendens) display more than 80% of mortality rate against both the species at the dosage of 2â¯×â¯1016 (two-fold-higher dosage used in larval assays). Thus the biosafety assessment suggests that A. flavus display higher toxicity against the non-targets and it is not-recommended to apply it directly to the aquatic habitat of dengue mosquito which shares their living space with other beneficial insects.
Assuntos
Aedes/efeitos dos fármacos , Aspergillus flavus/metabolismo , Dengue/prevenção & controle , Vetores de Doenças , Micotoxinas/toxicidade , Animais , Carboxilesterase/efeitos dos fármacos , Crustáceos/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios Enzimáticos , Feminino , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/patologia , Glutationa Transferase/efeitos dos fármacos , Inseticidas/toxicidade , Larva/efeitos dos fármacos , Dose Letal Mediana , Mortalidade , Mosquitos Vetores/efeitos dos fármacos , Superóxido Dismutase/efeitos dos fármacosRESUMO
Entomopathogenic fungi are feasible and effective against the agricultural pest. In the current research we investigated the bioactive comparison of two widely accepted entmopathogens (Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae, (basionym)) against the Spodoptera litura (Fab.) through the assessment of larval tolerance and regulation of antioxidants and non-target impact on the earth worm, E. eugeniae, along with commercial pesticides. The entomopathogenic fungus exposure resulted in the modification of the levels of detoxification enzymes as well as significant increases in catalase and superoxide dismutase activity after exposure to the entomopathogenic fungus. Bioassay results showed that B. bassiana and M. anisopliae displayed larval mortality against third and fourth instars. Correspondingly, sub-lethal concentrations of B. bassiana showed development impairment as compared to M. anisopliae. Gut-histology revealed that mycotoxins dosage (4â¯×â¯105) showed significant changes in the midgut tissues as compared to control larvae. The non-target screening through artificial soil assay on the earth worm E. eugeniae, with mycotoxins B. bassiana (5â¯×â¯108 conidia/ml/kg) and M. anisopliae (5â¯×â¯108 conidia/ml/kg) showed less toxicity as compared to Monocrotophos (10â¯ppm/kg). Current results suggest that the fungal mycotoxins of M. anisopliae and B. bassiana significantly reduce the development of lepidopteran pests, while having only lesser impact on beneficial earthworms.
Assuntos
Beauveria , Metarhizium , Micotoxinas/farmacologia , Oligoquetos/efeitos dos fármacos , Controle Biológico de Vetores/métodos , Spodoptera/microbiologia , Animais , Beauveria/crescimento & desenvolvimento , Bioensaio , Larva/crescimento & desenvolvimento , Larva/microbiologia , Metarhizium/crescimento & desenvolvimento , Spodoptera/crescimento & desenvolvimento , Esporos Fúngicos/crescimento & desenvolvimentoRESUMO
Insects have developed tolerance against mycoses caused by entomopathogenic fungi through several humoral and cellular mechanisms. Antioxidant enzymes such as superoxide dismutase, lipid peroxidase, and peroxidase can play a role in defense against mycosis, but the physiological interactions between the fungus and the insect are not well characterized. In this study, the effects of infection by entomopathogenic fungus, Aspergillus flavus on the antioxidant defense system of Spodoptera litura, were investigated. The fungi, A. flavus exposure resulted in modification of the levels of antioxidant enzymes, as well as significant decline in phenoloxidase titers and the total hemocyte count 48â¯h post exposure. A significant increase was observed in detoxifying enzymes. All these results suggest that A. flavus infects S. litura by directly acting on the immune system, resulting in decreased immune function. Bioassay results showed that A. flavus affects third and fourth instar larvae of S. litura. This report supports the importance of A. flavus as a candidate for biological control of S. litura.
Assuntos
Aspergillus flavus/patogenicidade , Larva/fisiologia , Peroxidases/metabolismo , Spodoptera/fisiologia , Superóxido Dismutase/metabolismo , Animais , Bioensaio , Hemócitos/citologia , Sistema Imunitário/imunologia , Larva/enzimologia , Monofenol Mono-Oxigenase/metabolismo , Spodoptera/enzimologia , Spodoptera/crescimento & desenvolvimento , Spodoptera/metabolismoRESUMO
Extracts from Justicia adhatoda L. (Acanthaceae) strongly reduced the fitness of the mosquito, Aedes aegypti Linn. The methanolic extracts inhibited several enzymes responsible for protecting insects from oxidative and other damage, including glutathione-S-transferase, superoxide dismutase, cytochrome P450, and α- and ß-esterases. They increased repellency (maximum repellency at 100 ppm) in host-seeking adult females using the "arm-in cage assay." Histopathological examination showed the extracts led to serious midgut cell damage. Justicia adhatoda extracts led to reduced fecundity and oviposition of gravid females compared to controls. The extracts led to substantially reduced A. aegypti survival. We infer that the extracts have potential to reduce pathogen transmission by suppressing population growth of A. aegypti, and possibly other mosquito species.
Assuntos
Aedes/efeitos dos fármacos , Repelentes de Insetos/farmacologia , Justicia/química , Extratos Vegetais/farmacologia , Aedes/enzimologia , Aedes/fisiologia , Animais , Feminino , Fertilidade/efeitos dos fármacos , Humanos , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Larva/enzimologia , Larva/fisiologia , Oviposição/efeitos dos fármacosRESUMO
Aedes aegypti Linn is one of the most important mosquito species. The vectors are responsible for causing deadly diseases like dengue and dengue hemorrhagic fever. Several chemical pesticides used to control these dengue vectors caused severe toxic significances on human health and other non-target beneficial insects. Therefore the current investigation has been made to access the bio-efficacy of the crude seed extracts of T. chebula against the dengue vector Ae. aegypti. The GC-MS analysis of crude seed extracts of T. chebula identified nine chemical compounds with major peak area in the 1,2,3-Benzenetriol (61.96%), followed by Tridecanoic acid (09.55%). Ae. aegypti larvae showed dose dependent mortality rate was observed between the treatments. Prominent protection rate at greater concentrations of 100ppm and moderate protection at 75 and 50ppm was observed in the repellent assay. Lethal concentration (LC50 and LC90) of fourth instar larvae of Ae. aegypti was observed in 138 and 220ppm concentration respectively. Similarly, the seed extracts showed 100% adulticidal activity at the concentration of 400ppm at 30min of exposure time. Phytochemicals present in the seed extracts of T. chebula significantly affects the major portions of the midgut tissues of Ae. aegypti at the concentration of 100ppm. The toxicological evaluation of seed extracts also proved non-toxic towards the A. bouvieri and Tx. splendens aquatic predatory insects. Hence, the present result suggest that bio-rational plant derived T. chebula could be incorporated in the dengue vector control and have no adverse effects on non-target beneficial insects.
Assuntos
Aedes/efeitos dos fármacos , Inseticidas/farmacologia , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Sementes , Terminalia , Animais , Relação Dose-Resposta a Droga , Insetos/efeitos dos fármacos , Larva/efeitos dos fármacos , Controle de Mosquitos/métodosRESUMO
Resistance to treatments with Temephos or plant derived oil, Pb-CVO, between a field collected Wild Strain (WS) and a susceptible Laboratory Strain (LS) of Ae. aegypti were measured. The Temephos (0.1mg/L) showed the greatest percentage of mosquito mortality compared to Pb-CVO (1.5mg/L) in LS Ae. aegypti. However, WS Ae. aegypti was not significantly affected by Temephos (0.1mg/L) treatment compare to the Pb-CVO (1.5mg/L). However, both strains (LS and WS) when treated with Pb-CVO (1.5mg/L) displayed steady larval mortality rate across all instars. The LC50 of Temephos was 0.027mg in LS, but increased in WS to 0.081mg/L. The LC50 of Pb-CVO treatment was observed at concentrations of 0.72 and 0.64mg/L for LS and WS strains respectively. The enzyme level of α- and ß-carboxylesterase was reduced significantly in both mosquito strains treated with Pb-CVO. Whereas, there was a prominent deviation in the enzyme ratio observed between LS and WS treated with Temephos. The GST and CYP450 levels were upregulated in the LS, but decreased in WS, after treatment with Temephos. However, treatment with Pb-CVO caused both enzyme levels to increase significantly in both the strains. Visual observations of the midgut revealed cytotoxicity from sub-lethal concentrations of Temephos (0.04mg/L) and Pb-CVO (1.0mg/L) in both strains of Ae. aegypti compared to the control. The damage caused by Temephos was slightly less in WS compared to LS mosquito strains.
Assuntos
Inseticidas , Óleos Voláteis , Temefós , Aedes/efeitos dos fármacos , Aedes/enzimologia , Aedes/crescimento & desenvolvimento , Animais , Resistência a Inseticidas , Larva/efeitos dos fármacos , Piper betle/efeitos dos fármacos , Óleos de PlantasRESUMO
The antifungal effects of Citrullus colocynthis extract (Hexane, chloroform, methanol, and water) were tested in vitro on Fusarium oxysporum f. sp. lycopersici (Sacc.) W. C. Snyder & H. N. Hans (FOL), the causal agent of Fusarium wilt. Of these, methanol and water extract at 10% showed the highest inhibition of mycelial growth of FOL by 12.32 and 23.61 mm respectively. The antifungal compounds were identified through Fourier transform infrared (FT-IR) spectroscopy and gas chromatography-mass spectroscopy (GC-MS). The methanol extract was compatible with the biocontrol agent Trichoderma viride. The antagonistic fungi were mass-cultured under laboratory conditions using sorghum seeds. Both T. viride and C. colocynthis methanol extract was also tested alone and together against FOL under both in vitro and in vivo conditions. The combination of T. viride and C. colocynthis showed the highest percentage of antifungal activity (82.92%) against FOL under in vitro conditions. This study revealed that induced systemic resistance (ISR) in enhancing the disease resistance in tomato plants against Fusarium wilt disease. The combined treatment of T. viride and C. colocynthis significantly reduced the disease incidence and index by 21.92 and 27.02% in greenhouse conditions, respectively. Further, the induction of defense enzymes, such as peroxidase (PO), polyphenol oxidase (PPO), ß-1,3-glucanase, and chitinase were studied. The accumulation of defense enzyme was greater in plants treated with a combination of T. viride and C. colocynthis compared to the control. Reduction of wilt disease in tomato plants due to the involvement of defense-related enzymes is presumed through this experiment.
Assuntos
Citrullus colocynthis , Fusarium , Solanum lycopersicum , Antifúngicos/farmacologia , Metanol , Espectroscopia de Infravermelho com Transformada de Fourier , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologiaRESUMO
Aegle marmelos (L.) Correa belongs to the family Rutaceae is generally known as "bael fruit tree" occuring across the south Asian countries. The current investigation screened the main derivatives from crude ethanolic extracts of the Bael tree leaf and evaluated activity effects on the larvae and adults of Aedes aegypti (L.) Dengue vector mosquito and a non-target aquatic predator. The GC-MS results showed that the peak area was found to be profound in N-methyl-1-adamantaneacetamide (N-M 1a) followed by oleic acid (OA) with 63.08 and 11.43% respectively. The larvicidal activity against the fourth instar larvae and the crude Ex-Am showed prominent mortality rate (93.60%) at the maximum dosage of 100 ppm. The mortality rate of N-M 1a and OA was occurred at 10 ppm (97.73%) and 12 ppm (95.4%). The repellent activity was found to be prominent at crude Ex-Am (50 ppm) as compared to the pure compounds (N-m 1a and OA) with maximum protection time up to 210 min. The non-target screening of Ex-Am, N-M 1a, and OA on mosquito predator Tx. splendens showed that they are scarcely toxic even at the maximum dosage of 1000 ppm (34.13%), 100 ppm (27.3%), and 120 ppm (31.3%) respectively. Thus, the present investigation clearly proved that the crude Ex-Am and their major derivatives Nm 1-a and OA showed their acute larval toxicity as well as potential mosquito repellent against the dengue mosquito and eco-safety against the mosquito predator.
Assuntos
Aedes , Aegle , Dengue , Repelentes de Insetos , Inseticidas , Amantadina , Animais , Contenção de Riscos Biológicos , Etanol , Larva , Mosquitos Vetores , Ácido Oleico , Extratos Vegetais , Folhas de Planta , ÁrvoresRESUMO
The effects of crude ethanol derived leaf extract Trichodesma indicum (Linn) (Ex-Ti) and their chief derivatives were accessed on the survival and development of the dengue mosquito Ae. aegypti also their non-toxic activity against mosquito predator. T. indicum is recognized to be the vital weed plant and a promising herb in the traditional ayurvedic medicine. In this study, the GC-MS chromatogram of Ex-Ti showed higher peak area percentage for cis-10-Heptadecenoic acid (21.83%) followed by cycloheptadecanone (14.32%). The Ex-Ti displayed predominant mortality in larvae with 96.45 and 93.31% at the prominent dosage (200 ppm) against III and IV instar. Correspondingly, sub-lethal dosage against the enzymatic profile of III and IV instar showed downregulation of α,ß-carboxylesterase and SOD protein profiles at the maximum concentration of 100 ppm. However, enzyme level of GST as well as CYP450 increased significantly dependent on sub-lethal concentration. Likewise, fecundity and hatchability of egg rate of dengue mosquito decreased to the sub-lethal concentration of Ex-Ti. Repellent assay illustrates that Ex-Ti concentration had greater protection time up to 210 min at 100 ppm. Also, activity of Ex-Ti on adult mosquito displayed 100% mortality at the maximum dosage of 600, 500 and 400 ppm within the period of 50, 60 and 70 min, respectively. Photomicrography screening showed that lethal dosage of Ex-Ti (100 ppm) produced severe morphological changes with dysregulation in their body parts as matched to the control. Effects of Ex-Ti on the Toxorhynchites splendens IV instar larvae showed less mortality (43.47%) even at the maximum dosage of 1500 ppm as matched to the chemical pesticide Temephos. Overall, the present research adds a toxicological valuation on the Ex-Ti and their active constituents as a larvicidal, repellent and adulticidal agents against the global burdening dengue mosquito.
Assuntos
Aedes/efeitos dos fármacos , Boraginaceae/química , Repelentes de Insetos/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Carboxilesterase , Culicidae/efeitos dos fármacos , Dengue/prevenção & controle , Feminino , Fertilidade/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Larva/efeitos dos fármacos , Praguicidas/farmacologia , Extratos Vegetais/análise , Folhas de Planta/químicaRESUMO
Plants naturally produce bioactive compounds along with many secondary metabolites which serve as defensive chemical against herbivorers including insect pests. One group of these phytochemicals are the 'Essential Oils' (EO's), which possess an extensive range of biological activity especially insecticidal and insect repellents. This review provides a comprehensive viewpoint on potential modes of action of biosafety plant derived Essential Oils (EO's) along with their principal chemical derivatives against larvae and adult mosquito vectors of dengue virus. The development and use of Essential Oils (EO's) effectively applied in small rural communities provides an enormous potential for low cost effective management of insect vectors of human pathogens which cause disease.
Assuntos
Dengue/prevenção & controle , Repelentes de Insetos/análise , Inseticidas/análise , Óleos Voláteis/química , Óleos de Plantas/química , Aedes , Animais , Dengue/transmissão , Humanos , Repelentes de Insetos/química , Inseticidas/química , Larva , Mosquitos VetoresRESUMO
Use of environmentally friendly, decomposable natural products for effective vector control has gained considerable momentum in modern society. In this study, essential oil of Sphaeranthus indicus (Si-EO) was extracted and further phytochemical screening revealed fourteen compounds with prominent peak area percentage of 24.9 and 22.54% in 3,5-di-tert-butyl-4-hydroxybenzaldehyde and benzene,2-(1,1-dimethylethyl)-1,4-dimethoxy, respectively. The Si-EO was further evaluated for their larvicidal response against Culex quinquefasciatus and Aedes aegypti at different dosages (62.5, 125, 250 and 500 ppm). The Si-EO displayed prominent larvicidal activity at higher concentration (500 ppm) against both species of mosquitoes. The LC50 and LC90 values of oils were observed at 130 and 350 ppm against C. quinquefasciatus larvae and at 140 and 350 ppm against A. aegypti larvae, respectively. Repellent bioassay established higher protection rate at 200 ppm up to 120 min against both the mosquitoes. However, adulticidal response displayed higher mortality rate only at 700 and 800 ppm against C. quinquefasciatus and A. aegypti, respectively. Toxicological screening against mosquito predator Toxorhynchites splendens revealed that the Si-EO was harmless even at the concentration of 1500 ppm. Overall, these results suggest that the Si-EO plays a significant role as a new bio-rational product against ecological burden mosquito vectors which provides an eco-friendly alternative to synthetic pesticides.
Assuntos
Aedes/efeitos dos fármacos , Asteraceae/efeitos dos fármacos , Culex/efeitos dos fármacos , Repelentes de Insetos/farmacologia , Inseticidas/análise , Larva/efeitos dos fármacos , Óleos Voláteis/química , Folhas de Planta/química , Animais , Vetores de Doenças , Humanos , Repelentes de Insetos/química , Inseticidas/química , Mosquitos VetoresRESUMO
Comparative toxicity of two chemical pesticides (temephos and monocrotophos) versus a plant-derived betel leaf oil Piper betle (L.) to earthworm Eudrilus eugeniae (Kinberg) and redworm Eisenia fetida Savigny, historically: Eisenia foetida (Savigny 1826), was evaluated. Mortality rate was more prominent in temephos at 100 µg concentration to both the earthworms in filter paper test (FPT) as well as 10 mg concentration in artificial soil test (AST). In contrast, P. betle does not display much mortality rate to both the earthworms even at 1000 mg of treatment concentrations. The lethal concentration (LC50) value was observed at 3.89 and 5.26 mg/kg for temephos and monocrotophos against E. eugeniae and 3.81 and 5.25 mg/kg to E. fetida, respectively. Whereas, LC50 value of betel leaf oil was only observed at 3149 and 4081 mg/kg to E. eugeniae and E. fetida, respectively. Correspondingly, the avoidance or attraction assay also displayed that earthworms were more sensitive to the soil containing chemical pesticides. Whereas, the avoidance percentage was decreased in the P. betle oil. Similarly, sublethal concentration of chemical pesticides (5 and 6.5 mg) significantly reduced the earthworm weight and growth rate. However, P. betle oil did not change the developmental rate in the duration of the assay (2, 7 and 14 days) even at 4000 mg treatment concentration. The enzyme ratio of CAT and SOD was also affected significantly after exposure to the chemical pesticides (6.5 mg/kg). Hence, our study implied the risk assessment associated with the chemical pesticides and also recommends plant-derived harmless P. betle oil against beneficial species as an alternative pest control agent.
Assuntos
Óleos Voláteis/química , Oligoquetos/química , Praguicidas/toxicidade , Animais , SoloRESUMO
Plant extracts with their enriched chemical constituents have established potential alternative mosquito control agents. In this research, we developed an eco-friendly mosquitocidal agent from Alangium salvifolium leaves against the dengue and Zika virus vector Aedes aegypti and we investigated its biosafety on the mosquito aquatic predator Toxorhynchites splendens. Results showed that the methanolic extract of A. salvifolium leaves was composed by eight main compounds, with major peak area for hexadecenoic acid (21.74%). LC50 and LC90 values calculated on Ae. aegypti fourth instar larvae were 104.80 and 269.15 ppm respectively. The methanolic extract tested at 100 ppm decreased the α-ß carboxylesterase and SOD ratio significantly and upregulated the GST and CYP450 level. The A. salvifolium methanolic extract displayed significant repellent and adulticidal activity at 100 and 400 ppm respectively. The treatment with 100 ppm of the methanolic extract led to 210 min of protection from Ae. aegypti bites. Four hundred parts per million of the extract showed 98% adult mortality within 30 min from the treatment. Lastly, biosafety assays on the mosquito aquatic predator Tx. splendens showed that the toxicity of the A. salvifolium extract was significantly lower if compared to the cypermethrin-based treatments. The methanolic extract of A. salvifolium showed a maximum of 47.3% mortality rate at the concentration of 1000 ppm, while 0.7 ppm of cypermethrin achieved 91.3% mortality rate on Tx. splendens. Overall, our study enhances basic knowledge on how to improve natural larvicidal agents against dengue and Zika virus mosquito vector with harmless responses on non-target aquatic predators.
Assuntos
Aedes/crescimento & desenvolvimento , Alangiaceae/química , Inseticidas/análise , Larva/crescimento & desenvolvimento , Extratos Vegetais/química , Folhas de Planta/química , Animais , Contenção de Riscos Biológicos , Dengue , Repelentes de Insetos , Controle de Mosquitos/métodosRESUMO
Toxicological screening of Swietenia mahagoni Jacq. (Meliaceae, West Indies Mahogany) against the lepidopteran pest Spodoptera litura was examined. Phytochemical screening through GC-MS analysis revealed nine peaks with prominent peak area % in Bis (2-ethylhexyl) phthalate (31.5%) was observed. The larvae exposed to discriminating dosage of 100â¯ppm deliver significant mortality rate compare to other treatment concentrations. The lethal concentrations (LC50 and LC90) was observed at the dosage of 31.04 and 86.82â¯ppm respectively. Sub-lethal concentrations (30â¯ppm) showed higher larval and pupal durations. However, pupal weight and mean fecundity rate reduced significantly. Similarly, the adult longevity reduced significantly in dose dependent manner. Midgut histology studies showed that the methanolic extracts significantly disturbs the gut epithelial layer, lumen and brush border membrane compare to the control. The soil assay on a non-target beneficial organism, the soil indicator earthworm Eudrilus eugeniae, with extracts from S. mahagoni (200â¯mg/kg) showed no toxicity compared to Monocrotophos at the dosage of 10â¯ppm/kg. Current results suggest that this bio-rational plant product from S. mahagoni displays a significant effect to reduce lepidopteran pests with low toxicity to other beneficial species.
Assuntos
Meliaceae/toxicidade , Oligoquetos/efeitos dos fármacos , Spodoptera/efeitos dos fármacos , Animais , Cromatografia Gasosa-Espectrometria de Massas , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Compostos Fitoquímicos/análise , Extratos Vegetais/toxicidade , Pupa/efeitos dos fármacos , Índias OcidentaisRESUMO
Pinocembrin (5, 7- dihydroxy flavanone) is the most abundant chiral flavonoid found in propolis, exhibiting antioxidant, antimicrobial and anti-inflammatory properties. However, the effect of Pinocembrin on allergic response is unexplored. Thus, current study aimed at investigating the effects of Pinocembrin on IgE-mediated allergic response in vitro. A special emphasis was directed toward histidine decarboxylase (HDC) and other pro-allergic and pro-inflammatory mediators. Preliminary studies, using a microbiological model of Klebsiella pneumoniae, provided first evidences that suggest Pinocembrin as a potential thermal stable inhibitor for HDC. Applying docking analysis revealed possible interaction between Pinocembrin and mammalian HDC. In vitro studies validated the predicted interaction and showed that Pinocembrin inhibits HDC activity and histamine in IgE-sensitized RBL-2H3 in response to dinitrophenol (DNP)-bovine serum albumin (BSA) stimulation. In addition, Pinocembrin mitigated the damage in the mitochondrial membrane, formation of cytoplasmic granules and degranulation as indicated by lower ß-hexoseaminidase level. Interestingly, it reduced range of pro-inflammatory mediators in the IgE-mediated allergic response including tumor necrosis factor (TNF)-α, interleukin (IL)-6, nitric oxide (NO), inducible NO synthase (iNOS), phosphorylation of inhibitory kappa B (IкB)-α, prostaglandin (PGE)-2 and cyclooxygenase (COX)-2. In conclusion, current study suggests Pinocembrin as a potential HDC inhibitor, and provides the first evidences it is in vitro anti-allergic properties, suggesting Pinocembrin as a new candidate for natural anti-allergic drugs.