Lethal Concentration 50 Values Research Articles

Evaluation of Preclinical Toxicity of Methanolic Extract of Sargassum tenerrimum using the Zebrafish Model

Introduction: In the field of biomedicine, marine algae have gained significant attention due to the abundance of bioactive compounds they contain. However, studies on the chronic toxicity of algae are limited. Aim: To evaluate the in-vitro, in-vivo acute, and subchronic toxicity of Sargassum tenerrimum (S. tenerrimum) in an adult zebrafish model. Materials and Methods: The current preclinical toxicological interventional study was conducted at the Department of Pharmacology, Sri Ramachandra Medical College and Research Institute, SRIHER, Chennai, Tamil Nadu, India, in September 2022. The algae S. tenerrimum was extracted with methanol using Soxhlet extraction. In-vitro toxicity of S. tenerrimum was performed using the MTT (3-[4,5-dimethylthiazol-2-yl]- 2,5 diphenyl tetrazolium bromide) assay on the SH-SY5Y cell line. Acute toxicity was carried out for 96 hours according to Organisation for Economic Cooperation and Development (OECD) 203 guidelines, and subchronic toxicity was carried out for 14 days on the zebrafish model using the immersion method. Additionally, histopathological changes were observed after the acute toxicity study, and the Lethal Concentration 50 (LC50) value was analysed. Results: The MTT assay of the methanolic extract of S. tenerrimum revealed an LC50 value of 140.014 μg/mL. An acute toxicity study conducted on zebrafish for 96 hours showed an LC50 value of 504.669 mg/L. Subchronic toxicity was done for 14 days, and on the 14th day of exposure, the LC50 value was found to be 404.196 mg/L. Histopathological changes were observed at higher concentrations (800 mg/L) of algal extract. Conclusion: The present study revealed that the methanolic extract of S. tenerrimum showed a toxic effect at higher concentrations on the zebrafish model. However, at lower concentrations, S. tenerrimum was deemed safe for further exploration of pharmacological activities in a zebrafish model.

Toxicity of mixture of polyethylene microplastics and Up Grade® pesticide on Oreochromis niloticus juvenile: I. Hemato-biochemical and histopathological alterations

Acute toxicity experiments were conducted to determine the lethal concentration 50 (LC50) of the Up Grade®46% SL for Oreochromis niloticus. Our results showed that the 96-h LC50 value of UPGR for O. niloticus was 29.16 mg L-1. To study hemato-biochemical effects, fish were exposed for 15 days to individual UPGR at 2.916 mg L-1, individual polyethylene microplastics (PE-MPs) at 10 mg L-1, and to their combinations UPGR+PE-MPs. UPGR exposure induced significant decrease in account of red blood cells (RBCs) and white blood cells (WBCs), platelets, monocytes, neutrophils, eosinophils, and the concentrations of hemoglobin (Hb), hematocrit (Hct), and mean corpuscular hemoglobin concentration (MCHC) than other treatments, compared to the control group. Sub-acute UPGR exposure significantly increase lymphocytes, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH), compared to the control group. In conclusion, UPGR and PE-MPs displayed antagonistic toxic effects due to maybe the sorption of UPGR onto PE-MPs.

PHYSIOLOGICAL EFFECTS OF LEAD ,CADMIUM AND THEIR MIXTURE ON SOME ORGANS OF Alburnus Mossulensis FISH

Alburnus mossulensis has been exposed to lead and cadmium for (96)h in order to determination lethal concentration 50 (LC50) value. A total of 140 fish used in this experiment divided into two groups each group contain 70 fishes .The first group exposure to pbcl2 while the second group exposure to cdcl2. Method of Finney Probit Analysis used to analysis data. LC50 value for PbCl2 and CdCl2 was (57.8 and 29.6) mg/l respectively. Then used about 200 fishes divided into 4 groups, the first group exposure to 1/2LC50 of PbCl2 ,the second group exposure to 1/2LC50 CdCl2 while the third groups contained (1/2LC50 PbCl2+1/2LC50 of CdCl2) as so as control group for peroids (1,4,7 and 14) days to determination level of antioxidants Glutathione (GSH) and the level of lipid peroxidation (Malondialdehyde MDA) . The testes were carried out as three replications, lead ,cadmium and their mixture induced oxidative stress . The results of this study explained significant decrease of the level Glutathione and significant increase (Tukey test, P˂0.05) of the level of Malondialdehye compared with control in all treatments . It is possible to conclude that lead and Cadmium have cytotoxic effects, Fish mortality rates increase with increasing concentrations used and increasing exposure periods.

Acute toxicity of three herbicide formulations of Astyanax altiparanae (Characiformes, Characidae), an emerging neotropical fish model species

ABSTRACT Herbicides are used in agriculture to control harmful crop weeds, prevent algae proliferation, and enhance macrophyte growth. Herbicide contamination of water bodies might exert toxic effects on fish in different development stages. Sperm, embryos, and adults of Astyanax altiparanae were used as a model to examine the detrimental effects of the following herbicide formulations: Roundup Transorb® (glyphosate), Arsenal® NA (imazapyr), and Reglone® (diquat). The lethal concentration 50 (LC50) values for adults using glyphosate and imazapyr were 3.14 mg/L and 4.59 mg/L, respectively, while the LC50 was higher than 28 mg/L for diquat. For the initial stages of embryo development, LC50 values were 16.52 mg/L glyphosate, 9.33 mg/L imazapyr, and 1084 mg/L diquat. Inhibition of sperm motility was noted at 252 mg/L glyphosate, 137 mg/L imazapyr, and 11,300 mg/L diquat, with an average sperm viability of 12.5%, 73.2%, and 89.3%, respectively, compared to 87.5% detected to control. A. altiparanae exhibited different sensitivities to the herbicide formulations investigated in the developmental stages evaluated. Roundup Transorb® exposure was more toxic for adults, while Arsenal® NA was most harmful for early embryonic development and inhibited sperm motility. Reglone® demonstrated low toxicity for A. altiparanae compared to Roundup Transorb® and Arsenal® NA. A. altiparanae may be considered an emerging fish model for toxicological studies for the neotropical region due to its wide distribution and biological characteristics.

Cytotoxicity activity oil of Anguilla marmorata (Q.) Gaimard

Eel fish (Anguilla marmorata (Q.) Gaimard) contains unsaturated fatty acids such as omega-3 and omega-6. Furthermore, EPA and DHA are forms of omega-3 and are known to treat various diseases such as atherosclerosis, cancer, inflammation, heart disease, stroke, lupus, hypertension, impaired growth and intelligence, diabetes, and act as antifungal agents. This study aimed to determine the cytotoxic activity of eel fish oil extract against Artemia salina leach shrimp larvae using the brine shrimp lethality test (BSLT) method. It also aimed to determine the lethal concentration 50 (LC₅₀) value of the oil, which is the concentration that could cause the death of 50% of the test animal population. The cytotoxicity testing was carried out using the larvae of Artemia salina leach shrimp larvae aged 48 hrs and eel fish oil extract at concentrations of 50, 100, 150, 200, 250, 300, 350, 400, 450, and 500 ppm with five repetitions. Furthermore, the cytotoxic effect was observed by calculating the number of shrimp larvae mortality, while the probit analysis was used to determine the LC50 value of the oil. The results showed that the eel fish oil extract had the highest bioactivity against Artemia salina leach shrimp larvae at concentrations of 200, 250, 300, 350, 400, 450, and 500 ppm, respectively, and its LC₅₀ value was 232.6802 ppm, which is <1000 ppm. Therefore, it was concluded that the oil is toxic to Artemia salina leach shrimp larvae and has the potential to be further investigated as an anticancer agent.

Determination of The Lethal Concentration 50% (Lc50) of Cadmium Chloride in mosquito fish Gambusia holbrooki

In this study 24,48 and 96-h exposure of male mosquito fish Gambusia holbrooki to cadmium chloride (CdCl2.H20) was accomplished to determine the cadmium lethal concentration 50 (LC50) in mosquito fish G. holbrooki, The data obtained were statistically evaluated by the use of EPA computer program based on Finney’s Probit Analysis Method and a (24,48 and 96h) LC50 values for Gambusia holbrooki were found to be(37.29 , 42.733 and 50.178) mg/l respectively .

Using Rhizhopora apiculata Extract for Mosquito Larvae Control

Temephos is the most commonly used synthetic larvicide to control vectors of several diseases. Currently in some areas there has been resistance of larvae to temephos, so natural larvicides are needed as an alternative. Rhizophora apiculata contains flavonoid compounds that are respiratory toxins to some larvae. This research was conducted in March - Juny 2022, to determine the inhibitory of mangrove extract against mosquito larvae in brackish water. Samples were collected from the Bakar Bakau Dumai, Riau Indonesia. The experiment was setted in a single factor experimental design. Mangrove leaves are finely ground and kneaded while mixed with water and deposited for 6 minutes and filtered. This extract solution was mixed with brackish water to obtain a test medium of 500 l with a concentration of 6 (a1), 9 (a2) and 12% (a3), positive control or 1 g of abate powder (a4) and negative control or brackish water (a0). A total of 20 mosquito larvae were put into the media and their mortality was observed at 0, 15, 30, 45 and 60 minutes after introduction. The mortality of larvae were then analyzed using probit analysis to obtain LC50 (Lethal Concentration 50) and LT50 (Lethal Time 50) values. R. apiculata extract is toxic to mosquito larvae, where larval death has been seen since 15 minutes and continues until 60 minutes after introduction. At the 60th minute the mortality rate is as follows; a1 (60 %), a2 (80 %), a3 (100 %), a4 (100 %), and a0 a1 ( %). Based on the results of the above probit values ​​in the LC50 and LT50 tests on R. apiculata leaves, the LC50 value is 9,732 while the LT50 value is estimated at 21,217.

Synergistic property of piperonyl butoxide, diethyl maleate, triphenyl phosphate and verapamil hydrochloride with deltamethrin and ivermectin against Rhipicephalus microplus ticks

The present study was taken up to evaluate the synergistic properties of piperonyl butoxide (PBO), diethyl maleate (DEM), triphenyl phosphate (TPP) and verapamil (VER) with deltamethrin (DLM) and ivermectin (IVM) against DLM and IVM resistant tick populations collected from Madhya Pradesh and Punjab states of India. The collected field tick populations were resistant to DLM (Resistance Factor [RF] in the range of 21.71–32.98) and IVM (RF in the range of 1.89–4.98). A strong synergism between DLM and, IVM with PBO and IVM with VER was noticed. The synergistic efficacy of PBO and VER with IVM in reducing the lethal concentration 50 (LC50) value (1.69–5.72 times for PBO and 3.00–10.62 times for VER) of IVM in resistant ticks suggest that a combination of these synergists with IVM can significantly enhance the effectiveness of IVM against IVM-resistant Rhipicephlaus microplus populations gradually establishing in the different parts of the country. The synergistic efficiency of PBO with DLM in reducing the LC50 value was 2.65 and 18.01 times, respectively, against DLM- resistant two R. microplus populations (KTN and LDH). The study revealed the gradual establishment of DLM and IVM resistant populations in the surveyed states suggesting the need to adopt required resistance management strategies. The use of synergists with DLM and IVM has emerged as an effective approach for controlling the acaricide-resistant ticks.

Acute Toxicity Level of Pulutan (Urena lobata) Leaf Extract on Zebrafish (Danio rerio) and its Analysis by In Silico Study

Pulutan (Urena lobata) is one of medicinal plant used to treat some diseases traditionally and pre-clinical studies have showed its efficacy. However, the study about its safety has not been evaluated completely. An acute toxicity test has to be performed in order to screen for its safety. The objective of study to determine the acute toxicity level of Urena lobata (U. lobata) leaf extract on embryo phase, juvenile and adult of zebrafish (Danio rerio) and the role of its active constituents through in silico methods. This was an experimental laboratory study using embryo, juvenile and adult of zebrafish (Danio rerio). The leaf of U. lobata was extracted by decoction methods and the extract was diluted from 12000 mg/L to 500 mg/L. The animals were exposed to the extracts for 96 hours. Toxicity level of herbs was defined using lethal concentration-50 (LC-50) obtained through linear regression. In silico study was performed using a web-based software application (iLAB ACD). The LC-50 values of U. lobata leaf extract for embryo, juvenile and adult of zebrafish (Danio rerio) were 2548 mg/L, 8748 mg/L and 8088 mg/L, respectively. Acute toxicity level of U. lobata on embryo is higher compared to juvenile and adult of zebrafish. After identification of active compound and in silico study was performed, Stigmasterol and β-sitosterol in U. lobata showed high toxicity level based on LD-50 value. Level toxicity of U. lobata on zebrafish embryo was moderate (0.5-5.0 g/L) and it shows teratogenic effect, meanwhile, its effects on juvenile and adult fish were considered mild (5.0-15.0 g/L).

Laboratory efficacy of selected synthetic insecticides against second instar invasive fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae.

Maize is the most essential crop of China and its productivity has been recently endangered by the fall armyworm (FAW), Spodoptera frugiperda. Chemical pesticides are one of the most important strategies for managing FAW on a short-term basis. The seven synthetic insecticides including novel and conventional belong to four chemical group, spinetoram and spinosad (spinosyns), lambda-cyhalothrin, cypermethrin and bifenthrin (pyrethroids), abamectin (avermectins), broflinilide (diamides), were assessed for their efficiency in causing mortality to second instar S. frugiperda larvae at 24, 48 and 72 h post-treatment at five different serial concentrations (10 to 0.625 mg liter-1). The second instar S. frugiperda larvae were susceptible to the tested synthetic insecticides, however, the toxicity index of synthetic insecticides was estimated based on lethal concentration 50 (LC50), while, LC50 was calculated from the data of larval mortality. The broflanilide and abamectin proved to be the most toxic having the highest toxicity index of 100 and 78.29%, respectively, followed by cypermethrin and bifenthrin were showed toxicity index of 75.47 and 66.89%, respectively. The LC50 values were 0.606 and 0.774 mg liter-1 for broflanilide and abamectin, respectively, followed by cypermethrin and bifenthrin were showed LC50 values of 0.803 and 0.906 mg liter-1 at 72 h post-treatment. Rest of the other synthetic insecticides were showed moderate toxicity index of 42.11 to 62.09%, based on LC50 values were 1.439 to 0.976 mg liter-1 at 72 h post-treatment. The efficiency of synthetic insecticides was increased by increasing concentration level and exposure time. The screened synthetic insecticides among seven insecticides perhaps, provide basis for the development of novel insecticides for controlling S. frugiperda population after further research to evaluate and validate the laboratory results in the field.

Polymer-based nanostructures loaded with piperine as a platform to improve the larvicidal activity against Aedes aegypti

Piperine is an alkaloid extracted from the seed of Piper spp., which has demonstrated a larvicidal effect against Ae. aegypti. The incorporation of piperine into nanostructured systems can increase the effectiveness of this natural product in the control of Ae. aegypti larvae. In this study, we evaluated the effectiveness of piperine loaded or not into two nanostructured systems (named NS-A and NS-B) prepared by the nanoprecipitation method. The Ae. aegypti larvae were exposed to different concentrations of piperine loaded or not (2 to 16 ppm) and the mortality was investigated after 24, 48, and 72 hours. The nanostructures prepared were spherical in shape with narrow size distribution and great encapsulation efficiency. The lethal concentration 50 (LC50) for non-loaded piperine were 13.015 ppm (24 hours), 8.098 ppm (48 hours), and 7.248 ppm (72 hours). The LC50 values found for NS-A were 35.378 ppm (24 hours), 12.091 ppm (48 hours), and 8.011 ppm (72 hours), whereas the values found for NS-B were 21.267 ppm (24 hours), 12.091 ppm (48 hours), and 8.011 ppm (72 hours). Collectively, these findings suggested that non-loaded piperine caused higher larval mortality in the first hours of exposure while the nanostructured systems promoted the slow release of piperine and thereby increased the larvicidal activity over time. Therefore, loading piperine into nanostructured systems might be an effective tool to improve the larval control of vector Ae. aegypti.

Impact of Nitrogen Fertilizer use on Soil Ecosystem Integrity in the Greater Port Harcourt Region, Nigeria

Fertilizers are used in agriculture to increase crop yields, but if they are misused, they can harm the integrity of soil ecosystems. The study's aim was to look at the impact of inorganic fertilizers on soil microbial populations in selected soils in the Greater Port Harcourt Area using Lethal Concentration 50 (LC50). The results revealed that the use of inorganic fertilizer altered soil microbial characteristics in three different settings: agricultural, urban, and industrial. For agricultural areas the maximum NPKB mean value was 0.70±0.76 ppm which was higher than the mean value of the control location of 0.23±0.00 ppm. In the agricultural area, UREA tolerant fungi had a lower LC50 mean value (0.43±0.09 ppm) than the control, which had a mean value of 0.46±0.00 ppm. The mean values in the industrial and urban areas were significantly different (p = 0.001). This study concluded that applying UREA and NPK fertilizers to study area soils lowered the pH of soils in agricultural sites (A1, A2, and A3). Fertilizer use in the study areas increased the population of microorganisms at threshold concentrations but was harmful at concentrations of 1.50 % or higher. Furthermore, findings revealed that microorganisms were more tolerant to fertilizers in agricultural areas (higher LC50 values) than in urban and industrial areas (lower LC50 values). According to the findings of this study, fertilizers used in the study areas were linked to soil microorganisms developing tolerance to NPK and UREA. Farmers should use the recommended amounts of fertilizer to ensure the soil ecosystem's integrity.

Accelerating the pace of ecotoxicological assessment using artificial intelligence

Species Sensitivity Distribution (SSD) is a key metric for understanding the potential ecotoxicological impacts of chemicals. However, SSDs have been developed to estimate for only handful of chemicals due to the scarcity of experimental toxicity data. Here we present a novel approach to expand the chemical coverage of SSDs using Artificial Neural Network (ANN). We collected over 2000 experimental toxicity data in Lethal Concentration 50 (LC50) for 8 aquatic species and trained an ANN model for each of the 8 aquatic species based on molecular structure. The R2 values of resulting ANN models range from 0.54 to 0.75 (median R2 = 0.69). We applied the predicted LC50 values to fit SSD curves using bootstrapping method, generating SSDs for 8424 chemicals in the ToX21 database. The dataset is expected to serve as a screening-level reference SSD database for understanding potential ecotoxicological impacts of chemicals.

Toxicity of sphagneticola trilobata extracts against spodoptera litura larva

Spodoptera litura is one of the polyphagous pests that cause damage to many agricultural commodities. Chemical control method was known as a major method use by farmers. Application of plant-based insecticide is an effort to decrease the negative effects of using synthetic insecticides. Sphagneticola trilobata is a weeds species which has potential to use as plant-based insecticides material. This study aims to determine the toxicity of S. trilobata extract in S. litura, as an effort to obtain alternative control materials that are more environmentally friendly. The material used is the leaves and flowers of S. trilobata extracted using water. The treatment concentration consisted of control, 20 ml / l, 40 ml / l, 60 ml / l, and 80 ml / l which were repeated 5 times. The application method used is the residual method on the leaves. Mortality data were analyzed using probit analysis to obtain a Lethal Concentration 50 (LC50) value. The results showed that flower extract was more toxic compared to leaf extract with LC50 value of 277.5 ml / l.

Components and acute toxicity of nanoherbal haramonting (Rhodomyrtus tomentosa)

Introduction: Rhodomyrtus tomentosa (haramonting), a typical plant of North Sumatera, Indonesia, contains important medicinal ingredients. Nano sized drugs have high loading capacities and can be given at high concentrations. This study aimed to determine the components and toxicity of nanoherbal haramonting. It also aimed to determine the effect of nanoherbal haramonting on the histology of the liver, kidneys, lungs, heart and brain. Methods: High-energy milling was performed to produce nanoherbal haramonting. Thin-layer chromatography was utilised to determine the chemical components of the nanoherb. Antioxidant tests were performed by using the 1,1-diphenyl-2-picryhydrazil method. The three-stage of lethal dose 50 (LD50) which comprised the dose orientation test, preliminary test and actual phase test/LD50 determination, and the Thomson–Weil formula was applied to measure the lethal concentration 50 (LC50) of nanoherbal haramonting. Organs were collected for histological investigation after 14 days of the lethality test. Results: Nanoherbal haramonting had an average diameter distribution of 600.1 nm ± 135.8. It contained flavonoids, steroids, glycosides, saponins and tannins. Its LC50 and LD50 values were 2961.535 ppm and 10.4 ± 0.135 mg/kg BW, respectively. The histology of the heart, kidney, lungs, heart and brain were changed and affected by nanoherbal haramonting treatment at each dose level. Conclusion: Nanoherbal haramonting has strong antioxidative activity and small size, can be effectively used as medicine in the future because it contains secondary metabolite compounds that can be developed as drugs. However, it has mild toxicity.

EFFECTIVITY OF EXTRACT LEAF, FRUIT, ROOT MANGROVE Avecennia marina ON Aedes aegypti

Inhibiting the life of the Aedes aegypti mosquito is the mian way that is done to eradicate DBF, which is popularly done by chemically synthetic insecticides can be used air pollution and poisoning of humans so it needs safer natural incecticides such as compounds derived from mangrove plants. Mangrove Avecennia marina contains saponis, flavonoids, and alkaloids can act as stomach poisons resulting in larval death. The study was conducted in Februari-Maret 2019. The purpose of the study was to deteremine the efectiveness of extracts of leaves, fruit Avecennia marina mangrove root that quickly inhibit the growth of Aedes aegypyi larvae. The method used was the experimental method, the location of the research sample taking in Kayu Ara Village, Siak Riau Province. Results showed the mangrove leaves at a concentration of 12% mosquito larvae deaths reached 99 tails in the 120th minute, results showed the mangrove fruit at a concentration of 12% mosquito larvae deaths reached 96 tails in the 120th minute, Results showed the mangrove root at a concentration of 12% mosquito larvae deaths reached 85 tails in the 120th minute, analyzed using probit analysis to obtain LC50 (Lethal Concentration 50) and LT50 (Lethal Time 50) values. The LC50 probit analysis velue is estimate leaves 2.721, estimate fruit 1.584 dan estimate root 1,232. Whereas at LT50 estimate leaves 2.841, fruit 1.579, root 1.115.

EFFECTIVITY OF NIPAH (Nypa fruticans) EXTRACT ON (Aedes aegypti) LARVAE IN BRACKISH WATER

The most commonly used method of vektor control is temephos (the synthetic larvicide). Currently in some areas there has been resistance of aedes aegypti larvae to temephos, so that natural larvicide is required as an alternative. Nypa exctract contains flavonoid compounds that are respiratory toxins that can kill aedes aegypty larvae.This research was conducted in January - February 2019. The purpose of this study was to determine the inhibitory power of nipah extract against larvae in brackhish water. The results of this study are expected to increase knowledge and provide information about the pontential of nipah as a soursce of bioactive compounds. The method used is the experimental method, where the location of the research sampel was obtained at one sampling location point in the Sungai Kayu Ara village, Siak Riau province. The results showed that the average mortality of larvae in nipah laeves in the 60th minute was 55, 80, 100 and 100%. While root extracts have larvae deaths as many as 60 minutes, namely 100, 90, 90, and 100%. For the average mortality of larvae at the root of nipah there are 60 minutes, which are 95, 100, 100 and 100%. As wel as positive and negative controls as a comparison. So it can be compared to 3 administration of nipah extract both leaves, roots and midrib so that the three conncentrations used are better than the use of midrib extract compared to leaf and root extract. It can be concluded that the more concentration used the higher the mortality of larvae is the concentration of 12%. For the concentration used the percentage of larvae mortality in the test media is as much as 6%, 9% and 12%. Every death of larvae has reristance to different bodies so that at the 30th minute there is a difference in mortality of larvae wich a given concentration. The larvae species used are aedes aegyti larvae. The highest mortality of dead es was found in midrib extract and also positive controls. So that the death of larvae is very effective against the given solution has the same ability. The mortality of A. aegypti larvae were then analyzed using probit analysis to obtain LC50 (Lethal Concentration 50) and LT50 (Lethal Time 50) values. The results of the probit analysis of leaf, root and midrib extracts are the estimation of LC50 1.493, 2.618, 0.005. while leaf , root and midrib extracts at the LT50 estimate were 2.841, 1.579, 2.227

Larvicidal Activity of Ketapang Leaf Fraction (Terminalia catappa L) on Aedes aegypti Instar III.

BACKGROUND:Mosquito control is essential in preventing mosquito-borne diseases. Natural substances originated from plants possessed the great potential of insecticidal properties, the resistance occurs at a slower rate compared to the synthetics, with less toxicity to other living creatures.AIM:This study aimed to identify the fraction of ketapang leaf (Terminalia catappa L) with larvicidal activity on Aedes aegypti instar III larvae, the concentration of ketapang active leaf fraction comparable to temephos, and Lethal Concentration 50 (LC50).METHODS:This study was experimental in vitro. The experiment was performed with five different concentrations of ketapang leaf water-ethanol fraction, i.e. 1200 ppm, 1400 ppm, 1600 ppm, 1800 ppm, 2000 ppm. Observation of morphological damage of mosquito larvae was conducted with the microscope and ImageJ application. Data analysis was performed using One Way ANOVA. LC50 was determined with probit analysis.RESULTS:Phytochemical screening revealed a water-ethanol fraction of ketapang leaf contained tannin, saponin, and flavonoid compounds. The water-ethanol fraction with 1800 ppm concentration possessed significant larvicidal effect comparable to temephos. Probit test revealed an LC50 value of 1563.082 μg/ml.CONCLUSION:Water-ethanol fraction of ketapang leaf possessed high biolarvicidal activity against Ae. aegypti larvae instar III comparable to temephos.

Bright red-emitting highly reliable styryl probe with large stokes shift for visualizing mitochondria in live cells under wash-free conditions

Bright red-emitting pyridinium cyanine based styryl probe 2 is synthesized in good yields. Probe 2 demonstrated a large Stokes’ shift (Δλ ≈ 128 nm, 4227 cm−1 in DCM) and excellent fluorescent quantum yield (Φf1 ≈ 0.2 - 0.7) due to strong Intra-molecular charge transfer (ICT). Probe 2 was found to exhibit exceptional selectivity for cellular mitochondria in both normal (COS-7) and cancer (A549) cell lines. Probe 2 is readily applicable as a “wash-free” dye to visualize mitochondria as it does not require post-staining washing prior to imaging. Styryl probe 2 also showed an excellent biocompatibility as the calculated LC50 (lethal concentration, 50%) value was > 20 μM. Probe 2 emission did not show any interferences from anionic species or other biological molecules. Probe 2 is readily excitable (λex∼460 and λem∼618 nm) with the available laser (454 nm) in commercial microscopes and thus it can be a useful probe for mitochondrial tracking in live cells.

RiHSPRO2, a nematode resistance protein-like homolog from a wild crucifer Rorippa indica (L.) Hiern, is a promising candidate to control mustard aphid Lipaphis erysimi

Nematode resistance protein HSPRO2 of Arabidopsis thaliana has important roles in defence response to the bacterium (Pseudomonas syringae) and shows response against oxidative stress and salicylic acid. We have explored the gene encoding it from Rorippa indica (L.) Hiern, a wild relative of cultivated crucifers experimentally challenged with mustard aphid Lipaphis erysimi. The gene seems to be a strong candidate for aphid tolerance in cultivated mustards. Presently we are reporting the results of a time-course quantitative relative expression analysis of HSPRO2 of R. indica where we have observed ~ tenfold increase in its expression in R. indica at 12 hours post infestation with L. erysimi. We have also isolated the full-length gene (1314 bp) by both 5′ and 3′ RACE (Rapid Amplification of cDNA Ends). Genome walking experiment identified the promoter sequence. Expression, purification and characterisation of RiHSPRO2 showed that it encodes for a 437 amino acid peptide. The 66 kDa recombinant RiHSPRO2 protein was purified for studying its efficacy against L. erysimi in an artificial diet-based insect bioassay that revealed LC50 (Lethal Concentration 50) values of RiHSPRO2 significantly within limits against L. erysimi. The present study might have a significant implication in future towards aphid management program of Brassica juncea through the development of aphid-tolerant transgenic plants.