Larvicidal, ovicidal and repellent activities of marine sponge Cliona celata (Grant) extracts against Anopheles stephensi Liston (Diptera: Culicidae)

OBJECTIVE@#To evaluate the larvicidal, ovicidal and repellent properties of solvent extracts of marine sponge Cliona celata (C. celata) (Grant) against the malarial vector Anopheles stephensi (An. stephensi) Liston.@*METHODS@#Marine sponge C. celata was thoroughly washed with distilled water and shade dried for 48 h. Then the sponges were homogenized and extracted sequentially with hexane, ethyl acetate and methanol. Larvicidal and ovicidal activities were tested at four different concentrations viz., 62.5, 125.0, 250.0 and 500.0 ppm. For repellent study extracts were taken in three different concentrations viz., 5.0, 2.5, 1.0 mg/cm at.@*RESULTS@#Among the three solvent extracts of C. celata, methanol extract showed the highest larvicidal activity at 500 ppm against the fourth instar larvae of An. stephensi. The LC50 and LC90 values of C. celata methanol extract were recorded as 80.61 and 220.81 ppm against An. stephensi larvae respectively. High ovicidal activity of 91.2% was recorded at 500 ppm concentration of methanol extract. The haxane extract was found to be the most effective protectant against the adult female mosquitoes of An. stephensi. The mean protection time recorded in hexane extract was up to 245 min at 5 mg/cm(2) dosage against An. stephensi adults.@*CONCLUSIONS@#The screening results suggest that the hexane and methanol extracts of C. celata are promising in mosquito control. Considering these bioactivities, C. celata could be probed further to obtain some novel pesticidal molecules.

Larvicidal, ovicidal and repellent activities of marine sponge Cliona celata (Grant) extracts against Anopheles stephensi Liston (Diptera: Culicidae)

Objective: To evaluate the larvicidal, ovicidal and repellent properties of solvent extracts of marine sponge Cliona celata (. C. celata) (Grant) against the malarial vector Anopheles stephensi (. An. stephensi) Liston. Methods: Marine sponge C. celata was thoroughly washed with distilled water and shade dried for 48 h. Then the sponges were homogenized and extracted sequentially with hexane, ethyl acetate and methanol. Larvicidal and ovicidal activities were tested at four different concentrations viz., 62.5, 125.0, 250.0 and 500.0 ppm. For repellent study extracts were taken in three different concentrations viz., 5.0, 2.5, 1.0 mg/cm at. Results: Among the three solvent extracts of C. celata, methanol extract showed the highest larvicidal activity at 500 ppm against the fourth instar larvae of An. stephensi. The LC50 and LC90 values of C. celata methanol extract were recorded as 80.61 and 220.81 ppm against An. stephensi larvae respectively. High ovicidal activity of 91.2% was recorded at 500 ppm concentration of methanol extract. The haxane extract was found to be the most effective protectant against the adult female mosquitoes of An. stephensi. The mean protection time recorded in hexane extract was up to 245 min at 5 mg/cm2 dosage against An. stephensi adults. Conclusions: The screening results suggest that the hexane and methanol extracts of C. celata are promising in mosquito control. Considering these bioactivities, C. celata could be probed further to obtain some novel pesticidal molecules.

Feeding deterrent and growth inhibitory activities of PONNEEM, a newly developed phytopesticidal formulation against Helicoverpa armigera (Hubner)

<p><b>OBJECTIVE</b>To assess the feeding deterrent, growth inhibitory and egg hatchability effects of PONNEEM on Helicoverpa armigera (H. armigera).</p><p><b>METHODS</b>Five oil formulations were prepared at different ratios to assess the feeding deterrent, growth inhibitory and egg hatchability effects on H. armigera.</p><p><b>RESULTS</b>Invariably all the newly formulated phytopesticidal oil formulations showed the feeding deterrent and growth inhibitory activities against H. armigera. The maximum feeding deterrent activity of 88.44% was observed at 15 µL/L concentration of PONNEEM followed by formulation A (74.54%). PONNEEM was found to be effective in growth inhibitory activities and egg hatchability at 10 µL/L concentration. It exhibited statistically significant feeding deterrent activity and growth inhibitory activity compared with all the other treatments.</p><p><b>CONCLUSIONS</b>PONNEEM was found to be effective phytopesticidal formulation to control the larval stage of H. armigera. This is the first report for the feeding deterrent activity of PONNEEM against H. armigera. This newly formulated phytopesticide was patented in India.</p>

Antibacterial activity of some actinomycetes from Tamil Nadu, India

<p><b>OBJECTIVE</b>To isolate novel actinomycetes and to evaluate their antibacterial activity.</p><p><b>METHODS</b>Three soil samples were collected from Vengodu (village) in Kanchipuram district, Tamil Nadu, India. Actinomycetes were isolated using serial dilution and plating method on actinomycetes isolation agar.</p><p><b>RESULTS</b>Totally 35 isolates were obtained on the basis of colony characteristics on actinomycetes isolation agar. All the isolates were screened for antibacterial activity by cross streak method. Medium and optimization of day were done for the potent strains using Nathan's agar well diffusion method. Isolation of bioactive compounds from significant active isolates was done by using different media. The most active isolate VAS 10 was identified as Actinobacterium Loyola PBT VAS 10 (accession No. JF501398) using 16s rRNA sequence method. The hexane, ethyl acetate, dichloromethane and butanol extracts of VAS 10 were tested against bacteria. The maximum antibacterial activity was observed in dichloromethane and ethyl acetate; maximum zones of inhibition were observed against Enterococcus durans. The rRNA secondary structure and the restriction sites of Actinobacterium Loyola VAS 10 were predicted using Genebee and NEBCutter online tools respectively.</p><p><b>CONCLUSIONS</b>The present study showed that among the isolated actinomycetes, Actinobacterium Loyola PBT VAS 10 (accession No. JF501398) showed good antibacterial activity against the tested bacteria.</p>

Ovicidal activity of Atalantia monophylla (L) Correa against Spodoptera litura Fab. (Lepidoptera: Noctuidae)

<p><b>OBJECTIVE</b>To evaluate the efficacy of Atalantia monophylla (A. monophylla) leaf in different solvent crude extracts and fractions against eggs of Spodoptera litura (S. litura).</p><p><b>METHODS</b>Hexane, ethyl acetate and chloroform solvent extracts of A. monophylla leaf and 12 fractions from hexane extract were screened at 5.0%, 2.5%, 1.0% and 0.5% for crude extracts and 1 000, 500, 250 and 125 mg/kg for fractions against the eggs of S. litura for the ovicidal activity. LC50 and LC90 were calculated using probit analysis.</p><p><b>RESULTS</b>Hexane crude extract showed maximum ovicidal activity of 61.94% at 5.0% concentration with a correlation value of r (2)=0.81, and least LC50 value of 3.06%. Hexane extract was fractionated using silica gel column chromatography and 12 fractions were obtained. Fraction 9 was active which showed maximum ovicidal activity of 75.61% at 1 000 mg/kg with the LC50 value of 318.65 mg/kg and LC90 value of 1 473.31 mg/kg. In linear regression analysis, significant and high correlation (r (2)=0.81%) was seen between concentration and ovicidal activity of hexane crude extracts and its active fraction.</p><p><b>CONCLUSIONS</b>As per our knowledge, this is the first report for ovicidal activity of A. monophylla against S. litura, A. monophylla could be used for the management of S. litura and other insect pests.</p>

Antidiabetic and Hypolipidemic effect of methanol extract of Lippia nodiflora L. in streptozotocin induced diabetic rats

Objective: To assess the antidiabetic and hypolipidemic properties of Lippia nodiflora (L. nodiflora).Methods:Acute toxicity test was done to check the toxicity of L. nodiflora methanol extract and oral glucose tolerance test was performed in normal rats. L. nodiflora methanol extract at three dose levels was administerd orally to streptozotocin (STZ) (40mg/kg bw) induced diabetic rats for 15 days. The various parameters were studied including body weight, fasting blood glucose levels, plasma insulin, lipid profile, glycogen content, glycoslylated hemoglobin (HbA1c) and serum marker enzyme levels in normal, treated and diabetic rats. Histochemical analysis of pancreas was also carried out in normal, treated and diabetic rats. Results: The treatment group with the extract at three dose levels showed a significant increase in the liver, muscle glycogen and serum insulin level and a significant decrease in fasting blood glucose, glycosylated hemoglobin levels and serum marker enzyme levels. The total cholesterol and serum triglycerides levels were also significantly reduced and the high density lipoprotein level was significantly increased upon treatment with the L. nodiflora methanol extract. Histochemical study of pancreas also confirmed the biochemical findings. Acute toxicity studies revealed the non-toxic nature of the L. nodiflora methanol extract. Conclusions: The results of the experiments presented here suggest that methanol extract of L. nodiflora exerts significant antidiabetic and hypolipidaemic effect in STZ-induced diabetic rats.