Preliminary screening of plant essential oils against larvae of Culex quinquefasciatus Say (Diptera: Culicidae)

Preliminary screenings of 22 plant essential oils were tested for mortality of the mosquito larvae Culex quinquefasciatus under laboratory conditions. Percent (%) mortality of the mosquito larvae were obtained for each essential oil. At different exposure periods, viz. 1, 3, 6, 12 and 24 h among the 22 plant oils tested, eight oils viz., aniseed, calamus, cinnamon, clove, lemon, orange, thyme, and tulsi oils gave promising results on larvicidal activity. For larvicidal screening bioassay, the mortality was recorded at different exposure periods viz., 1, 3, 6, 12 and 24 h, and it was found that larval mortality increased when exposure time increased. The clove oil was found to be the most effective treatment. In the preliminary screening, clove oil gave 100% mortality at all exposure periods. Vetiver oil recorded 36.2, 61.2, 76.2, 87.5 and 100% mortality in 1, 3, 6, 12 and 24 h, respectively. Results of this study show that the essential oils may be a potent source of natural larvicides.Key words: Screening, essential oils, Culex quinquefasciatus, Larvicidal

Plants used as Medicine by Paliyar Tribes of Shenbagathope in Virudhunagar District of Tamilnadu, India

The traditional medicinal uses of 58 angiospermic plant species belonging to 54 genera of 31 families for various diseases and ailments like wounds, cuts, stomach pain, diabetes, fever, cold, poisonous bites etc., by the Paliyar tribes of Shenbagathope in Virudhunagar district of Tamilnadu, India, are mentioned. Generally, fresh part of the plant is used for the preparation of medicine. When fresh plant parts are not available, dried parts are also used. Attention should be made on proper exploitation and utilization of these ethnomedicinally important plant species

ADULTICIDAL ACTIVITY OF BOTANICAL OILS BY IMPREGNATED PAPER ASSAY AGAINST CULEX QUINQUEFASCIATUS SAY

Objective: The present study was undertaken with the aim of finding out the efficacy of essential oils (EOs) as anti-mosquito agents for commercial purposes. Plant source insecticides as an alternative to chemical insecticide, this study were evaluated to assess the knock-down and adulticidal prospective of the essential oils against Culex quinquefasciatus. The plant essential oil is largely cultivated throughout India and in all Tropical countries.Methods: The selected botanical essential oils were procured from commercial producers of plant essential oils and aromatic substances were used in this study. Knock-down and Adulticidal bioassay was performed according to WHO protocol. A single dose of the essential oils was used in the preliminary screening. 20 adult mosquitoes (3-5 d old glucose fed mosquitoes) were exposed on treated paper for one hour and knocked down and live mosquitoes were counted at 5 minute intervals.Results: Among the twenty three oils tested, 100% knock-down and adult mortality was recorded at 10%/cm2dose of calamus, camphor, cinnamon, citronella, clove, eucalyptus, lemongrass, pine, thyme and tulsi oils respectively. At 10 % concentration, clove oil (KT50 =1.8 and KT90 = 2.03 min) was found to be the most potential treatment. After 15 min exposure period clove oil registered the lowest knock-down dosewhich was calculated as (KD50 =1.8 %/cm2and KD90 =11.2 %/cm2). The lower and upper 95 % confidence limits for clove oil were calculated as 0.2 and 4.2 min respectively.Conclusion: From the results it can be concluded that the adult of the Cx. quinquefasciatus were susceptible to the essential oils. Such findings would be useful in promoting research aiming at the development of new agent for mosquito control on basis of chemical compounds from indigenous plant sources as an alternative to chemicals

PHYTOCHEMICAL CONSTITUENTS AND HYPOGLYCEMIC EFFECT OF GYMNEMIC ACID EXTRACTS FROM BIG AND SMALL LEAF VARIETIES OF Gymnema Sylvestre R.Br

Phytochemical and hypoglycemic effects of two varieties of Gymnema sylvestre were studied. The leaves of Big-leaf (MCL) and the small-leaf (ZMGL) varieties were grown in Uka Tarsadia University, Bardoli, India. Water, ethanol, methanol, petroleum ether, haxane and chloroform were used for phytochemical extraction from the dried leaves. Gymnemic acid was extracted and purified from the two varieties by Thin Layer Chromatography (TLC). Four groups of matured whisker rats (six per group) were induced with high-glucose level. Three groups were treated with standard drug Glibenclamide (5mg/kg), gymnemic acid extracts from MCL and ZMDL respectively while the fourth group served as experimental control. Hypoglycemic activities of extracts were evaluated using animals’ blood sample. Result showed water and methanol are best solvents for phytochemical extraction from the plant and the yield is higher in ZMGL than MCL. Also, gymnemic acid yield varied. From the results, hypoglycemic activities from the animals’ blood revealed that treatments from both MCL and ZMGL are not significantly different from standard drug Glibenclamide. The study concluded that water or methanol is appropriate solvent for phytochemical extraction from G. sylvestre leaves and extract from both lines of the plant could be utilized to reduce blood glucose levelKeywords: phytochemical extraction, extraction solvents, gymnemic acid, hypoglycemic effect

Culture of Efficient Marine Microalgae, Their Biochemical Composition and its Antibacterial Activity against Human Pathogens

Marine microalgae have been used for a long time as food for humans such as Chlorella vulgaris, Spirulina platensis and Nannochloropsis bacillaris and for animals in aquaculture. The biomass of these microalgae and the compounds they produce have been shown to possess several biological applications with numerous health benefits. The three marine microalgae (Chlorella vulgaris, Spirulina platensis and Nannochloropsis bacillaris) were collected from Vellar estuary, South east coast of India. These three microalgae were cultivated in respective media (BG11, Conway, and Zarrouk) and estimated their biochemical composition (Protein content, Carbohydrate (CHO) analysis, Total lipids, Chlorophyll, Carotenoids and antibacterial activity. Simultaneously, these cultures were cultivated in flask containing 500 ml of respective media at lab condition for a period of one month and their growth, pH, biomass, CO2 fixation and carbon content were determined. Based on the growth rate, the pH of three microalgae in media was observed at lab condition. During maximum growth and biomass, the pH was found to be ranged between 9 and 11 for Spirulina platensis; 7 and 9 for Chlorella vulgaris; 8 and 9 for Nannochloropsis bacillaris. The Spirulina platensis and Chlorella vulgaris reached maximum growth rate and produced maximum biomass. Further, Chlorella vulgaris and Spirulina platensis attained maximum biomass in media at lab condition, also fixed highest level of carbon dioxide in media but they did not produce maximum biomass, though the growth of Nannochloropsis bacillaris were found high in media at lab condition. Among the three microalgae, Chlorella vulgaris and Spirulina platensis produced highest biochemical (Protein estimation) compounds. Hence, Chlorella vulgaris and Spirulina platensis were selected as efficient microalgae for antibacterial activity against human pathogen. This study revealed that certain green algae and blue green microalgae having high growth, pH, CO2 fixation, carbon content and biochemical composition paves the way for pharmaceutical activity. Antibacterial activity against human pathogen (Klebsiella pneumoniae, Proteus mirabilis, Vibrio cholera, Salmonella typhi and Escherichia coli) was evaluated.The crude and fractionated extraction of Chlorella and Spirulina were dissolved in different solvents like ethanol, methanol, chloroform and diethyl ether. The extracts were applied to 6 mm dry sterile disc in aliquots of 30 μL of solvent, allowed to dry at room temperature and placed on agar plates seeded with microorganisms. The bacteria were maintained on nutrient agar plates and incubated at 37˚ C for 24 hrs. Zones of growth inhibition were measured after incubation from all the extracts and tested twice at a concentration of 30 mg disc-1 was evaluated for Chlorella and Spirulina with their potential health benefits.Keywords: Chlorella vulgaris, Spirulina platensis, Nannochloropsis bacillaris, CO2 fixation, Biochemical composition, Pharmaceutical activit

The Application of Microalgae an Impending Bio-Fertilizer: Maize Cultivation as a Model

The increasing demand of food crops and decrease in productivity due to continuous use of chemical fertilizer has not only resulted in decline of crop yield, loss of fertility and degradation of soil but has also led us one step back in achieving sustainable agriculture. The use of algal bio-fertilizer provides an effective, ecofriendly and non-polluting approach in improving the productivity of crop by both nitrogen fixation and photosynthesis. Algal bio-fertilizers improve soil structure and increase yield productivity even if applied in a small area. The application of algal bio-fertilizers in plants has resulted in increase in root, shoot length with number of leaves and hence overall growth of the plant has been increased. India being one of the largest producer and consumer of pulses requires abundant amount of pulse production to fulfill the demands of ever growing populations which can be achieved by using algal bio-fertilizers.Microalgae efficiently utilize and remove the nitrogen and phosphorus present in wastewater and assimilate these in valuable algal biomass. Yet, besides macronutrients such as N, P and K, microalgae also contain plant growth-promoting substances such as vitamins, carotenoids, amino acids and antifungal substances. In this study, the valorisation of microalgae as an organic slow-release fertilizer is presented.The fertilizer potential of both fresh water and marine microalgal biomass was determined; more specifically dried microalgal biomass, cultivated on microalgae in various natural and chemical methods. In the first stage the mineralization rate of both types of biomass was determined. Also a dosage toxicity test for Ca2+ and Na+ was performed using seedlings of lettuce and garden cress, respectively. Subsequently, a greenhouse maize growth experiment was performed, wherein the fertilizer potential of both types of microalgal biomass was compared with conventional inorganic and organic microalgae fertilizers. The growth rate of the maize plants and the maize yield were assessed for each fertilizer treatment, as well as the leave composition and the water, sugar and carotenoid concentrations in the maize seed. The results of the study show there was no significant difference in plant growth between the fertilizer treatments with microalgae and the conventional algae fertilizer. This demonstrates the potential of microalgae an impending fertilizer for agriculture applications.Keywords: Microalgae, Agriculture, Bio-fertilizer, Maize, Application

The Application of Microalgae an Impending Bio-Fertilizer: Maize Cultivation as a Model

The increasing demand of food crops and decrease in productivity due to continuous use of chemical fertilizer has not only resulted in decline of crop yield, loss of fertility and degradation of soil but has also led us one step back in achieving sustainable agriculture. The use of algal bio-fertilizer provides an effective, ecofriendly and non-polluting approach in improving the productivity of crop by both nitrogen fixation and photosynthesis. Algal bio-fertilizers improve soil structure and increase yield productivity even if applied in a small area. The application of algal bio-fertilizers in plants has resulted in increase in root, shoot length with number of leaves and hence overall growth of the plant has been increased. India being one of the largest producer and consumer of pulses requires abundant amount of pulse production to fulfill the demands of ever growing populations which can be achieved by using algal bio-fertilizers.Microalgae efficiently utilize and remove the nitrogen and phosphorus present in wastewater and assimilate these in valuable algal biomass. Yet, besides macronutrients such as N, P and K, microalgae also contain plant growth-promoting substances such as vitamins, carotenoids, amino acids and antifungal substances. In this study, the valorisation of microalgae as an organic slow-release fertilizer is presented.The fertilizer potential of both fresh water and marine microalgal biomass was determined; more specifically dried microalgal biomass, cultivated on microalgae in various natural and chemical methods. In the first stage the mineralization rate of both types of biomass was determined. Also a dosage toxicity test for Ca2+ and Na+ was performed using seedlings of lettuce and garden cress, respectively. Subsequently, a greenhouse maize growth experiment was performed, wherein the fertilizer potential of both types of microalgal biomass was compared with conventional inorganic and organic microalgae fertilizers. The growth rate of the maize plants and the maize yield were assessed for each fertilizer treatment, as well as the leave composition and the water, sugar and carotenoid concentrations in the maize seed. The results of the study show there was no significant difference in plant growth between the fertilizer treatments with microalgae and the conventional algae fertilizer. This demonstrates the potential of microalgae an impending fertilizer for agriculture applications.Keywords: Microalgae, Agriculture, Bio-fertilizer, Maize, Application

Molecular Biomarkers of Vascular Dysfunction in Obstructive Sleep Apnea

Untreated and long-lasting obstructive sleep apnea (OSA) may lead to important vascular abnormalities, including endothelial cell (EC) dysfunction, hypertension, and atherosclerosis. We observed a correlation between microcirculatory reactivity and endothelium-dependent release of nitric oxide in OSA patients. Therefore, we hypothesized that OSA affects (micro)vasculature and we aimed to identify vascular gene targets of OSA that could possibly serve as reliable biomarkers of severity of the disease and possibly of vascular risk. Using quantitative RT-PCR, we evaluated gene expression in skin biopsies of OSA patients, mouse aortas from animals exposed to 4-week intermittent hypoxia (IH; rapid oscillations in oxygen desaturation and reoxygenation), and human dermal microvascular (HMVEC) and coronary artery endothelial cells (HCAEC) cultured under IH. We demonstrate a significant upregulation of endothelial nitric oxide synthase (eNOS), tumor necrosis factor-alpha-induced protein 3 (TNFAIP3; A20), hypoxia-inducible factor 1 alpha (HIF-1α?? and vascular endothelial growth factor (VEGF) expression in skin biopsies obtained from OSA patients with severe nocturnal hypoxemia (nadir saturated oxygen levels [SaO2]<75%) compared to mildly hypoxemic OSA patients (SaO2 75%–90%) and a significant upregulation of vascular cell adhesion molecule 1 (VCAM-1) expression compared to control subjects. Gene expression profile in aortas of mice exposed to IH demonstrated a significant upregulation of eNOS and VEGF. In an in vitro model of OSA, IH increased expression of A20 and decreased eNOS and HIF-1α expression in HMVEC, while increased A20, VCAM-1 and HIF-1αexpression in HCAEC, indicating that EC in culture originating from distinct vascular beds respond differently to IH stress. We conclude that gene expression profiles in skin of OSA patients may correlate with disease severity and, if validated by further studies, could possibly predict vascular risk in OSA patients