Combinations of binary and tertiary toxic effects of extracts of Euphorbia pulcherima latex powder with other plant derived molluscicides against freshwater vector snails
R Yadav, A Singh
compounds and fascioliasis, indoplanorbis exustus, lymnaea acuminata, toxicity
R Yadav, A Singh. Combinations of binary and tertiary toxic effects of extracts of Euphorbia pulcherima latex powder with other plant derived molluscicides against freshwater vector snails. The Internet Journal of Toxicology. 2008 Volume 7 Number 1.
Molluscicidal activity of different plant moieties in different combinations (binary or tertiary) were tested against freshwater vector snail
The freshwater snail
Plant product molluscicides are a focus of attention as a suitable alternative to synthetic molluscicides to their low cost, easy availability, biodegradability and non-toxic to human beings (5,7,8,9). It has been observed that molluscicidal activity of latex, stem bark and leaf of
The present study deals with the use latex powder of
Materials and Methods
The euphorbious plant
Rutin (C27H30O16) (EC NO-205-814-1), ellagic acid (C14O6O8) (4,4,5,5,6,6-Hexahydroxydiphenic acid, 2,6,2,6-dilactone) (EC NO-207-508-3), betulin (C30H50O2) (Lup-20 (2a)-ene-3β-28-diol) (EC NO-207-475-6) supplied by Sigma Chemical Co. P.O. Box 14508 St. Louis. Mo. 63178 USA 314-771-5750, taraxerol extracted from the stem bark of
The experiment was conducted in two freshwater earthen cemented ponds, 29.28 m2 in area and 9.19 m3 water volumes. Water analysis for various physico-chemical parameters, viz. temperature, pH and dissolved O2 and alkalinity was observed. Water temperature ranged from 27.4-28.60C. The other parameters were within the following range total alkalinity 43-62 ppm, pH 6.8-7.7, and dissolved oxygen 7.8-10.3 mg/L (13).
Mortality was recorded at 24h intervals up to 96h. Lethal concentrations LC50 values, upper and lower confidence limits (UCL, LCL) and slope values were calculated by computer programme for analysis of bioassay data POLO computer programme of (14). The regression coefficient was determined between exposure time and different values of LC50 (15).
Toxicity of latex powder of
Toxicity against both the freshwater snails
Regarding the tertiary combinations (1:1:1) of
Statistical analysis of the data on the toxicity brings several important points. The χ2- test for goodness of fit (heterogeneity) demonstrated that the mortality counts were not found to be significantly heterogeneous and other variables, for example, resistance, did not significantly affect the LC50 values, as these were within the 95% confidence limits. The dose mortality graphs exhibited steep slope values. The steepness of the slope line indicated a large increase in the mortality of snails with a relatively small increase in the concentration of the toxicant.
It is evident from the results shows that
The increased in mortality with increased in exposure periods could be affected by several factors, which may be acting separately or conjointly. For example, uptake of active moiety is time dependent, which leads progressive increase the entrance of the drug and its effects in the snail body (16,17). Singh and Singh 2005 (18) was reported that aqueous latex extract of the
The increase in toxicity of LC50 values in single treatment of the aqueous extracts of latex of
Obviously natural conditions of the toxicity of tested plants were reduced. The reason for reduced toxicity could be soil particle adsorption or acceleration of the toxicant degradation process by temperature (19). A similar trend was reported by (20), in which the toxicity persistence of plant
The LC values, as these were found to lie within the 95% confidence limits. The dose mortality graphs exhibit steep slope values. The steepness of the slope line indicates that there is a large increase in mortality of snails with relatively small increase in the concentration of the toxicant. The slope is, thus an index of the susceptibility of the target animal to the molluscicide used. A steep slope is also indicative of rapid absorption and onset of effects. Even though the slope alone is not a very reliable indicator of toxicological mechanism, yet it is a useful parameter, for such a study (21).
In conclusion it may be stated that binary and tertiary combinations of
One of the authors (Ram P. Yadav) is thankful to Council of Scientific and Industrial Research, Govt. of India, New Delhi (CSIR sanction no. 13 (8190-A)/Pool/2007 dated 4-12-2007) for award of the SRA under Pool Scientist scheme.