Antimicrobial and hemolytic activity of fish epidermal mucus Cynoglossus arel and Arius caelatus

Objective:To study the antimicrobial,hemolytic activity and immunomodulatory activity of fish epidermal mucus and their chemical constituents from Cynoglossus arel(C.arel) and Alius caelatus(A.caelatus).Mucus plays an important role in the prevention of colonization by parasites,bacteria and fungi.Methods:Epidermal mucus was obtained from two marine fishes,lyophilized and the chemical composition of epidermal mucus was analysed by FT-IR analysis.The in vitro antimicrobial activity against human pathogens(fungi,gram positive and gram-negative bacteria) and also the hemolytic activity and immunomodulatory activity were determined.Results:Totally ten human pathogens were tested against the fish mucus.Out of the ten pathogens,five pathogens have proved to be sensitive to the mucus.Maximum zone of inhibition was observed against Vibrio cholera(V.cholera)(9 mm and 2 mm in diameter),followed by Staphylococcus aureus(S.aureus) with a inhibition zone of(6 mm and 3 mm),Streptococcus areus(S.areus)(5 mm and 4 mm),Vibrio parahemolyticus(V.parahemolyticus)(4 mm and 5 mm) respectively.Conclusions:The present investigation has revealed that positive progresses in the fish mucus extracts against human pathogens and hemolytic activity.But further efforts are required for the purification and isolation of the active antimicrobial compounds in order to establish their possible applications.

Larvicidal and pupicidal activity of spinosad against the malarial vector Anopheles stephensi

Objective:To investigate the larvicidal and pupicidal activity of spinosad against Anopheles stephensi Listen.Methods:Spinosad from the actinomycete,Saccharopolyspora spinosa was tested against Anopheles stephensi at different concentrations（0.01,0.02,0.04,0.06 and 0.08 ppm.）, and against first to fourth instar larvae and pupae.Results:The larval mortality ranged from 36.1±1.7 in（0.01 ppm） to 79.3±1.8（0.08 ppm） the first instar larva.The LC50 and LC90 values of first, second,third and fourth instar larva were 0.001,0.031,0.034,0.036 and 0.0113,0.102,0.111,0.113, respectively.The pupal mortality ranged from 33.0±2.0（0.01 ppm） to 80.0±0.9（0.08 ppm）.The LC50 and LC90 values were 0.028 and 0.1020,respectively.The reduction percentage of Anopheles larvae was 82.7%,91.4%and 96.0%after 24,48,72 hours,respectively,while more than 80% reduction was observed after 3 weeks.Conclusions:In the present study spinosad effectively caused mortality of mosquito larvae in both the laboratory and field trial.It is predicted that spinosad is likely to be an effective larvicide for treatment of mosquito breeding sites.

Antibacterial activity of starfish Stellaster equestris from Southeast Coast of India

Objective:To isolate and characterize the antibacterial compounds from starfish Stellaster equestris(S.equestris).Methods:The whole body was extracted with high polar and medium polar solvents such as methanol and ethanol.The antibacterial activity has been tested against human bacterial pathogens using standard disc diffusion method.Results:The starfish S.equestris was collected from Mudasalodai,southeast coast of India.the maximum zone inhibition[(9.7±0.3)mm]against Escherichia coli(E.coli)and Vibrioparahaemolyticus at 100%concentration and minimum was Staphylococcus aureus[(4.0±0.6)mm].The crude ethanol extract showed maximum zone of inhibition in E.coli[(9.70±0.33)mm]and the lowest concentration exhibited the minimum inhibition activity against all bacterial pathogens.The fractions showed the maximum inhibition zone in Klebsiella oxytoca(5.00±0.82 mm),Salmonella typhi(S.typhi)(5.00±0.82)and Staphylococcus aureus[(3.0±2.3)mm].One way ANOVA analysis of antibacterial activity showed no significant difference at 0.05%level(P>0.05).The crude ethanol extract showed the minimum inhibitory concentration against E.coli(100%),Klebsiella pneumoniae The present investigation exhibited that the crude methanol extract showed the minimum inhibitory concentration against Klebsiella pneumonia,Proteus mirabilis,S.typhi,Staphylococcus aureus and Vibrio cholerae at 100%whereas E.coli was at 75%concentration.No bacterial growth was observed against Klebsiella oxytoca at 100%concentration.Conclusions:(75%),S.typhi(100%)and Vibrio cholerae(100%).The fraction exhibited equestris have remarkable antimicrobial activities against human bacterial pathogens.Further fraction has been characterised by using GC-MS and ^(1)H and ^(13)NMR spectroscopy analysis.The result of the present study indicates that the crude and fractions of starfish S.

Studies on antimicrobial activity and brine shrimp lethality of crude samples of six different species of puffer ifshes

Objective:To evaluate the antimicrobial activity and brine shrimp lethality activity of six different species of puffer fishes,includingCyclichthys orbicularis,Diodon holocanthus,Canthigaster solandri,Arthron hispidus,A.inermis andLagocephalua inermis(L.inermis).Methodology:The puffer fishes were collected from Annangkovil Fish Landing Centre(Lattitude 11°30.47'N;Longitude 79°47.02'E),Parangipettai,Southeast Coast of India during summer season because of availability.Fresh tissue samples were collected from the clearly washed specimens,extracted with methanol at 37°C for 3 days and filtered through Whatman No.1 filter paper.The solvents such as methanol and ethanol were concentrated by using rotary evaporator under reduced pressure.The dark brown gummy mass was stored at 4°C for further analysis.Prepared crude samples were analysed with human pathogens to assess the antibacterial activity and this was carried out by using standard disc diffusion method.The brine shrimp lethality was calculated as the percentage of mortality which was firstly calculated by dividing the number of dead larvae by the total number and then multiplied to 100%.Results:The antibacterial activity of crude extract of puffer fishes were exhibited against 10 different human bacterial pathogens.Among the ten human pathogens,Arthron hispidus showed maximum zone of inhibition(8 mm)againstStaphylococcus aureus whileL.inermis showed minimum activity(1 mm)againstProteus mirabilis and no zone of inhibition was observed againstStaphylococcus aureus.Brine shrimp lethality was examined with six puffer fish extracts.Cyclichthys orbicularis showed maximum mortalities as 100%andL.inermis showed minimum mortalities as 70%at a concentration of 500μg/mL.Conclusion:In conclusion,the study showed the preliminary investigation of crude extracts of puffer fishes about the prominent activity against human bacterial pathogens.The extracts had a good cytotoxic potential against brine shrimpArtemina salina.

Studies on antioxidant properties of starfish Luidia maculata(Muller&Troschel,1842)off Parangipettai,Southeast coast of India

Objective:To investigate the antioxidant properties of starfish Luidia maculata.Methods:The crude ethanol extract was partially purified using liquid-liquid partition and size exclusion chromatography.The antioxidant properties of partially purified fractions were determined using the following methods:determination of total phenolic content,DPPH radical scavenging assay,hydrogen peroxide radical scavenging assay and reducing power assay.Results:Among the five fractions,collected fraction 3,4 and 5 exhibited antioxidant potential.Total phenolic content was high(360μg GAE/g)in fraction 3.In DPPH assay,fraction 3 showed the highest IC_(50)value 0.27 mg/mL and hydrogen peroxide scavenging assay showed the highest IC_(50)value of 0.07 mg/mL in fraction 5.Whereas,fraction 3 showed the highest absorbance(0.3)in reducing power assay when compared to fraction 4 and 5.Conclusions:In conclusion,the present study shows the extract of starfish Luidia maculata(F3)possesses good antioxidant activity.