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1.

Objective

To investigate the short and long term efficacy of a commercial air ionizer in killing Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae) mites.

Methods

The effect of a commercial ionizer on D. pteronyssinus and D. farinae was evaluated in the laboratory, using a specially designed test. Mortality was assessed after 6, 16 and 24 hours for direct exposure and after 24, 36, 48, 60 and 72 hours for exposure in simulated mattress. New batches of mites were used for each exposure time.

Results

LT50 for direct exposure of ionizer was 10 hours for D. pteronyssinus and 18 hours for D. farinae. The LT50 for exposure in simulated mattress was 132 hours or 5.5 days for D. pteronyssinus and 72 hours or 3 days for D. farinae. LT95 for direct exposure of ionizer was 36 hours for D. pteronyssinus and D. farinae. Meanwhile, the LT95 for exposure in simulated mattress was 956 hours or 39.8 days for D. pteronyssinus and 403 hours or 16.8 days for D. farinae.

Conclusions

This study demonstrates the increasing mite mortalities with increasing exposure time of a commercial ionizer and suggests that negative ions produced by an ionizer kill dust mites and can be used to reduce natural mite populations on exposed surfaces such as floors, clothes, curtains, etc. However, there is reduced efficacy on mites inside stuffed materials as in mattresses and furniture.  相似文献   

2.

Objective

To examined the immediate and 24 hours post- irradiation germicidal effects of UV-C lamp on eggs and adults of house dust mites Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae).

Methods

This study investigated the immediate and 24 hours post irradiation mortalities of adult mites exposed to UV-C at different exposure times (5 mins, 10 mins, 15 mins, 20 mins, 30 mins and 60 mins) and distances (10 cm, 25 cm, 35 cm, 45 cm and 55 cm). Fresh eggs of the 2 dust mites were also irradiated at 10, 35 and 55 cm for 0.5, 1, 2, 3, and 5 minutes, and observed daily post- irradiation for up to 7 days.

Results

Highest immediate mortality of 100% occurred with direct irradiation at 10 cm distance from UV-C lamp and for 60 mins, for both species of mites. The post 24 hours mean mortality rates were (58.4±17.4)% for D. pteronyssinus and (27.7±9.7)% for D. farinae when irradiated for 1 hour at 55 cm distance under UV-C lamp. When mites were irradiated in the presence of culture media, the highest mortality rates were lower compared to the direct irradiation; at 10 cm distance and 60 mins exposure, the mean mortality was (74.0±6.8)% for D. pteronyssinus and (70.3±6.7)% for D. farinae. Egg hatchability for both species of mites was also notably reduced by greater than 50% following irradiation.

Conclusions

Ultraviolet C irradiation is lethal to an array of organisms by damaging their nucleic acids (DNA and RNA). This study demonstrates the increasing mite mortalities with increasing exposure times and decreasing distances.  相似文献   

3.

Objective

To investigate the acaricidal activity of different extracts from Syzygium cumini (S. cumini) (Pomposia) againsst Tetranychus urticae Koch (T. urticae) and the biochemical changes in antioxidants enzymes.

Methods

Six extracts of S. cumini (Pomposia) at concentrations of 75, 150 and 300µg/mL were used to control T. urticae (Koch).

Results

The ethanol extract showed the most efficient acaricidal activity agent against T. urticae (98.5%) followed by hexane extract (94.0%), ether and ethyl acetate extract (90.0%). The LC50 values of the promising extract were 85.0, 101.0, 102.0 and 98.0µg/mL, respectively. The activities of enzymes including ascorbate peroxidase (APX), peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) in susceptible mites were increased. The activities of all antioxidant enzymes reach the maximum value in mites at LC50 with ethanol and ethyl acetate extracts, respectively.

Conclusions

The extract of S. cumini has acaricidal acivity against T. urticae, and the ethanol extract is the most efficient.  相似文献   

4.

Objective

To assess the in-vitro antibacterial activity and anti-inflammatory activity of orally administered different extracts (Hydro-alcoholic, methanolic, ethyl acetate and hexane) of Rauvolfia tetraphylla (R. tetraphylla) root bark in Carrageenan induced acute inflammation in rats.

Methods

In-vitro antibacterial activity was evaluated for extracts against four Gram positive and four Gram negative bacteria by using cylinder plate assay. Hydro-alcoholic extract (70% v/v ethanol) at 200, 400 and 800 mg/kg doses and methanolic, ethyl acetate and hexane extracts at doses 100, 200 and 400 mg/kg were tested for anti-inflammatory activity in Carrageenan induced rat paw oedema model and paw thickness was measured every one hour up to 6 hrs.

Results

All extracts of R. tetraphylla root bark showed good zone of inhibition against tested bacterial strains. In Carrageenan induced inflammation model, hydro-alcoholic and methanolic extract of R. tetraphylla root bark at three different doses produced significant (P<0.001) reduction when compared to vehicle treated control group and hexane, ethyl acetate extracts.

Conclusions

In the present study extracts of R. tetraphylla root bark shows good in-vitro antibacterial activity and in-vivo anti-inflammatory activity in rats.  相似文献   

5.

Objective

To investigate the toxicity of methanol extract of various parts (Root, Stem, Leaf, Flower and Fruit) of Lantana camara (L. Camara) in Artemia salina.

Methods

The methanol extracts of L. camara were tested for in vivo brine shrimp lethality assay.

Results

All the tested extract exhibited very low toxicity on brine shrimp larva. The results showed that the root extract was the most toxic part of L. camara and may have potential as anticancer agent.

Conclusions

Methanolic extract of L. camara is relatively safe on short-term exposure.  相似文献   

6.

Objective

To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria (E. coronaria) and Caesalpinia pulcherrima (C. pulcherrima) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi).

Methods

The ovicidal activity was determined against three mosquito species at various concentrations ranging from 50-450 ppm under the laboratory conditions. The hatch rates were assessed 48 h after treatment. The repellent efficacy was determined against three mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm2 under the laboratory conditions.

Results

The crude extract of E. coronaria exerted zero hatchability (100% mortality) at 250, 200 and 150 ppm for Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The crude extract of C. pulcherrima exerted zero hatchability (100% mortality) at 375, 300 and 225 ppm for Cx. quinquefasciatus, Ae. aegypti and An. Stephensi, respectively. The methanol extract of E. coronaria found to be more repellenct than C. pulcherrima extract. A higher concentration of 5.0 mg/cm2 provided 100% protection up to 150, 180 and 210 min against Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The results clearly showed that repellent activity was dose dependent.

Conclusions

From the results it can be concluded the crude extracts of E. coronaria and C. pulcherrima are an excellent potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.  相似文献   

7.

Objective

To explore the prevention of recurrent candiduria using natural based approaches and to study the antimicrobial effect of Hibiscus sabdariffa (H. sabdariffa) extract and the biofilm forming capacity of Candida albicans strains in the present of the H. sabdariffa extract.

Methods

In this particular study, six strains of fluconazole resistant Candida albicans isolated from recurrent candiduria were used. The susceptibility of fungal isolates, time-kill curves and biofilm forming capacity in the present of the H. sabdariffa extract were determined.

Results

Various levels minimum inhibitory concentration of the extract were observed against all the isolates. Minimum inhibitory concentration values ranged from 0.5 to 2.0 mg/mL. Time-kill experiment demonstrated that the effect was fungistatic. The biofilm inhibition assay results showed that H. sabdariffa extract inhibited biofilm production of all the isolates.

Conclusions

The results of the study support the potential effect of H. sabdariffa extract for preventing recurrent candiduria and emphasize the significance of the plant extract approach as a potential antifungal agent.  相似文献   

8.

Objective

To evaluate aqueous and ethanol extract of Cassia didymobotrya leaves against immature stages of Culex quinquefasciatus.

Methods

The mortality rate of immature mosquitoes was tested in wide and narrow range concentration of the plant extract based on WHO standard protocol. The wide range concentration tested in the present study was 10 000, 1 000, 100, 10 and 1 mg/L and narrow range concentration was 50, 100, 150, 200 and 250 mg/L.

Results

2nd instar larvae exposed to 100 mg/L and above concentration of ethanol extract showed 100% mortality. Remaining stages such as 3rd, 4th and pupa, 100% mortality was observed at 1 000 mg/L and above concentration after 24 h exposure period. In aqueous extract all the stages 100% mortality was recorded at 1 000 mg/L and above concentration. In narrow range concentration 2nd instar larvae 100% mortality was observed at 150 mg/L and above concentration of ethanol extract. The remaining stages 100% mortality was recorded at 250 mg/L. In aqueous extract all the tested immature stages 100% mortality was observed at 250 mg/L concentration after 24 h exposure period. The results clearly indicate that the rate of mortality was based dose of the plant extract and stage of the mosquitoes.

Conclusions

From this study it is confirmed and concluded that Cassia didymobotrya is having active principle which is responsible for controlling Culex quinquefasciatus. The isolation of bioactive molecules and development of simple formulation technique is important for large scale implementation.  相似文献   

9.

Objective

To assess the larvicidal and irritant activities of the hexane extracts of leaves of Citrus sinensis (C. sinensis) against the early fourth instars and female adults of Aedes aegypti (Ae. aegypti).

Methods

The larvicidal potential of the prepared leaf extract was evaluated against early fourth instar larvae of Ae. aegypti using WHO protocol. The mortality counts were made after 24 h and LC50 and LC90 values were calculated. The efficacy of extract as mosquito irritant was assessed by contact irritancy assays. Extract-impregnated paper was placed on a glass plate over which a perspex funnel with a hole on the top was kept inverted. Single female adult, 3-day old unfed/blood-fed, was released inside the funnel. After 3 min of acclimatization time, the time taken for the first take-off and total number of flights undertaken during 15 min were scored.

Results

The citrus leaf extracts from hexane possessed moderate larvicidal efficiency against dengue vector. The bioassays resulted in an LC50 and LC90 value of 446.84 and 1 370.96 ppm, respectively after 24 h of exposure. However, the extracts were proved to be remarkable irritant against adults Ae. aegypti, more pronounced effects being observed on blood-fed females than unfed females. The extract-impregnated paper was thus proved to be 7–11 times more irritable as compared with the control paper.

Conclusions

The hexane extracts from C. sinensis leaves are proved to be reasonably larvicidal but remarkably irritant against dengue vector. Further studies are needed to identify the possible role of extract as adulticide, oviposition deterrent and ovicidal agent. The isolation of active ingredient from the extract could help in formulating strategies for mosquito control.  相似文献   

10.

Objective

To evaluate the consequence of oral administration of Calliandra portoricensis (C. portoricensis) leaf extract on the stomach and pancreas in Swiss albino mice.

Methods

Three groups of mice (B, C and D) were treated with 4 mg/kg of C. portoricensis extract. Group A was the control and received an equivalent volume of distilled water. Group B received C. portoricensis leaf extract for 7 days, Group C received C. portoricensis leaf extract for 14 days, and Group D received C. portoricensis leaf extract for 28 days. At different stages in the study, the mice were sacrificed and the stomach and pancreas were excised and fixed in 10% formol saline for histological analysis.

Results

The result showed a normal microstructural outline in groups B and C as compared with the control. However, animals in group D showed disorganization of the mucosa and discontinuation of epithelial lining of the stomach while the islets of Langerans in the pancreas were at various degree of degeneration as compared with the control mice.

Conclusions

The present finding suggests that chronic administration (28 days as seen in this study) of C. portoricensis leaf extract may inhibit the proper function of the stomach and pancreas.  相似文献   

11.

Objective

To assess the molluscicidal and cercariacidal activities of aqueous extracts of Balanites aegyptiaca (B. aegyptiaca) against Ethiopian Biomphalaria pfeifferi (B. pfeifferi), Lymnaea natalensis (L. natalensis) and Schistosoma mansoni (S. mansoni) cercariae.

Methods

Extracts of seeds, endocarp, mesocarp, and fruit of B. aegyptiaca were tested for their activities against adult B. pfeifferi and L. natalensis. The cercariacidal activity of the seeds of the plant was also evaluated against S. mansoni. Bioassays were carried out following the methods recommended by WHO. Snail mortalities were compared between each plant part and snail species, and LC50 and LC90 values for the plant parts tested were computed. The cercariacidal activity of the plant was assessed by exposing the mice to the cercariae pre-exposed to aqueous extract of B. aegyptiaca seeds.

Results

For the molluscicidal activities of seeds, endocarp, mesocarp and whole fruit, the LC50 values against B. pfeifferi were 56.32, 77.53, 65.51 and 66.63 mg/L, respectively, while the respective LC90 values were 77.70, 120.04, 89.50 and 97.55 mg/L. Similarly, the LC50 values for the seeds, endocarp, mesocarp and whole fruit against L. natalensis were 80.33, 92.61, 83.52 and 87.84 mg/L, respectively, while the respective LC90 values were 102.30, 138.21, 115.42 and 127.69 mg/L. B. pfeifferi were found to be more susceptible to B. aegyptiaca than L. natalensis. S. mansoni cercariae exposed to 15 mg/L of extract of seeds were incapable of infecting mice. The mean egg load of tissue was reduced in mice infected with the cercariae exposed to 5 and 10 mg/L of the extract.

Conclusions

The aqueous extracts of different parts of B. aegyptiaca exhibited reasonable molluscicidal activity against B. pfeifferi and L. natalensis, as well as cercariacidal activity against S. mansoni cercariae. However, comprehensive laboratory evaluation is recommended prior to field tests of the plant parts since their impact on other aquatic biota is not known.  相似文献   

12.

Objective

To identify the larvicidal activity of the seagrass extracts.

Methods

Seagrass extracts, Syringodium isoetifolium (S. isoetifolium), Cymodocea serrulata and Halophila beccarii, were dissolved in DMSO to prepare a graded series of concentration. Batches of 25 early 4th instars larvae of Aedes aegypti (Ae. aegypti) were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts (0.01 mg – 0.1 mg). After 24 h the mortality rate was identified with the formulae [(% of test mortality – % of control mortality)/(100 – % of control mortality)] × 100. Each experiment was conducted with three replicates and a concurrent control group. A control group consisted of 1 mL of DMSO and 199 mL of distilled water only.

Results

: The root extract of S. isoetifolium showed maximum larvicidal activity with minimum concentration of extract of LC50= 0.0 604 ± 0.0 040)µg/mL with lower confidence limit (LCL) – upper confidence limit (UCL) = (0.051–0.071) and LC90=0.0 972µg/mL followed by leaf extract of S. isoetifolium showed LC50= (0.062 ± 0.005)µg/mL. The regression equation of root and leaf extract of S. isoetifolium for 4th instar larvae were Y= 4.909 + 1.32x (R2= 0.909) and Y= 2.066 + 1.21x (R2 =0.897) respectively. The results of the preliminary phytochemical constituents shows the presence of saponin, steroids, terpenoid, phenols, protein and sugars.

Conclusions

From the present study the ethanolic extracts of seagrass of S. isoetifolium possesses lead compound for development of larvicidal activity.  相似文献   

13.

Objective

To evaluate the mosquito larvicidal activity of Pongamia pinnata (P. pinnata) extracts against three mosquito vectors.

Methods

The methanol and hydroalcohol extracts of bark part of P. pinnata L were tested against fourth instar larvae of Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi. The mortality was observed 24 h and 48 h after treatment, data was subjected to probit analysis to determine lethal concentration (LC50 and LC90) to kill 50 and 90 percent of treated larvae of tested species.

Results

The larval mortality was found in both methanol and hydroalcohol extracts of P. pinnata against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi with LC50 values of 84.8, 118.2 and 151.7 ppm; 97.7, 128.3 and 513 ppm. The highest larval mortality was found in methanol extract of P. pinnata when comparable to the hydroalcohol extract.

Conclusions

These results suggest that both methanol and hyrdoalcohol extracts have the potential to be used as an ideal ecofriendly approach for the control of disease vectors. This could lead to isolation of novel natural larvicidal compounds.  相似文献   

14.

Objective

To evaluate the antimicrobial activity of Turbinaria conoides (T. conoides), Padina gymnospora (P. gymnospora) and Sargassum tenerrimum against human bacterial and fungal pathogens.

Methods

The antimicrobial activities of the extracts against various organisms were tested by using disc diffusion method.

Results

The methanol extract showed the better result than the other extracts. Whereas, the strong antibacterial inhibition was noted in methanol extracts of P. gymnospora against Bacillus subtilus (26.33±1.86) and the mild inhibition of ethanol extracts from T. conoides against Klebsiella pneumoniae (2.33±0.51). Acetone extraction of P. gymnospora had strong antifungal inhibition against Cryptococcus neoformans (23.00±1.78), and acetone extract of T. conoides had mild inhibition against Aspergillus niger (3.00±0.89).

Conclusions

The seven different solvent extracts of seaweeds used in the present study have shown significant bacterial action. Further, a detailed study on the principle compound in the seaweeds which is responsible for antimicrobial activity is still needed and it can be achieved by using advanced separation techniques.  相似文献   

15.

Objective

To determine the major changes in the microstructure of Candida albicans (C. albicans) after treatment with Euphorbia hirta (E. hirta) L. leaf extract.

Methods

Transmission electron microscopy was used to study the ultrastructural changes caused by E. hirta extract on C. albicans cells at various exposure time.

Results

It was found that the main abnormalities were the alterations in morphology, lysis and complete collapse of the yeast cells after 36 h of exposure to the extract. Whereas the control cultures showed a typical morphology of Candida with a uniform central density, typically structured nucleus, and a cytoplasm with several elements of endomembrane system and enveloped by a regular, intact cell wall.

Conclusions

The significant antifungal activity shown by this methanol extract of E. hirta L. suggests its potential against infections caused by C. albicans. The extract may be developed as an anticandidal agent.  相似文献   

16.

Objective

To determine repellent activity of hexane, ethyl acetate, benzene, chloroform and methanol extract of Cardiospermum halicacabum (C. halicacabum) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi).

Methods

Evaluation was carried out in a net cage (45 cm×30 cm×25 cm) containing 100 blood starved female mosquitoes of three mosquito species and were assayed in the laboratory condition by using the protocol of WHO 2005; The plant leaf crude extracts of C. halicacabum was applied at 1.0, 2.5, and 5.0 mg/cm2 separately in the exposed area of the fore arm. Only ethanol served as control.

Results

In this observation, the plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity was dependent on the strength of the plant extracts. The tested plant crude extracts had exerted promising repellent against all the three mosquitoes.

Conclusions

From the results it can be concluded the crude extract of C. halicacabum was potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.  相似文献   

17.

Objective

To evaluate the antimicrobial activity of ethanolic extract of Ecballium elaterium (E. elaterium) fruits alone against Staphylococcus aureus (S. aureus) strains and Candida albicans (C. albicans) strains, or in combination with penicillin against Staphylococcus areus strains.

Methods

Evaluation of the antimicrobial activity or synergy interaction was carried out using microdilution method.

Results

The results showed that ethanolic extract of E. elaterium fruits has antimicrobial activity against methicillin resistant S. aureus (MRSA), methicillin sensitive S. aureus (MSSA) and C. albicans. This extract showed a significant decrease in minimum inhibitory concentrations (MIC) of penicillin against both MRSA and MSSA strains. Fractional inhibitory concentration index (FIC) between penicillin and ethanolic extract of E. elaterium fruits against these test strains was less than 0.5.

Conclusions

This study suggests that ethanolic extract of E. elaterium fruits has antimicrobial activity against S. aureus and C. albicans and there is a possibility of concurrent use of penicillin and E. elaterium extract in combination in the treatment of infections caused by MRSA and MSSA strains. A wider study is needed to identify the effective components, the mode of action and the possible toxic effect in vivo of these ingredients.  相似文献   

18.

Objective

To survey malaria prevalence in Sarbaz from April 2009 to October 2010.

Methods

Epidemiological data of 1 464 confirmed malarial patients were analyzed according to demographic status, sex, age, nationality, isolated species and residence place.

Results

The majority of patients were male 950 (64.8%) but 514 (35.2%) were female. 82.5% of patients were Iranian, 14% Pakistani immigrants, and 3.5% Afghan immigrants. Data collected showed that 90% of isolated species were Plasmodium vivax, 7.8% Plasmodium falciparum, and 2.2% Plasmodium malariae and mixed species.

Conclusions

Therefore, it is crystal clear that refugees should be prohibited by government and controlled by experts in health centers in order to campaign effectively with this life threating disease.  相似文献   

19.

Objective

To identify the unusual breeding sites of two dengue vectors, i.e. Aedes albopictus (Ae. albopictus) and Aedes aegypti (Ae. aegypti).

Methods

During the second half of 2010, we performed an occasional survey in rural (Teluk Tempoyak) and urban (Gelugor) areas of Penang Island, Malaysia, to identify cryptic breeding sites.

Results

In the rural area, we found heterogeneous immature stages of Ae. albopictus in the water bowl of an encaged bird. We also observed Ae. aegypti eggs deposited in the flush tank of a toilet in the urban area.

Conclusions

It can be concluded that both breeding patterns can increase contact with hosts (humans and birds) and presumably population densities of Ae. albopictus and Ae. aegypti, thereby potentially boosting the risks for spread and transmission of arboviral diseases.  相似文献   

20.

Objective

To explore the antispermatogenic and testicular antisteroidogenic activities of Feronia limonia fruit pulp southern India.

Methods

Fourty Wistar male albino rats (Rattus norvegicus) were equally divided into four groups. Experimental groups were administered with the ethanolic extract of Feronia limonia (F. limoni) fruit pulp at doses of 250 and 500 mg/kg body weight once daily for 55 days. All treated rats had corresponding recovery groups. At the end of each treatment periods, various spermatological indices, tissue biochemicals and testicular enzymes levels were analysed. Blood profiles were also estimated.

Results

Compared with the control, the F. limonia fruit pulp at both dose levels did not decrease body weight, which were associated with decline in epididymal sperm count, motility, viability and increased percent of abnormal sperm. Further, F. limonia fruit pulp at 500 mg/kg body weight markedly reduced the epididymal and testicular protein content by 24.58% and 29.86%, respectively, as well as the glucose-6-phosphate dehydrogenase and Δ5-3β-hydroxy steroid dehydrogenase) levels by 42.82% and 38.08%, respectively, while a significant elevation was observed in testicular cholesterol and ascorbic acid content. A gradual recovery of all parameters was observed after 55 days of treatment withdrawal. No significant alterations in haematological indices were observed.

Conclusions

The present findings indicate that F. limonia fruit pulp may have reversible antispermatogenic and antisteroidogenic properties, and could partially support the traditional use as male contraceptive.  相似文献   

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