Objective To screen the antimalarial compounds of daphnetin derivatives against Plasmodium falciparum in vitro. Method Plasmodium faciparum （FCC1） was cultured in vitro by a modified method of Trager and Jensen. Ant...Objective To screen the antimalarial compounds of daphnetin derivatives against Plasmodium falciparum in vitro. Method Plasmodium faciparum （FCC1） was cultured in vitro by a modified method of Trager and Jensen. Antimalarial compounds were screened by microscopy-based assay and microfluorimetric method. Results DA79 and DA78 showed potent antimalarial activity against Plasmodiumfalciparum cultured in vitro. Conclusion Though the relationship between the structures of daphnetin derivatives and their antimalarial activities has not been clarified yet, this study may provide a new direction for discovery of more potential antimalarial compounds.展开更多
Objective To compare the schizontocidal activity of recrystallized or crude daphnetin against malaria parasites in vivo. Methods Schizontocidal activity of recrystallized or crude daphnetin at various dosages was a...Objective To compare the schizontocidal activity of recrystallized or crude daphnetin against malaria parasites in vivo. Methods Schizontocidal activity of recrystallized or crude daphnetin at various dosages was assessed in mice infected with Plasmodium berghei ANKA using a 4-day suppress assay. Results The comparison of the reduction rate of parasitemia caused by either recrystallized or crude dephnetin showed that ED50 of crude daphnetin was 18.36 mg/kg, with 95% confidence limit of 5.96-56.54 mg/kg while ED50 of recrystallized daphnetin was 11.46 mg/kg, with 95% confidence limit of 8.63-15.22 mg/kg. Conclution The results indicate that the efficacy of recrystallized daphnetin is 37.6% higher than that of crude daphnetin.展开更多
[Objectives]To observe the effects of daphnetin on mastitis induced by Staphylococcus aureus in mice.[Methods]18 postpartum ICR female mice were used to establish mastitis animal model,and were randomly divided into t...[Objectives]To observe the effects of daphnetin on mastitis induced by Staphylococcus aureus in mice.[Methods]18 postpartum ICR female mice were used to establish mastitis animal model,and were randomly divided into three groups(A,B,and C)with 6 mice in each group.Group A:blank control group;group B:S.Aureus model group;group C:S.Aureus model+daphnetin group.The experimental groups were injected 1 mL of 1.0×104 CFU/100μL of S.aureus of along the nipple catheter.The suspension was placed in the 3 rd and 4 th pairs of mammary glands,and the control group was injected with the same dose of normal saline.On the second day after infection,the rats in group A,B and C were given drugs by gavage,while the rats in group A and B were given normal saline and the rats in group C were given daphnetin once a day for 6 consecutive days.Blood samples were collected from living eyeballs,and blood cells were analyzed by automatic flow cytometer after anticoagulation.[Results]The NLR and Systemie Immune Inflammati-on Index(SII)in the blood of mastitis mice induced by S.aureus were significantly higher than those in the control group(P<0.01),suggesting that neutrophil to lymphocyte ratio(NLR)and SII can be used as diagnostic indicators of mastitis,and the levels of NLR and SII decreased significantly after daphnetin intervention.[Conclusions]NLR and SII showed high levels in mastitis mice,which are valuable for the diagnosis of mastitis and the evaluation of its prognosis.After the intervention of daphnetin,both of them decreased significantly,indicating that daphnetin has a good prognosis trend in mastitis mice induced by S.aureus.展开更多
Background Although there are several drugs and drug combinations for the treatment of Pneumocystis carinii (P. carinii) pne umonia, all drugs have the toxicity as well as low efficacy. Iron chelators have been prop...Background Although there are several drugs and drug combinations for the treatment of Pneumocystis carinii (P. carinii) pne umonia, all drugs have the toxicity as well as low efficacy. Iron chelators have been proposed as a source of new drugs for combating these infections. We hypothesized that iron chelators would suppress the growth of P. carinii by deprivation of the nutritional iron required for growth. In this study, a short-term axenic culture system of P. carinii was established. Daphnetin (7,8-dihydroxycoumarin), a known iron chelator, was demonstrated to exhibit in vitro activity against P. carinii in this system. Methods P. carinii organisms were obtained from the lungs of immunosuppressed rats. The culture system consisted of Iscove Dulbecco Eagle’s Minimum Essential Medium (IMDM), supplemented with S-adenosyl-L-methionine, N-acetylglucosamine, putrescine, L-cysteine, L-glutamine, 2-mercaptoethanol, and fetal bovine serum, and was maintained at 37℃, in 5% CO 2, 95% O 2, at the optimal pH of 8.0. The culture system was used to assess the effect of daphnetin on the proliferation of P. carinii organisms. The ultrastructures of the treated organisms were observed by transmission electron microscopy.Results The number of cysts and trophozoites increased 8- to 9-fold and 11- to 12-fold, respectively, after 10 days of culture. Daphnetin was found to suppress the growth of P. carinii in a dose-dependent manner at concentrations between 1 μmol/L and 20 μmol/L. The inhibitory activity was suppressed by the chelation of daphnetin with ferrous sulfate in a 2∶1 molar ratio, but it was not suppressed by mixing the culture medium with magnesium sulfate. Reduction of P. carinii numbers after treatment with daphnetin correlated with morphological changes in the organisms, as determined by transmission electron microscopy.Conclusions Daphnetin can suppress the growth of P. carinii in vitro. The efficacy o f daphnetin in suppressing the the growth of P. carinii in vitro is related to its ability to chelate iron.展开更多
文摘Objective To screen the antimalarial compounds of daphnetin derivatives against Plasmodium falciparum in vitro. Method Plasmodium faciparum （FCC1） was cultured in vitro by a modified method of Trager and Jensen. Antimalarial compounds were screened by microscopy-based assay and microfluorimetric method. Results DA79 and DA78 showed potent antimalarial activity against Plasmodiumfalciparum cultured in vitro. Conclusion Though the relationship between the structures of daphnetin derivatives and their antimalarial activities has not been clarified yet, this study may provide a new direction for discovery of more potential antimalarial compounds.
基金This work was supported by grants from the National Natural Science Foundation of China (No. 39970669) and Artemisinin Science Foundation.
文摘Objective To compare the schizontocidal activity of recrystallized or crude daphnetin against malaria parasites in vivo. Methods Schizontocidal activity of recrystallized or crude daphnetin at various dosages was assessed in mice infected with Plasmodium berghei ANKA using a 4-day suppress assay. Results The comparison of the reduction rate of parasitemia caused by either recrystallized or crude dephnetin showed that ED50 of crude daphnetin was 18.36 mg/kg, with 95% confidence limit of 5.96-56.54 mg/kg while ED50 of recrystallized daphnetin was 11.46 mg/kg, with 95% confidence limit of 8.63-15.22 mg/kg. Conclution The results indicate that the efficacy of recrystallized daphnetin is 37.6% higher than that of crude daphnetin.
基金Supported by Project of Innovation and Entrepreneurship Training Program for College Students in Guangxi Zhuang Autonomous Region in 2022(S202210599060)Basic Ability Improvement Project for Young and Middle-aged Teachers in Guangxi Zhuang Autonomous Region in 2020(2020KY13027)Project of Scientific Research and Technological Development Plan of Baise City in 2020(Encyclopedia[2020]No.47).
文摘[Objectives]To observe the effects of daphnetin on mastitis induced by Staphylococcus aureus in mice.[Methods]18 postpartum ICR female mice were used to establish mastitis animal model,and were randomly divided into three groups(A,B,and C)with 6 mice in each group.Group A:blank control group;group B:S.Aureus model group;group C:S.Aureus model+daphnetin group.The experimental groups were injected 1 mL of 1.0×104 CFU/100μL of S.aureus of along the nipple catheter.The suspension was placed in the 3 rd and 4 th pairs of mammary glands,and the control group was injected with the same dose of normal saline.On the second day after infection,the rats in group A,B and C were given drugs by gavage,while the rats in group A and B were given normal saline and the rats in group C were given daphnetin once a day for 6 consecutive days.Blood samples were collected from living eyeballs,and blood cells were analyzed by automatic flow cytometer after anticoagulation.[Results]The NLR and Systemie Immune Inflammati-on Index(SII)in the blood of mastitis mice induced by S.aureus were significantly higher than those in the control group(P<0.01),suggesting that neutrophil to lymphocyte ratio(NLR)and SII can be used as diagnostic indicators of mastitis,and the levels of NLR and SII decreased significantly after daphnetin intervention.[Conclusions]NLR and SII showed high levels in mastitis mice,which are valuable for the diagnosis of mastitis and the evaluation of its prognosis.After the intervention of daphnetin,both of them decreased significantly,indicating that daphnetin has a good prognosis trend in mastitis mice induced by S.aureus.
文摘Background Although there are several drugs and drug combinations for the treatment of Pneumocystis carinii (P. carinii) pne umonia, all drugs have the toxicity as well as low efficacy. Iron chelators have been proposed as a source of new drugs for combating these infections. We hypothesized that iron chelators would suppress the growth of P. carinii by deprivation of the nutritional iron required for growth. In this study, a short-term axenic culture system of P. carinii was established. Daphnetin (7,8-dihydroxycoumarin), a known iron chelator, was demonstrated to exhibit in vitro activity against P. carinii in this system. Methods P. carinii organisms were obtained from the lungs of immunosuppressed rats. The culture system consisted of Iscove Dulbecco Eagle’s Minimum Essential Medium (IMDM), supplemented with S-adenosyl-L-methionine, N-acetylglucosamine, putrescine, L-cysteine, L-glutamine, 2-mercaptoethanol, and fetal bovine serum, and was maintained at 37℃, in 5% CO 2, 95% O 2, at the optimal pH of 8.0. The culture system was used to assess the effect of daphnetin on the proliferation of P. carinii organisms. The ultrastructures of the treated organisms were observed by transmission electron microscopy.Results The number of cysts and trophozoites increased 8- to 9-fold and 11- to 12-fold, respectively, after 10 days of culture. Daphnetin was found to suppress the growth of P. carinii in a dose-dependent manner at concentrations between 1 μmol/L and 20 μmol/L. The inhibitory activity was suppressed by the chelation of daphnetin with ferrous sulfate in a 2∶1 molar ratio, but it was not suppressed by mixing the culture medium with magnesium sulfate. Reduction of P. carinii numbers after treatment with daphnetin correlated with morphological changes in the organisms, as determined by transmission electron microscopy.Conclusions Daphnetin can suppress the growth of P. carinii in vitro. The efficacy o f daphnetin in suppressing the the growth of P. carinii in vitro is related to its ability to chelate iron.
