Dear Editor,Lassa virus(LASV)is the causative agent of the acute viral hemorrhagic Lassa fever(LF),which is classified into Mammarenavirus within the Arenaviridae family,with a single-stranded,negative-sense,bisegment...Dear Editor,Lassa virus(LASV)is the causative agent of the acute viral hemorrhagic Lassa fever(LF),which is classified into Mammarenavirus within the Arenaviridae family,with a single-stranded,negative-sense,bisegmented RNA genome.Due to its high pathogenicity and lethality,LASV is considered as a priority threat to public health,with an estimated cases of 300,000 infections and 5000 deaths annually.LASV was first isolated and described as a clinical entity in 1969 in Lassa,Nigeria(Garry,2023).LASV isolates of different geographic and host origins are highly diverse in genomic sequences and phylogenetically classified into up to seven lineages,with each lineage predominately localized in specific countries.Although the research on LF has been carried out for decades since the pathogen first characterized,there is no approved antiviral drugs or vaccines for clinical use against LASV to date(Grant et al.,2023).One possible reason that hindered the development of countermeasures is that the preclinical studies on authentic LASV are restricted in high bio-containment biosafety level 4(BSL-4)facilities.In this letter,we describe isolation,and characterization of the LASV from the clinical samples.And we applied a coadministration assay of antiviral drugs for LASV by using a clinically isolated Mammarenavirus lassaense strain in the BSL-4 facility,aiming to investigate new therapeutic strategies for LASV infection.展开更多
Oil-producing crops,including Helianthus annuus L.(H.annuus,Sunflower),have been used for the treatment of different human diseases since ancient times.This study aims to determine the antimicrobial and cytotoxic pote...Oil-producing crops,including Helianthus annuus L.(H.annuus,Sunflower),have been used for the treatment of different human diseases since ancient times.This study aims to determine the antimicrobial and cytotoxic potential of different polarities of seeds and flower extracts of locally grown H.annuus by well-established bioassays.To achieve the objects,the plant extracts were prepared from both flowers and seeds powder samples individually with methanol solvent by using a Soxhlet extraction method.The antimicrobial and cytotoxic potential of the flowers and seed extracts were determined by the in vitro diffusion and brine shrimp method(BSL).The results of the antimicrobial potential of both prepared flower and seed extracts of various polarities at different concentrations showed promising potential against the gram-positive and gram-negative bacterial strains,within the range of inhibition zone 0–20 mm.Among the flower extracts,the highest potential was obtained in water extract and the lowest potential was in butanol extract followed by water>ethyl acetate>hexane>methanol>chloroform>butanol extracts.However,from the seed extracts,the highest potential was obtained in water extract and the lowest potential was in the methanol extract followed by water>hexane>butanol>ethyl acetate>chloroform>methanol extract.On the other hand,the results of cytotoxicity among the flowers extracts against the brine shrimp method where the highest LC50 against brine shrimp nauplii were found to be 31.25μg/mL in water extract and the lowest LC50 was 1345.86μg/mL in chloroform extract followed by water>ethyl acetate>hexane>butanol>methanol>chloroform extract.Similarly,different polarities of seed extracts,the highest LC50 against brine shrimp nauplii was shown to be 109.56μg/mL in butanol extract and the lowest LC50 was 1513.56μg/mL in ethyl acetate extract followed by butanol>hexane>water>methanol>chloroform>ethyl acetate extract.In conclusion,the results showed that both flowers and seeds extracts at various concentrations have promising potential against the positive and negative bacterial strains and the highest potential water extract could be used as natural broad-spectrum antibiotics as herbal medicine to treat different human infectious diseases.展开更多
基金supported by the National Key Research and Development Program of China(2022YFC2303300,2023YFC2605504)the National Natural Science Foundation of China(82172273 and 31670165)the Open Research Fund Program of the State Key Laboratory of Virology of China(2023JZZD-01).
文摘Dear Editor,Lassa virus(LASV)is the causative agent of the acute viral hemorrhagic Lassa fever(LF),which is classified into Mammarenavirus within the Arenaviridae family,with a single-stranded,negative-sense,bisegmented RNA genome.Due to its high pathogenicity and lethality,LASV is considered as a priority threat to public health,with an estimated cases of 300,000 infections and 5000 deaths annually.LASV was first isolated and described as a clinical entity in 1969 in Lassa,Nigeria(Garry,2023).LASV isolates of different geographic and host origins are highly diverse in genomic sequences and phylogenetically classified into up to seven lineages,with each lineage predominately localized in specific countries.Although the research on LF has been carried out for decades since the pathogen first characterized,there is no approved antiviral drugs or vaccines for clinical use against LASV to date(Grant et al.,2023).One possible reason that hindered the development of countermeasures is that the preclinical studies on authentic LASV are restricted in high bio-containment biosafety level 4(BSL-4)facilities.In this letter,we describe isolation,and characterization of the LASV from the clinical samples.And we applied a coadministration assay of antiviral drugs for LASV by using a clinically isolated Mammarenavirus lassaense strain in the BSL-4 facility,aiming to investigate new therapeutic strategies for LASV infection.
文摘Oil-producing crops,including Helianthus annuus L.(H.annuus,Sunflower),have been used for the treatment of different human diseases since ancient times.This study aims to determine the antimicrobial and cytotoxic potential of different polarities of seeds and flower extracts of locally grown H.annuus by well-established bioassays.To achieve the objects,the plant extracts were prepared from both flowers and seeds powder samples individually with methanol solvent by using a Soxhlet extraction method.The antimicrobial and cytotoxic potential of the flowers and seed extracts were determined by the in vitro diffusion and brine shrimp method(BSL).The results of the antimicrobial potential of both prepared flower and seed extracts of various polarities at different concentrations showed promising potential against the gram-positive and gram-negative bacterial strains,within the range of inhibition zone 0–20 mm.Among the flower extracts,the highest potential was obtained in water extract and the lowest potential was in butanol extract followed by water>ethyl acetate>hexane>methanol>chloroform>butanol extracts.However,from the seed extracts,the highest potential was obtained in water extract and the lowest potential was in the methanol extract followed by water>hexane>butanol>ethyl acetate>chloroform>methanol extract.On the other hand,the results of cytotoxicity among the flowers extracts against the brine shrimp method where the highest LC50 against brine shrimp nauplii were found to be 31.25μg/mL in water extract and the lowest LC50 was 1345.86μg/mL in chloroform extract followed by water>ethyl acetate>hexane>butanol>methanol>chloroform extract.Similarly,different polarities of seed extracts,the highest LC50 against brine shrimp nauplii was shown to be 109.56μg/mL in butanol extract and the lowest LC50 was 1513.56μg/mL in ethyl acetate extract followed by butanol>hexane>water>methanol>chloroform>ethyl acetate extract.In conclusion,the results showed that both flowers and seeds extracts at various concentrations have promising potential against the positive and negative bacterial strains and the highest potential water extract could be used as natural broad-spectrum antibiotics as herbal medicine to treat different human infectious diseases.
