Mechanistic action of the acute toxicity of Bajitian(Morinda officinalis)in zebrafish embryos

Objectives:To investigate acute toxicity of Bajitian(Morinda officinalis)in zebrafish embryos.Methods:Zebrafish embryos at 48-h post fertilization(hpf)were exposed to Bajitian ethanol extract for72 h.The causative action of a delay in yolk sac absorption by Bajitian was investigated by RT-PCR analysis of lipid metabolism-related microsomal triglyceride transfer protein(MTP),apolipoprotein CII(ApoC2)and lipogenesis-related liver x receptor(LXR)genes.The effect of Bajitian eliciting an inflammatory response was studied by exposing 72 hpf myeloperoxidase(MPO):GFP transgenic zebrafish embryos to Bajitian extract for 4 h.Assessment was done by TUNEL,caspase-3/7,and RT-PCR analysis of the apoptosis related pathway B-cell lymphoma 2 associated X protein(Bax),Nuclear factor kappa-lightchain-enhancer of activated B cells(NF-k B)genes,neutrophil development-related stem cell leukaemia(SCL)and transcription factor PU.1 genes,to reveal the causative action of Bajitian reducing neutrophils.Results:RT-PCR analysis found that Bajitian extract had no effect on the expression of MTP or ApoC2 genes,but upregulated LXR gene,which might explain the delay in yolk sac absorption.Analysis of the inflammatory response showed that compared with negative controls,Bajitian extract significantly(P<.05)reduced the number of neutrophils in MPO:GFP embryos.TUNEL,caspase-3/7,and RT-PCR analysis of Bax and NF-k B genes found that Bajitian extract did not trigger the cell apoptosis.Further RT-PCR analysis found that Bajitian extract did not affect SCL expression,but did lead to down-regulation of PU.1.The inhibition of neutrophil development/differentiation may explain the decline in the total number of neutrophils following Bajitian treatment,which could be attributed to the anti-inflammatory effects found clinically for this drug.Conclusions:This study demonstrated that Bajitian caused a delay in yolk sac absorption and a decrease neutrophil in zebrafish embryos,which may be related to the inhibition of neutrophil development.

Discovery of New Iridoids as Farnesoid X Receptor Agonists from Morinda officinalis: Agonistic Potentials and Molecular Stimulation

The investigation of Morinda officinalis led to the isolation of twelve compounds(1-12),including three new iridoid glycosides morindallns A-C(1-3)and nine known compounds(4-12).Their structural identifications were conducted using HRMS,1D and 2D NMR,and electronic circular dichroism(ECD)spectra as well as quantum chemical computations.Compound 6 displayed the most significantly agonistic activity against farnesoid X receptor(FXR)with an EC_(50) value of 7.18 μM,and its agonistic effect was verified through the investigation of FXR downstream target genes including small heterodimer partner 1(SHP1),bile salt export pump(BSEP),and organic solute transporter subunit alpha and beta(OSTα and OSTβ).The potential interaction of compound 6 with FXR was analyzed by molecular docking and molecular dynamics stimulation,revealing that amino acid residues Leu287;Thr288,and Ser332 played a crucial role in the activation of compound 6 towards FXR.These findings suggested that compound 6 could be regarded as a potential candidate for the development of FXR agonists.

Endophytic fungal communities associated with leaves,stems and roots of four medicinal plants in South China

Amomum villosum,Aquilaria sinensis,Morinda officinalis,and Pogostemon cablin are well-known medicinal plants in South China for their particular pharmacological activities,but their endophytic fungi have been rarely reported.Here,the endophytic fungal communities associated with the leaves,stems,and roots of the four medicinal plant species were investigated by high-throughput sequencing technology.From the four medicinal plant species,a total of 169,149 sequences(reads)of endophytic fungi were harvested and clustered into 791 operational taxonomic units(OTUs)assigned to the Kingdom Fungi.These OTUs taxonomically spanned five phyla,27 classes,75 orders,167 families,and 291 genera.At the genus level,Phyllosticta,Candida,Zasmidium,and Cryptococcus were the major genera detected in A.villosum;Nigrospora,Tylopilus,Arthrobotrys,Coniosporium,and Corynespora were the dominant genera isolated in A.sinensis;Ochroconis,Cercospora,Aspergillus,and Cyphellophora were the dominant genera detected in M.officinalis;and Cladophialophora,Meira,Sakaguchia,and Penicillium were the major genera isolated in P.cablin.Among the four medicinal plant species,M.officinalis had the highest endophytic fungal diversity(H′>4.25),however A.sinensis had the lowest(H′<2.37).There were significant differences in endophytic fungal communities among different organs in the same plant species.

巴戟天MoTPS基因及其启动子克隆与分析

为探究巴戟天中MoTPS基因的序列特征及其在生长素IAA处理下的表达模式。本研究利用RT-PCR获得3个巴戟天MoTPS基因的全长c DNA序列,分别命名为MoTPS1、MoTPS2和MoTPS3。基因序列分析显示,基因全长分别为2841、2126和2144 bp,开放阅读框(ORF)分别为2481、1668和1943 bp,分别编码826、555和640个氨基酸。序列分析结果显示,3个MoTPS基因编码蛋白均为亲水性的不稳定蛋白,3个基因的氨基酸序列含有萜类特有的天冬氨酸(DDXXD)富集基序及RXR保守基序,并含有萜类ClassⅠ超级家族结构域。同源比对分析显示3个MoTPS基因氨基酸序列与咖啡树匹配的TPS基因同源性均达到75%以上。系统进化树分析表明MoTPS1基因属于TPS-f亚族分支,而MoTPS2和MoTPS3基因同属于TPS-d亚族分支。启动子克隆得到序列长度为739 bp的MoTPS3基因启动子,其含有多种光响应、激素响应顺式元件,如G-box、Sp1、P-box、TGA-element等。荧光定量PCR分析表明3个MoTPS基因在巴戟天根、茎、叶中稳定表达且具有组织特异性;经生长素IAA处理后,3个MoTPS基因在根中的相对表达量均显著上调。因此研究推测,3个MoTPS基因参与巴戟天根中萜类次生代谢物合成过程且生长素IAA对MoTPS基因的表达调控发挥重要作用。