The transcription factor MYB1 activates DGAT2 transcription to promote triacylglycerol accumulation in sacha inchi (Plukenetia volubilis L.) leaves under heat stress.

Triacylglycerol (TAG) accumulation is frequently triggered in vegetative tissues experiencing heat stress, which may increases plant basal plant thermo-tolerance by sequestering the toxic lipid intermediates that contribute to membrane damage or cell death under stress conditions. However, stress-responsive TAG biosynthesis and the underlying regulatory mechanisms are not fully understood. Here, we investigated the lipidomic and transcriptomic landscape under heat stress in the leaves of sacha inchi (Plukenetia volubilis L.), an important oilseed crop in tropical regions. Under heat stress (45 °C), the content of polyunsaturated TAGs (e.g., TAG18:2 and TAG18:3) and total TAGs were significantly higher, while those of unsaturated sterol esters, including ZyE 28:4, SiE 18:2 and SiE 18:3, were dramatically lower. Transcriptome analysis showed that the expression of PvDGAT2-2, encoding a type II diacylglycerol acyltransferase (DGAT) that is critical for TAG biosynthesis, was substantially induced under heat stress. We confirmed the function of PvDGAT2-2 in TAG production by complementing a yeast mutant defective in TAG biosynthesis. Importantly, we also identified the heat-induced transcription factor PvMYB1 as an upstream activator of PvDGAT2-2 transcription. Our findings on the molecular mechanism leading to TAG biosynthesis in leaves exposed to heat stress have implications for improving the biotechnological production of TAGs in vegetative tissues, offering an alternative to seeds.

Sesquiterpenes and polyphenols with glucose-uptake stimulatory and antioxidant activities from the medicinal mushroom Sanghuangporus sanghuang.

A chemical investigation on the fermentation products of Sanghuangporus sanghuang led to the isolation and identification of fourteen secondary metabolites (1-14) including eight sesquiterpenoids (1-8) and six polyphenols (9-14). Compounds 1-3 were sesquiterpenes with new structures which were elucidated based on NMR spectroscopy, high resolution mass spectrometry (HRMS) and electronic circular dichroism (ECD) data. All the isolates were tested for their stimulation effects on glucose uptake in insulin-resistant HepG2 cells, and cellular antioxidant activity. Compounds 9-12 were subjected to molecular docking experiment to primarily evaluate their anti-coronavirus (SARS-CoV-2) activity. As a result, compounds 9-12 were found to increase the glucose uptake of insulin-resistant HepG2 cells by 18.1%, 62.7%, 33.7% and 21.4% at the dose of 50 µmol·L-1, respectively. Compounds 9-12 also showed good cellular antioxidant activities with CAA50 values of 12.23, 23.11, 5.31 and 16.04 µmol·L-1, respectively. Molecular docking between COVID-19 Mpro and compounds 9-12 indicated potential SARS-CoV-2 inhibitory activity of these four compounds. This work provides new insights for the potential role of the medicinal mushroom S. sanghuang as drugs and functional foods.

Fructooligosaccharides protect against OVA-induced food allergy in mice by regulating the Th17/Treg cell balance using tryptophan metabolites.

Fructooligosaccharides (FOS) can change gut microbiota composition and play a protective role in food allergy (FA). Furthermore, the protective mechanism of FOS against FA is unclear. In this study, intestinal flora and tryptophan (Trp) metabolites were investigated in a mouse model with FA supplemented with FOS. Meanwhile, we injected aryl hydrocarbon receptor antagonists (AhR-A) into a mouse model of FA supplemented with FOS to investigate whether T helper cell (Th) 17/regulatory T (Treg) cell balance was affected. Our research studies showed that dietary intake of FOS provided moderate protection from the intestinal inflammation induced by ovalbumin (OVA). This protective effect disappeared in AhR-A mice. The OVA mice manifestations had significantly lower bacterial richness, when compared to the normal control (NC) mice. Among fecal bacteria, the abundance of Akkermansiaceae (family level) and Verrucomicrobia (phylum level) increased and Ruminococcacere (phylum level) decreased in the feces of allergic mice. These changes were reversed by FOS treatment. FOS modulated the gut microbiome profiles that were altered in OVA mice, which showed an increase in the abundance of Ruminococcacere (phylum level) and a decrease in the abundance of Akkermansiaceae (family level) and Verrucomicrobia (phylum level). Liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis of Trp metabolites showed significant reductions in the level of kynurenine (kyn) in the serum of OVA mice, as compared to NC and FOS mice. Conversely, the levels of Trp and 5-hydroxytryptamine (5-HT) were significantly increased in OVA mice. Correlation analysis revealed a negative relationship between the relative abundance of Verrucomicrobiae (class level) and Akkermansiaceae (family level) with kyn, and a positive relationship with 5-HT. FOS significantly reduced interleukin-17A (IL-17A) and retinoic acid-associated nuclear orphan receptor-γt (RORγt) in FOS mice but not in AhR-A mice. FOS increased the level of interleukin-10 (IL-10) and Forkhead box P3 (Foxp3) in FOS mice but not in AhR-A mice. These findings suggest that FOS ameliorates allergic symptoms and impacts Th17/Treg balance in mice by modulating the gut microbiota composition and Trp metabolites. FOS may serve as an effective tool for the treatment of FA by regulating immune and gut microbiota.

New meroterpenoid compounds from the culture of mushroom Panus lecomtei.

Two new meroterpenoid compounds (1 and 2) together with five known meroterpenoid derivatives (3-7) were isolated from solid culture of mushroom Panus lecomtei. The structures of new compounds were confirmed by the analysis of NMR and HR-ESI-MS spectroscopic data. The biosynthetic pathway of 1-7 was postulated. All isolated compounds were evaluated for antibacterial activities against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Bacillus Calmette-Guérin. Compound 3 exhibited weak antibacterial activity against Bacillus Calmette-Guérin with the inhibition rate of 83.6% at 100 µmol·L-1. Other compounds showed no antibacterial activities against all tested pathogens at 100 µmol·L-1.

[Nitrogen metabolism and secondary metabolism regulation of Atropa belladonna by exogenous NO under NaCl stress].

Atropa belladonna seedlings were used as experimental materials and cultivated by soil culture method. Different concentrations(0,0.05,0.1,0.2,0.5 mmol·L~(-1))of NO donor sodium nitroprusside(SNP) were sprayed on the leaves. The effects of different concentrations of SNP and different treatment time(4,8,12,16 d) on nitrogen metabolism, secondary metabolite content, precursor content of tropane alkaloid synthesis pathway and expression of key enzyme genes under 100 mmol·L~(-1) NaCl stress were studied. The results showed that with the prolongation of salt stress, the nitrogen metabolism and the accumulation of secondary metabolites of A. belladonna were inhibited to some extent. After treatment with different concentrations of exogenous SNP, the ammonium nitrogen content decreased dramatically, and the contents of nitrate nitrogen, free amino acid, soluble protein and the activities of key enzymes of nitrogen metabolism(NR, GS, GDH) were all greatly improved; the contents of precursor amino acids(ornithine, arginine) and polyamines(Put, Spd, Spm) in the secondary metabolic pathway have increased to varying degrees. The qRT-PCR analysis showed that exogenous SNP treatment can effectively promote the high expression of key enzyme genes PMT, TRⅠ and H6H in the secondary metabolic pathway of A. belladonna, and the production of hyoscyamine and scopolamine were increased notably. In summary, the application of appropriate concentration of SNP can effectively alleviate the inhibition of salt stress on the nitrogen metabolism and secondary metabolism of Atropa belladonna, and enhance its salt tolerance. Overall, 0.1 mmol·L~(-1) and 0.2 mmol·L~(-1) SNP treatment achieved the most remarkable effect.

Antioxidant and Antiapoptotic Polyphenols from Green Tea Extract Ameliorate CCl4-Induced Acute Liver Injury in Mice.

OBJECTIVE: To investigate the phenolic composition, antioxidant properties, and hepatoprotective mechanisms of polyphenols from green tea extract (GTP) in carbon tetrachloride (CCl4)-induced acute liver injury mouse model. METHODS: High-performance liquid chromatography was used to analyze the chemical composition of the extract. Antioxidant activity of GTP was assessed by O2∙-, OH∙, DPPH∙, and ferric-reducing antioxidant power (FRAP) assay in vitro. Sixty Kunming mice were divided into 6 groups including control, model, low-, medium-, and high-doses GTP (200, 400, 800 mg/kg) and vitamin E (250 mg/kg) groups, 10 in each group. GTP and vitamin E were administered at a level of abovementioned doses twice per day for 7 days prior to exposure to a single injection of CCl4. Hepatoprotective effects of GTP were evaluated in a CCl4-induced mouse model of acute liver injury, using commercial enzyme linked immunosorbent assay kits, histopathological observation, terminal deoxynucleotidyl transferase-mediated dUTPNick-end labeling (TUNEL) assay and Western blot. RESULTS: GTP contained 98.56 µg gallic acid equivalents per milligram extract total polyphenols, including epicatechingallate, epigallocatechin gallate, epicatechin, and epigallocatechin. Compared with the model group, low-, medium-, or high doses GTP significantly decreased serum levels of alanine aminotransferase and aspartate transaminase (P<0.01). Histopathological observation confirmed that pretreatment of GTP prevented swelling and necrosis in CCl4-exposed hepatocytes. Hepatoprotective effects of low-, medium-, and high-dose GTP were associated with eliminating free radicals and improving superoxide dismutase, catalase, and glutathione peroxidase activity in the liver. Additionally, low-, medium-, and high-dose GTP decreased cell apoptosis in the CCl4-exposed liver (P<0.01). Phosphorylated nuclear factor kappa-B (NF-κB), p53, Bcl-2 associated x protein/B-cell lymphoma/leukemia-2 gene, cytochrome C, and cleaved caspase-3 levels were downregulated compared with the model group (P<0.01). CONCLUSION: GTP achieves hepatoprotective effects by improving hepatic antioxidant status and preventing cell apoptosis through caspase-3-dependent signaling pathways.

[Cloning and expression analysis of calmodulin gene from Pinellia ternate].

According to the data of Pinellia ternate transcriptome,two calmodulin genes were cloned and named as Pt Ca M1 and PtCa M2 respectively. The results of bioinformatics analysis showed that Pt Ca Ms genes contained a 450 bp open reading frame,encoding149 amino acids.The identity of the coding sequences was 80%,and the identity of amino acids sequence was 91%. Pt Ca Ms genes contained EF-hand structure domain,belonging to the Ca M families. The Real-time PCR analysed the expression patterns of Pt Ca Ms in different tissues and different treatments. RESULTS:: showed that Pt Ca M1 and Pt Ca M2 gene were the highest expression level in tuber. Under Ca Cl2 treatment,the expressions of Pt Ca Ms were significantly higher than the control. Under EGTA,La Cl3 and TFP treatments,the expression level of Pt Ca Ms decreased gradually. In this study,the Pt Ca Ms gene were successfully cloned from P. ternate,which laid a foundation for the functional characteristic of Pt Ca Ms gene and the synthesis of alkaloids from P. ternata for further study.

[Protective effect of Sanhuangyinchi Fang drug serum on hydrogen peroxide-induced DNA oxidative damage in LO2 cells].

OBJECTIVE: To study the protective effect of Sanhuangyinchi Fang drug serum (SF) against hydrogen peroxide-mediated DNA oxidative damage in LO2 cells. METHODS: The LO2 cells were randomly divided into the control group, H(2)O(2) group, SF groups (5%, 10%, and 15%) and vitE group. The morphological features of the treated LO2 cells were observed under inverted microscope. The viability of the treated cells was assessed with CCK-8 method, and the activity of SOD, CAT and GSH-PX were detected biochemically. Reactive oxygen species (ROS) levels, the content of 8-OHdG, and DNA damage of the cells were evaluated by flow cytometry, ELISA, and Comet assay, respectively. RESULTS: Compared with H(2)O(2) group, the cells in SF groups (10% and 15%) and vitE group showed higher cell survival rate (P<0.05) and higher SOD, CAT, GSH-PX (P<0.05) and ROS scavenging activities (P<0.01) with markedly decreases the content of 8-OHdG (P<0.01) and reduced tailing ratio, tail length, tail moment and Olive tail moment (P<0.05). CONCLUSION: SF drug serum, especially at the concentration of 15%, can protect LO2 cells from H(2)O(2)-mediated DNA oxidative damage.

Ophiobolins P-T, five new cytotoxic and antibacterial sesterterpenes from the endolichenic fungus Ulocladium sp.

Five ophiobolane sesterterpenes, ophiobolins P-T, and three known compounds, 6-epi-21,21-O-dihydroophiobolin G, 6-epi-ophiobolin G and 6-epi-ophiobolin K, were isolated from the acetone extract of the endolichenic fungus Ulocladium sp. by using OSMAC method. Their structures were elucidated on the basis of spectroscopic analysis. The absolute configuration of the 18,19-diol moieties in ophiobolin Q was assigned using the Frelek's method. The cytotoxic effects on KB and HepG2 cell lines, antibacterial activity against Bacillus subtilis, methicillin-resistant Staphylococcus aureus, and Bacille Calmette-Guerin were evaluated for all isolated compounds. Ophiobolin T and 6-epi-ophiobolin G exhibited the most potent cytotoxic activity against HepG2 with IC50 of 0.24 and 0.37 µM, respectively. In antibacterial assay, ophiobolins P and T showed moderate antibacterial activity against B. subtilis and meticillin-resistant S. aureus. Ophiobolin T also displayed moderate antibacterial activity against the Bacille Calmette-Guerin strain.

Polyketides with antimicrobial activity from the solid culture of an endolichenic fungus Ulocladium sp.

Two new polyketides, 7-hydroxy-3, 5-dimethyl-isochromen-1-one (1) and 6-hydroxy-8-methoxy-3a-methyl-3a,9b-dihydro-3H-furo[3,2-c]isochromene-2,5-dione (2), along with eleven known compounds, 5'-methoxy-6-methyl-biphenyl-3,4,3'-triol (3), 7-hydroxy-3-(2-hydroxy-propyl)-5-methyl-isochromen-1-one (4), rubralactone (5), isoaltenuene (6), altenuene (7), dihydroaltenuenes A (8), altenusin (9), alterlactone (10), 6-O-methylnorlichexanthone (11), norlichexanthone (12), and griseoxanthone C (13) were isolated from the culture of the endolichenic fungus Ulocladium sp. Compound 2 was obtained as a racemate with an unprecedented chemical skeleton. The NMR data assignments for 3 and 4 were achieved for the first time. Compounds 1-13 were screened for their antimicrobial and radical scavenging activities. Compound 1 showed some antifungal activity against Candida albicans SC 5314 with IC(50) of 97.93 ± 1.12 µM. Compounds 11-13 showed strong activity against Bacillus subtilis with IC(50) in the range of 1-5 µM. Compound 12 significantly inhibited the growth of methicillin-resistant Staphylococcus aureus with IC(50) of 20.95 ± 1.56 µM. Compounds 9 and 10 showed strong radical scavenging activity in comparison with vitamin C. The plausible biosynthetic pathways for compounds 1, 2, and 4-8 were discussed.

Chemical constituents from endophytic fungus Fusarium oxysporum.

A new oxysporidinone analogue (1) and a new 3-hydroxyl-2-piperidinone derivative (2), along with the known compounds (-)-4,6'-anhydrooxysporidinone (3), (+)-fusarinolic acid (4), gibepyrone D (5), beauvercin (6),cerevisterol (7), fusaruside (8), and (2S,2'R,3R,3'E,4E,8E)-1-O-D-glucopyranosyl-2-N-(2'-hydroxy-3'-octadecenoyl)-3-hydroxy-9-methyl-4,8-sphingadienine (9) were isolated from Fusarium oxysporum. Compounds 1-9 were evaluated for cytotoxicity using the MTT method against cancer cell lines, PC-3, PANC-1, and A549. Beauvericin showed cytotoxicity against PC-3, PANC-1, and A549 with IC(50) value of 49.5 ± 3.8, 47.2 ± 2.9, and 10.4 ± 1.6µM, respectively. Beauvericin also exhibited anti-bacterial activity towards methicillin-resistant Staphylococcus aureus (MIC=3.125 µg/mL) and Bacillus subtilis (MIC=3.125 µg/mL).