Inhibitory effect and possible mechanism of phenyllactic acid on Aspergillus flavus spore germination.

Phenyllactic acid (PLA) has gained a lot of attention due to its broad antimicrobial activity, but the mechanism of its antifungal action has been barely reported until now. Herein, the inhibitory activity of PLA against Aspergillus flavus spore germination and its mechanism were preliminarily investigated. Results indicated that PLA had a strong antifungal activity against A. flavus with the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of 6 and 12 mg/ml, respectively. As observed by scanning electron microscopy (SEM), the A. flavus spores displayed wrinkled and shrunken appearance after treatment with PLA. In addition, the permeability and integrity of A. flavus cell membrane were changed obviously after PLA treatment as indicated by the propidium iodide (PI) staining results, which was further confirmed by a rise in electric conductivity and increased leakage of intracellular protein and nucleic acid. Furthermore, reduced activities of mitochondrial ATPase and dehydrogenases caused by PLA were also observed in A. flavus spores, with a result of remarkable decrease in ATP synthesis. Therefore, it could be concluded that PLA was effective in inhibiting spore germination of A. flavus mainly by disrupting cell membrane and interfering with mitochondrial energy metabolism.

Effects of NADH Availability on 3-Phenyllactic Acid Production by Lactobacillus plantarum Expressing Formate Dehydrogenase.

It is well known that cofactors play a key role in the production of different compounds in bioconversion processes, while the high cost of cofactors limits their usage in industrial applications. In the present study, a NADH regeneration system was successfully developed in Lactobacillus plantarum by expressing the fdh gene coding for formate dehydrogenase (FDH) from Candida boidinii. Results indicated that the FDH was expressed with the highest activity of 0.82 U/mg of protein when cells entered early stationary phase. In addition, the expression of FDH increased the intracellular level of NADH and NADH/NAD+ ratio in L. plantarum, and therefore, enhanced the NADH-dependent production of 3-phenyllactic acid (PLA) in repeated and fed-batch bioconversions. In brief, the results demonstrate that the NADH regeneration by expressing FDH is a promising strategy for producing NADH-dependent microbial metabolites in L. plantarum.

[Expression of proteins related neurodegeneration in autopsy brains of the aged].

OBJECTIVE: To recognize relationship of protein related neurodegeneration abnormal aggregation in the aged brains with their cognitive and motor functions. METHODS: Brain tissues from the consecutive autopsy cases of the aged from January 2005 to December 2006 in PLA General Hospital were carried out for immunohistochemical staining with beta amyloid, tau, α-synuclein and ubiquitin antibodies. The consortium to establish a registry for Alzheimer's disease (CERAD) was used to semi-quantitatively analyze Aß positive core plaques density and Braak staging for tau positive neurofibrillary tangles (NFTs) and α-synuclein positive Lewy bodies. In addition, Aß positive cerebral amyloid angiopathy (CAA), neuritic plaques and various ubiquitin positive structures were also observed. The relationship of these protein abnormal depositions in the aged brains with cognitive and motor functions were analyzed. RESULTS: In brain tissues of 16 consecutive autopsy cases of the aged from 78 to 95 years, there were 13 cases with Aß positive core plaques, their density was 2 cases with sparse, 2 cases with moderate and 9 cases with frequent, respectively, according to CREAD.Eight cases with Aß positive CAA were found, including 6 cases of mild CAA and 2 cases of severe CAA. There were 12 cases with tau positive NFTs, including 6 cases with Braak stageI-II, 4 cases with stage III-IV and 2 cases with stage V-VI. There were 5 cases with frequent Aß core plaques, meanwhile existing numerous tau/ubiquitin positive neuritic plaques and Braak stage IV-VI of tau positive NFTs, all of them presented cognitive dysfunction. Among 4 other cases with frequent Aß core plaques, only one case coexisted α-synuclein positive Lewy bodies showed moderate cognitive impairment, remaining 3 cases did not present cognitive dysfunction. There were 4 cases with α-synuclein positive Lewy bodies in the brainstem, and all of these cases presented parkinsonian motor dysfunction. 13 cases with ubiquitin positive structures were found. CONCLUSIONS: Beta amyloid protein positive deposit in the aged brain is an important marker of normal brain aging and cognitive impairment; frequent Aß core plaques in the neocortex plus Braak IV and above tau positive NFTs are closely related to cognitive dysfunction of Alzheimer's disease; α-synuclein positive Lewy bodies in the brainstem is one of the important pathological markers of parkinsonian motor disorders; ubiquitin deposition involves the development of some characteristic structures of several neurodegenerative diseases.

The protective effect of Ergolide in osteoarthritis: In vitro and in vivo studies.

Osteoarthritis (OA), a prevalent degenerative condition, occurs due to the deterioration of joint tissues and cells. Consequently, safeguarding chondrocytes against damage caused by inflammation is an area of future research emphasis. There is growing evidence that Ergolide (ERG) has multiple biological functions. Nevertheless, it is still uncertain whether it can hinder the advancement of OA. In this study, we investigate the ERG's potential to reduce inflammation and protect cartilage. ERG treatment in vitro effectively inhibited the excessive production of pro-inflammatory substances, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX2), and tumor necrosis factor-α (TNF-α), leading to their complete suppression. Furthermore, ERG suppressed the production of matrix-degrading enzymes (ADAMTS-5) and matrix metalloproteinase 13 (MMP13), consequently impeding the breakdown of extracellular matrix (ECM) and restraining the synthesis of collagenase II and Aggrecan. Through the P38/MAPK pathway, we discovered that ERG hinders the activation of NF-κB in chondrocytes induced by IL-1ß. The protective effect of ERG was enhanced by the p38 MAPK inhibitor SB203580. In vivo, ERG further demonstrated protective effects on cartilage in animal models of DMM. In conclusion, the study has discovered that ERG exhibits innovative therapeutic potential in the context of OA.

Selenium Deficiency Can Promote the Expression of VEGF and Inflammatory Factors in Cartilage Differentiation and Mediates Cartilage Injury.

Selenium plays a crucial role as a micronutrient, primarily exerting its biological functions through selenoproteins. It has been established that selenium deficiency adversely impacts cartilage development, leading to alterations in chondrocyte function. In regions with low selenium intake, endemic osteochondrosis has been documented, characterized by compromised growth plate and articular cartilage formation. Vascular endothelial growth factor (VEGF) stands out as a pivotal angiogenic factor, with elevated levels contributing significantly to vascular invasion into chondrocytes. This VEGF-mediated invasion serves as a key signal, prompting morphological changes in the growth plate and initiating cartilage remodeling. In animal models, the selenium deficiency group exhibited heightened levels of the cartilage damage marker matrix metalloproteinases 13 (MMP13). This resulted in articular cartilage degeneration, accompanied by a substantial increase in VEGF expression within the growth plate and articular cartilage, as compared to the normal group. In a chondrogenic progenitor cell (CPC) differentiation model, insufficient selenium induced chondrocyte damage and upregulated inflammatory factors such as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX2). The selenium-deficient groups showed elevated expressions of VEGF, VEGFR2, MMP13, Collagen X, and Angiopoietin 1, accelerating the degradation of the extracellular matrix (ECM), which further promoted the development of cartilage-related diseases. Taken together, these findings provide novel insights for a better understanding of the role of low selenium in cartilage degeneration and angiogenesis. They shed light on the intricate influence of low selenium levels on the development of articular cartilage, emphasizing the interconnected pathways and processes involved.

Explore the impact of hypoxia-related genes (HRGs) in Cutaneous melanoma.

BACKGROUND: Cutaneous melanoma (CM) has an overall poor prognosis due to a high rate of metastasis. This study aimed to explore the role of hypoxia-related genes (HRGs) in CM. METHODS: We first used on-negative matrix factorization consensus clustering (NMF) to cluster CM samples and preliminarily analyzed the relationship of HRGs to CM prognosis and immune cell infiltration. Subsequently, we identified prognostic-related hub genes by univariate COX regression analysis and the least absolute shrinkage and selection operator (LASSO) and constructed a prognostic model. Finally, we calculated a risk score for patients with CM and investigated the relationship between the risk score and potential surrogate markers of response to immune checkpoint inhibitors (ICIs), such as TMB, IPS values, and TIDE scores. RESULTS: Through NMF clustering, we identified high expression of HRGs as a risk factor for the prognosis of CM patients, and at the same time, increased expression of HRGs also indicated a poorer immune microenvironment. Subsequently, we identified eight gene signatures (FBP1, NDRG1, GPI, IER3, B4GALNT2, BGN, PKP1, and EDN2) by LASSO regression analysis and constructed a prognostic model. CONCLUSION: Our study identifies the prognostic significance of hypoxia-related genes in melanoma and shows a novel eight-gene signature to predict the potential efficacy of ICIs.

[The secondary metabolites of the HS-3 Alternaria sp. fungus associated with holothurians].

OBJECTIVE: The metabolites of HS-3 associated with holothurians were studied, which was identified by molecular biology as Alternaria sp.. METHODS: The holothurians were gathered from the Sea of Zhifu Islet, Shandong Province. HS-3 Alternaria sp. was culternitived in potato medium, and four compound was got by TLC, chromatography and HPLC, and 1-hydroxyl-3-methylanthracene-9,10-dione (1), chrysophanol (2), sterigmatocystin (3) and cerebroside (4) were elucated by modern spectrum. CONCLUSION: All of this provides scientific data for further study of holothurians, and the four coumpouns are isolated from the microbe associated with holothurians for the first time.

[Study on the second metabolisms from fungus HS-1 Epicoccum spp. from the sea cucumber in Yellow Sea].

OBJECTIVE: To get active metabolites from the microbes associated with sea cucumber. METHODS: Fungus was isolated from the sea cucumber, and the species was identified by molecular biology, and then was cultivated in GYP medium, and the metabolites were got by chromatography. Their structures were identified by comprehensive spectroscopic methods. RESULTS: Fungus HS-1 Epicocum sp. was isolated from the sea cucumber in Weihai, Yellow Sea. Four compounds were got as 5-methyl-6-hydroxy-8-methyoxy-3-methylisochroman (1), 8-hydroxy-3-methylisochroman-1-one (2), peroxy-ergosterol (3) and succinic acid (4). CONCLUSION: Fungus HS-1 Epicocum spp. is first isolated from the sea cucumber sample, this research provides new idea for further development of sea cucumber.

[The secondary metabolites of the mangrove endophytic fungi ZZF13 and Guignardia sp. 4382 from the South China Sea].

OBJECTIVE: The secondary metabolites of the fungus ZZF13 isolated from the leaves of the mangrove sample Kandelia candel in Zhanjiang and Guignardia sp. 4382 isolated from bark of Kandelia candel (endophyte) of Mai Po, Hong Kong were studied. METHODS: The compounds were isolated by siliga gel, and their structures were identified by IR, MS and NMR. RESULTS: Four compounds were isolated from the culture of this strain. Their structures were identified as Bacillpsporin C (1), 5-carboxymellein (2), 5-methylmellein (3) and 1-(2,6-dihydroxyphenyl) butanone (4). CONCLUSION: The compounds 2 - 4 are isolated from the Guignardia sp. of Marine fungi for the first time.

Antioxidant and antihyperlipidemic activities of polysaccharides from sea cucumber Apostichopus japonicus.

Polysaccharides (AJP) were prepared from Apostichopus japonicus by protease hydrolysis method. Antioxidant activity in vitro and antihyperlipidemic activity in vivo was investigated. Chemical composition analysis indicated that AJP was mainly composed of glucosamine, galactosamine, glucuronic acid, mannose, glucose, galactose and fucose, with an average molecular weight of about 36.2 kDa. The antioxidant capacities of AJP were, respectively, evaluated by the assays of scavenging DPPH, hydroxyl and superoxide radicals, and reducing power in vitro. It showed potent free radical scavenging activities and reducing power. Serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein (LDL-C) decreased significantly and high-density lipoprotein cholesterol (HDL-C) increased significantly after treatment of hyperlipidemic Wistar rats with AJP. These results suggest that AJP may prove to be a potential candidate of the natural antioxidants as a therapeutic agent for hyperlipidemia.

Isolation and characterization of a new benzofuran from the fungus Alternaria sp. (HS-3) associated with a sea cucumber.

A new compound, 4-acetyl-5-hydroxy-3, 6, 7-trimethylbenzofuran-2(3H)-one (1), together with two known compounds, 2-carboxy-3-(2-hydroxypropanyl) phenol (2) and 5-methyl- 6-hydroxy-8-methyoxy-3-methylisochroman (3) were isolated from the fungus Alternaria sp. (HS-3) associated with a sea cucumber from the Yellow Sea in China. Their structures were elucidated by spectral methods.

Antioxidant activity of chito-oligosaccharides on pancreatic islet cells in streptozotocin-induced diabetes in rats.

AIM: To investigate the antioxidant activity of chito-oligosaccharides (COSs) on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS: The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis. The activities of glutathione peroxidase and superoxide dismutase, total antioxidant capacity, and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS: COSs can prohibit the apoptosis of pancreatic islet cells. All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically. Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets, loss of pancreatic cells, and nuclear pyknosis of pancreatic cells. CONCLUSION: COSs possess various biological activities and can be used in the treatment of diabetes mellitus.