Correction: The emerging role of medical foods and therapeutic potential of medical food-derived exosomes.

[This corrects the article DOI: 10.1039/D3NA00649B.].

The emerging role of medical foods and therapeutic potential of medical food-derived exosomes.

Medical food is consumed for the purpose of improving specific nutritional requirements or disease conditions, such as inflammation, diabetes, and cancer. It involves partial or exclusive feeding for fulfilling unique nutritional requirements of patients and is different from medicine, consisting of basic nutrients, such as polyphenols, vitamins, sugars, proteins, lipids, and other functional ingredients to nourish the patients. Recently, studies on extracellular vesicles (exosomes) with therapeutic and drug carrier potential have been actively conducted. In addition, there have been attempts to utilize exosomes as medical food components. Consequently, the application of exosomes is expanding in different fields with increasing research being conducted on their stability and safety. Herein, we introduced the current trends of medical food and the potential utilization of exosomes in them. Moreover, we proposed Medi-Exo, a exosome-based medical food. Furthermore, we comprehensively elucidate various disease aspects between medical food-derived exosomes (Medi-Exo) and therapeutic natural bionanocomposites. This review highlights the therapeutic challenges regarding Medi-Exo and its potential health benefits.

Purification and Characterization of a Major Extracellular Chitinase from a Biocontrol Bacterium, Paenibacillus elgii HOA73.

Chitinase-producing Paenibacillus elgii strain HOA73 has been used to control plant diseases. However, the antimicrobial activity of its extracellular chitinase has not been fully elucidated. The major extracellular chitinase gene (PeChi68) from strain HOA73 was cloned and expressed in Escherichia coli in this study. This gene had an open reading frame of 2,028 bp, encoding a protein of 675 amino acid residues containing a secretion signal peptide, a chitin-binding domain, two fibronectin type III domains, and a catalytic hydrolase domain. The chitinase (PeChi68) purified from recombinant E. coli exhibited a molecular mass of approximately 68 kDa on SDS-PAGE. Biochemical analysis indicated that optimum temperature for the actitvity of purified chitinase was 50ºC. However, it was inactivated with time when it was incubated at 40ºC and 50ºC. Its optimum activity was found at pH 7, although its activity was stable when incubated between pH 3 and pH 11. Heavy metals inhibited this chitinase. This purified chitinase completely inhibited spore germination of two Cladosporium isolates and partially inhibited germination of Botrytis cinerea spores. However, it had no effect on the spores of a Colletotricum isolate. These results indicate that the extracellular chitinase produced by P. elgii HOA73 might have function in limiting spore germination of certain fungal pathogens.

Green tea changes serum and liver metabolomic profiles in mice with high-fat diet-induced obesity.

SCOPE: Green tea (GT) consumption helps to prevent and control obesity by stimulating hepatic lipid metabolism. However, GT-induced changes in serum and liver metabolomes associated with the anti-obesity effects are not clearly understood. The aim of this study was to identify and validate metabolomic profiles in the livers and sera of GT-fed obese mice to elucidate the relationship between GT consumption and obesity prevention. METHODS AND RESULTS: Serum and liver metabolites were analyzed in mice fed normal diet, high-fat diet (HFD), HFD with GT, and HFD with crude catechins, using LC-quadrupole TOF MS. The addition of 1% GT to HFD reduced adipose tissue and the levels of blood triglycerides, glucose, insulin, and leptin elevated in HFD-fed mice. We proposed an HFD-induced obesity pathway and validated it by investigating the key regulatory enzymes of mitochondrial ß-oxidation: carnitine palmitoyltransferase-1 and -2, acyl-coenzyme A dehydrogenase, and acetyl-coenzyme A acyltransferase. The results showed that HFD-induced abnormal mitochondrial ß-oxidation was moderated by the consumption of caffeine- and theanine-enriched GT. CONCLUSION: Results of LC/MS-based metabolomic analysis of obese mice showed changes associated with abnormal lipid and energy metabolism, which were alleviated by GT intake, indicating the mechanism underlying the anti-obesity effects of GT.

Neuroprotective effects of the cyanidin-3-O-beta-d-glucopyranoside isolated from mulberry fruit against cerebral ischemia.

This study investigated the neuroprotective effects of cyanidin-3-O-beta-d-glucopyranoside (C3G) from the mulberry fruits on neuronal cell damage. A 1% HCl-MeOH mulberry fruit extract was shown to have a cytoprotective effect on PC12 cells that had been exposed to hydrogen peroxide. The extract inhibited the cerebral ischemic damage caused by oxygen glucose deprivation (OGD) in PC12 cells. The neuroprotective effect of the mulberry fruit extract was further demonstrated in vivo using a mouse-brain-injury model with a transient middle cerebral artery occlusion (MCAO). C3G was isolated as a neuroprotective constituent from the mulberry fruit extract. Compared with the control group, C3G had neuroprotective effects on the PC12 cells exposed to hydrogen peroxide in vitro and on cerebral ischemic damage in vivo.

(-)-3,5-Dicaffeoyl-muco-quinic acid isolated from Aster scaber contributes to the differentiation of PC12 cells: through tyrosine kinase cascade signaling.

Aster scaber T. (Asteraceae) has been used in traditional Korean and Chinese medicine to treat bruises, snakebites, headaches, and dizziness. (-)-3,5-Dicaffeoyl-muco-quinic acid (DQ) isolated from A. scaber induced neurite outgrowth in PC12 cells. It has been reported that the activation of the extracellular signal regulated kinase 1/2 (Erk 1/2) and phosphoinositide 3 (PI3) kinase plays a crucial role in the NGF-induced differentiation of PC12 cells. This study showed that the effect of DQ on neurite outgrowth is mediated via the Erk 1/2 and PI3 kinase-dependent pathways like NGF. Furthermore, DQ stimulated the phosphorylation of Trk A. Overall, DQ elicited the differentiation of PC12 cells through Trk A phosphorylation followed by Erk 1/2 and PI3 kinase activation.

Phospholipids from Bombycis corpus and their neurotrophic effects.

Three phospholipids (4-6) and three aromatic amines (1-3) were obtained from the methanol extract of Bombycis corpus. Based on spectral data, their structures have been elucidated as nicotiamide (1), cytidine (2), adenine (3), 1-O-(9Z-octadecenoyl)-2-O-(8Z,11Z-octadecadienoyl) sn-glycero-3-phosphorylcholine (4), 1,2-di-O-hexadecanoyl-sn-glycero-3-phosphorylcholine (5) and 1,2-di-O-9Z-octadecenoyl-sn-glycero-3-phosphorylcholine (6). We examined the effects of compounds on synthesis of NGF in cultured astrocytes. By RT-PCR analysis, expresison of NGF mRNA in astrocytes cultured in serum-starvation increased after the addition of phospholipid (10 microM). The NGF content in the culture medium was significantly increased by compound 5, compared with the control value. These results suggest that three phospholipid compounds isolated from the methanol extract of Bombycis corpus may exert neurotrophic effects by stimulation of NGF synthesis in astrocytes.