Mei Hua's research while affiliated with Institute of Plant Protection, Chinese Academy of Agricultural Sciences and other places

The mechanism by which ginsenosides from Panax quinquefolium L. transform into rare saponins by different processing methods and their antitumour effects have yet to be fully elucidated. Our study aimed to detect the effect of amino acids and processing methods on the conversion of ginsenosides in American ginseng to rare ginsenosides, using 8 monomeric ginsenosides as substrates to discuss the reaction pathway and mechanism. S180 tumour-bearing mice were established to study the antitumour effects of American ginseng total saponins (AGS-Q) or American ginseng total saponins after transformation (AGS-H) synergistic CTX. The results showed that aspartic acid was the best catalyst, and the thermal extraction method had the best effect. Under the optimal conditions, including a reaction temperature of 110°C, an aspartic acid concentration of 5%, a reaction time of 2.5 h and a liquid-solid ratio of 30 mL/g, the highest conversion of Rk1 and Rg5 was 6.58 ± 0.11 mg/g and 3.74 ± 0.05 mg/g, respectively. In the reaction pathway, the diol group saponins participated in the transformation process, and the triol group saponins basically did not participate in the transformation process. AGS-Q or AGS-H synergistic CTX, or AGS-H synergistic CTX/2 could significantly increase the tumour inhibition rate, spleen index and white blood cell count, had a significant upregulation effect on IL-2 and IL-10 immune cytokines; significantly restored the ratio of CD4+/CD8+; and significantly inhibited the level of CD4+CD25+. AGS-Q or AGS-H synergistic with CTX or CTX/2 can significantly upregulate the expression of Bax and cleaved-Caspase-3 and inhibit the expression of antiapoptotic protein Bcl-2. AGS synergistic CTX in the treatment of S180 tumour-bearing mice can improve the efficacy and reduce toxicity.

In this study, we analyzed the composition and content of 25 free amino acids in 32 batches of different forms of Cervi Cornu Pantotrichum(CCP; one-branched, two-branched, and three-branched) from 15 producing areas. The clustering analysis and orthogonal partial least squares discriminant analysis(OPLS-DA) were performed based on the content of 25 free amino acids. Potential differential metabolites were identified based on VIP value. The results showed that there were 25 free amino acids in CCP, and the average content of essential, non-essential, and total amino acids was 6.13, 32.99, and 39.12 mg·g~(-1), respectively. The clustering analysis and OPLS-DA demonstrated that 25 free amino acids had different content among the three forms of CCP, of which two-branched CCP samples were separately gathered into a group. Five differential components, including glutamic acid, tryptophan, ornithine, γ-aminobutyric acid, and hydroxylysine, were screened out as potential quality markers for the identification of different forms of CCP. This study provides a theoretical basis for the quality evaluation, processing, and utilization of different forms of CCP.

Sediment is a key issue in the production and marketing of plant beverages, as is ginseng beverages. The formation of sediment in ginseng beverages is a gradual process. This work describes the formation of sediment from different parts of ginseng and describes the color and clarity of the liquid and the amount and morphology of the sediment. The results showed there are significant differences in the sediment formation speed, morphology and transmittance for the aqueous extracts prepared from different parts of ginseng. The amounts of sediment generated from the different parts of ginseng is as follows: main root > rhizome > fibrous root. Free amino acids, Ba, Ca, Ni, and Sr concentrations are significantly and positively correlated with the transmittance. The total saponins, Al, Fe, and Mn concentrations are significantly and negatively correlated with the transmittance. There are obvious crystals and more Ca in the fibrous root sediment. We analyzed and compared the chemical components in the sediment and extract. The results show that the main components of the sediment are carbohydrates and protein. According to the partition coefficient the contents of protein, ginsenosides (Rb1, Rb2, Rb3, Rf) and some ions (Al, Fe, Ca, and Na) contribute more to the formation of the sediment than the other investigated components.

The activation of hepatic stellate cells (HSC) plays a key role in the progression of hepatic fibrosis, it is essential to remove activated HSC through apoptosis to reverse hepatic fibrosis. Schisandrin B (Sch B) is the main chemical component of schisandrin lignan, and it has been reported to have good hepatoprotective effects. However, Schisandrin B on HSC apoptosis remains unclear. In our study, we stimulated the HSC-T6 and LX-2 cell lines with TGF-β1 to induce cell activation, and the proliferation and apoptosis of the activated HSC-T6 and LX-2 cells were detected after treatment with different doses of Schisandrin B. Flow cytometry results showed that Sch B significantly reduced the activity of activated HSC-T6 and LX-2 cells and significantly induced apoptosis. In addition, the cleaved-Caspase-3 levels were increased, the Bax activity was increased, and the Bcl-2 expression was decreased in HSC-T6 and LX-2 cells treated with Sch B. Our study showed that Sch B inhibited the TGF-β1-induced activity of hepatic stellate cells by promoting apoptosis.

Sediment is a key issue in the beverage industry. This study confirmed that reversible and irreversible sediments were formed during low-temperature storage of ginseng extract. The first 30 days of storage are the critical period for sediment formation. As the time of storage extends, the chemical composition changes. The composition interaction model verified that the cross-linking of protein–pectin, protein–oxalic acid and Ca2+–pectin was the main cause of the turbidity of ginseng extract. Based on the characterization of irreversible sediment (IRS), there are typical structures of proteins, polysaccharides and calcium oxalate dihydrate (COD) crystals. Glucose, galacturonic acid, aspartate, glutamic acid, leucine, Ca, K, Al, Mg, Na and Fe are the main monomer components. Effective regulation of these ingredients will greatly help the quality of ginseng beverages.

In this study, the effects of ginseng water-soluble dietary fiber (ginseng-SDF) on metabolism, appetite and colon health in rats were investigated. The results showed that ginseng-SDF could improve the glucolipid metabolism, especially in the triglyceride levels. Ginseng-SDF also increased satiety and delayed gastric emptying by regulating the appetite hormone levels as ghrelin, glucagon-like peptide-1, peptide YY, and cholecystokinin. In addition, ginseng-SDF improved intestinal structures and enhanced fecal short-chain fatty acids concentrations (especially acetic acid and butyric acid). More importantly, ginseng-SDF affected the abundance of Firmicutes and Bacteroides, and significantly promoted the proliferation of probiotics and cellulolytic bacteria such as Lactobacillus, Bifidobacterium and Ruminococcus_bromii. Among them, Bifidobacterium pseudolongum, Lactobacillus helveticus and R. bromii were correlated with blood glucose and blood lipid levels. These results suggested that ginseng-SDF could alter the intestinal flora structure, promote colon health, and ultimately have a positive impact on glucolipid metabolism and energy homeostasis.

As an important component of ginseng, the in vivo benefits of ginseng water-soluble dietary fiber (ginseng-SDF) have not been fully revealed. To explore these benefits, healthy rats were given ginseng-SDF (200, 400, and 800 mg/kg body weight/day) by gavage for 15 days. The results showed that ginseng-SDF significantly improved the rats’ growth performance and serum antioxidant status. Insulin-like growth factor (IGF-1 and IGF-2) and immunoglobulin (IgA, IgM, and IgG) levels in the ginseng-SDF groups were increased. High-dose ginseng-SDF significantly increased the cecal butyric acid proportion compared with the K group. Ginseng-SDF increased the abundance of Firmicutes and promoted the proliferation of probiotics such as Lactobacillus, and cellulose decomposers such as Ruminococcus and Clostridium in cecal microflora. These altered microflora were correlated with growth performance, antioxidant status and immunoglobulin indexes. The above results suggested that ginseng-SDF might have positive effects on growth, oxidative-immune levels and cecal health in rats.

Ginseng saponins (GS) are the main active compounds in Panax ginseng and have been proven to be highly effective in attenuating the side effects of chemotherapy. However, there have been no reports on the mechanism of action of GS. Treatment with GS has certain benefits, including decreasing the toxicity levels in the liver [alanine aminotransferase (ALT), albumin (ALB), alkaline phosphatase (ALP), aspartate transaminase (AST)], reducing oxidative stress [malondialdehyde (MDA), nitric oxide (NO)], diminishing inflammatory factors [interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α) levels], and augmenting the levels of glutathione (GSH) and superoxide dismutase (SOD). The pharmacokinetics study showed that the area under the curve from 0 to 24 hr (AUC 0–24 hr) of 4‐ketocyclophosphamide (4‐KetoCTX) and carboxyphosphamide (CPM) was significantly increased after GS treatment. This study found that GS treatment can reduce chloroacetaldehyde (CAA) production by affecting CYP3A4, CYP2B6, and CYP2C9 protein expression in the liver. For the metabolomics study, GS attenuated the abnormalities of amino acid metabolic pathways in CP‐induced liver injuries of rats and significantly enhanced the l‐arginine level while reducing the serum nitric oxide (NO) level. This outcome was confirmed by the inhibition of the activities of NO synthase in the liver of rats.

Ginseng (Panax ginseng C.A. Meyer) is the most famous edible Chinese herbal medicine. In the present study, soluble dietary fiber of ginseng (ginseng‐SDF, 8.98% content) was extracted from ginseng residue, and its physicochemical characterization, structure, and biological activities were studied. Ginseng‐SDF was an acidic heteropolysaccharide (uronic acid, 4.42% content) rich in protein, amino acids, and mineral elements. Glucose was its main monosaccharide composition (58.03%). Ginseng‐SDF had a porous microstructure, a typical cellulose I structure and a large number of hydroxyl functional groups. These chemical composition and structural characteristics gave ginseng‐SDF a good water solubility (98.56%), oil‐holding capacity (OHC) (3.01 g/g), and biological activities, as the antioxidant activity (13.35 μM TE/g, 105.17 μM TE/g, 54.20 μM TE/g for DPPH, ABTs, and FRAP assays, respectively), glucose diffusion retardation index (GDRI, 33.33%–7.43%), and α‐amylase/α‐glucosidase inhibitory activities (IC50, 6.70 mg/ml, and 4.89 mg/ml, respectively). The results suggested that ginseng residue is a valuable source of functional dietary fiber, and the ginseng‐SDF has a potential use in antioxidant and hypoglycemic foods. Practical applications Ginseng has long been popular as a health food in Asia, North America, and Europe. Ginseng residue is rich in polysaccharides, dietary fiber, proteins, and other components, which is also of great research value. However, there are few studies focus on the soluble dietary fiber of ginseng at present. The research shows that ginseng residue is a valuable source of functional dietary fiber. The chemical components and structural characteristics give ginseng‐SDF a noteworthy antioxidant activity and enzyme inhibitory activity in vitro. These properties and biological activities indicate that ginseng‐SDF has application value in antioxidant and hypoglycemic foods.

Ginsenoside Rk1, a saponin component produced by heat-processed ginseng, possesses anti-inflammatory and antitumor activities. The aim of our study was to explore the effects of Rk1 on Lipopolysaccharide (LPS)-induced depression-like behavior in mice and to observe its effects on oxidative stress, the inflammatory response and brain-derived neurotrophic factor (BDNF) - tropomyosin-related kinase B (TrkB) signaling. After mice were pretreated with Rk1 (5, 10, and 20 mg/kg), the immobility time in both the forced swimming test (FST) and the tail suspension test (TST) was reduced, suggesting that Rk1 effectively improved depression-like symptoms. Rk1 (10 and 20 mg/kg) and Fluoxetine (Flu, 20 mg/kg) increased the activity of the antioxidant enzyme SOD in the brain and protected against lipid peroxidation. Different concentrations of Rk1 (10 and 20 mg/kg) and Flu significantly decreased the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1 in serum, while Rk1 (5, 10, and 20 mg/kg) and Flu reduced the concentrations of IL-6 in a dose-dependent manner. Western blot analysis showed that the administration of Rk1 (20 mg/kg) and Flu significantly downregulated the level of Sirt1 and that Rk1 (5, 10, and 20 mg/kg) and Flu inhibited the p-NF-κb/NF-κb and p-IκB-α/IκB-α ratios, which indicated that the neuroprotective effect of Rk1 may be related to the suppression of inflammation. In addition 5, 10 and 20 mg/kg Rk1 significantly attenuated the LPS-induced decreases in BDNF and TrkB. These results indicated that Rk1 acts as an antidepressant through its antioxidant activity, the inhibition of neuroinflammation, and the positive regulation of the BDNF-TrkB pathway. This study may help develop active ginsenoside-based compounds for neurodegenerative diseases.