Effects of Saponins from the Root Bark of Aralia elata on the Transport of Chondroitin Sulfate in Caco-2 Cell Monolayers and Rats

Chondroitin sulfate is not digested at all in the mouse small intestine but may suppress interleukin 6 expression induced by tumor necrosis factor-α

Salmon nasal cartilage proteoglycan (PG) was orally administered to mice. The PG digest was recovered from the small intestine, and its sugar chain size and unsaturated disaccharide content were examined. The elution position of the PG digest following Sepharose CL-4B chromatography was consistent with that of actinase-digested PG prior to administration. The PG digest was incubated with chondroitinase ABC, which resulted in the elution pattern of the unsaturated disaccharides being identical to that of the degraded product of actinase-digested PG. The core protein of PG was digested in the mouse small intestine, but chondroitin sulfate, which is the sugar chain of PG, was not degraded at all. Then, the effects of chondroitin 4- and 6-sulfates on human colon cancer cells were examined. These chondroitin sulfates were found to suppress the expression of interleukin-6 induced by TNF-α. Overall, the chondroitin sulfate chain may act on the intestinal epithelium and suppress inflammation of the intestinal tract.

Anti-inflammatory effects of the Aralia elata and Cirsium japonicum in Raw264.7 cells and in vivo colitis model in mice and dogs

Ulcerative colitis (UC) is a severe inflammatory disease that has spread throughout the world. Cirsium japonicum (CJ) and Aralia elata (AE) are natural herbs with potent antioxidative antidiabetics and anti-inflammatory effects. In this investigation, we studied the defensive role of the combination of CJ and AE against LPS-induced inflammation in RAW 264.7 cells, dextran sulfate sodium (DSS)-induced colitis in mice, and acetic acid-induced colitis in dogs. MTT assay was performed to identify the toxic effect of CJ and AE extracts. NO, and MDA level was also measured by NO and MDA assay. To measure the pro-inflammatory protein expression, a western blot was performed. To induce colitis, 3% DSS was used for mice and 6% acetic acid was used for dogs. Histopathology and colonoscopy were executed to detect the effect of extracts. CJ and AE pretreatment reduced the level of NO, MDA, and the expression of pro-inflammatory proteins cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in RAW 264.7. Compared to the separate doses of CJ and AE, the combined dose of CJ and AE significantly reduced clinical symptoms induced by DSS in mice and acetic acid in dogs including weight loss, bloody stool, shortening of the colon, and the severity of colitis and degree of histological damage in the colon. Therefore, these results indicated that a combined dose of CJ and AE has a protective effect against LPS-induced RAW 264.7 cells, DSS-mediated colonic inflammation in mice, and acetic acid-induced colitis in dogs.

Multiomics analysis of soybean meal induced marine fish enteritis in juvenile pearl gentian grouper, Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂

As an important protein source, soybean products can cause intestinal inflammation and injury in many animals including human beings, particularly infants and juvenile individuals. Research in this field has been performed for terrestrial animals and fish, but still lacks integrity and systematicness. In this study, the main biological processes in the intestinal tract of marine fish juvenile pearl gentian grouper in the state of soybean meal-induced enteritis (SBMIE) were analyzed. A total of 720 groupers with an approximate initial weight of 12.5 g were randomly divided into three groups: the fish meal (FM) control group, the 20% SBM group (SBM20), and the SBM40 group (n = 4). Three iso-nitrogenous and iso-lipidic diets were prepared and fed to fish for 10 weeks. Each barrel contained a water volume of about 1 m3 in and was exposed to natural light and temperature. Results indicated that the growth and physiology of groupers fed with SBM were significantly negatively affected, with the gene expressions of intestinal structural protein abnormal. 16SrDNA high-throughput sequencing showed that the intestinal microflora played an important role in the pathogenesis of pearl gentian grouper SBMIE, which may activate a variety of pathogen pattern recognition receptors, such as toll-like receptors (TLRs), RIG-I-like receptors, and nod-like receptors. Transcriptome analysis revealed that changes of the SBMIE signaling pathway in pearl gentian groupers were conservative to some extent than that of terrestrial animals and freshwater fish. Moreover, the TLRs-nuclear factor kappa-B signaling pathway becomes activated, which played an important role in SBMIE. Meanwhile, the signal pathways related to nutrient absorption and metabolism were generally inhibited. Metabolomics analysis showed that isoflavones and saponins accounted for a large proportion in the potential biomarkers of pearl gentian grouper SBMIE, and most of the biomarkers had significantly positive or negative correlations with each other; 56 metabolites were exchanged between intestinal tissues and contents, which may play an important role in the development of enteritis, including unsaturated fatty acids, organic acids, amino acids, vitamins, small peptides, and nucleotides, etc. These results provide a basic theoretical reference for solving the intestinal issues of fish SBMIE and research of inflammatory bowel disease in mammals.

The Saponin-Mediated Enhanced Uptake of Targeted Saporin-Based Drugs is Strongly Dependent on the Saponin Structure

Saponins are a group of plant glycosides consisting of a steroid or triterpenoid aglycone to which one or more sugar chains are attached. They exhibit cell membrane–permeabilizing properties and, thus, have been investigated for their therapeutic potential. Recently, at a nonpermeabilizing concentration saponinum album from Gypsophila paniculata L. has been described to enhance the cytotoxicity of a chimeric toxin in a cell culture model. To elucidate whether this enhancing effect is also mediated by other saponins, we analyzed the ability of seven different saponins to enhance the cytotoxicity of a targeted chimeric toxin. The chimeric toxin is composed of saporin, a plant ribosome-inactivating toxin, a cleavable adapter, and human epidermal growth factor (EGF). Cytotoxicity on EGF receptor (EGFR)-bearing cells was analyzed both alone and after combined application of saponin and chimeric toxin. Only two of the tested saponins, quillajasaponin and saponinum album, enhanced cytotoxicity by more than 1000-fold, whereas the enhancement factors of the other saponins were only approximately 10-fold. In contrast to saponinum album, quillajasaponin enhanced the cytotoxicity both on control cells lacking EGFR and on target cells, indicating that, in this case, the enhancement is not target cell receptor specific. This is also the case for some of the saponins with low enhancement factors. Saponinum album resulted in a more than 13,600-fold receptor-specific enhancement, decreasing the 50% inhibitory concentration (IC50) from 2.4 nM to 0.18 pM, which renders it the best option to promote saporin-3-based drug uptake while retaining specificity for the EGFR.

Aralia elata var. mandshurica (Rupr. & Maxim.) J.Wen: An overview of pharmacological studies

PURPOSE

Aralia elata var. mandshurica (Rupr. & Maxim.) J.Wen syn. A. mandshurica Rupr. & Maxim is evaluated for its medicinal application. The aim of this study is to analyze pharmacological studies on A. elata var. mandshurica published until December 2015.

METHODS

The information regarding the chemistry, safety, effectiveness, and pharmacological and clinical effects of A. elata was systematically collected from the scientific literature through library catalogs; online services such as E-library.ru, Medline/PubMed, Scopus, Web of Science, and Google Scholar.

RESULTS

A. elata is often considered an example of a medicinal plant used in Chinese, Korean, and Japanese traditional medicine. However, the contemporary applications of Aralia in officinal medicine result primarily from a large number of pharmacological and clinical investigations carried out in the former USSR in the mid-20th century. Since the 1950s, medicinal preparations from radices of A. elata and radices of A. mandshurica have secured an established position within Russian/USSR medicine as evidenced by the inclusion of the drug in recent editions of the National Pharmacopoeia of the USSR and in the Register of Medicinal Preparations of Russia. Pharmacological studies on animals have shown that Aralia increases physical working capacity and affords a stress-protective effect against a broad spectrum of harmful factors including cold stress, immobilization, UV irradiation, and low air pressure. The phytoadaptogen exerts an effect on the central nervous, reproductive, immune, respiratory, and gastrointestinal systems; the metabolic syndrome including hypolipidemic and antidiabetic effects; and blood coagulation. Together with general properties of adaptogens, Aralia has its own specificity, which manifests in cardioprotective and antiarrhythmic activities. Studies on isolated organs, cells, and enzymes have revealed that Aralia preparations exhibit antioxidant activities and enhance sarcoplasmic reticulum Ca²⁺-ATPase activity, inhibit endoplasmic reticulum stress-associated apoptosis markers (GRP78, CHOP, Caspase-12, and JNK), and increase phosphorylation of STAT3 and Bcl2/Bax ratio; they also show cytotoxic activities against some tumor cell lines; affect NF-κB and PPARs activities; and regulate biosynthesis of pro-inflammatory cytokines and inflammation-related protein expression, tissue respiration, and oxygen consumption. In healthy subjects, Aralia increases mental performance, working capacity, and endurance of movement. Numerous clinical trials have shown the efficiency of Aralia preparations in patients with traumatic brain injury (accompanied with asthenic syndrome and neurotic reactions, depression, neurasthenia, and psychasthenia), neurological diseases (accompanied with astheno-depressive and astheno-hypochondriasis syndromes), myasthenia syndrome (accompanied with chronic post-influenza arachnoiditis), and arterial hypotension. Aralia tincture and "Saparal" are useful as antiviral remedies. Radioprotective properties of Aralia have been reported in pregnant women. Synergistic antiobesity effect was reported for the combination of A. mandshurica and Engelhardtia chrysolepis extracts and antidiabetic effect for the combination of Aralia and glipizide. Promising stress-relieving effects of Aralia are reported for professionals whose work requires a high level of attention. Its proposed ability to moderate stress-induced damage and dysfunction in the cardiovascular tissue might make Aralia the adaptogen of choice among patients with higher risk for cardiovascular diseases. Because Aralia extract administration appears to affect plasma glucose level and hepatic lipid accumulation and ameliorate hyperinsulinemia, it might also provide benefits and be the adaptogen of choice for patients with obesity and diabetes.

CONCLUSION

This review describes the considerable diversity of pharmacological effects of A. elata reported in numerous studies carried out in the former USSR and other countries, which have been confirmed over >47 years of use of the plant as an official medicinal remedy. The knowledge discussed in this review can be applied to the expansion of the use of this high-value plant in the pharmacotherapy of European and other countries and for the further discovery of new drugs based on the secondary metabolites of this plant. Modern approaches in mechanisms of action, including a study of gene expression profiling, suggest the most up-to-date challenges for the future research of Aralia.

Enhancing the intestinal absorption of low molecular weight chondroitin sulfate by conjugation with α-linolenic acid and the transport mechanism of the conjugates

The purpose of this report was to demonstrate the effect of amphiphilic polysaccharides-based self-assembling micelles on enhancing the oral absorption of low molecular weight chondroitin sulfate (LMCS) in vitro and in vivo, and identify the transepithelial transport mechanism of LMCS micelles across the intestinal barrier. α-Linolenic acid-low molecular weight chondroitin sulfate polymers(α-LNA-LMCS) were successfully synthesized, and characterized by FTIR, (1)HNMR, TGA/DSC, TEM, laser light scattering and zeta potential. The significant oral absorption enhancement and elimination half-life (t₁/₂) extension of LNA-LMCS2 in rats were evidenced by intragastric administration in comparison with CS and LMCS. Caco-2 transport studies demonstrated that the apparent permeability coefficient (Papp) of LNA-LMCS2 was significantly higher than that of CS and LMCS (p<0.001), and no significant effects on the overall integrity of the monolayer were observed during the transport process. In addition, α-LNA-LMCS micelles accumulated around the cell membrane and intercellular space observed by confocal laser scanning microscope (CLSM). Furthermore, evident alterations in the F-actin cytoskeleton were detected by CLSM observation following the treatment of the cell monolayers with α-LNA-LMCS micelles, which further certified the capacity of α-LNA-LMCS micelles to open the intercellular tight junctions rather than disrupt the overall integrity of the monolayer. Therefore, LNA-LMCS2 with low cytotoxicity and high bioavailability might be a promising substitute for CS in clinical use, such as treating osteoarthritis, atherosclerosis, etc.

Dietary soya saponins increase gut permeability and play a key role in the onset of soyabean-induced enteritis in Atlantic salmon ( Salmo salar L.)

Saponins are naturally occurring amphiphilic molecules and have been associated with many biological activities. The aim of the present study was to investigate whether soya saponins trigger the onset of soyabean-induced enteritis in Atlantic salmon (Salmo salar L.), and to examine if dietary soya saponins increase the epithelial permeability of the distal intestine in Atlantic salmon. Seven experimental diets containing different levels of soya saponins were fed to seawater-adapted Atlantic salmon for 53 d. The diets included a fishmeal-based control diet, two fishmeal-based diets with different levels of added soya saponins, one diet containing 25% lupin kernel meal, two diets based on 25% lupin kernel meal with different levels of added soya saponins, and one diet containing 25% defatted soyabean meal. The effect on intestinal morphology, intestinal epithelial permeability and faecal DM content was examined. Fish fed 25% defatted soyabean meal displayed severe enteritis, whereas fish fed 25% lupin kernel meal had normal intestinal morphology. The combination of soya saponins and fishmeal did not induce morphological changes but fish fed soya saponins in combination with lupin kernel meal displayed significant enteritis. Increased epithelial permeability was observed in fish fed 25% defatted soyabean meal and in fish fed soya saponin concentrate independent of the protein source in the feed. The study demonstrates that soya saponins, in combination with one or several unidentified components present in legumes, induce an inflammatory reaction in the distal intestine of Atlantic salmon. Soya saponins increase the intestinal epithelial permeability but do not, per se, induce enteritis.