Rubus suavissimus S. Lee extract increases early adipogenesis in 3T3-L1 preadipocytes

Rubus suavissimus S. Lee Extract Alleviates Oxidative Stress and Inflammation in H2O2-Treated Retinal Pigment Epithelial Cells and in High-Fat Diet-Fed Mouse Retinas

BACKGROUND

Age-related macular degeneration (AMD) is the most common cause of visual disorders in the aged population and is characterized by the formation of retinal pigment epithelium (RPE) deposits and dysfunction/death of the RPE and photoreceptors. It is supposed that both oxidative stress and inflammation play a critical role in the pathogenesis of AMD. The development of therapeutic strategies against oxidative stress and inflammation in AMD is urgently needed. Rubus suavissimus S. Lee (RS), a medicinal plant growing in the southwest region of China, has been used as an herbal tea and medicine for various diseases.

METHODS

In this project, we evaluate the therapeutic potential of RS extract for AMD. We prepared RS extracts from dried leaves, which contained the main functional compounds.

RESULTS

RS extract significantly increased cell viability, upregulated the expression of antioxidant genes, lowered the generation of malondialdehyde and reactive oxygen species, and suppressed inflammation in H2O2-treated human RPE cells. In the in vivo study, treatment with RS extract attenuated body weight gain, lowered cholesterol and triglyceride levels in the liver and serum, increased antioxidant capacity, and alleviated inflammation in the retina and RPE/choroid of mice fed a high-fat diet.

CONCLUSIONS

Our findings suggest that RS extract offers therapeutic potential for treating AMD patients.

Integrating Constituents Absorbed into Blood, Network Pharmacology, and Quantitative Analysis to Reveal the Active Components in Rubus chingii var. suavissimus that Regulate Lipid Metabolism Disorder

Rubus chingii var. suavissimus (S. K. Lee) L. T. Lu (RS)—a sweet plant also known as Tiancha distributed in the south of China where it is used as a beverage—recently gained extensive attention as adjuvant therapy of diabetes and hypertension. Although pharmacological studies indicate that RS has beneficial effects in regulating lipid metabolism disorder characteristics, the active chemicals responsible for this effect remains unclear. The present study aims to predict the effective substances of RS on regulating lipid metabolism disorder through the analysis of the chemical profile of RS, the absorbed prototype components in rat plasma, and network pharmacology. Also, a UPLC method able to quantify the screened potential effective chemicals of RS products was established. First, a total of 69 components—including diterpene, triterpenoids, flavonoids, polyphenols, and lignans—were systematically characterized in RS. Of those, 50 compounds were detected in the plasma of rats administered with RS extract. Through network pharmacology, 9 potential effective components, 71 target genes, and 20 pathways were predicted to be involved in RS-mediated regulation of lipid metabolism disorder. The quantitative analysis suggested that the contents of potential effective components varied among samples from different marketplaces. In conclusion, the presented results provide a chemical basis for further research of Rubus chingii var. suavissimus.

1H NMR-based urinary metabonomic study of the antidiabetic effects of Rubus Suavissimus S. Lee in STZ-induced T1DM rats

Long-term hyperglycemia associated with diabetes mellitus (DM) causes damage to various organs and tissues, including the eyes, kidneys, heart, blood vessels and nerves. Rubus Suavissimus S. Lee (RS), a shrub whose leaves are used in traditional Chinese medicine (TCM), has been shown to exert hypoglycemic effects in DM patients. However, the underlying mechanism is unclear. This was investigated in the present study in a rat model of streptozotocin-induced type 1 diabetes mellitus (T1DM) by ¹H NMR analysis. We identify 9 metabolites whose levels were altered in T1DM rats compared to control rats, namely, lactate, acetate, pyruvate, succinate, 2-oxoglutarate, citrate, creatinine, allantoin, and hippurate, which are mostly related to glycolysis/gluconeogenesis, pyruvate metabolism, TCA cycle, and other metabolism. The observed pathologic changes in the levels of these metabolites in T1DM rats were reversed by treatment with RS. Thus, RS exerts effects in T1DM rats by regulating the three abnormal metabolic pathways synergistically. These findings provide supporting evidence for the therapeutic efficacy of this TCM formulation in the treatment of DM.

Development of a Multifunction Set Yogurt Using Rubus suavissimus S. Lee (Chinese Sweet Tea) Extract

Rubus suavissimus S. Lee leaves, also known as Chinese sweet tea or Tiancha, are used in folk medicine in southern China. This study evaluated the impact of the addition of Chinese sweet tea extract (0.25%, 0.5%, and 1%) on the chemical composition, organoleptic properties, yogurt culture viability, and biological activities (i.e., antioxidant, anticancer, and antihypertensive activities) of yogurt. Seven phenolic compounds were reported in Chinese sweet tea for the first time. The numbers of the yogurt culture were similar across all yogurt treatments. The yogurt supernatant with 0.25%, 0.5%, and 1% Chinese sweet tea extract had a total phenolic content that was 3.6-, 6.1-, and 11.2-fold higher, respectively, than that of the control yogurt. The biological activities were significantly increased by the addition of Chinese sweet tea extract: Yogurt with the addition of 1% Chinese sweet tea extract had the highest biological activities in terms of the antioxidant activity (92.43%), antihypertensive activity (82.03%), and inhibition of the Caco-2 cell line (67.46%). Yogurt with the addition of 0.5% Chinese sweet tea extract received the highest aroma and overall acceptability scores. Overall, Chinese sweet tea extract is a promising food ingredient for producing functional yogurt products that may substantially contribute to reducing the risk of developing chronic diseases such as cancer and cardiovascular disease.

1H-NMR Metabolomics Analysis of the Effect of Rubusoside on Serum Metabolites of Golden Hamsters on a High-Fat Diet

Rubusoside is a natural sweetener and the active component of Rubus suavissimus. The preventive and therapeutic effect of rubusoside on high-fat diet-induced (HFD) serum metabolite changes in golden hamsters was analyzed by ¹H-NMR metabolomics to explore the underlying mechanism of lipid metabolism regulation. ¹H-NMR serum metabolomics analyses revealed a disturbed amino acid-, sugar-, fat-, and energy metabolism in HFD animals. Animals supplemented with rubusoside can partly reverse the metabolism disorders induced by high-fat diet and exerted good anti-hypertriglyceridemia effect by intervening in some major metabolic pathways, involving amino acid metabolism, synthesis of ketone bodies, as well as choline and 4-hydroxyphenylacetate metabolism. This study indicates that rubusoside can interfere with and normalize high-fat diet-induced metabolic changes in serum and could provide a theoretical basis to establish rubusoside as a potentially therapeutic tool able to revert or prevent lipid metabolism disorders.

Chinese Sweet Leaf Tea (Rubus suavissimus) Mitigates LPS-Induced Low-Grade Chronic Inflammation and Reduces the Risk of Metabolic Disorders in a C57BL/6J Mouse Model

Chronic exposure to minute doses of endotoxin elicits intestinal inflammation and impairs the gut barrier function, potentially resulting in systemic inflammation with elevated concentrations of biomarkers associated with metabolic syndrome. This study aimed to investigate the preventive effects of the Rubus suavissimus S. Lee leaf extract in a model of low-grade systemic inflammation. The predominant compounds found in the leaf extract are gallic acids, ellagic acid, and rubusoside. Results of the present study showed that R. suavissimus leaf extract supplementation could help preserve intestinal barrier integrity by upregulating the expression of the tight junction proteins [e.g., zonula occluden-1 (ZO-1) and junctional adhesion molecule-1 (JAMA)] and mucin (MUC)-4 and also suppress the release of plasmatic proinflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, and monocyte chemotactic protein (MCP)-1, while restoring the production of anti-inflammatory adiponectin. We subsequently determined that the leaf extract contributes to restoring glucose metabolic homeostasis through maintaining insulin sensitivity. Furthermore, our mechanistic finding demonstrated that the R. suavissimus leaf extract supplementation prevented systemic inflammation-driven impaired insulin sensitivity in white adipose tissues (WATs) by modulating the expression of peroxisome-proliferator-activated receptor-γ (PPAR-γ) and insulin receptor subset-1 (IRS-1). Altogether, our findings suggest that the above supplementation contributes to restoring immune and metabolic homeostasis to enhance the overall health of the host thereby preventing the early onset of metabolic disorders such as obesity and type 2 diabetes.

Metabolomics analysis of the protective effect of rubusoside on palmitic acid-induced lipotoxicity in INS-1 cells using UPLC-Q/TOF MS

Diabetes is one of the most severe chronic diseases worldwide.