Protein tyrosine phosphatase 1B inhibitory activities of ursane-type triterpenes from Chinese raspberry, fruits of Rubus chingii

Vasorelaxant effects of biochemical constituents of various medicinal plants and their benefits in diabetes

Endothelial function plays a pivotal role in cardiovascular health, and dysfunction in this context diminishes vasorelaxation concomitant with endothelial activity. The nitric oxide-cyclic guanosine monophosphate pathway, prostacyclin-cyclic adenosine monophosphate pathway, inhibition of phosphodiesterase, and the opening of potassium channels, coupled with the reduction of calcium levels in the cell, constitute critical mechanisms governing vasorelaxation. Cardiovascular disease stands as a significant contributor to morbidity and mortality among individuals with diabetes, with adults afflicted by diabetes exhibiting a heightened cardiovascular risk compared to their non-diabetic counterparts. A plethora of medicinal plants, characterized by potent pharmacological effects and minimal side effects, holds promise in addressing these concerns. In this review, we delineate various medicinal plants and their respective biochemical constituents, showcasing concurrent vasorelaxant and anti-diabetic activities.

Bioactive components, pharmacological effects, and drug development of traditional herbal medicine Rubus chingii Hu (Fu-Pen-Zi)

Rubus chingii Hu (Chinese Raspberry), known as Fu-Pen-Zi in Chinese, a woody perennial plant of the genus Rubus in the Rosaceae family, has specific nutritional and medicinal values, which is considered food-medicine herb in China for thousands of years to treat impotence, premature ejaculation, enuresis, frequent urination, and other diseases. This review aims to summarize recent advances in the bioactive components, pharmacological effects, and drug development and utilization of Rubus chingii Hu, hoping to provide useful support for its further research and clinical application. The bioactive components in Rubus chingii Hu contain mainly terpenoids, flavonoids, alkaloids, phenolic acids, polysaccharides, and steroids. The main pharmacological effects are their anti-oxidant, anti-inflammatory, and anti-tumor capacity on human health. Rubus chingii Hu is a very valuable food-medicine herb. The development of Rubus chingii Hu-related drugs is relatively single, which is limited to traditional Chinese medicine and prescriptions. Therefore, it is vital to pay interest to Rubus chingii Hu and its bioactive components in the future and extend its scientific application.

Rubus chingii Hu. unripe fruits extract ameliorates carbon tetrachloride-induced liver fibrosis and improves the associated gut microbiota imbalance

BACKGROUND

The unripe fruits of Rubus chingii Hu. ("Fu-peng-zi" in Chinese) is a well-known herbal tonic in traditional Chinese medicine (TCM) for tonifying liver and kidney. However, little is known regarding its therapeutic efficacy against liver fibrosis and the underlying mechanism.

METHODS

The current research aims to explore the potential of Rubus chingii Hu. unripe fruits extract (RF) in the treatment of liver fibrosis and explore the underlying mechanism. RF was administered (450 and 900 mg·kg^- 1 of body weight per day) orally to male C57BL/6 mice with CCl₄-induced liver fibrosis for 3 weeks. The histopathological changes and fibrosis stage in liver tissue were assessed using hematoxylin and eosin (H&E) and Sirius red staining. The distribution of α-SMA and Col1A1 in the liver was analyzed to determine the hepatic stellate cells (HSCs) activation using immunohistochemistry and immunofluorescent analysis. Various biochemical markers in serum (ALT, AST) and liver (Hyp, IL1-β, IL6, TNF-α and MCP-1) were observed to assess the liver's injury, fibrosis, and inflammation. In liver tissue, fibrosis-associated proteins including α-SMA, TGF-β1, Smad2/3, p-Smad2/3, and Smad4 were detected through a Western blot assay. Pyrosequencing-based analysis of bacterial 16 S ribosomal RNA from variable regions V3-V4 of fecal samples characterized the gut microbiota. Spearman's rank correlation analysis was performed for the association between altered bacterial genera by RF and pharmacodynamics parameters.

RESULTS

Three weeks of RF treatment can significantly lower liver inflammatory levels, pathological abnormalities, and collagen fibrous deposition in mice with CCl₄-induced liver fibrosis. The expressions of α-SMA and Col1A1 were lowered by RF, while the expression levels of TGF-β/Smads signaling pathway-related proteins, including TGF-β1, p-Smad2/3, and Smad4, were dramatically decreased by RF. The RF treatment significantly increased or reduced 18 different bacterial species, restoring the CCl₄-induced gut microbiota imbalance to the normal group's levels. According to correlation analysis, the bacterial genera Bifidobacterium and Turicibacter were the most significant in restoring CCl₄-induced liver fibrosis.

CONCLUSIONS

RF can reduce liver damage and delay the onset of liver fibrosis through modulating TGF-β/Smads signaling pathway. Furthermore, RF's anti-liver fibrosis effect was related to balancing the gut microbial community, partly attained by increasing Bifidobacterium and Turicibacter in liver fibrosis.

Approaches to Decrease Hyperglycemia by Targeting Impaired Hepatic Glucose Homeostasis Using Medicinal Plants

Liver plays a pivotal role in maintaining blood glucose levels through complex processes which involve the disposal, storage, and endogenous production of this carbohydrate. Insulin is the hormone responsible for regulating hepatic glucose production and glucose storage as glycogen, thus abnormalities in its function lead to hyperglycemia in obese or diabetic patients because of higher production rates and lower capacity to store glucose. In this context, two different but complementary therapeutic approaches can be highlighted to avoid the hyperglycemia generated by the hepatic insulin resistance: 1) enhancing insulin function by inhibiting the protein tyrosine phosphatase 1B, one of the main enzymes that disrupt the insulin signal, and 2) direct regulation of key enzymes involved in hepatic glucose production and glycogen synthesis/breakdown. It is recognized that medicinal plants are a valuable source of molecules with special properties and a wide range of scaffolds that can improve hepatic glucose metabolism. Some molecules, especially phenolic compounds and terpenoids, exhibit a powerful inhibitory capacity on protein tyrosine phosphatase 1B and decrease the expression or activity of the key enzymes involved in the gluconeogenic pathway, such as phosphoenolpyruvate carboxykinase or glucose 6-phosphatase. This review shed light on the progress made in the past 7 years in medicinal plants capable of improving hepatic glucose homeostasis through the two proposed approaches. We suggest that Coreopsis tinctoria, Lithocarpus polystachyus, and Panax ginseng can be good candidates for developing herbal medicines or phytomedicines that target inhibition of hepatic glucose output as they can modulate the activity of PTP-1B, the expression of gluconeogenic enzymes, and the glycogen content.

The chromosome-scale reference genome of Rubus chingii Hu provides insight into the biosynthetic pathway of hydrolyzable tannins

Rubus chingii Hu (Fu-Pen-Zi), a perennial woody plant in the Rosaceae family, is a characteristic traditional Chinese medicinal plant because of its unique pharmacological effects. There are abundant hydrolyzable tannin (HT) components in R. chingii that provide health benefits. Here, an R. chingii chromosome-scale genome and related functional analysis provide insights into the biosynthetic pathway of HTs. In total, sequence data of 231.21 Mb (155 scaffolds with an N50 of 8.2 Mb) were assembled into seven chromosomes with an average length of 31.4 Mb, and 33 130 protein-coding genes were predicted, 89.28% of which were functionally annotated. Evolutionary analysis showed that R. chingii was most closely related to Rubus occidentalis, from which it was predicted to have diverged 22.46 million years ago (Table S8). Comparative genomic analysis showed that there was a tandem gene cluster of UGT, carboxylesterase (CXE) and SCPL genes on chromosome 02 of R. chingii, including 11 CXE, eight UGT, and six SCPL genes, which may be critical for the synthesis of HTs. In vitro enzyme assays indicated that the proteins encoded by the CXE (LG02.4273) and UGT (LG02.4102) genes have tannin hydrolase and gallic acid glycosyltransferase functions, respectively. The genomic sequence of R. chingii will be a valuable resource for comparative genomic analysis within the Rosaceae family and will be useful for understanding the biosynthesis of HTs.

Characteristics of Food Protein-Derived Antidiabetic Bioactive Peptides: A Literature Update

Diabetes, a glucose metabolic disorder, is considered one of the biggest challenges associated with a complex complication of health crises in the modern lifestyle. Inhibition or reduction of the dipeptidyl peptidase IV (DPP-IV), alpha-glucosidase, and protein-tyrosine phosphatase 1B (PTP-1B) enzyme activities or expressions are notably considered as the promising therapeutic strategies for the management of type 2 diabetes (T2D). Various food protein-derived antidiabetic bioactive peptides have been isolated and verified. This review provides an overview of the DPP-IV, PTP-1B, and α-glucosidase inhibitors, and updates on the methods for the discovery of DPP-IV inhibitory peptides released from food-protein hydrolysate. The finding of novel bioactive peptides involves studies about the strategy of separation fractionation, the identification of peptide sequences, and the evaluation of peptide characteristics in vitro, in silico, in situ, and in vivo. The potential of bioactive peptides suggests useful applications in the prevention and management of diabetes. Furthermore, evidence of clinical studies is necessary for the validation of these peptides’ efficiencies before commercial applications.

A link between chemical structure and biological activity in triterpenoids

BACKGROUND

Plants with triterpenoid compounds in nature have various biological activities and are reported in many scientific works of literature. Triterpenoids are compounds that draw the attention of scientists because of their wide source, wide variety, high medicinal value, and anti-tumor properties. However, a lack of approach to understand their chemical structures has limited the fundamental comprehension of these compounds in cancer cell therapy.

OBJECTIVE

To seek anti-cancer activity of the structures of triterpenoid compounds and their derivatives, we summarized a number of plants and their derivatives that are a source of potential novel therapeutic anti-cancer agents.

METHODS

This work focuses on relevant 1036 patents and references that detail the structure of organic compounds and derivatives for the treatment of tumors.

RESULT

Compared to tetracyclic triterpenoid, pentacyclic triterpenoid has contributed more to improve the autophagic signaling pathways of cancer cells.

CONCLUSION

The heterogenous skeleton structure of triterpenoids impaired the programmed cell death signaling pathway in various cancers.

Flavonoids and Terpenoids with PTP-1B Inhibitory Properties from the Infusion of Salvia amarissima Ortega

An infusion prepared from the aerial parts of Salvia amarissima Ortega inhibited the enzyme protein tyrosine phosphatase 1B (PTP-1B) (IC₅₀~88 and 33 μg/mL, respectively). Phytochemical analysis of the infusion yielded amarisolide (1), 5,6,4′-trihydroxy-7,3′-dimethoxyflavone (2), 6-hydroxyluteolin (3), rutin (4), rosmarinic acid (5), isoquercitrin (6), pedalitin (7) and a new neo-clerodane type diterpenoid glucoside, named amarisolide G (8a,b). Compound 8a,b is a new natural product, and 2–6 are reported for the first time for the species. All compounds were tested for their inhibitory activity against PTP-1B; their IC₅₀ values ranged from 62.0 to 514.2 μM. The activity was compared to that of ursolic acid (IC₅₀ = 29.14 μM). The most active compound was pedalitin (7). Docking analysis predicted that compound 7 has higher affinity for the allosteric site of the enzyme. Gas chromatography coupled to mass spectrometry analyses of the essential oils prepared from dried and fresh materials revealed that germacrene D (15) and β-selinene (16), followed by β-caryophyllene (13) and spathulenol (17) were their major components. An ultra-high performance liquid chromatography coupled to mass spectrometry method was developed and validated to quantify amarisolide (1) in the ethyl acetate soluble fraction of the infusion of S. amarissima.

Evaluating Traditional Chinese Medicine and Herbal Products for the Treatment of Gestational Diabetes Mellitus

Gestational diabetes mellitus is the most common metabolic disorder during pregnancy with health consequences for both lives during and after pregnancy. Studies found that many pregnant women turn to complementary and alternative medicine for health maintenance or symptom relief, such as herbal medicine and acupuncture from traditional Chinese medicine. With the growing popularity of traditional Chinese medicine, we conducted a systemic search in PubMed, Web of Science, and Embase databases on research studies that investigated traditional Chinese medicine during pregnancy. The resultant hits were further searched in relation to all diabetes mellitus. In total, we found three major herbal medicine/herbal products that were associated with glycemic control in gestational diabetes, including Zuo Gui Wan, red raspberry leaves, and Orthosiphon stamineus. We further reviewed them and their relatives in relation to type 2 diabetes mellitus and found more evidence of metabolic benefits. None of the herbal medicine and products examined reported toxicity in the experimental models. Overall, treatments of gestational diabetes by western or alternative interventions are grossly understudied. It is critical to have a standardized protocol when evaluating efficacy of herbal medicine and produce quality results for women and their health-care providers to make informed treatment decisions.