A new labdane diterpenoid from Scoparia dulcis improving pancreatic function against islets cell apoptotic by Bax/Bcl-2/Caspase-3 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Scoparia dulcis has been identified as a significant ethnopharmacological substance in the Li, Zhuang, and Dai ethnic groups of China. Traditional medicine use S. dulcis to treat numerous illnesses, most notably diabetes. The considerable antidiabetic properties of this herbal remedy have been established by several clinical investigations and animal experiments. The islet is the intended target of S. dulcis, although the cause of its activity and mechanism for diabetes treatment is unclear. The diterpenoids from S. dulcis have been shown in the literature to have significant hypoglycemic efficacy and to protect islet cells in vitro. Diterpenoids may be the components of this herbal remedy that preserve islets, but further research is needed. AIM OF THE STUDY: This study was projected to investigate the new diterpenoid scoparicol E from S. dulcis and examined its islet-protective effect and the potential mechanism both in vitro and in vivo. METHODS: The structure of the novel diterpenoid scoparicol E was clarified by employing a wide range of spectroscopic methods. Using CCK-8 tests, cytotoxicity and antiapoptotic activity of scoparicol E were detected. Serum biochemical analysis and pathologic examination were performed to study the protective effect of scoparicol E against islet damage. The specific mechanism of action of scoparicol E was investigated through the mitochondrial membrane potential, Annexin V-FITC flow cytometry, and western blotting. RESULTS: Scoparicol E reduced MLD-STZ-induced hyperglycemia in mice and increased insulin and islet apoptosis. Scoparicol E effectively suppressed the Bax/Bcl-2/Caspase-3 pathway, according to the in vivo western blot investigation. Scoparicol E showed significant antiapoptotic action in vitro. We also showed that scoparicol E might prevent islet cells from dying by inhibiting the Bax/Bcl-2/Caspase-3 pathway. The Annexin V-FITC flow cytometry results revealed that MIN6 cell apoptosis was considerably decreased following scoparicol E intervention, showing anti-islet cell apoptosis action. Furthermore, the Caspase-3-mediated apoptosis pathway depends on cytochrome c and the potential of the mitochondrial membrane. Scoparicol E prevented the release of cytochrome c, restored the mitochondrial membrane potential, and prevented MIN6 cell apoptosis. CONCLUSION: We demonstrated the new diterpenoid scoparicol E could protect islet cells apoptosis by modulating the Bax/Bcl-2/Caspase-3 pathway.

New aphidicolane diterpenoids with glucose consumption promoting and cell viability enhancing activities from Scoparia dulcis.

Two new aphidicolane diterpenoids, termed Scopadulinol A (1) and B (2), were obtained from whole plants of Scoparia dulcis. Their structures were elucidated by applying various spectroscopic techniques, including 1D- and 2D-NMR and HR-ESI-MS. The absolute configurations of 1 and 2 were determined by applying the calculated electronic circular dichroism (ECD). In addition, both compounds were tested for their effects on glucose consumption in HL-7702 cells and on palmitic acid (PA) induced viability in MIN6 cells at different concentrations. The results showed that they significantly promoted glucose consumption and attenuated the PA-induced decrease of cell viability. Additionally, 2 was tested to determine whether it could activate AMP-activated protein kinase (AMPK), but it showed no such effect at the tested dosage. These results indicated that the new compounds might promote glucose consumption through other pathways but not by activating AMPK. Collectively, we highlighted the isolation of two new aphidicolane diterpenoids from S. dulcis and found that they could promote glucose consumption and attenuate PA-induced decrease of cell viability.

The Gut Microbial Co-Abundance Gene Groups (CAGs) Differentially Respond to the Flavor (Yao-Wei) of Chinese Materia Medica.

The property theory is a unique principle instructing traditional Chinese doctors to prescribe proper medicines against diseases. As an essential part of it, the five-flavor theory catalogs various Chinese materia medicas (CMMs) into five flavors (sweet, bitter, sour, salty, and pungent) based on their taste and medical functions. Although CMM has been successfully applied in China for thousands of years, it is still a big challenge to interpret CMM flavor via modern biomarkers, further deepening its elusiveness. Herein, to identify the correlation between gut microbiota and CMM flavor, we selected 14 CMMs with different flavors to prepare their aqueous extracts, quantified the contained major chemical components, and then performed full-length 16S rRNA sequencing to analyze the gut microbiota of C57BL/6 mice administrated with CMM extracts. We found that flavones, alkaloids, and saponins were the richest components for sweet-, bitter-, and pungent-flavored CMMs, respectively. Medicines with merged flavors (bitter-pungent and sweet-pungent) displayed mixed profiles of components. According to gut microbial analysis, modulation of CMMs belonging to the same flavor on the taxonomic classification was inconsistent to an extent, while the functional sets of gut microbiota, co-abundance gene groups (CAGs), strongly and differentially responded to distinct flavors. Moreover, these correlations were in line with their pharmacological actions. Therefore, the gut microbial functional sets (CAGs) could act as the possible indicator to reflect CMM flavor, rather than the composition of microbial community.

Two new scopadulane diterpenoids from Scoparia dulcis attenuated palmitate-induced viability in MIN6 cells.

Two new scopadulane diterpenoids, termed Scopadulcic acids D (1, SDD) and E (2, SDE), together with two known analogues (3 and 4) were isolated from Scoparia dulcis. Their structures were elucidated by comprehensive spectroscopic analysis. The absolute configurations of 1 and 2 were determined by calculated electronic circular dichroism (ECD). Meanwhile, X-ray crystallographic analysis was applied to determine the absolute configuration of 1. All compounds were tested for their effect on attenuating palmitate-induced viability at the concentrations of 25 and 50 µM. The results showed that they significantly attenuated the palmitate-induced viability in MIN6 cells.