The rhizosphere microbiome and its influence on the accumulation of metabolites in Bletilla striata (Thunb.) Reichb. f.

BACKGROUND: Bletilla striata (Thunb.) Reichb. f. (B. striata) is a perennial herbaceous plant in the Orchidaceae family known for its diverse pharmacological activities, such as promoting wound healing, hemostasis, anti-inflammatory effects, antioxidant properties, and immune regulation. Nevertheless, the microbe-plant-metabolite regulation patterns for B. striata remain largely undetermined, especially in the field of rhizosphere microbes. To elucidate the interrelationships between soil physics and chemistry and rhizosphere microbes and metabolites, a comprehensive approach combining metagenome analysis and targeted metabolomics was employed to investigate the rhizosphere soil and tubers from four provinces and eight production areas in China. RESULTS: Our study reveals that the core rhizosphere microbiome of B. striata is predominantly comprised of Paraburkholderia, Methylibium, Bradyrhizobium, Chitinophaga, and Mycobacterium. These microbial species are recognized as potentially beneficial for plants health. Comprehensive analysis revealed a significant association between the accumulation of metabolites, such as militarine and polysaccharides in B. striata and the composition of rhizosphere microbes at the genus level. Furthermore, we found that the soil environment indirectly influenced the metabolite profile of B. striata by affecting the composition of rhizosphere microbes. Notably, our research identifies soil organic carbon as a primary driving factor influencing metabolite accumulation in B. striata. CONCLUSION: Our fndings contribute to an enhanced understanding of the comprehensive regulatory mechanism involving microbe-plant-metabolite interactions. This research provides a theoretical basis for the cultivation of high-quality traditional Chinese medicine B. striata.

The Extracts Derived from Artemisia japonica Thunb. Leaves Mitigate Oxidative Stress and Inflammatory Response Induced by LPS in RAW264.7 Cells through Modulation of the Nrf2/HO-1 Signaling Pathway.

Artemisia japonica Thunb. has been used as a traditional Chinese medicine and a vegetable for thousands of years in China. However, there are few reports on the chemical composition and biological activity of its leaves. Thus, this study aimed to evaluate the chemical composition, antioxidant and anti-inflammatory effects of water extracts of A. japonica leaves and their underlying mechanisms. A total of 48 compounds were identified in the water extract using UPLC-QTOF-MS2 analysis, with phenolic acids, particularly chlorogenic acid compounds, being the predominant components. The ethyl acetate fraction (EAF) contained most of the total phenolic content (385.4217 mg GAE/g) and displayed superior antioxidant capacity with the IC50DPPH•, IC50ABTS•+, and OD0.5reducing power at 10.987 µg/mL, 43.630 µg/mL and 26.883 µg/mL, respectively. Furthermore, EAF demonstrated potent antioxidant and anti-inflammatory effects in LPS-induced RAW264.7 cells by upregulating the Nrf2/HO-1 signal pathway. These findings highlight that A. japonica leaves possess remarkable abilities to mitigate inflammation and oxidative stress, suggesting their potential utilization as medicinal agents and food additives for promoting human health.