Daurichromenic Acid from the Chinese Traditional Medicinal Plant Rhododendron dauricum Inhibits Sphingomyelin Synthase and Aβ Aggregation

Abstract

Species of the genus Rhododendron have been used in traditional Chinese medicine, with the medicinal herb “Manshanfong” used as an expectorant and for the treatment of acute bronchitis. Daurichromenic acid (DCA), a constituent of Rhododendron dauricum, is a meroterpenoid with antibacterial, anti-HIV, and anti-inflammatory activities. However, the mechanisms underlying these pharmacologic activities are poorly understood. To develop new drugs based on DCA, more information is required regarding its interactions with biomolecules. The present study showed that DCA inhibits the activity of the enzyme sphingomyelin synthase, with an IC50 of 4 µM. The structure–activity relationships between DCA and sphingomyelin synthase were evaluated using derivatives and cyclized hongoquercin A. In addition, DCA was found to inhibit amyloid β aggregation. These results may help in the design of effective drugs based on DCA.

Synthetic Biology-Based Discovery of Diterpenoid Pyrones from the Genome of Eupenicillium shearii

“…Some meroterpenoids, including fungal DPs, have been reported to inhibit aggregation of Aβ in vitro. ,− Thus, we evaluated the inhibitory activity of compounds 1 – 9 on Aβ42 aggregation, and most of them, especially 4 , 7 , and 8 , moderately suppressed aggregation after incubation for 24 h (Figure ).…”

Transcriptome and Flavonoid Compounds Metabolome Analyses Reveal the Mechanisms of Heat Stress in Rhododendron with Exogenously Applied Calcium

“…Rhododendron, belonging to Ericaceae, includes more than one thousand species distributed throughout the world [1]. As a horticultural, edible, and medicinal plant, Rhododendron has been widely cultivated for its ornamental, commercial, and medicinal value [2][3][4]. Due to its phytochemical potential, multiple components in Rhododendron are used as traditional remedies for different diseases [1,5,6].…”

“…Among these components, flavonoids, with many biological activities (e.g., antimicrobial, anti-inflammatory, antioxidant activities, etc. ), have been found to be present in Rhododendron plants [4,7].…”

Amyloid β aggregation induces human brain microvascular endothelial cell death with abnormal actin organization

“…In this imaging method, Aβ aggregates can be visualized by fluorescence microscopy by adding 0.1–0.01% of QD-labeled Aβ to unlabeled Aβ [ 10 ]. Subsequently, we developed a microliter scale high-throughput screening system for Aβ aggregation inhibitors that applies this imaging method [ 11 ], and screened various aggregation inhibitors [ [12] , [13] , [14] , [15] , [16] ]. This QD-based imaging method has also been applied to visualize the aggregation process of tau, α-synuclein, and serum amyloid A [ 17 , 18 ].…”