Monoterpenoids from the Fruits of Amomum tsao-ko Have Inhibitory Effects on Nitric Oxide Production

Abstract

In our search for novel plant-derived inhibitors of nitric oxide (NO) with potential for treating inflammatory diseases, the phytochemicals of Amomum tsao-ko fruits were investigated, leading to the isolation of one bicyclic nonane (1), three menthene skeleton monoterpenoids (2–4), and two acyclic monoterpenoids (5 and 6). Their structures were identified using one- and two-dimensional nuclear magnetic resonance spectroscopy, and mass spectrometry. To the best of our knowledge, compounds 2–5 were obtained from the genus Amomum for the first time. All isolates were tested for their ability to inhibit lipopolysaccharide-stimulated NO overproduction in RAW264.7 cells. Compound 4 was found to inhibit NO production. Western blotting analysis indicated that active compound 4 can regulate inducible NO synthase expression. In addition, lipopolysaccharide-induced interleukin 1 beta and interleukin-6 overproduction was reduced in a concentration-dependent manner.

De novo transcriptome assembly, gene annotation, and EST-SSR marker development of an important medicinal and edible crop, Amomum tsaoko (Zingiberaceae)

“…In addition, A. tsaoko is also a top-grade spice known as one of the "five spices" in food seasoning [1]. In recent years, A. tsaoko has been considered to have a broader utilization value and proven to have biological activities, such as anti-oxidation [2,3], antibacterial [4], anti-inflammation [5], antidiabetic [6], anti-tumor [7], and anticonvulsant properties [8]. In addition, A. tsaoko is a TCM that has been prescribed for the treatment of COVID-19 [9][10][11][12].…”

Tetracera loureiri Extract Regulates Lipopolysaccharide-Induced Inflammatory Response Via Nuclear Factor-κB and Mitogen Activated Protein Kinase Signaling Pathways

“…This study investigated any inhibitory effects of ETL on these pro-inflammatory mediators. We examined the release of TNF-α, IL-1β, and IL-6 in LPS-induced cells, using RT-PCR and ELISA [ 20 ]. We found that ETL treatment significantly decreased the expression of TNF-α, IL-1β, and IL-6 at the mRNA level ( Figure 5 a).…”

Characterization, Hypoglycemic Activity, and Antioxidant Activity of Methanol Extracts From Amomum tsao-ko: in vitro and in vivo Studies

“…As a traditional Chinese medicine, A. tsao-ko has been studied by a few researchers at home and abroad (4)(5)(6)(7)(8)(9). Using water extraction, ethanol extraction, and petroleum ether extraction, Liu et al performed a comprehensive chemical investigation and found that the peel and the seeds of A. tsao-ko contained a variety of chemical components, including saccharide, protein, amino acids, phenolic compounds, tannins, organic acids, saponins, flavonoids, anthraquinone, coumarin, lactones, steroids, terpenoids, volatile oil, anthocyanins, and so on (32).…”

“…A. tsao-ko can not only be used as an edible spice but also has therapeutic effects on stomach disorders, dyspepsia, nausea, abdominal pain, and throat infections, as recorded in the Chinese Pharmacopoeia . Flavonoids, coumarins, phenols, and diterpenoids were found as bioactive constituents in A. tsao-ko extracts, which have been reported to have the activity of anti-obesity ( 4 ), bone health promotion ( 5 ), anti-inflammation ( 6 ), and anti-proliferation ( 7 ). He et al found that amomutsaokols A-K, diarylheptanoids, tsaokopyranols A–M, and 2,6-epoxy diarylheptanoids from a 50% ethanol-water extract of A. tsao-ko demonstrated significant α-glucosidase inhibitory activity ( 8 , 9 ).…”