Differential annotation of converted metabolites (DAC-Met): Exploration of Maoto (Ma-huang-tang)-derived metabolites in plasma using high-resolution mass spectrometry

KAMPOmics: A framework for multidisciplinary and comprehensive research on Japanese traditional medicine

Traditional Japanese medicines, known as "Kampo medicines", are pharmaceutical-grade multi-herbal treatments that are integrated within the modern medical system in Japan. Although basic and clinical research including placebo-controlled double-blind trials is attempting to clarify their effectiveness and mechanisms of action, such studies are seriously limited due to the multi-targeted, multi-component "long-tail" properties of Kampo medicines, which are fundamentally different from modern western therapeutics. However, recent progress in high-throughput analytical technology, coupled with an exponential increase in biomedical information on various levels from molecular biology to clinical "big" data, is enabling us to commence a multidisciplinary and comprehensive investigation of Kampo medicines based on multi-omics, bio-informatics, and systems biology. In addition to deriving an inclusive understanding of the benefits and mechanisms of Kampo medicines, "KAMPOmics" may lead to the development of new principles to control and treat diseases in a systems-oriented manner. Furthermore, elucidation of "sho" and "mibyo" - classical concepts of Kampo, which loosely approximate to the notions of "precise medicine" and "pre-symptomatic aberration", respectively - may contribute to the development of patient-oriented medicine, an area attracting enormous growth and interest in contemporary medicine.

Ephedrae Herba and Cinnamomi Cortex interactions with G glycoprotein inhibit respiratory syncytial virus infectivity

Although respiratory syncytial virus (RSV) is a major cause of respiratory tract infection in children, no effective therapies are available. Recently, RSV G, the attachment glycoprotein, has become a major focus in the development of therapeutic strategies against RSV infection. Treatment of RSV-infected cultured cells with maoto, a traditional herbal medicine for acute febrile diseases, significantly reduced the viral RNA and titers. RSV attachment to the cell surface was inhibited both in the presence of maoto and when RSV particles were pre-treated with maoto. We demonstrated that maoto components, Ephedrae Herba (EH) and Cinnamomi Cortex (CC), specifically interacted with the central conserved domain (CCD) of G protein, and also found that this interaction blocked viral attachment to the cellular receptor CX3CR1. Genetic mutation of CX3C motif on the CCD, the epitope for CX3CR1, decreased the binding capacity to EH and CC, suggesting that CX3C motif was the target for EH and CC. Finally, oral administration of maoto for five days to RSV-infected mice significantly reduced the lung viral titers. These experiments clearly showed the anti-RSV activity of EH and CC mixed in maoto. Taken together, this study provides insights for the rational design of therapies against RSV infection.

Protein druggability assessment for natural products using in silico simulation: A case study with estrogen receptor and the flavonoid genistein

Traditional herbal medicine (THM) comprises a vast number of natural compounds. Most of them are metabolized into different structures after administration, which makes the clarification of THM's mode of action more complicated. To evaluate the biological activities of those components and metabolites, in silico simulation technology is helpful. We focused on mixed-solvent molecular dynamics (MD) simulation for druggability assessment of natural products. Mixed-solvent MD is an in silico simulation method for the exploration of ligand-binding sites on target proteins, which uses water and an organic molecule mixture. The selection of organic small molecules is an important factor for predicting the characteristics of natural products. In this study, we used the known crystal structure of estrogen receptors with genistein as a test case and explored fragments reflecting the characteristics of natural products. We found that structures with a 4-pyrone structure are more often included in the natural products database compared with the DrugBank database, and we selectively detected the known-binding sites of estrogen receptor α and β. The results indicate that the 4-pyrone structure might be promising for predicting the protein druggability of flavonoids. Additionally, mixed-solvent MD simulation discriminates the selectivity of genistein between estrogen receptor β and α, indicating that the simulation can be evaluated using indices that differ from those of traditional ligand docking. Although this approach is still in its early stages, it has the potential to provide valuable information for understanding the diverse biological activities of natural products.

Identification of herbal components as TRPA1 agonists and TRPM8 antagonists

Transient receptor potential (TRP) channels are non-selective cation channels that are implicated in analgesia, bowel motility, wound healing, thermoregulation, vasodilation and voiding dysfunction. Many natural products have been reported to affect the activity of TRP channels. We hypothesize that numerous traditional herbal medicines (THMs) might exert their pharmacological activity through modulating the activity of TRP channels. The present study aimed to evaluate the effects of flavonoid aglycones and their glycosides, which are the main components of many THMs, on the TRP channel subtypes. A Ca²⁺ influx assay was performed using recombinant human TRPA1, TRPV1, TRPV4 and TRPM8 cell lines. Our findings showed that flavonoid aglycones and glycycoumarin activated TRPA1. In particular, isoflavone and chalcone compounds displayed potent TRPA1 agonistic activity. Furthermore, flavone aglycones showed concomitant potent TRPM8 inhibiting activity. Indeed, flavone, isoflavone aglycones, non-prenylated chalcones and glycycoumarin were found to be TRPM8 inhibitors. Hence, flavonoid aglycones metabolized by lactase-phlorizin hydrolase and β-glucosidase in the small intestine or gut microbiota of the large intestine could generate TRPA1 agonists and TRPM8 antagonists.