The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged as a pandemic and has inflicted enormous damage on the lives of the people and economy of many countries worldwide. However, therapeutic agents against SARS-CoV-2 remain unclear. SARS-CoV-2 has a spike protein (S protein), and cleavage of the S protein is essential for viral entry. Nattokinase is produced by Bacillus subtilis var. natto and is beneficial to human health. In this study, we examined the effect of nattokinase on the S protein of SARS-CoV-2. When cell lysates transfected with S protein were incubated with nattokinase, the S protein was degraded in a dose- and time-dependent manner. Immunofluorescence analysis showed that S protein on the cell surface was degraded when nattokinase was added to the culture medium. Thus, our findings suggest that nattokinase exhibits potential for the inhibition of SARS-CoV-2 infection via S protein degradation.

Kanazawa Sutra (KanS) is a medicinal thread that is used for the treatment of anal fistula. It is used as a substitute for Kshara Sutra (KS) which is used in Ayurvedic medicine. KanS is composed of Ficus carica latex (FCL), Capsicum annuum tincture (CAT), Achyranthes fauriei Kshara (which is processed ash from the whole plant) and powdered Curcuma longa rhizome (CLR). In this study, we evaluated the ingredients of KanS by measuring nitric oxide (NO) production in murine macrophage-like cell line J774.1 as well as examining cytotoxicity to rat skeletal muscle myoblasts (L6) and L6 differentiation, with a view to improving its pharmacological effect. We focused on Mallotus japonicus bark (MJB), which is described in the Japanese Pharmacopeia and belongs to the Euphorbiaceae family. Its biological activities were evaluated in a similar manner to the evaluation of KanS ingredients. We found that MJB extracts showed similar biological activity to Euphorbia neriifolia latex (ENL), an ingredient of KS. We conclude that the NO inhibitory activity of KanS is mainly due to CLR, and its cytotoxicity to L6 and inhibitory activity on L6 differentiation are mainly due to CLR and FCL. As CAT has no characteristic activity, the biological activity and the anal fistula treatment ability of KanS would be improved by substituting MJB for CAT.

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Background/Aim: The inflammatory response plays an important role in the activation and progression of many inflammation-related diseases. Cannabis sativa and Morinda citrifolia have long been used in folk medicine to treat inflammation. Cannabidiol is the most abundant nonpsychoactive phytocannabinoid in C. sativa and exhibits antiinflammatory activity. The objective of this study was to examine the anti-inflammatory effect of cannabidiol in combination with M. citrifolia and compare its effects with those of cannabidiol alone. Materials and Methods: RAW264 cells stimulated with lipopolysaccharide (200 ng/ml) were treated with cannabidiol (0-10 μM), M. citrifolia seed extract (0-100 μg/ml), or a combination of both for 8 or 24 h. Following the treatments, nitric oxide production in the activated RAW264 cells and the expression of inducible nitric oxide synthase were assessed. Results: Our results showed that combination of cannabidiol (2.5 μM) and M. citrifolia seed extract (100 μg/ml) exhibited more efficient inhibition of nitric oxide production than cannabidiol treatment alone in lipopolysaccharide-stimulated RAW264 cells.The combination treatment also reduced the expression of inducible nitric oxide synthase. Conclusion: These results suggest that the anti-inflammatory effect of combined treatment with cannabidiol and M. citrifolia seed extract causes a reduction in the expression of inflammatory mediators.

Four young researchers presented their studies in the field of traditional Japanese herbal medicine (Wakan‐yaku) at the third annual young researcher forum entitled “Respecting and Breaking Traditions,” held 1 week before the 2022 annual meeting of the Japan Society of Medical and Pharmaceutical Sciences for Traditional Medicine. Dr. Yokogawa presented her research focusing on the mechanism of the Ayurveda drug‐eluting string, Kshara Sutra, in treating anal fistulas, reporting on its effects on the anal tissue in an anal fistula rat model and its antibacterial activity against Escherichia coli and Staphylococcus aureus, the causative organisms of anal fistulas. Mr. Nakamichi presented his research focusing on the relationship between the efficacy of Kampo medicines with anti‐obesity effects and intestinal microbiota composition. His results partially revealed that bofutsushosan and boiogito affect lipid metabolism in mice and correlate with the intestinal microbiota composition. Dr. Manse reported the anti‐inflammatory activity of diterpenoid components in Enmei‐so (Isodonis Herba), revealing its novel inhibitory activity on nitric oxide released from activated macrophages and on inflammatory cytokines, and identified active components contributing to the inhibition and the mechanism of action. Mr. Yoshikawa reported the anticancer activity of small molecular compounds isolated from the medicinal plants, Valeriana fauriei and Hypericum erectum. His results suggest that five compounds may increase the sensitivity of human cervical carcinoma cells to adriamycin via HSP105 expression suppression. The event was conducted online, and included 78 participants. We intend to hold and improve this forum in 2023 and the future.