SPAGYRIC HERBALISM

Japanese Hinoki root essential oil may support better sleep at home

Pilot study suggests an underused forestry resource could offer new value in aroma-based relaxation products

Kyushu University

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Hinoki roots contain aromatic compounds and can be used to produce essential oils. This study examined the potential of essential oil derived from these roots to support sleep in middle-aged women, while exploring a higher-value use of an underused forestry resource. 

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Credit: Kuniyoshi Shimizu/Kyushu University

Fukuoka, Japan—Sleep problems are common in middle age, particularly among women in their 40s and 50s. In a new study published on September 1, 2026, in the Journal of Wood Science, researchers explored whether essential oils derived from Hinoki (Chamaecyparis obtusa), known as Japanese cypress, roots could help improve sleep quality. Participants reported fewer nighttime awakenings, improved morning feelings, and brain-wave patterns suggesting smoother sleep onset.

Hinoki is widely used as timber in Japan, but its roots are often left unused after logging. These roots contain aromatic compounds and can be used to produce essential oils. Although essential oils derived from Hinoki branches and leaves have been studied previously, much less is known about those obtained from its roots.

“We wanted to address two questions: whether essential oil production could add value to underused Hinoki roots and whether that oil could improve sleep,” says Associate Professor Kuniyoshi Shimizu from Kyushu University’s Faculty of Agriculture. “In our earlier work, we examined sleep quality over a single day in a laboratory-like setting. However, sleep is strongly influenced by daily routines and the home environment. Therefore, we decided to examine the effect of repeated use over two weeks in participants’ own bedrooms using both subjective assessments and physiological measurements.”

Twelve Japanese women aged 35–60 years took part in a single-blind crossover study. Each participant used Hinoki root essential oil for two weeks and an unscented control for two weeks. At bedtime, participants placed three drops of the oil in a paper cup, inhaled the aroma for 10 seconds, and then left the cup about 30 cm from their nose while they slept. Their sleep was monitored using a wearable brain-wave headband, a smartwatch, and a questionnaire completed each morning.

Repeated use of Hinoki root essential oil was associated with favorable changes in several measures of sleep. By day 13, participants reported feeling less sleepy upon waking and more recovered from fatigue than when using the control. Smartwatch measurements also showed fewer nighttime awakenings. Brain-wave recordings further indicated that, after seven days of using the Hinoki essential oil, participants showed greater delta-wave activity around sleep onset, a pattern consistent with a smoother transition into deeper sleep. Participants rated the Hinoki aroma as more relaxing, comfortable, likable, elegant, nostalgic, and woody than the control.

“By combining physiological measurements with participants’ subjective assessments, we were able to examine sleep from multiple perspectives under everyday home conditions, which was an important aspect of this study,” emphasizes Shimizu. “Our findings suggest that repeated use of Hinoki root essential oil at home may support sleep initiation, sleep continuity, and feeling refreshed in the morning.”

One possible application is the development of Hinoki root-based aroma products for use in bedrooms or other relaxation settings. Because the study used a simple method—placing a small amount of essential oil near the bed—it may also provide a useful model for evaluating aromatic materials under everyday home conditions. More broadly, the findings may encourage the use of Hinoki roots and other forestry residues as higher-value materials rather than leaving them underused. Further research would be needed to determine appropriate products, doses, and usage conditions.

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For more information about this research, see "Sleep improvement by Kagawa Hinoki root volatiles in middle-aged women: a home-based pilot study” Fadilla Zennifa, Akiko Isa, Erika Tomimatsu, Yanli Xu, Ryuma Taki, Hiroo Yasutomi, Naotoshi Yasumori, Kuniyoshi Shimizu, Journal of Wood Science, https://doi.org/10.1186/s10086-026-02296-3

About Kyushu University 
Founded in 1911, Kyushu University is one of Japan's leading research-oriented institutes of higher education, consistently ranking as one of the top ten Japanese universities in the Times Higher Education World University Rankings and the QS World Rankings. The university is one of the seven national universities in Japan, located in Fukuoka, on the island of Kyushu—the most southwestern of Japan’s four main islands with a population and land size slightly larger than Belgium. Kyushu U’s multiple campuses—home to around 19,000 students and 8000 faculty and staff—are located around Fukuoka City, a coastal metropolis that is frequently ranked among the world's most livable cities and historically known as Japan's gateway to Asia. Through its VISION 2030, Kyushu U will “drive social change with integrative knowledge.” By fusing the spectrum of knowledge, from the humanities and arts to engineering and medical sciences, Kyushu U will strengthen its research in the key areas of decarbonization, medicine and health, and environment and food, to tackle society’s most pressing issues.

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Journal

Journal of Wood Science

DOI

10.1186/s10086-026-02296-3

Method of Research

Randomized controlled/clinical trial

Subject of Research

People

Article Title

Sleep improvement by Kagawa Hinoki root volatiles in middle-aged women: a home-based pilot study

Article Publication Date

1-Sep-2026

COI Statement

The Kagawa Hinoki's root essential oil (KHREO) used in this study was provided by Ouken Co., Ltd., which had no control over the task design, analysis, interpretation, and writing of this manuscript. The authors declare that they have no known competing financial interests or personal relationships that could influence the work reported in this paper.

SPAGYRIC HERBALISM

Comprehensive review catalogs over 240 natural compounds from a widely used medicinal plant genus

What are flavonoids, and why focus on erythrina?

Bentham Science Publishers

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New review in Current Topics in Chemistry brings together decades of research on flavonoids isolated from Erythrina plants, a group long valued in traditional medicine and natural product chemistry.

Plants have always been a rich source of chemical inspiration for scientists, offering molecules that can inform new medicines, agricultural products, and more. Among the most chemically interesting plant groups is the genus Erythrina, a group of flowering trees and shrubs found throughout tropical and subtropical regions worldwide, which has drawn sustained interest from natural product chemists for its diverse array of specialized compounds. A new review, published ahead of print in Current Topics in Chemistry, brings together and organizes the flavonoids specifically reported from this genus, offering researchers a consolidated reference point for a body of work that has built up over many years.

What Are Flavonoids, and Why Focus on Erythrina?

Flavonoids are a large family of plant-derived compounds known for their structural diversity and wide range of biological activities, making them a frequent subject of study in pharmacognosy and natural product chemistry. Erythrina species have proven to be an especially productive source of these compounds, and the genus has built up a substantial scientific record documenting the many different flavonoid structures found within it. This review focuses specifically on compiling and classifying that record, rather than examining what these compounds do biologically.

Cataloging 243 Compounds

The review compiles a total of 243 flavonoids that have been isolated and structurally characterized specifically from Erythrina species. These compounds span several distinct structural classes: flavanones, flavones, isoflavanones, isoflavans, isoflav-3-enes, and isoflavones, each representing a slightly different variation on the core flavonoid chemical framework. The review draws on findings across numerous plant parts, including leaves, stem bark, stem wood, root bark, twigs, and root wood, reflecting how differently a single genus can distribute its chemistry across its own anatomy.

A Genus Rich in Novel and Unusual Chemistry

One of the review's central observations is the structural diversity of Erythrina's flavonoid chemistry is, with many of the compiled compounds representing novel natural products first identified within this genus. The review also highlights a particular chemical signature running through much of this diversity: a notable prevalence of prenylated and oxygenated flavonoids, meaning flavonoids modified with extra carbon-based side chains (prenyl groups) or additional oxygen-containing groups. These structural modifications are often associated with distinctive biological and chemical properties, and their frequent occurrence across Erythrina species underscores the genus's distinct phytochemical profile compared to other plant sources of flavonoids.

A Deliberately Focused Scope

The author is explicit about the review's boundaries: this is a compilation and structural classification exercise, not an assessment of the compounds' biological activity or of how they were extracted and purified in the lab. Isolation methods and biological activity data are intentionally excluded from scope. The focus is itself useful by consolidating structural information on 243 compounds into a single organized reference; the review gives researchers a practical starting point for further work, whether that is comparing newly isolated compounds against what is already known, identifying gaps in specific plant parts or species that have not been well studied, or informing future research into the biological potential of these molecules.

The review, "Flavonoids from the Genus Erythrina: A Review Article," was authored by Zelalem Yibralign Desta.

Read the published article here: https://bit.ly/3Tp3yR4

Article title: Flavonoids from the Genus Erythrina: A Review Article

DOI: https://doi.org/10.2174/0129504023486314260724073452

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Journal

Current Topics in Chemistry

DOI

10.2174/0129504023486314260724073452

Article Title

Flavonoids from the Genus Erythrina: A Review Article

SPAGYRIC HERBALISM

Natural insecticide made by nanoemulsification of compounds found in garlic and spearmint found to be effective on adzuki bean beetles with low non-target impacts

Researchers develop a new environmentally friendly insecticide against the adzuki bean beetle—a known legume pest—from nanoemulsions of diallyl disulfide and carvone

Kyushu University

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Diallyl disulfide (DDS) is an organosulfur compound derived from garlic and (R)-carvone (Car) is a monoterpenoid derived from spearmint. These compounds were processed into oil-in-water nanoemulsions via ultrasonication. The nanoemulsions exhibited high toxicity and improved insecticidal efficacy against the adzuki bean beetle. Additionally, the nanoemulsions of both only DDS and its mixture with Car exhibited relatively low toxicity against the Anisopteromalus calandrae, a parasitic wasp that is the natural enemy of adzuki bean beetle.

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Credit: Midori Tuda/Kyushu University

Fukuoka, Japan—In an effort to develop more environmentally friendly alternatives to synthetic insecticides, researchers from Kyushu University have developed and tested a new insecticide made from compounds derived from garlic and spearmint.

In their paper published in Ecotoxicology and Environmental Safety, the research team processed diallyl disulfide, an organosulfur compound derived from garlic, and R-carvone, a monoterpenoid from spearmint, into an emulsion of nanometer-sized droplets of oil-in-water. These nanoemulsions were then tested on a known legume pest called the adzuki bean beetle. They found that the insecticidal efficacy of the individual compounds was enhanced, and mixing the two compounds together added to their toxicity towards the pest.

“When people hear the term “insecticide,” they often think of synthetic chemicals that could be damaging to people and the environment. However, plants have evolved to produce compounds with potent insecticidal activity as a means of defending themselves from insect attack,” explains Urvashi Sahu, a JSPS postdoctoral fellow at Kyushu University’s Faculty of Agriculture and first author of the study. “In our research, we aim to develop ways to enhance the effect of natural insecticides.”

The team decided to utilize nanotechnology to develop a natural insecticide against the adzuki bean beetle Callosobruchus chinensis, a legume pest that causes significant postharvest losses. The compounds they turned to were diallyl disulfide (DDS) and R-carvone (Car), the active compounds found in garlic and spearmint, respectively. These are the compounds that give the plants their distinct odors.

Ultrasonication was used to emulsify both DDS and Car into oil-in-water droplets about 50-60 nm in diameter. These nanoemulsions were then placed in a container with adzuki bean beetles to test their insecticidal efficacy.

“We found that processing the compounds into nanoemulsions greatly enhanced their toxicity against the beetles. DDS showed a 30.5% increase in toxicity and Car toxicity increased by 8.2%,” continues Sahu.

Furthermore, the nanoemulsions had relatively low toxicity to Anisopteromalus calandrae, a known parasitic wasp that infects adzuki bean beetle larvae. Specifically, when half of the adzuki bean beetles die from the pesticide, only up to 22% of the wasps perished. This means that using both the nanoemulsions and parasitoid wasps can potentially enhance the effectiveness of pest control. The nanoemulsions were also safe on adzuki seeds and enhanced their root growth. No residual compounds were detected on the seeds themselves.

The next step for the team is to verify the efficacy of their new nanoemulsion under real-world environmental conditions and at large-scale grain and legume storage facilities. They also hope to elucidate the mechanism of how these nanoemulsions work to control the lifespan of the adzuki bean beetle.

“We will be looking into whether our insecticide can be effective on other pests. Our goal is to commercialize this technology as a sustainable, environmentally friendly alternative to pest control and management,” concludes Professor Midori Tuda, who led the research team. “Applying new technologies to compounds already found in nature holds massive potential for the future of science, agriculture, and humanity.”

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For more information about this research, see "Enhanced toxicity of diallyl disulfide and carvone nanoemulsions against a stored bean pest and their nontarget effects on its parasitoid and seed viability," Urvashi Sahu, Eman Ahmed Mohamed Helmy, Midori Tuda, Ecotoxicology and Environmental Safety, https://doi.org/10.1016/j.ecoenv.2026.120374

About Kyushu University 
Founded in 1911, Kyushu University is one of Japan's leading research-oriented institutions of higher education, consistently ranking as one of the top ten Japanese universities in the Times Higher Education World University Rankings and the QS World Rankings. Located in Fukuoka, on the island of Kyushu—the most southwestern of Japan’s four main islands—Kyushu U sits in a coastal metropolis frequently ranked among the world’s most livable cities and historically known as Japan’s gateway to Asia. Its multiple campuses are home to around 19,000 students and 8,000 faculty and staff. Through its VISION 2030, Kyushu U will “drive social change with integrative knowledge.” By fusing the spectrum of knowledge, from the humanities and arts to engineering and medical sciences, Kyushu U will strengthen its research in the key areas of decarbonization, medicine and health, and environment and food, to tackle society’s most pressing issues.

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Journal

Ecotoxicology and Environmental Safety

DOI

10.1016/j.ecoenv.2026.120374 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Enhanced toxicity of diallyl disulfide and carvone nanoemulsions against a stored bean pest and their nontarget effects on its parasitoid and seed viability,

Drug-induced nephrotoxicity of aminoglycosides and the role of medicinal plants as nephroprotective agents

When life-saving antibiotics become a threat to the kidneys

Bentham Science Publishers

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The study, "Drug-Induced Nephrotoxicity of Aminoglycosides and the Role of Medicinal Plants as Nephroprotective Agents," was carried out by Astha Chaudhary, Monika Singh, Moumita Barman, and S. Sadish Kumar in the Journal of Current Indian Science.

A new review article examines how a widely used class of antibiotics damages the kidneys, how that damage is detected and measured clinically, and how a range of medicinal plants—backed by documented bioactive compounds—may offer a safer, side-effect-free means of protecting kidney tissue in patients who cannot avoid these drugs.

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When Life-Saving Antibiotics Become a Threat to the Kidneys

Aminoglycosides are among the most effective antibiotics available for treating serious bacterial infections, including those caused by organisms that have developed resistance to other drug classes. They are routinely used in hospital settings for infections of the lungs, bloodstream, and urinary tract. Among all aminoglycosides, amikacin (AK) is notable for having the broadest spectrum of activity and the least susceptibility to bacterial resistance mechanisms—properties that make it particularly valuable when other options have failed. It works by binding to a specific site on the bacterial ribosome, the 30S subunit, disrupting protein synthesis and ultimately killing the bacterial cell. The problem is that aminoglycosides do not confine their effects to bacteria. Once in the body, they are preferentially taken up by the cells lining the proximal tubules of the kidney—the section of the nephron responsible for filtering waste and reabsorbing essential molecules—through a receptor called megalin, which actively pulls the drug into the cell. Once inside, the accumulated drug triggers a cascade of damaging cellular events that ends in tubular cell death. The clinical result is nephrotoxicity: kidney function declines, waste products that the kidneys should be clearing begin to accumulate in the blood, and in severe cases, acute kidney injury follows. Drugs as a class account for approximately 20% of all nephrotoxicity cases, but among elderly patients—who are more likely to need powerful antibiotics and whose kidneys are already less resilient—that figure rises to as high as 66%, making drug-induced kidney damage a pressing and growing clinical concern.

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How Kidney Damage Is Detected — and Which Plants May Help Prevent It

Clinicians assess kidney function and detect nephrotoxicity primarily through blood and urine tests that measure four markers: Blood Urea Nitrogen (BUN), serum creatinine concentration, Glomerular Filtration Rate (GFR), and creatinine clearance. A rise in serum creatinine of 50% or more, or a fall in creatinine clearance of equivalent magnitude, is the accepted diagnostic threshold for nephrotoxicity. These markers reflect how effectively the kidneys are filtering waste from the blood, and their deterioration signals that tubular damage is already underway. The review then turns to the central question it sets out to address: whether medicinal plants can intervene in this process and protect kidney tissue without introducing the additional side effects that synthetic nephroprotective agents often carry. The authors survey a range of plants with documented nephroprotective properties—including Aegle marmelos, Bauhinia purpurea, Cassia auriculata, Glycyrrhiza glabra, Orthosiphon stamineus, Pistacia atlantica, Vernonia cinerea, Costus afer, Euphorbia paralias, Descurainia sophia, and Trema guineensis—and examine the bioactive molecules responsible for their protective effects. Across these plants, three broad mechanisms of protection are identified: anti-inflammatory activity, which reduces the inflammatory response triggered by drug-induced tubular injury; antioxidant activity, which neutralises the reactive oxygen species that aminoglycosides generate inside kidney cells and that drive much of the cellular damage; and cytoprotective activity, which stabilises cell membranes and supports the survival of tubular epithelial cells under chemical stress. Together, these properties position plant-derived compounds as agents capable of interrupting the cellular damage cascade at multiple points simultaneously—an advantage over single-mechanism synthetic drugs.

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A Case for Plant-Based Kidney Protection — and the Research Still Needed

The practical implication of this review is that herbal medicine may have a meaningful and underexplored role in protecting patients who require aminoglycoside therapy from its most serious side effect. Because these plant compounds act through biological pathways that are distinct from the drug's antibacterial mechanism, there is no inherent reason why nephroprotective plant extracts could not be administered alongside aminoglycosides without compromising the antibiotic's therapeutic effect — though this remains to be demonstrated rigorously in clinical trials. The authors note that herbal remedies, by their nature, are generally free of the adverse effects associated with synthetic drugs, making them particularly attractive as adjunct therapies in patients who are already carrying a high medication burden. However, the review is grounded in existing preclinical and pharmacological literature rather than in new experimental data, and the authors implicitly acknowledge that the transition from documented bioactive properties to validated clinical nephroprotection requires further structured investigation — including standardised extraction protocols, dose-response studies, and ultimately controlled trials in patients receiving aminoglycoside therapy. The research was led by corresponding author Dr. Monika Singh, alongside co-authors Astha Chaudhary, Moumita Barman, and S. Sadish Kumar.

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Article title: Drug-Induced Nephrotoxicity of Aminoglycosides and the Role of Medicinal Plants as Nephroprotective Agents

DOI: 10.2174/012210299X475179260612063500

Read the published article here: https://bit.ly/3RoiPAQ

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DOI

10.2174/012210299X475179260612063500 

Article Title

Drug-induced Nephrotoxicity of Aminoglycosides and the Role of Medicinal Plants as Nephroprotective Agents

SPAGYRIC HERBALISM

Unlocking nature's pharmacy: Key regulator found for boosting active ingredients in traditional Chinese medicine

Nanjing Agricultural University The Academy of Science

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A model for the role of PnMYB38 in MeJA-induced saponin biosynthesis.

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Credit: Horticulture Research

Sanchi ginseng (Panax notoginseng) is a cornerstone of traditional Chinese medicine, prized for its saponins—bioactive compounds with anti-inflammatory, cardiovascular, and anticancer properties. Yet the molecular machinery controlling saponin production has remained largely unknown. Now, researchers have identified a master regulator, the transcription factor PnMYB38, that acts as a molecular switch linking plant hormone signals to saponin biosynthesis. This discovery opens the door to precision breeding and metabolic engineering strategies that could boost the medicinal quality of this valuable herb.

For decades, scientists have known that methyl jasmonate (MeJA)—a plant hormone involved in stress responses—can significantly enhance saponin accumulation in P. notoginseng. However, the specific transcription factors (TFs) that translate this hormonal signal into increased saponin production remained unidentified. Transcription factors are proteins that bind to DNA and control which genes are turned on or off. Among them, the MYB family is one of the largest and most important in plants, regulating everything from growth to stress responses to the production of medicinal compounds. Due to these challenges, there is an urgent need for systematic research into how MeJA signaling is connected to saponin biosynthesis through MYB transcription factors.

A team of researchers from Kunming University of Science and Technology, in collaboration with the Wenshan Academy of Agricultural Sciences, published (DOI: 10.1093/hr/uhag052) their findings in Horticulture Research (Volume 13, Issue 6, 2026). The study combined genome-wide screening, multi-omics profiling, and molecular experiments to identify and characterize the MYB transcription factor family in P. notoginseng and pinpoint the key regulator responsible for MeJA-induced saponin production.

The research team identified 110 MYB genes in the P. notoginseng genome and found that MeJA treatment significantly altered the expression of 84 of them. By integrating transcriptomic and metabolomic data, they pinpointed PnMYB38 as a central hub in the regulatory network. Functional experiments confirmed that PnMYB38 directly binds to and activates the promoters of two critical saponin biosynthesis genes: PnSE (squalene epoxidase) and PnDS (dammarenediol-II synthase). This activation triggers a cascade that boosts the production of dammarane-type saponins, including notoginsenoside R₁—one of the most pharmacologically active compounds in Sanchi ginseng. The study also revealed that PnMYB38 is localized in the cell nucleus, consistent with its role as a transcriptional regulator. Through yeast one-hybrid (Y1H) assays, electrophoretic mobility shift assays (EMSA), and dual-luciferase (LUC) reporter assays, the researchers provided multiple lines of evidence confirming the direct and specific interaction between PnMYB38 and the target gene promoters.

"We've essentially found the missing link between the plant hormone signal and the production of these valuable medicinal compounds," the authors said. "PnMYB38 is the master switch that translates the methyl jasmonate cue into a blueprint for saponin biosynthesis. Understanding this mechanism not only solves a long-standing puzzle in plant biology but also gives us a precise molecular tool to improve the quality of Sanchi ginseng through breeding and genetic engineering."

This discovery has immediate and far-reaching implications for the cultivation and improvement of P. notoginseng. By targeting PnMYB38, breeders could develop varieties with consistently higher saponin content, reducing the variability that currently plagues commercial production. The findings also establish a clear regulatory model—the "MeJA–PnMYB38–saponin biosynthesis" pathway—that could guide metabolic engineering efforts in other medicinal plants. Furthermore, the study provides a foundation for using CRISPR/Cas9 gene-editing technology to precisely modulate saponin production. As demand for plant-based medicines continues to grow worldwide, this research offers a pathway to more sustainable, reliable, and high-quality production of one of traditional medicine's most treasured resources. The RNA-seq data generated in this study are publicly available through the China National GeneBank (CNGBdb) under project number PRJCA048040.

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References

DOI

10.1093/hr/uhag052

Original Source URL

https://doi.org/10.1093/hr/uhag052

Funding information

Financial support from the Major Science and Technology Special Project of Yunnan Province (Grant No. 202202AG050021) and National Science Foundation of China (Grant No. 32360151). The Ability Establishment of Sustainable Use for Valuable Chinese Medicine Resources (Grant No. 2060302). Kunming University of Science and Technology Research Startup Fund (Grant No. KKZ3202560055).

About Horticulture Research

Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.

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Journal

Horticulture Research

DOI

10.1093/hr/uhag052 

Subject of Research

Not applicable

Article Title

The transcription factor PnMYB38 orchestrates methyl jasmonate-induced saponin biosynthesis in Panax notoginseng