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
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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.
view moreCredit: 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.
Journal
Ecotoxicology and Environmental Safety
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
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.
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.
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.
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.
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
Article Title
Drug-induced Nephrotoxicity of Aminoglycosides and the Role of Medicinal Plants as Nephroprotective Agents
