Israeli Study Finds Etrog Citron Phytochemicals Are Potent Antivirals Against Many Viruses Including SARS-CoV-2
Nikhil Prasad Fact checked by:Thailand Medical News Team Sep 10, 2025 3 hours, 48 minutes ago
Medical News: Ancient fruit with modern medical promise
Scientists from Ben-Gurion University of the Negev, Israel and Ariel University, Israel have found that the Etrog citron (Citrus medica), a fruit long used in cultural and healing traditions, holds extraordinary antiviral potential. This
Medical News report covers the study, which shows that compounds within the fruit can prevent viruses from entering human cells while also stopping them from reproducing once inside the body.
Israeli Study Finds Etrog Citron Phytochemicals Are Potent Antivirals Against Many Viruses Including SARS-CoV-2
The urgent need for new antivirals
The COVID-19 pandemic revealed how unprepared the world is when it comes to antiviral drugs. Vaccines helped, but constant mutations of the virus showed how quickly protection can be weakened. Currently, only a few viruses—such as HIV, hepatitis C, and influenza—have specific treatments. These drugs are costly, sometimes toxic, and often lose their effectiveness due to resistance. As a result, scientists are increasingly turning to natural plants, and the Etrog citron has emerged as one of the most promising solutions.
The antiviral compounds inside Etrog citron
The research identified a wide range of phytochemicals with powerful antiviral activity:
-Flavonoids such as quercetin, hesperidin, rutin, and catechin that can block viral enzymes, interfere with replication, and prevent viruses from attaching to human cells. Laboratory comparisons revealed that quercetin was even more effective than some established drugs against coronaviruses.
-Coumarins like scopoletin and umbelliferone, which have demonstrated activity against HIV, hepatitis B, and coronaviruses by blocking viral entry into host cells.
-Terpenes including carvacrol, limonene, and geraniol, which not only contribute to the fruit’s fragrance but also directly bind viral proteins, disrupting their ability to infect.
Together, these natural compounds form a broad-spectrum antiviral defense system.
How Etrog citron compounds target SARS-CoV-2
Several of the plant’s chemicals were shown to directly attack SARS-CoV-2, the virus that causes COVID-19. Quercetin, one of the most abundant flavonoids in Citrus medica, can bind to and block the virus’s RNA-dependent RNA polymerase, an enzyme the virus needs to copy itself. Remarkably, laboratory tests found quercetin to be more effective than Remdesivir, one of the few drugs approved during the pandemic. Hesperidin, another flavonoid present in the fruit’s peel and seeds, was found to interfere with the virus’s ability to attach to the ACE2 receptor on human cells, effectively blocking viral entry. Epicatechin, also present in the fruit pulp and peel, disrupts the interaction between the virus’s spike protein and ACE2, preventing infection at the earliest stage. Among the terpenes, carvacrol displayed strong binding activity to the spike protein and the main viral protea
se, both critical for the virus’s replication and spread. Collectively, these compounds show that Etrog citron contains a unique natural blend capable of targeting SARS-CoV-2 through multiple pathways, making it especially promising for COVID-19 and future coronavirus outbreaks.
The challenge of absorption and delivery
One of the biggest hurdles is that many of these phytochemicals are poorly absorbed in the human body. To overcome this, researchers are testing advanced delivery systems such as nanoparticles, phytosomes, and emulsifying techniques. For example, quercetin delivered in a phytosome form was absorbed twenty times more efficiently and displayed stronger antiviral action. Other experiments showed that combining citron extracts with metallic nanoparticles boosted their ability to block viruses.
Building the future of natural antiviral medicine
Although most of the results so far are from laboratory and animal studies, the researchers believe human trials are urgently needed. They propose a roadmap involving detailed chemical profiling, long-term safety studies, and well-structured clinical trials. If successful, Etrog citron could become a foundation for the development of a new generation of plant-based antiviral treatments that are safer and more affordable.
Nature’s answer to viral threats
The Etrog citron study demonstrates that ancient fruits may still hold the keys to solving modern medical crises. With its unique mix of flavonoids, coumarins, and terpenes, supported by modern nanotechnology, the fruit shows promise as a natural safeguard against future pandemics. While further testing is necessary, this research opens the door to an exciting possibility—that a fruit once valued mainly for tradition and culture could help protect humanity against deadly viruses.
The study findings were published in the peer reviewed journal: Pharmaceutics.
https://www.mdpi.com/1999-4923/17/9/1173
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