Why Rue demands scientific caution
By Shafinah Ahmad Suhaimi
As interest in natural and traditional remedies continues to grow, scientists are once again turning their attention to Rue, a herb long used across cultures for its perceived healing properties. While laboratory studies suggest that Rue may offer anti-inflammatory, antimicrobial, and anticancer effects, researchers stress that these findings remain preliminary. Without evidence from human clinical trials, experts caution that unverified claims and improper use could pose significant health risks, including toxicity and severe skin reactions.
Rue (Ruta spp.), a group of shrubs from the Rutaceae family, has a long history in traditional medicine. Across different regions, it has been used to address menstrual disorders, pregnancy-related complications, digestive discomfort, and various skin ailments. In Chinese traditional practices, Rue is commonly brewed into herbal teas to relieve fevers and colds. This accumulated ethnopharmacological knowledge, passed down through generations of traditional healers, has played an important role in sparking modern scientific interest in the plant’s potential medicinal value.
Building on these traditional uses, researchers in pharmacognosy have begun to examine Rue more closely at the molecular level. Studies have identified several bioactive compounds in the plant, including alkaloids, flavonoids, and coumarins. These compounds are known to exhibit antimicrobial, antiviral, and anticancer properties in laboratory settings. In vitro experiments on cancer cell lines have shown that certain coumarins may selectively target breast and colorectal cancer cells while causing less damage to healthy cells. Such selectivity, scientists note, is a desirable characteristic in the early stages of drug discovery and suggests that Rue-derived compounds could serve as promising leads for future pharmaceutical development.
Risks and misuse raise concerns
Despite these encouraging findings, experts are quick to emphasise that most existing evidence comes from laboratory experiments or animal studies. Translating such results into safe and effective treatments for humans is a complex process that requires extensive clinical testing. Without this critical step, the therapeutic potential of Rue remains speculative.
Moreover, the risks associated with improper use of Rue are well documented. At high doses, the plant has been linked to adverse effects such as dermatitis, nausea, vomiting, miscarriages, and phototoxic reactions. In particular, compounds known as furanocoumarins have been associated with cases of photodermatitis, where contact with the plant followed by sunlight exposure can cause blistering, swelling, and severe skin inflammation. These risks underscore the dangers of assuming that “natural” automatically means “safe.”
Health professionals are increasingly concerned about the growing commercialisation of Rue-based products, many of which are marketed with claims of being “clinically proven.” In reality, such claims often rely solely on laboratory data rather than evidence from human trials. Researchers warn that this can mislead the public and encourage self-treatment, especially among individuals seeking alternative therapies for serious or chronic illnesses.
A cautious path forward
Scientists maintain that Rue’s bioactive compounds remain scientifically interesting and worthy of further investigation. History offers several examples of successful modern medicines that originated from plants, such as aspirin from willow bark and paclitaxel from the yew tree. However, these breakthroughs only became possible after rigorous testing to establish safety, dosage, efficacy, and long-term effects.
Before Rue can be considered for medical use, its compounds must undergo the same stringent evaluation process, including clinical trials to assess potential interactions with existing medications and risks to vulnerable populations. Until such evidence is available, medical practitioners advise the public to consult healthcare professionals before using Rue for therapeutic purposes and to remain sceptical of anecdotal or exaggerated claims.
For now, researchers emphasise that Rue should not be viewed as a replacement for established, evidence-based treatments. Instead, it should be approached as a subject of ongoing scientific inquiry, one that holds promise but demands caution.
Dr Shafinah Ahmad Suhaimi is a researcher at the Department of Biomedical Science, Pusat Pakar Klinikal dan Penyelidikan Kanser (formerly known as Advanced Medical and Dental Institute), Universiti Sains Malaysia (USM)
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