Exposure to persistent stressors can induce depression-like symptoms, even in the fruit fly Drosophila melanogaster. This is evidenced by a decrease in motivation, diminished courtship behavior, reduced interest in sweet nutrients, and a reluctance to traverse experimental gaps. However, a collaborative study by researchers from Johannes Gutenberg University Mainz (JGU) in Germany and the BENFRA Botanical Dietary Supplements Research Center in Portland, Oregon, reveals that certain traditional medicinal plants exhibit a degree of efficacy in alleviating these symptoms.
The research highlights the ability of two Ayurvedic medicine plants to enhance resilience to chronic stress when administered preventatively to the flies. Intriguingly, these stressed insects, when exposed to the prophylactic plant treatment, no longer exhibited behaviors indicative of depression. The findings of this study have been documented in research papers published in the journal Nutrients.
Plants containing biologically-active ingredients can help the organism deal with stress
Led by Professor Roland Strauss, the research group at Johannes Gutenberg University (JGU) has employed the Drosophila melanogaster model to delve into the mechanisms underpinning stress resilience and its impact on the nervous system.
According to Strauss, “Chronic stress can induce depression-like states even in the fruit fly, evident in alterations to their behavior.” Collaborating with the BENFRA Botanical Dietary Supplements Research Center in the USA, the research group explored botanicals enhancing neurological and functional resilience, particularly in aging.
JGU researchers concentrate on testing extracts from botanicals and natural substances rooted in traditional Asian medicine, often marketed as dietary supplements. The premise is that certain plants possess elevated levels of active constituents or substances showcasing notable biological activity. These adaptogens are believed to aid the body in adapting to heightened physical and emotional stress.
Helen Holvoet, a doctoral candidate in Professor Strauss's team and lead author of the research papers, notes, “An advantage over conventional drugs could be that medicinal plants contain blends of various active botanical substances that act on different sites of the stress axis.”
She emphasizes the potential synergistic effect of these substances in countering stress, suggesting they might yield fewer undesirable effects compared to administering individual substances in pure form. Additionally, dietary supplements hold promise as complementary medications alongside pharmacotherapies.
In their collaborative project, Professor Strauss's team explored stress treatment using two Ayurvedic medicinal plants: Withania somnifera (ashwagandha or the sleep berry) and Centella asiatica (Indian pennywort). The results indicated that when administered preventatively, both plants bolstered resilience to chronic stress, preventing the onset of depression-like states in the flies exposed to stress.
Chlorogenic acid identified as substance relevant to the treatment of stress
Regarding Withania somnifera, Dr. Burkhard Poeck, a participant in the experiments, emphasized the impact of the root preparation method, noting that aqueous extracts showed superior prophylactic effects compared to alcohol extracts. This underscores the significance of considering production methods when dealing with dietary supplements.
The Mainz team, in collaboration with partners in Portland, achieved notable results with Centella asiatica. They identified chlorogenic acid, a specific component, as a prophylactic anti-stress substance. Chlorogenic acid, present in various botanicals and notably abundant in coffee beans, as well as traditional herbs like valerian and St. John's wort, has long been recognized for its stress-relieving properties.
The analysis of these medicinal substances not only imparts insights into their effects on neuronal stress but also provides starting points for fundamental resilience research. Professor Roland Strauss explained, “In this case, we were able to pinpoint a relevant target protein for chlorogenic acid in Drosophila, the protein phosphatase calcineurin.” In humans, calcineurin is widespread in body organs, particularly concentrated in the nervous system, where it interacts with numerous proteins and mediates various signaling pathways.