Luteolin Boosts Longevity in Adult Female Flies but Early Exposure Shortens Lifespan

Luteolin, a natural plant compound found in foods such as celery, fennel, herbs, fruits, and vegetables, has attracted scientific interest for its antioxidant and anti-inflammatory properties. A new study suggests its relationship with ageing may be more complicated than simply being good or bad for longevity.

The study, 'Luteolin promotes healthy ageing in adult females but shortens lifespan after embryonic exposure in Drosophila melanogaster,' was published in Frontiers in Nutrition. Researchers examined how luteolin affected the lifespan and health of fruit flies when given at different stages of life, while also asking whether males and females responded in the same way.

Their central finding was striking: luteolin benefited adult female flies, had little effect on adult males, and produced harmful long-term effects when exposure occurred during development. The results suggest that the biological impact of a dietary compound can depend heavily on when it is consumed and who is exposed to it.

Adult females gained the clearest longevity benefits

The researchers used Drosophila melanogaster, or fruit flies, a widely used model for ageing because they have short lifespans and share several important nutrient-sensing and longevity pathways with other organisms. Flies received luteolin at 50 μg/mL, and researchers tracked lifespan alongside body weight, movement and resistance to oxidative stress.

Adult females showed the strongest response since their median lifespan increased by 11.6%, while maximum lifespan also rose significantly. Adult males given the same treatment showed no significant lifespan extension, making biological sex one of the clearest factors influencing the outcome.

The benefit was not limited to how long the females lived. After 10 days of luteolin supplementation, females performed better in climbing tests, suggesting improved physical function. Their body weight did not change significantly, and survival during experimentally induced oxidative stress showed an improvement trend, although that particular difference was not statistically significant.

The more intriguing observation came from the short-term experiment. Females given luteolin for only 10 days during early adulthood continued to show longevity benefits later, with maximum lifespan increasing by 17% compared with the solvent-control group. This suggests that continuous lifelong supplementation was not required to produce a lasting effect in these flies.

The researchers also checked whether the benefit could pass to the next generation. It did not: male and female offspring of luteolin-treated mothers showed no significant lifespan difference, suggesting the observed protection acted mainly on the females that directly received luteolin.

Luteolin changed several systems linked with ageing

Rather than acting through one biological pathway, luteolin appeared to reshape several systems involved in maintaining cellular health. Gene-expression analysis of adult females found 132 genes significantly upregulated and 146 downregulated after treatment. The affected pathways included energy metabolism, the pentose phosphate pathway, fatty-acid metabolism, oxidative phosphorylation, lysosomes, autophagy, immune signalling, and other processes associated with longevity.

Antioxidant defences changed: Luteolin increased expression of Cat, which encodes catalase, and CncC, a regulator related to antioxidant protection. Catalase activity itself increased significantly. Catalase helps break down hydrogen peroxide, potentially reducing oxidative damage that can accumulate as organisms age.

The compound altered major nutrient-sensing pathways: Genes associated with IIS/PI3K–mTOR signalling were suppressed, while AMPK- and MAPK-related signals were activated. These pathways help cells decide how to use energy, respond to stress and manage damaged cellular components. Autophagy-related genes Atg5 and Atg8a increased, alongside immune regulators Dif and Relish, pointing toward improved cellular cleanup and immune homeostasis.

Metabolism shifted as well: NADPH increased by roughly 1.88-fold, while several intermediates of the TCA cycle decreased. Serine and glutamine increased, while glutamate, aspartate, phenylalanine, valine and glutathione decreased. The researchers interpret the overall pattern as metabolic remodelling that could lower mitochondrial stress while strengthening the cell's capacity to deal with oxidative pressure.

Changes even reached the epigenetic level, where chemical modifications help control how genes are used. Luteolin-treated females showed higher levels of the histone modifications H3K36me3, H3K9ac and H3K27ac, alongside reduced expression of the histone methyltransferase genes Ash1 and Set1. The authors propose that metabolism, nutrient sensing and epigenetic regulation may work together rather than independently to support the longevity effect.

Early exposure produced the opposite result

The most important caution from the study appeared when luteolin exposure occurred during development. Embryonic exposure accelerated development: more flies reached the pupal and adult stages earlier, and larval width increased. Hormonal patterns changed too, with ecdysone rising by about 1.42-fold in third-instar larvae and juvenile hormone increasing by approximately 1.18-fold in eight-day-old pupae.

That faster development did not translate into healthier ageing. Adults exposed to luteolin during embryonic development had a significantly shorter lifespan. Female body weight was also lower by day 30. Signs of lasting biological disruption remained after the flies reached adulthood. One-day-old females exposed during development had juvenile hormone levels about 1.32 times higher, reduced catalase expression and activity, and abnormal regulation of insulin-signalling genes. The authors suggest that altered endocrine signalling, weakened antioxidant defences and disturbed IIS regulation could help explain why early exposure produced the opposite outcome from adult supplementation.

These findings fit a broader idea in biology known as the Developmental Origins of Health and Disease, where exposures during sensitive stages of development can leave lasting effects on metabolism and adult health. In this experiment, the same compound associated with longer life when given to adult females became detrimental when encountered during development.

The study does not show that people should take luteolin supplements to live longer. Only one luteolin concentration was tested; the mechanistic findings are largely associations rather than proof of cause and effect, and detailed molecular analyses focused on females. Most importantly, these experiments were conducted in fruit flies, so mammalian and human studies are needed before concluding human healthy ageing.

The researchers acknowledge that the concentration used in the flies represents a pharmacological upper-bound experiment and is roughly 200–1,900 times higher than typical peak plasma concentrations reported after human oral exposure. Luteolin also has poor bioavailability in humans because it is rapidly metabolised, making direct translation from the fly experiment particularly difficult.

The broader message is more interesting than a simple claim that luteolin extends lifespan. This research shows how strongly a nutritional intervention can depend on sex, developmental stage and biological context. In adult female flies, luteolin was associated with longer and healthier life through changes involving antioxidant defences, nutrient sensing, autophagy, immunity, metabolism and epigenetic regulation. During development, the same compound disturbed hormonal and metabolic balance and ultimately shortened adult life.