Tissue-resident macrophages are essential for skin homeostasis. This study investigated whether lipopolysaccharide (LPS)-activated macrophages affect senescence and rejuvenation in human dermal fibroblasts. Human monocytic THP-1 cells were stimulated with Pantoea agglomerans–derived LPS (1–1000 ng/mL), and culture supernatants were collected. These were applied to two NB1RGB fibroblast populations: young, actively dividing cells (Young cells) and senescent cells with high population doubling levels and reduced proliferation (Old cells). Senescence markers P16, P21, and Ki-67 were analyzed at gene and protein levels. Conditioned medium from Old cells induced senescence in Young cells, increasing P16 and P21 expression levels. This effect was suppressed by cotreatment with LPS-activated THP-1 supernatant. Old cells treated with the LPS-activated supernatant exhibited decreased P16 and P21 levels as well as increased Ki-67 expression, indicating partial rejuvenation. These effects were not observed following treatment with unstimulated THP-1 supernatants or LPS alone. Overall, these findings suggest that secretory factors from LPS-activated macrophages can suppress cellular senescence and promote human dermal fibroblast rejuvenation, highlighting the potential role of macrophage activation in regulating cellular aging and offering a promising strategy for skin aging intervention.

The present study examined the effects of foods containing lipopolysaccharides from Pantoea agglomerans (LPSp) on eye–nose allergic symptoms using a double-blind, placebo-controlled, randomized, parallel-group comparative research design. Sixty-three Japanese individuals aged 20–65 years with eye–nose allergic symptoms were included in this study and assigned to the LPS (480 μg/day)-containing food and placebo groups. Data on the subjective eye–nose allergic symptoms and antiallergic medication during the 8-week period were evaluated. The immunoglobulin E (IgE) and eosinophil counts were measured as indicators that may be correlated with allergy. No significant group differences were found in the change in eye–nose allergic symptoms from baseline. However, the LPS group showed a significantly shorter duration of antiallergic medication use and lower total antiallergic drug score than the placebo group. The corrected nasal allergy score calculated by taking into account the antiallergic drug score at week 8 was predominantly lower in the LPS group. The IgE to house dust and cedar pollen and eosinophil counts tended to be lower in the LPS group, and the total IgE and eosinophil counts were significantly lower in the LPS group at week 4. In conclusion, our results indicate that LPS-containing foods alleviate eye–nose allergic symptoms and consequently lower the use of antiallergic drugs (UMIN000049974).

In this study, the effects of foods containing lipopolysaccharide (LPS) from Pantoea agglomerans (LPSp) on immunity were preliminarily investigated using a double-blind, placebo-controlled, randomized, parallel-group comparative study design. Thirty healthy subjects aged ≥ 20 years (four males and twenty-six females; mean age 49 ± 9.2 years) were randomly assigned to the LPS-containing food group (488 μg/day; LPS) or placebo group. Each food was consumed for 8 weeks, and a subjective survey of cold symptoms (Wisconsin Upper Respiratory Symptom Questionnaire) and allergic symptoms of the eyes and nose were conducted. Phagocytic capacity and lymphocyte counts were measured as indicators of immune function. There were no significant between-group differences with respect to any of the investigated items. On sub-group analysis of eye–nose allergy symptom score, confined only to subjects who reported eye–nose allergic symptoms in previous years, the LPS group showed a trend toward milder symptoms compared to the placebo group. In addition, when the symptom scores were compared only for subjects who developed eye–nose allergies during the study period, the LPS group showed significantly lower overall scores and eye symptom scores compared to the placebo group. These results suggest that the consumption of LPS-containing foods may alleviate or prevent eye–nose allergies. There were no statistically predominant changes in hematology and blood biochemistry tests, indicating that continued consumption of LPS-containing foods is safe. (UMIN000046154).