Sesquiterpene glucosides from Shenzhou honey peach fruit showed the anti-aging activity in the evaluation system using yeasts

Valorization of Citrus peels: GC/MS-based metabolites profiling, multivariate analysis, and antiaging potential

Aging and agro-waste are major challenges. Natural ingredients are preferred in skincare. This study intended to isolate the essential oils (EO) from the leftover peels obtained from three commonly edible Citrus species fruit peels, namely Citrus paradisi (grapefruit), Citrus sinensis (sweet orange), and Citrus deliciosa (mandarin). Gas chromatography/mass spectrometry analysis identified volatile constituents in EO and headspace aroma. Multivariate analysis distinguished between the three species. The antiaging effects of Citrus EO were assessed in vitro and in silico, studying volatile interactions with target enzymes. C. sinensis peels had the highest oil yield, rich in monoterpenes. C. paradisi and C. deliciosa contained sesquiterpenes. Limonene dominated the hydrodistilled EO: 94.50% in C. paradisi, 96.80% in C. sinensis, and 80.66% in C. deliciosa. Unsupervised multivariate analysis of Citrus species revealed that  d-limonene, γ-terpinene, and β-pinene are the key phytochemical markers contributing to their diverse chemical composition. C. paradisi exhibited the highest enzyme inhibitory activity, with IC50 values of 12.82, 27.58, and 18.16 µg/mL for tyrosinase, elastase, and collagenase, respectively. In silico studies showed that the volatiles can inhibit the tested antiaging enzymes. According to these findings, the investigated agro-waste might slow aging in skin care.

Amarogentin from Gentiana rigescens Franch Exhibits Antiaging and Neuroprotective Effects through Antioxidative Stress

In the present study, the replicative lifespan assay of yeast was used to guide the isolation of antiaging substance from Gentiana rigescens Franch, a traditional Chinese medicine. A compound with antiaging effect was isolated, and the chemical structure of this molecule as amarogentin was identified by spectral analysis and compared with the reported data. It significantly extended the replicative lifespan of K6001 yeast at doses of 1, 3, and 10 μM. Furthermore, amarogentin improved the survival rate of yeast under oxidative stress by increasing the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), and these enzymes' gene expression. In addition, this compound did not extend the replicative lifespan of sod1, sod2, uth1, and skn7 mutants with K6001 background. These results suggested that amarogentin exhibited antiaging effect on yeast via increase of SOD2, CAT, GPx gene expression, enzyme activity, and antioxidative stress. Moreover, we evaluated antioxidant activity of this natural products using PC12 cell system, a useful model for studying the nervous system at the cellular level. Amarogentin significantly improved the survival rate of PC12 cells under H₂O₂-induced oxidative stress and increased the activities of SOD and SOD2, and gene expression of SOD2, CAT, GPx, Nrf2, and Bcl-x1. Meanwhile, the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) of PC12 cells were significantly reduced after treatment of the amarogentin. These results indicated that antioxidative stress play an important role for antiaging and neuroprotection of amarogentin. Interestingly, amarogentin exhibited neuritogenic activity in PC12 cells. Therefore, the natural products, amarogentin from G. rigescens with antioxidant activity could be a good candidate molecule to develop drug for treating neurodegenerative diseases.