Neurodegenerative disorders are characterized by a progressive process of degeneration and neuronal death, where oxidative stress and neuroinflammation are key factors that contribute to the progression of these diseases. Therefore, two major pathways involved in these pathologies have been proposed as relevant therapeutic targets: The nuclear transcription factor erythroid 2 (Nrf2), which responds to oxidative stress with cytoprotecting activity; and the nuclear factor NF-κB pathway, which is highly related to the neuroinflammatory process by promoting cytokine expression. Caffeic acid phenethyl ester (CAPE) is a phenylpropanoid naturally found in propolis that shows important biological activities, including neuroprotective activity by modulating the Nrf2 and NF-κB pathways, promoting antioxidant enzyme expression and inhibition of proinflammatory cytokine expression. Its simple chemical structure has inspired the synthesis of many derivatives, with aliphatic and/or aromatic moieties, some of which have improved the biological properties. Moreover, new drug delivery systems increase the bioavailability of these compounds in vivo, allowing its transcytosis through the blood-brain barrier, thus protecting brain cells from the increased inflammatory status associated to neurodegenerative and psychiatric disorders. This review summarizes the biosynthesis and chemical synthesis of CAPE derivatives, their miscellaneous activities, and relevant studies (from 2010 to 2023), addressing their neuroprotective activity in vitro and in vivo.

Germacranes are a type of sesquiterpene lactones with anti-inflammatory and cytotoxic properties against cancer cell lines. In this in vitro study, erioflorin and erioflorin acetate were isolated and purified from the leaves of Podanthus mitiqui Lindl (Mitique or Mitriu), a shrub endemic to Chile and traditionally used in Mapuche medicine to treat urinary and digestive disorders. Their effects on advanced prostate cancer cell lines (DU-145 and 22Rv1) were evaluated. Cytotoxicity was assessed using real-time cell death and clonogenic assays. Apoptosis was determined by measuring reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), and apoptotic cell percentage through flow cytometry. Gene expression of BAX and BCL-2 was analyzed via RT-qPCR, while NF-κB activation was studied in DU-145 cells and human monocytic NF-κB reporter assays using LPS stimulation and alkaline phosphatase activity quantification. Erioflorin acetate exhibited the highest cytotoxicity, with IC₅₀ values of 35.1 µM (22Rv1) and 27.3 µM (DU-145), compared to erioflorin, which had IC₅₀ values of 50.3 µM and 56.5 µM, respectively. Both compounds increased ROS levels, reduced ΔΨm, and induced apoptosis. RT-qPCR analysis revealed that erioflorin elevated the BAX/BCL-2 ratio, and both compounds inhibited NF-κB activation by preventing IκBα phosphorylation. In conclusion, the findings demonstrate that erioflorin and erioflorin acetate exert significant in vitro cytotoxic and cytostatic effects on prostate cancer cells, supporting their potential as natural candidates for prostate cancer therapy.

Neurodegenerative disorders are characterized by a progressive process of degeneration and neuronal death, where oxidative stress and neuroinflammation are key factors that contribute to the progression of these diseases. Therefore, two major pathways involved in these pathologies have been proposed as relevant therapeutic targets: The nuclear transcription factor erythroid 2 (Nrf2), which responds to oxidative stress with cytoprotecting activity and the nuclear factor NF-κB pathway, which is highly related to the neuroinflammatory process by promoting cytokine expression. Caffeic acid phenethyl ester (CAPE) is a phenylpropanoid naturally found in propolis that shows important biological activities, including neuroprotective activity by modulating the Nrf2 and NF-kB pathways, promoting antioxidant enzyme expression and inhibition of proinflammatory cytokine expression. Its simple chemical structure has inspired the synthesis of many derivatives, with aliphatic and/or aromatic moieties, some of which have improved the biological properties. Moreover, new drug delivery systems increase the bioavailability of these compounds in vivo, allowing its transcytosis through the blood-brain barrier, thus protecting brain cells from the increased inflammatory status associated to neurodegenerative and psychiatric disorders. This review summarizes the biosynthesis and chemical synthesis of CAPE derivatives, their miscellaneous activities, and relevant studies (from 2010 to 2023) addressing their neuroprotective activity in vitro and in vivo.