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Bacopa monniera L. (family Scrophulariaceae) (BM) is an Ayurvedic medicine, clinically used for memory enhancing, epilepsy, insomnia and as a mild sedative. In this work, the free radical scavenging capacity of a methanol extract of BM and the effect on DNA cleavage induced by H2O2 UV-photolysis was investigated. In addition, we examined whether this plant extract is capable of reducing the hydrogen peroxide-induced cytotoxicity and DNA damage in human non-immortalized fibroblasts. It showed a dose-dependent free radical scavenging capacity and a protective effect on DNA cleavage. These results were confirmed by a significant protective effect on H2O2-induced cytoxicity and DNA damage in human non-immortalized fibroblasts. The antioxidant capacity of BM may explain, at least in part, the reported antistress, immunomodulatory, cognition-facilitating, antiinflammatory and antiaging effects produced by it in experimental animals and in clinical situations and may justify further investigation of its other beneficial properties. Moreover, this experimental evidence suggests that because of its antioxidant activity, this Ayurvedic drug may be useful in the treatment of human pathologies in which free radical production plays a key role.

Betula etnensis Raf. (Birch Etna) belonging to the Betulaceae family grows on the eastern slope of Etna. Many bioactive compounds present in Betula species are considered promising anticancer agents. In this study, we evaluated the effects of B. etnensis Raf. bark methanolic extract on a human colon cancer cell line (CaCo2). In order to elucidate the mechanisms of action of the extract, cellular redox status, cell cycle, and heme oxygenase-1 (HO-1) expression in ferroptosis induction were evaluated. Cell viability and proliferation were tested by tetrazolium (MTT) assayand cell cycle analysis, while cell death was evaluated by annexin V test and lactic dehydrogenase (LDH) release. Cellular redox status was assessed by measuring thiol groups (RSH) content, reactive oxygen species (ROS) production, lipid hydroperoxide (LOOH) levels and (γ-glutamylcysteine synthetase) γ-GCS and HO-1 expressions. The extract significantly reduced cell viability of CaCo2, inducing necrotic cell death in a concentration-depending manner. In addition, an increase in ROS levels and a decrease of RSH content without modulation in γ-GCS expression were detected, with an augmentation in LOOH levels and drastic increase in HO-1 expression. These results suggest that the B. etnensis Raf. extract promotes an oxidative cellular microenvironment resulting in CaCo2 cell death by ferroptosis mediated by HO-1 hyper-expression.

A quantitative study on the effect of senescence on mitochondrial D N A expression has been carried out by measuring the levels of the 12s rRNA and of the mRNA for the subunit I of cytochrome oxidase in several tissues of adult and senescent rats. The concentration of both RNA species/mitochondrial DNA molecule is significantly reduced in senescent brain and heart, as opposed to the respective adult tissues. No appreciable variation occurs in the liver. A 1-h pretreatment with acetyl-L-carnitine brings back the level of senescent brain and heart transcripts to that of adult tissues. The same treatment of adult rats does not cause significant changes in mitochondrial RNA content. These results suggest that the age-dependent impairment of both heavy-strand mitochondrial DNA transcription units is related to altered environmental conditions which acetyl-L-carnitine, a substance which acts by stimulating, directly or indirectly, the energy metabolism, is able to remove.

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