Unraveling the in vitro antitumor activity of Vismia baccifera against HepG2: role of hydrogen peroxide

Abstract

Currently natural products derived from plants are receiving huge attention because of their antitumor activities. In previous work we reported that an aqueous leaf extract of Vismia baccifera induced toxicity in HepG2. The present study focuses on the mechanisms of the cytotoxic actions induced by the extract. Results showed that V. baccifera was innocuous in non-transformed human HH4 hepatocytes. In HepG2 it caused deregulation of antioxidant status (increasing superoxide dismutase expression and decreasing glutathione levels and glutathione peroxidase activity) and accumulation of reactive oxygen species, particularly hydrogen peroxide. The extract induced a) cell cycle arrest at G2/M phase, b) phosphorylation of ATM (protein kinase ataxia-telangiectasia mutated) and γH2AX (γ-histone family 2A variant), c) caspase-3 activation, and e) deregulation of the Bax/Bcl family, increasing pro-apoptotic proteins. ATM did not seem to be involved in γH2AX activation. Co-incubation with catalase prevented the alterations elicited by V. baccifera in HepG2. Taking together, these results indicate that hydrogen peroxide mediates the HepG2 cytotoxic response and provide evidence for more in-depth studies of the signaling involved.

Ferrocene Functionalized Upconversion Nanoparticle Nanosystem with Efficient Near-Infrared-Light-Promoted Fenton-Like Reaction for Tumor Growth Suppression

“…The lifetime of the luminescence and the FRET efficiencies were measured and calculated according to the literature methods. , The ζ potentials and hydrodynamic diameters of liposomes in pure water (0.1 mg/mL) were determined using a Malvern Zetasizer Nano ZS90 at room temperature. Intracellular H 2 O 2 of AGS and MGC-803 cell lines was determined using the Hydrogen Peroxide Assay Kit according to the manufacturer’s protocol. − …”

Chemical Composition and Antibacterial activity of Essential Oils from Fruits of Vismia baccifera and Vismia macrophylla Collected at different Locations in Venezuelan Andes

“…On the other hand, Vismia baccifera (L.) Planch. & Triana, a species typically found in the Amazonian rainforest [17], is commonly used by indigenous populations as purgative, to treat urinary tract disorders, to protect against snake bites, skin diseases, as antirrheumatic, antipyretic, for the treatment of infected wounds and also as a mouth-wash and for women's douche [18][19][20].…”

A Comparative Screening and Evaluation of the Total Phenolics, Flavonoids, and Antioxidant Properties in the Seed Extracts of Punica Granatum L., Psidium Guajava L., and Vitis Vinifera L.

“…Hydroxyl atoms in biological system, which are among the most reactive species, are known to be extremely damaging, and hence, many plants have antioxidant activities that are useful for health [34]. In this finding, the antioxidant potential of a compound is attributed to the salvaging activity of these atoms as best precursors [35].…”