Protection or cytotoxicity mediated by a novel quinonoid-polyphenol compound?

Abstract

Abstract. Many natural and synthetic quinones and naphthoquinones possess a variety of beneficial pharmacological properties. In plants, the cytotoxic properties of quinones serve in their defensive roles against invading bacteria, fungi and parasites. In this regard many quinones as well as polyphenols, exerting generally toxicity at high dosages, are able to induce favorable hormetic responses at a low dosage. The novel chloronaphthoquinone derivative of quercetin (CHNQ) showed a profound cytotoxicity followed by enhancement of intracellular generation of oxidants in human neonatal B-HNF-3 fibroblasts. Its synthetic precursors, quercetin and 2-chloro-3-hydroxy-[1,4]naphthoquinone, failed to induce these effects, and paradoxically, only CHNQ at a low concetration provided partial protection of the cells against oxidative challenge. Thus, the novel quinonoid-polyphenol CHNQ might have a merit in the search for new prospective agents in prevention and management of ageing and ageing-related pathologies.

Myconoside Affects the Viability of Polarized Epithelial MDCKII Cell Line by Interacting with the Plasma Membrane and the Apical Junctional Complexes

“…The protection of plants from invading bacteria, fungi and parasites is achieved through the cytotoxic properties of their natural bioactive compounds. In this context, both quinones and polyphenols, which at high doses exhibit toxic properties, at low doses exhibit positive hormetic features [18,26,27]. As a derivative of quercetin, the 3,7-dihydroxy-2-[4-(2chloro-1,4-naphthoquinone-3-yloxy)-3-hydroxyphenyl]-5-hydroxychromen-4-one (CHNQ) exhibits high cytotoxicity leading to the generation of oxidants in human neonatal B-HNF-3 fibroblasts.…”

“…As a derivative of quercetin, the 3,7-dihydroxy-2-[4-(2chloro-1,4-naphthoquinone-3-yloxy)-3-hydroxyphenyl]-5-hydroxychromen-4-one (CHNQ) exhibits high cytotoxicity leading to the generation of oxidants in human neonatal B-HNF-3 fibroblasts. Synthetic precursors of CHNQ, quercetin and 2-chloro-3-hydroxy- [1,4]naphthoquinone, do not exhibit such strong effects, as only CHNQ at a low concentration partially protects cells against oxidative stress [27]. Curcumin [28], Ginkgo biloba [29], ginseng [30] and green tea [31] have similar hormetic-based chemo-and neuroprotective properties.…”

General toxicity assessment of the novel aldose reductase inhibitor cemtirestat

“…The immortalized mouse microglial cell line BV-2 was kindly provided by Dr. Blasi at the University of Perugia (Blasiet al, 1990) and was cultured under standard conditions in Dulbecco's modified eagle medium (DMEM, Sigma Aldrich), supplemented with 10% fetal bovine serum (FBS, PAA, Biotech, s. r. o., Bratislava, Slovakia), and 1% P/S (100 U/ml penicillin, 100 mg/ml streptomycin, K-Trade, s.r.o., Bratislava, Slovakia) and maintained in 5% CO 2 at 37 °C. Cells were used for 10 passages at maximum (Mrvova et al, 2015).…”

“…Subsequently, 100 μl of 10% sodium dodecyl sulfate in HCl (0.01 M) was added and the cells were incubated at 37 °C overnight for complete dissolution of generated formazan. The absorbance was spectrophotometrically recorded at 570 nm using the reference 690 nm (Mrvova et al, 2015;Viskupicova et al, 2017).…”

“…Next, the incubation medium was removed, the cells were washed twice with phosphate buffered saline (PBS) and the accumulated dye was solubilized with 2% acetic acid/ethanol mixture (1:1, v/v). The absorbance of the samples was read spectrophotometrically at 540 nm using a reference wavelength at 690 nm (Milackova et al 2015).…”