Phenol-Rich Feijoa sellowiana (Pineapple Guava) Extracts Protect Human Red Blood Cells from Mercury-Induced Cellular Toxicity

Abstract

Plant polyphenols, with broadly known antioxidant properties, represent very effective agents against environmental oxidative stressors, including mercury. This heavy metal irreversibly binds thiol groups, sequestering endogenous antioxidants, such as glutathione. Increased incidence of food-derived mercury is cause for concern, given the many severe downstream effects, ranging from kidney to cardiovascular diseases. Therefore, the possible beneficial properties of Feijoa sellowiana against mercury toxicity were tested using intact human red blood cells (RBC) incubated in the presence of HgCl2. Here, we show that phenol-rich (10–200 µg/mL) extracts from the Feijoa sellowiana fruit potently protect against mercury-induced toxicity and oxidative stress. Peel and pulp extracts are both able to counteract the oxidative stress and thiol decrease induced in RBC by mercury treatment. Nonetheless, the peel extract had a greater protective effect compared to the pulp, although to a different extent for the different markers analyzed, which is at least partially due to the greater proportion and diversity of polyphenols in the peel. Furthermore, Fejioa sellowiana extracts also prevent mercury-induced morphological changes, which are known to enhance the pro-coagulant activity of these cells. These novel findings provide biochemical bases for the pharmacological use of Fejioa sellowiana-based functional foods in preventing and combating mercury-related illnesses.

Novel Insights into Mercury Effects on Hemoglobin and Membrane Proteins in Human Erythrocytes

“…Taken together, the findings reported in this paper provide new insight in the Hg-induced alterations in human RBC using a cellular model system on hemoglobin and membrane proteins. Concerning the latter, our work represents the first study revealing alterations of specific membrane proteins, including those of the cytoskeleton, partially responsible for the morphological changes that are reported in our previous studies, consequent to exposure of intact cells in the presence of HgCl 2 [ 23 ]. In particular, the observed structural modification to band 3 could suggest an alteration in the RBC anionic exchange capability that deserves further investigations.…”

“…Furthermore, Wierzbicki et al [ 22 ] reported that workers occupationally exposed to mercuric vapors exhibited a statistically significant increase in blood coagulation along with increased thrombin generation. Interestingly, in vitro exposure of intact red blood cell (RBC) to mercuric chloride (HgCl 2 ) induces morphological changes [ 23 ], which increase their pro-coagulant activity [ 24 ]. RBC are indeed an important target of Hg toxicity because this metal preferentially accumulates in these cells [ 25 ].…”

Feijoa Fruit Peel: Micro-morphological Features, Evaluation of Phytochemical Profile, and Biological Properties of Its Essential Oil

“…The strong antioxidant activity of the feijoa fruit peel was already described on erythrocytes. Tortora et al [44] have recently observed that two polyphenol extracts, obtained from feijoa fruit peel and pulp, are protective against mercury-induced toxicity and oxidative stress, with the first one showing the best activity on intact human red blood cells treated with HgCl 2 [44].…”

Exploring the powerful phytoarsenal of white grape marc against bacteria and parasites causing significant diseases

“…Their employment as additives is broadly distributed in industry field to delay, prevent or eliminate damage caused by oxidation. Recently, some plant extracts have been reported to have good antioxidant and antimicrobial properties due to their polyphenolic and protein compounds (Piscopo et al 2019;Tortora et al 2019;Benabderrahmane et al 2018;Benabderrahmane et al 2019). Due to its complex composition, containing antioxidant dietary fibre, as well as extractable and non-extractable polyphenol content, grape marc extracts have a great potential to display extensive uses in agricultural, pharmaceutical and cosmetic industries among others (Bargiacchi et al 2017;Placha et al 2013;de O Ribeiro et al 2018;Tayengwa and Mapiye 2018).…”