Protective effect of Propolfenol® on induced oxidative stress in human spermatozoa

Human Sperm as an In Vitro Model to Assess the Efficacy of Antioxidant Supplements during Sperm Handling: A Narrative Review

Spermatozoa are highly differentiated cells that produce reactive oxygen species (ROS) due to aerobic metabolism. Below a certain threshold, ROS are important in signal transduction pathways and cellular physiological processes, whereas ROS overproduction damages spermatozoa. Sperm manipulation and preparation protocols during assisted reproductive procedures-for example, cryopreservation-can result in excessive ROS production, exposing these cells to oxidative damage. Thus, antioxidants are a relevant topic in sperm quality. This narrative review focuses on human spermatozoa as an in vitro model to study which antioxidants can be used to supplement media. The review comprises a brief presentation of the human sperm structure, a general overview of the main items of reduction-oxidation homeostasis and the ambivalent relationship between spermatozoa and ROS. The main body of the paper deals with studies in which human sperm have been used as an in vitro model to test antioxidant compounds, including natural extracts. The presence and the synergic effects of different antioxidant molecules could potentially lead to more effective products in vitro and, in the future, in vivo.

Hibiscus Flower and Olive Leaf Extracts Activate Apoptosis in SH-SY5Y Cells

Compounds of natural origin may constitute an interesting tool for the treatment of neuroblastoma, the most prevalent extracranial solid tumor in children. PRES is a commercially available food supplement, composed of a 13:2 (w/w) extracts mix of Olea europaea L. leaves (OE) and Hibiscus sabdariffa L. flowers (HS). Its potential towards neuroblastoma is still unexplored and was thus investigated in human neuroblastoma SH-SY5Y cells. PRES decreased the viability of cells in a concentration-dependent fashion (24 h IC₅₀ 247.2 ± 31.8 µg/mL). Cytotoxicity was accompanied by an increase in early and late apoptotic cells (AV-PI assay) and sub G0/G1 cells (cell cycle analysis), ROS formation, reduction in mitochondrial membrane potential, and caspases activities. The ROS scavenger N-acetyl-L-cysteine reverted the cytotoxic effects of PRES, suggesting a key role played by ROS in PRES-mediated SH-SY5Y cell death. Finally, the effects of OE and HS extracts were singularly tested and compared to those of the corresponding mixture. OE- or HS-mediated cytotoxicity was always significantly lower than that caused by PRES, suggesting a synergic effect. In conclusion, the present findings highlight the potential of PRES for the treatment of neuroblastoma and offers the basis for a further characterization of the mechanisms underlying its effects.

Chemical Profile, Antioxidant, Anti-Proliferative, Anticoagulant and Mutagenic Effects of a Hydroalcoholic Extract of Tuscan Rosmarinus officinalis

This study aimed to characterize the chemical profile of an ethanolic extract of Tuscan Rosmarinus officinalis (Roex) and to determine its in vitro bioactivity. The content of phenolic and flavonoid compounds, hydroxycinnamic acids and triterpenoids was determined, and high-performance liquid chromatography-diode array detection (HPLC-DAD) analysis revealed that rosmarinic acid and other hydroxycinnamic derivatives were the main constituents of the extract. Roex demonstrated to have both antioxidant activity and the capability to scavenge hydrogen peroxide in a concentration dependent manner. Moreover, NIH3T3 mouse fibroblasts and human breast adenocarcinoma cells MDA-MB-231 viability was influenced by the extract with an IC₅₀ of 2.4 × 10^-1 mg/mL and 4.8 × 10^-1 mg/mL, respectively. The addition of Roex to the culture medium of both the above cell lines, resulted also in the reduction of cell death after H₂O₂ pre-treatment. The Ames test demonstrated that Roex was not genotoxic towards both TA98 and TA100 strains, with and without S9 metabolic activation. The extract, by inactivating thrombin, showed to also have an anti-coagulating effect at low concentration values. All these biological activities exerted by Roex are tightly correlated to its phytochemical profile, rich in bioactive compounds.

Antioxidant Effect of the Castanea sativa Mill. Leaf Extract on Oxidative Stress Induced upon Human Spermatozoa

This study was aimed at evaluating in vitro the effects of a 75% v/v ethanolic extract of leaves of Castanea sativa Mill. (var. Bastarda Rossa, Mount Amiata, Tuscany, Italy) on ejaculated human sperm. Total polyphenols and total flavonoids contained in the extract were determined by a colorimetric assay and HPLC-DAD. The DPPH test and electrochemistry were utilized to study the antioxidant activity of the extract. Swim-up-selected sperm from 8 healthy men were treated with the C. sativa leaf extract at different dilutions (1 : 100, 1 : 200, and 1 : 500), and sperm motility was assessed following the WHO guidelines. Swim-up-selected spermatozoa were incubated with 100 μM H₂O₂ to induce lipid peroxidation (LPO) and with H₂O₂ and the leaf extract (1 : 100, 1 : 200, and 1 : 500) to test the antioxidant activity of the extract. The levels of LPO were determined by measuring malondialdehyde (MDA) concentrations. The treated samples were also analyzed by transmission electron microscopy (TEM) for ultrastructural evaluation. The chemical analysis showed that one-third ca. of the polyphenols in the C. sativa extract were made up of flavonoids, with hyperoside present in high concentration. A good antioxidant activity was demonstrated by both the DPPH test and electrochemical analysis. The C. sativa leaf extract did not decrease sperm motility at all tested dilutions. Treatment with H₂O₂ alone caused a significant increment in MDA levels (P = 0.006993), while the treatment with H₂O₂ plus C. sativa extract diluted to 1 : 100 and 1 : 200 significantly reduced MDA levels (P = 0.01476 and P = 0.01571, respectively), with respect to H₂O₂ alone. TEM analysis confirmed the protective effect of the extract on damage induced by LPO, in particular that occurring at the plasma membrane level. The C. sativa leaf extract could be used in human and farm animal protocols for gamete handling, such as techniques of assisted reproduction and cryopreservation of semen, all conditions in which oxidative stress is exacerbated.

Beyond the Biological Effect of a Chemically Characterized Poplar Propolis: Antibacterial and Antiviral Activity and Comparison with Flurbiprofen in Cytokines Release by LPS-Stimulated Human Mononuclear Cells

Bee propolis, especially Euro-Asian poplar propolis, is among the most well-known natural products traditionally used to treat pharyngitis and minor wounds. The aim of this research was to investigate the pharmacological properties responsible for poplar propolis effectiveness using, for the first time, different in vitro approaches applied to a chemically characterized sample. The anti-inflammatory activity was compared with flurbiprofen by determining pro-inflammatory cytokines released by lipopolysaccharide-stimulated human peripheral blood mononuclear cells (PBMC). The antibacterial activity against Gram+ and Gram- bacteria was assessed, as well as antiviral effects on H1N1 influenza a virus. Poplar propolis (5 and 25 µg/mL) exerted a concentration-dependent anti-inflammatory activity. In this range of concentrations, propolis effect was not inferior to flurbiprofen on cytokines released by lipopolysaccharide (LPS)-stimulated human PBMC. Poplar propolis was found to upregulate IL-6 and IL-1β in non-stimulated PBMC. S. aureus, S. pyogenes, and S. pneumoniae were the most susceptible bacterial strains with inhibitory concentrations ranging from 156 to 625 µg/mL. A direct anti-influenza activity was not clearly seen. Effective anti-inflammatory concentrations of propolis were significantly lower than the antibacterial and antiviral ones and results suggested that the anti-inflammatory activity was the most important feature of poplar propolis linked to its rationale use in medicine.

Protective Effect of N-Acetyl Cysteine on Chlorpyrifos-Induced Testicular Toxicity in Mice

Background

Chlorpyrifos (CPF), an organophosphate pesticide, is widely used in farms in order to preserve crops and fruits. Previous studies have shown that CPF exposure might cause chronic toxicity in male genital system. The present study investigated the protective effect of N-Acetyl Cysteine (NAC), a potent antioxidant against testicular toxicity of CPF in male mice.

Materials and Methods

In this experimental study, 42 adult male mice were divided into seven groups, CPF low (0.5 mg/kg.b.w) and high (5 mg/kg.b.w) doses groups, NAC group (35 mg/kg.b.w), NAC+CPF 0/5 mg/kg.b.w, NAC+CPF 5 mg/kg.b.w, dimethyl sulfoxide (DMSO, 0.75% solution mg/kg.b.w) and control group. All treatment were done intraperitoneally. Treatment was conducted for four consecutive weeks (five days each week). However NAC was injected to NAC+CPF groups five days before initiation of the treatment procedure. One week after the last injection, mice were sacrificed using anesthetic gas to evaluate alterations in testicular histology and sperm parameters.

Results

Seminiferous tubules area and diameter were significantly diminished in the group treated with 5 mg/kg CPF (P<0.05). CPF also statistically reduced sperm parameters (count and motility) and damaged sperm morphology) at both doses (P<0.05). However, NAC significantly improved spermatogonia, spermatocytes, spermatid cell counts as well as sperm parameters in mice treated with both CPF concentrations (P<0.05).

Conclusion

According to our results, NAC may significantly ameliorate CPF-induced damages to spermatogonia, spermatocytes, spermatids cell counts and sperm parameters.