Antioxidant activity of omega-3 derivatives and their delivery via nanocages and nanocones: DFT and experimental in vivo investigation

Antioxidant Chimeric Molecules: Are Chemical Motifs Additive? The Case of a Selenium-Based Ligand

We set up an in silico experiment and designed a chimeric compound integrating molecular features from different efficient ROS (Reactive Oxygen Species) scavengers, with the purpose of investigating potential relationships between molecular structure and antioxidant activity. Furthermore, a selenium centre was inserted due to its known capacity to reduce hydroperoxides, acting as a molecular mimic of glutathione peroxidase; finally, since this organoselenide is a precursor of a N-heterocyclic carbene ligand, its Au(I) carbene complex was designed and examined. A validated protocol based on DFT (Density Functional Theory) was employed to investigate the radical scavenging activity of available sites on the organoselenide precursor ((SMD)-M06-2X/6-311+G(d,p)//M06-2X/6-31G(d)), as well as on the organometallic complex ((SMD)-M06-2X/SDD (Au), 6-311+G(d,p)//ZORA-BLYP-D3(BJ)/TZ2P), considering HAT (Hydrogen Atom Transfer) and RAF (Radical Adduct Formation) regarding five different radicals. The results of this case study suggest that the antioxidant potential of chemical motifs should not be considered as an additive property when designing a chimeric compound, but rather that the relevance of a molecular topology is derived from a chemical motif combined with an opportune chemical space of the molecule. Thus, the direct contributions of single functional groups which are generally thought of as antioxidants per se do not guarantee the efficient radical scavenging potential of a molecular species.

Omega-3 supplementation in the treatment of polycystic ovary syndrome (PCOS) - a review of clinical trials and cohort

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women associated with cardiovascular disease and obesity. The possible benefits of omega-3 supplementation in this syndrome have been discussed much. This study is aimed to verify, based on the scientific data published, if there are any benefits in the omega-3 supplementation in the treatment of PCOS and to indicate its possible dosages for the treatment of polycystic ovary. The work consists of a systematic review of clinical trials and cohort of the MEDLINE/PubMed database from 2009 to October 2019. All studies that analyzed the omega-3 supplementation in women with PCOS were included. Cross-sectional studies, review articles, systematic reviews, meta-analysis, duplicates, studies in animals or cell culture, studies with omega-3 supplementation via food or associated with other supplementations were not included, except those involving vitamin E. In total, 21 articles were selected. Despite the heterogeneity of the studies selected, indirect benefits were observed mainly regarding the glycemic profile, such as insulin resistance reduction, lipid profile modulation (i.e. decrease in total cholesterol, triglycerides, and elevation of high-density lipoprotein), and the regulation of the androgenic profile. As for the anthropometric profile, the studies were scarce and most of them had no significant meaning. Regarding the antioxidant profile and inflammatory biomarkers, the findings differ among studies, but promising results were observed with different doses over 12 weeks of use, such as C-reactive protein (CRP) reduction. Thus, omega-3 fatty acids promote indirect benefits in the treating of women with PCOS. However, to reveal well-defined standards for dosage and supplementation time, further studies are needed.

The effect of hydro-alcoholic extract of Ceratonia Silique L. on spermatogenesis index in rats treated with cyclophosphamide: An experimental study

BACKGROUND

The aim of this study was to investigate the antioxidant effects of Ceratonia extract on improving the toxicity induced by cyclophosphamide (CP) on spermatogenesis. Materials and Methods: 54 male Wistar rats (4 months old) weighing 200-250 gr were randomly divided into 6 groups (n = 9/each).

OBJECTIVE

"group 1 (control) underwent the normal diet and water; group 2 (sham) received 2 ml/day normal saline; group 3 (positive control) received 300 mg/kg/day Ceratonia extract; group 4 (Ceratonia + CP) received Ceratonia extract (300 mg/kg/day) + 5 mg/kg/day CP (Endoxan, baxter oncology gmbh, Germany) after 4 hr; group 5 (CP) received 5 mg/kg/day CP + normal saline 4 hr after it; and group 6 (CP + Ceratonia) received Ceratonia extract (300 mg/kg/day) 4 hr after 5 mg/kg/day CP." 24 hr after the last gavage, heart blood sampling was performed to measure the levels of malondialdehyde (MDA), ferric reducing antioxidant power, testosterone, luteinizing hormone, and follicle-stimulating hormone. The left caudal epididymis was cut in the Ham's F10 and the released spermatozoa were used to analyze sperm parameters. The histology of the right testes was studied using stereological techniques and the left testes were used to measure the level of tissue MDA and ferric reducing antioxidant power.

RESULTS

A significant increase in the mean level of MDA (p = 0.013) was seen in the CP compared to the control group. Sperm motility (p = 0.001) and count (p = 0.002), serum and tissue total antioxidant (p ≤ 0.001) and serum testosterone levels (p = 0.019) decreased in the CP compared to the control group. Ceratonia extract could significantly prevent the adverse effects of CP on sperm motility (p < 0.001), the mean levels of tissue MDA (p = 0.018), serum total antioxidant (p = 0.045), and testosterone (p < 0.001).

CONCLUSION

The Ceratonia extract can modify the reproductive toxicity of CP in rat due to the presence of antioxidant compounds.

Molecular insight on the binding of monascin to bovine serum albumin (BSA) and its effect on antioxidant characteristics of monascin

Monascin (MS) is a yellow lipid-soluble azaphilonoid pigment identified from Monascus-fermented products with promising biological activities. This work studied interactions between MS and bovine serum albumin (BSA) as well as their influences on the antioxidant activity of MS. Experimental results demonstrated that the fluorescence emission of BSA was quenched by MS via static quenching mechanism and the formed BSA-MS complex was mainly maintained by hydrophobic and hydrogen bond interactions. Meanwhile, the probable binding pocket of MS located near site I of BSA and the corresponding conformational and structural alterations of BSA were determined. Furthermore, the molecular modeling approach was performed to understand the visual representation of binding mode between BSA and MS. It was noticeable that the BSA-MS complex exhibited reduced DPPH radical-scavenging ability, which might be attributed to the restraining effect of BSA on the relevant reaction pathways involved in antioxidation by MS.

Prdx6 is required to protect human corneal epithelial cells against ultraviolet B injury

BACKGROUND

The protective role of Prdx6 on rat corneal tissue against ultraviolet B injury in vivo has been confirmed previously. We further investigated the function and molecular mechanism of Prdx6 in human corneal epithelial cells under ultraviolet B radiation.

METHODS

The experimental groups were designed as follows: (1) Prdx6 RNAi, (2) Prdx6 RNAi + ultraviolet B radiation, (3) normal human corneal epithelial cells, (4) normal human corneal epithelial cells + ultraviolet B radiation, (5) wild-type Prdx6 overexpression, (6) wild-type Prdx6 overexpression + ultraviolet B radiation, (7) mutant-type Prdx6 overexpression, and (8) mutant-type Prdx6 overexpression + ultraviolet B radiation. The cell survival rate was detected by a Thiazolyl Blue Tetrazolium Bromide assay. Apoptosis, reactive oxygen species, and malondialdehyde were detected with a commercial kit. Gene expression was detected by real-time polymerase chain reaction.

RESULTS

We found the following results. (1) Compared to normal cells, the survival rates were 32%, 87%, and 58% under ultraviolet B radiation in the Prdx6 interference, wild-type overexpression, and mutant-type overexpression groups, respectively. The survival rates were decreased to 50% at 24 h and 31% at 48 h when the phospholipase A2 activity of Prdx6 was inhibited after ultraviolet B radiation. (2) Apoptosis, reactive oxygen species content, and malondialdehyde levels were increased when Prdx6 was downregulated. This phenomenon became more severe under ultraviolet B radiation. (3) The expression levels of apoptosis-related and antioxidant genes all changed along with the changes in expression of Prdx6.

CONCLUSION

(1) Both peroxidase and phospholipase A2 activities of Prdx6 are crucial for its protective role in corneal tissue. (2) Downregulated expression of Prdx6 resulted in high endoplasmic reticulum stress. (3) Apoptosis in human corneal epithelial cells with downregulated Prdx6 coupled with ultraviolet B radiation was related to the pathways of DNA damage and the death receptor. (4) Low levels of antioxidants are sufficient for maintaining homeostasis in human corneal epithelial cells without external stimuli. Under the condition that Prdx6 was downregulated, human corneal epithelial cells were more sensitive to ultraviolet B radiation.

Dietary chia seeds (Salvia hispanica) improve acute dyslipidemia and steatohepatitis in rats

Chia seeds (Salvia hispanica L.) are rich in omega fatty acids. Dyslipidemia and steatohepatitis are diseases that require effective treatments in obese and non-obese patients. The aim was to evaluate the effect of chia intake on acute tyloxapol (TI)-induced dyslipidemia, on acute carbon tetrachloride (TC)-induced steatohepatitis, and on mixed damage (TC+TI) in non-obese rats. Four experimental groups were fed for 4 weeks a diet with established rodent food (DE), and four groups were fed a diet with 15% added chia (DC). Plasma samples were analyzed for total cholesterol, triglycerides, glucose, biochemical liver damage markers, and tumor necrosis factor-α (TNF-α). Liver samples were used to quantify glycogen, catalase, lipid peroxidation, and TNF-α. A histopathological analysis was performed. DC intake partially or totally prevented steatohepatitis, and reduced lipids in the dyslipidemic groups. The hypolipidemic and hepatoprotective effects of chia may be correlated to its high content of α-linolenic acid (omega-3) and phenolics. PRACTICAL APPLICATIONS: Metabolic syndrome is associated with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH), which are currently the most common causes of chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC) worldwide. Dyslipidemia is a significant risk factor for NAFLD and NASH. Non-obese patients may have NAFLD or NASH. Metabolic syndrome and dyslipidemia are more strongly associated with NAFLD in non-obese than in obese patients. This is the first study evaluating the hypolipidemic and hepatoprotective effects of chia seed intake on acute dyslipidemia and/or steatohepatitis caused by the individual or combined administration of the inducers tyloxapol and carbon tetrachloride, respectively, in non-obese rats. The pharmacological effects of dietary chia are correlated to its high content of omega-3 and omega-6 (1:1), protein, dietary fiber, and phenolics. The results suggest that inclusion of chia in diets of non-obese patients with dyslipidemia and/or NAFLD/NASH may improve their health state and preventing cirrhosis or HCC.

Reduction of cisplatin-induced renal and hepatic side effects in rat through antioxidative and anti-inflammatory properties of Malva sylvestris L. extract

BACKGROUND

Cisplatin is widely used in the chemotherapy of solid organ cancers. However, its application is associated with serious side effects in various organs including the kidneys and liver.

OBJECTIVES

The aim of this study was to investigate the effects of mallow extract on the side effects of cisplatin in the kidneys and liver.

METHODS

Hydroalcoholic extract of mallow, at doses of 200, 400, and 600 mg/kg BW, was administered to the animals for seven days intraperitoneally (ip). Animals in the Cis + Mallow group received a dose of cisplatin (8 mg/kg, ip) on the third day. Renal and hepatic functional disturbances were evaluated by measuring concentrations of creatinine, urea-nitrogen, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in the plasma. In order to assess oxidative stress, malondialdehyde (MDA) and ferric reducing antioxidant power (FRAP) levels were measured in the kidney tissue. Then, degree of mRNA expressions of TNF-α and ICAM-1 were measured to examine renal inflammation. Hematoxylin and Eosin (H & E) staining of kidney and liver tissues was performed to study tissue damage and leukocyte infiltration.

RESULTS

Cisplatin increased levels of plasma creatinine, urea-nitrogen, AST, and ALT; levels of tissue damage and leukocytes infiltration in the kidneys and liver; and MDA level and expression of pro-inflammatory factors in the kidney tissue. Meanwhile, it decreased FRAP level in the kidney tissue. Pretreatment by mallow extract resulted in significant improvement in all measured variables although 200-mg and 400-mg doses yielded better results.

CONCLUSION

Results showed that mallow supplement protects the kidneys and liver against side effects of cisplatin, and reduces the resultant oxidative stress and inflammation.

Exploring the effect of oxygen-containing functional groups on the water-holding capacity of lignite

Graphene oxide with different degrees of oxidation was prepared and selected as a model compound of lignite to study quantitatively, using both experiment and theoretical calculation methods, the effect on water-holding capacity of oxygen-containing functional groups. The experimental results showed that graphite can be oxidized, and forms epoxy groups most easily, followed by hydroxyl and carboxyl groups. The prepared graphene oxide forms a membrane-state as a single layer structure, with an irregular surface. The water-holding capacity of lignite increased with the content of oxygen-containing functional groups. The influence on the configuration of water molecule clusters and binding energy of water molecules of different oxygen-containing functional groups was calculated by density functional theory. The calculation results indicated that the configuration of water molecule clusters was totally changed by oxygen-containing functional groups. The order of binding energy produced by oxygen-containing functional groups and water molecules was as follows: carboxyl > edge phenol hydroxyl >epoxy group. Finally, it can be concluded that the potential to form more hydrogen bonds is the key factor influencing the interaction energy between model compounds and water molecules.