Measuring antioxidant and prooxidant capacity using the Crocin Bleaching Assay (CBA)

Nanocrocin Protective Effects on Paraquat-Induced Oxidative Stress in the MRC-5 Cell Line

Paraquat (PQ) herbicide poisoning is a severe medical problem in developing countries without suitable therapy. This study aimed to investigate the effects of crocin (CCN) and nano crocin (NCCN) on PQ -induced toxicity in the MRC-5 cell line. The results showed that the particle size of NCCN was 140.3 ± 18.0 nm, and the zeta potential of the optimal crocin-loaded niosomes was 23.4 ± 2.8 mV. The NCCN was more effective than CCN in the inhibition of PQ-induced toxicity. Treatment of the MRC-5 cells leads to a decrease in ROS and an increase in SOD, CAT, GPX, and TAC levels in PQ-CCN and PQ-NCCN groups compared with the PQ group. These changes tended to be positively associated with the NCCN compared to CCN. Overall, NCCN was more effective than crocin in treating PQ-induced toxicity in vitro and deserved further preclinical consideration.

Anti-oxidative properties of nanocrocin in Zearalenone induced toxicity on Hek293 cell; The novel formulation and cellular assessment

BACKGROUND

Zearalenone (ZEA) is a mycotoxin produced by fungi and induces cytotoxicity by the generation of reactive oxygen species. The aim of this study was to evaluate and compare the nephroprotective effects of crocin and nano-crocin against ZEA-induced toxicity in HEK293 cell line via modulation of oxidative stress and special formulation to make nano-crocin.

METHOD

Nano-crocin physicochemical properties, such as size, load, appearance, and drug release profile were determined. Also, the viability of intoxicated HEK293 cells was evaluated by MTT assay. Furthermore, lactate dehydrogenase lipid Peroxidation (LPO), and oxidative stress biomarkers were measured.

RESULT

The best nano-crocin formulation with superior entrapment effectiveness (54.66 ± 6.02), more significant drug loading (1.89 ± 0.01), better zeta potential (-23.4 ± 2.844), and smaller particle size (140.3 ± 18.0 nm) was chosen. This study showed that treatment with crocin and nano-crocin in ZEA-induced cells, significantly decreased LDH and LPO levels and increased superoxide dismutase (SOD), catalase (CAT) activities, and total antioxidant capacity (TAC) levels compared to the control group. Moreover, nano-crocin had a more curative effect against oxidative stress than crocin.

CONCLUSION

Niosomal structure of crocin, when administered with the special formulation, may be more beneficial in reducing ZEA-induced in vitro toxicity than conventional crocin.

Enzymatic Synthesis of Lipophilic Esters of Phenolic Compounds, Evaluation of Their Antioxidant Activity and Effect on the Oxidative Stability of Selected Oils

The aim of the study was to compare the effect of the substituent and its position in the aromatic ring on the antioxidant activity of hexanoic acid esters obtained in reactions catalyzed by immobilized lipase B from Candida antarctica. 4-Hydroxybenzyl hexanoate, 2-hydroxybenzyl hexanoate, 4-methoxybenzyl hexanoate, and vanillyl hexanoate were obtained with conversion yields of 50 to 80%. The antioxidant activity of synthesized esters, their alcohol precursors and BHT (Butylated HydroxyToluene) was compared with DPPH (2,2-diphenyl-1-picrylhydrazyl), CUPRAC (cupric ion reducing antioxidant capacity), and CBA (crocin bleaching assay) methods. Furthermore, it was investigated whether the presence of vanillyl hexanoate in a concentration of 0.01 and 0.1% affected the oxidative stability of sunflower and rapeseed oils in the Rancimat test. It was observed that the antioxidant activity of hexanoic acid esters depends on the presence and position of the hydroxyl group in the aromatic ring. The highest activities were found for vanillyl alcohol, vanillyl hexanoate, and BHT. The addition of the ester and BHT significantly extended the induction times of the tested oils, and these compounds exhibited similar activity. Vanillyl hexanoate increased the induction time from 4.49 to 5.28 h and from 2.73 to 3.12 h in the case of rapeseed and sunflower oils, respectively.

Azocompounds as generators of defined radical species: Contributions and challenges for free radical research

Peroxyl radicals participate in multiple processes involved in critical changes to cells, tissues, pharmacueticals and foods. Some of these reactions explain their association with degenerative pathologies, including cardiovascular and neurological diseases, as well as cancer development. Azocompounds, and particularly AAPH (2,2'-Azobis(2-methylpropionamidine) dihydrochloride), a cationic water-soluble derivative, have been employed extensively as sources of model peroxyl radicals. A considerable number of studies have reported mechanistic data on the oxidation of biologically-relevant targets, the scavenging activity of foods and natural products, and the reactions with, and responses of, cultured cells. However, despite the (supposed) experimental simplicity of using azocompounds, the chemistry of peroxyl radical production and subsequent reactions is complicated, and not always considered in sufficient depth when analyzing experimental data. The present work discusses the chemical aspects of azocompounds as generators of peroxyl (and other) radicals, together with their contribution to our understanding of biochemistry, pharmaceutical and food chemistry research. The evidence supporting a role for the formation of alkoxyl (RO•) and other radicals during thermal and photochemical decomposition of azocompounds is assessed, together with the potential influence of such species on the reactions under study.

Natural antioxidants' effects on endoplasmic reticulum stress-related diseases

Endoplasmic reticulum (ER) stress is a normal molecular process induced by the over-accumulation of misfolded or unfolded proteins. ER stress induces the unfolded protein response (UPR), which reduces global protein synthesis, increases ER capacity and protein degradation, to restart ER homeostasis, allowing cell survival. However, the over-induction of UPR can also trigger inflammatory processes, tissue damage and cell death. ER stress is involved in several pathologies, like endothelial dysfunction, diabetes and heart, liver, kidney or neurological diseases. Although the progression of these diseases is the result of several pathological mechanisms, oxidative stress has been widely related to these pathologies. Moreover, ER stress can establish a progressive pathological cycle with oxidative stress. Therefore, the use of natural antioxidants, able to modulate both oxidative and ER stress, can be a new strategy to mitigate these diseases. This review is focused on the effects of natural antioxidant compounds on ER stress in endothelial dysfunction, diabetes and heart, liver, kidney or neurological diseases.

Inhibitory Effect of Crocin(s) on Lens α-Crystallin Glycation and Aggregation, Results in the Decrease of the Risk of Diabetic Cataract

The current study investigates the inhibitory effect of crocin(s), also known as saffron apocarotenoids, on protein glycation and aggregation in diabetic rats, and α-crystallin glycation. Thus, crocin(s) were administered by intraperitoneal injection to normal and streptozotocin-induced diabetic rats. The cataract progression was recorded regularly every two weeks and was classified into four stages. After eight weeks, the animals were sacrificed and the parameters involved in the cataract formation were measured in the animal lenses. Some parameters were also determined in the serum and blood of the rats. In addition, the effect of crocin(s) on the structure and chaperone activity of α-crystallin in the presence of glucose was studied by different methods. Crocin(s) lowered serum glucose levels of diabetic rats and effectively maintained plasma total antioxidants, glutathione levels and catalase activity in the lens of the animals. In the in vitro study, crocin(s) inhibited α-crystallin glycation and aggregation. Advanced glycation end products fluorescence, hydrophobicity and protein cross-links were also decreased in the presence of crocin(s). In addition, the decreased chaperone activity of α-crystallin in the presence of glucose changed and became close to the native value by the addition of crocin(s) in the medium. Crocin(s) thus showed a powerful inhibitory effect on α-crystallin glycation and preserved the structure-function of this protein. Crocin(s) also showed the beneficial effects on prevention of diabetic cataract.