Selenium nanoparticles (SeNPs) are well‐known bioactive compounds. Various chemical and biological methods have been applied to SeNP synthesis. Spirulina platensis is a widely used blue‐green microalgae in various industries. In this study, the biosynthesis of SeNPs using sodium selenite and Spirulina platens has been developed. The SeNP synthesis was performed at different cultivation condition including pH and illumination schedule variation. The SeNPs were characterized by FT‐IR, XRD, size, and zeta potential measurements, and the antioxidant activities of selected SeNPs were evaluated by DPPH and FRAP assays. FT‐IR analysis showed the production of SeNPs. The 12 h dark/12 h light cycles and continuous light exposure at pH 5 led to the production of stable SeNPs with sizes of 145 ± 6 and 171 ± 13 nm, respectively. Antioxidant activity of selected SeNPs was higher than sodium selenite. It seems that green synthesis is a safe method to produce SeNPs as well as a convenient method to scale‐up this production.

Diabetes is a metabolic complaint associated with oxidative stress and dysfunction of mitochondria. One of the most common complications of diabetes mellitus is neuropathy. This study evaluated the possible neuroprotective effects of syringic acid (SYR), a natural polyphenolic derivative of benzoic acid, on oxidative damage and mitochondria in the brain, spinal cord, and sciatic nerve of streptozotocin‐induced diabetic rats. Different groups of rats including normal control, diabetics (induced by streptozotocin), diabetic groups treated with 25, 50, and 100 mg/kg of SYR, and non‐diabetic group treated with only 100 mg/kg of SYR were treated for 6 weeks. Learning and memory function, physical coordination, and acetylcholinesterase (AChE) and antioxidant indexes, as well as mRNA expression of mitochondrial biogenesis, were measured in the brain, spinal cord, and sciatic nerves. Diabetic rats treated with 100 mg/kg SYR exhibited significantly improved learning, memory, and movement deficiency (p < 0.05). SYR 100 mg/kg also significantly upregulated the brain mRNA expression of PGC‐1α and NRF‐1, the key regulators of energy metabolism, oxidative phosphorylation, and mitochondrial biogenesis. In addition, SYR 100 mg/kg and SYR 50 mg/kg increased the mtDNA/nDNA ratio in the brain and the spinal cord of diabetic rats, respectively (p < 0.05). SYR attenuated the lipid peroxidation in all the tissues, but not significant effects were observed on GSH, AChE, catalase, and superoxide dismutase activity. In all the tests, nonsignificant differences were observed between the control and SYR 100 mg/kg groups. Moreover, SYR reduced inflammation and demyelination in sciatic nerves. This is the first study to reveal the regulation of mitochondrial biogenesis and energy metabolism by SYR, beyond its antioxidant role in the diabetic rats’ brain and spinal tissues.

Background: Diabetic nephropathy can lead to renal diseases; oxidative stress and mitochondrial dysfunction have critical roles in its development. Objectives: In this study, the effect of syringic acid (SYR), a natural phenolic acid, on diabetic nephropathy and mitochondrial biogenesis was examined. Methods: Diabetes was induced in rats by injecting streptozotocin. SYR (25, 50 and 100 mg/kg/day) was orally administered for 6 weeks. SYR effects on factors, such as antioxidant activities and mRNA expression level of mitochondrial biogenesis indexes, were evaluated. Results: In SYR-treated rats, blood glucose and ALP level were significantly reduced. SYR increased kidney GSH content in the diabetic group. Elevated renal catalase and superoxide dismutase activities in diabetic rats were restored to normal levels after treatment. SYR significantly reduced the renal TBARS level, which had increased in diabetic rats. This compound also significantly upregulated renal mRNA expression of PGC-1α and NRF-1, and increased mtDNA/nDNA ratio in diabetic rats. These values were reduced in the non-treated diabetic group. The results show improvement of histopathological damages of kidney in the SYR treated group in comparison with the diabetic group. Conclusion: According to the results, SYR alters renal antioxidant defense mechanisms. Also, it could be considered as a novel approach by targeting mitochondria in renal diabetic complications.

Objectives. Diabetic cardiomyopathy (DC) has become one of the serious complications in diabetic cases. In this study, we aimed to explore the syringic acid (SYR) protective effect against diabetes-induced cardiac injury in experimental rats. Methods. Rats were divided in control and streptozotocin-induced diabetic rats which were subdivided into diabetic controls, and three test groups (SYR at 25, 50, and 100mg/kg) and the nondiabetic group received 100mg/kg of SYR. All treatments were given SYR for 6 weeks. SYR effects on cardiac diagnostic markers, heart lipid peroxidation, protein carbonylation, antioxidant system, and changes of the heart mitochondrial mass and biogenesis were measured. Results. Diabetes induction prompted CK-MB, LDH levels in serum, cardiac catalase, and superoxide dismutase activity, as well as cardiac TBARs and carbonylated protein. SYR administration (100m/kg) attenuated CK-MB and LDH levels. Also, 50 and 100mg/kg of SYR reduced cardiac TBARs and carbonylated protein in diabetic rats. These treatments did not show any effects on GSH content, mtDNA, and mitochondrial biogenesis indices (PGC1- α, NRF1, NRF2, and TFAM) in heart tissue. Conclusions. SYR treatment showed protective effects on diabetic cardiomyopathy in rats by reducing lipid peroxidation and protein carbonylation. The possible mechanisms could be related to antioxidant activity of this phenolic acid. SYR might play a role of a protective factor in cardiac challenges in diabetes.

Resistance of many pathogens to available drugs is a global challenge and is leading to growing interest in natural alternative products. In this study, chemical composition and in vitro antibacterial and antifungal activities of the essential oil from Salvia mirzayanii were investigated. The chemical constituents of essential oil from S mirzayanii were analyzed by gas chromatography–mass spectrometry. The antimicrobial activity was determined by broth microdilution. The main identified compounds were 1,8-cineole (41.2 ± 1.3%), linalool acetate (11.0 ± 0.5%), and α-terpinyl acetate (6.0 ± 0.4%) (mL of essential oil/g of plant material). The MIC₉₅ were 0.03 to 0.5 µL/mL and 16 to 128 µL/mL for gram-positive and gram-negative bacteria, respectively. These results indicated that Salvia mirzayanii essential oil significantly inhibited the growth of standard and clinically isolated tested yeasts by MIC₅₀ 0.03 to 1 µL/mL. Potent antibacterial and antifungal activities of Salvia mirzayanii essential oil may be considered in future study, particularly against antibiotic-resistant cases.

Several diabetic complications are associated with forming advanced glycation end products (AGEs). Different chemical and natural compounds are able to prevent the development of these products. In this study, glycosylation was induced as a model by incubating bovine serum albumin (BSA) with glucose. Consequently, BSA was treated with glucose and different concentrations (1.25, 2.5, and 5μM) of syringic acid, gallic acid, ellagic acid, ferulic acid, paracoumaric acid, and caffeic acid for 4 and 6weeks. Biochemical experiments comprise measurements of fluorescent AGEs, protein carbonyl contents, total thiol, hemolysis tests, and also malondialdehyde (MDA) levels in RBC. These demonstrated the antiglycating mechanism of these phenolic acids. Most of the phenolic acids used in this study reduced MDA levels and protected thiol residues in protein structures. They also inhibited the formation of fluorescent AGEs and RBC lysis, except gallic acid. Moreover, ferulic acid, paracoumaric acid, and caffeic acid proteins significantly prevent carbonylation. Molecular docking and simulation studies showed that ellagic, caffeic, gallic, and syringic acids could interact with lysine and arginine residues in the active site of BSA and stabilize its structure to inhibit the formation of AGEs. Our results suggest that phenolic acid could be used as a potential phytochemical against protein glycation and related diabetic complications.