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In this study, we have identified a novel peptide NV14 with antioxidative functions from serine O‐acetyltransferase (SAT) of Artrospira platensis (Ap). The full sequence of ApSAT and its derived NV14 peptide “NVRIGAGSVVLRDV” (141–154) was characterized using bioinformatics tools. To address the transcriptional activity of ApSAT in response to induce generic oxidative stress, the spirulina culture was exposed to H2O2 (10 mM). The ApSAT expression was studied using RT‐PCR across various time points and it was found that the expression of the ApSAT was significantly upregulated on Day 15. The in vitro cytotoxicity assay against NV14 was performed in human dermal fibroblast cells and human blood leukocytes. Results showed that NV14 treatment was non‐cytotoxic to the cells. Besides, in vivo treatment of NV14 in zebrafish larvae did not exhibit the signs of developmental toxicity. Further, the in vitro antioxidant assays enhanced the activity of the antioxidant enzymes, such as SOD and CAT, due to NV14 treatment; and also significantly reduced the MDA levels, while increasing the superoxide radical and H2O2 scavenging activity. The expression of antioxidant enzyme genes glutathione peroxidase, γ‐glutamyl cysteine synthase, and glutathione S‐transferase were found to be upregulated in the NV14 peptide pretreated zebrafish larvae when induced with generic oxidative stress, H2O2. Overall, the study showed that NV14 peptide possessed potent antioxidant properties, which were demonstrated over both in vitro and in vivo assays. NV14 enhanced the expression of antioxidant enzyme genes at the molecular level, thereby modulating and reversing the cellular antioxidant balance disrupted due to the H2O2‐induced oxidative stress.

6-Gingerol (1) is one of the major components in ginger and developing new synthetic methodologies could bring semisynthetic analogs with improved therapeutic properties. Towards this, multigram scale isolation of 6gingerol with excellent purity was optimized using a simple and robust extraction, followed by column purification. Synthesis of 6-gingerdione, 7 from 6-gingerol was then achieved through selective -OTBDMS protection, DMP oxidation and deprotection reaction sequence for the first time. Compounds 1, 7 and 8 (dehydrozingerone) exhibited excellent cell-free antioxidant properties in DPPH, ABTS, superoxide radical scavenging assay and H 2 O 2 assay at 10-50 μM concentrations. The hemolytic study suggests that up to 50 μM, all three compounds did not exhibit toxicity to human erythrocytes. When H 2 O 2 treated zebrafish larvae groups (96hpf) were exposed to compounds 1, 7 and 8, it increases the SOD (19, 19.1 and 18.7 U/mg protein), CAT (18.1, 16.5,and 15.8 μmol/mg levels and decreases the lipid peroxidation level (13, 15 and 18 nmol/mg protein), respectively. In vivo ROS levels and degree of cell death were studied using DCFDA and Acridine orange assays. Compounds 1, 7 and 8 decreases the ROS and cell death level significantly. Taken together, compounds 1, 7 and 8 exhibit excellent antioxidant properties, counteract H 2 O 2 induced oxidative stress, reduces cell death in zebrafish larvae.

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This study investigates the antioxidant and antidiabetic activity of the WL15 peptide derived from Channa striatus on regulating the antioxidant property in the rat skeletal muscle cell line (L6) and enhancing glucose uptake via glucose metabolism. Increased oxidative stress plays a major role in the development of diabetes and its complications.Strategies are needed to mitigate the oxidative stress that can reduce these pathogenic processes. Our results showed that with treatment with WL15 peptide, the reactive oxygen species significantly decreased in L6 myotubes in a dose-dependent manner, and increased antioxidant enzymes help to prevent the formation of lipid peroxidation in L6 myotubes. The cytotoxicity of WL15 is evaluated in the L6 cells and found to be noncytotoxic at the tested concentration. Also, for the analysis of glucose uptake activity in L6 cells, the 2-(N-[7-nitrobenz-2-oxa-1,3-diazol-4-yl]amino)-2-deoxy-D-glucose assay was performed in the presence of wortmannin and genistein inhibitors. WL15 demonstrated antidiabetic activities through a dose-dependent increase in glucose uptake (64%) and glycogen storage (7.8 mM). The optimal concentration for the maximum activity was found to be 50 µM. In addition, studies of gene expression in L6 myotubes demonstrated upregulation of antioxidant genes and genes involved in the pathway of insulin signaling.In cell-based assays, WL15 peptide decreased intracellular reactive oxygen species levels and demonstrated insulin mimic activity by enhancing the primary genes involved in the insulin signaling pathway by increased glucose uptake indicating that glucose transporter type 4 (GLUT4) is regulated from the intracellular pool to the plasma membrane.

Human health may benefit from the study of natural compounds and phytoconstituents that can protect from inflammation. We investigated Nimbin (N1), a member of the ring C Seco-tetranortriterpenoids family, and its semi-natural analog deacetyl Nimbin namely N2 and N3 for their anti-inflammatory properties. As key findings, N1, N2, and N3 were able to improve wound healing by cell proliferation in a period of 24 h and were able to reduce the reactive oxygen species (ROS) production in Madin-Darby Canine Kidney cells which were screened using dichlorodihydro fluorescein diacetate (DCF-DA) staining. When the zebrafish larvae were subjected to DCF-DA assay N1, N2, and N3 were able to substantially reduce the ROS levels in a dose-dependent manner. In zebrafish larvae, the cell death indicates the fluorescent intensity due to acridine orange staining that was found to be dramatically decreasing upon the treatment of N1, N2, and N3. The cell membrane lipid peroxidation levels were also reduced in a dose-dependent manner upon the treatment of Nimbin and its analogs indicating lesser blue fluorescent levels. Among the Nimbin and its analogs, N2 was subjected to have better activity. To confirm the activity of N1, N2, and N3, in silico characterization was performed using Density functional theory and molecular docking. As a result, N2 exhibited the lowest