Anti-oxidant activity of 6-gingerol as a hydroxyl radical scavenger by hydrogen atom transfer, radical addition and electron transfer mechanisms

Encapsulation of gingerol into nanoliposomes: Evaluation of in vitro anti-inflammatory and anti-cancer activity

Nanoliposomes (NLs) are ideal carriers for delivering complex molecules and phytochemical products, but ginger by-products, despite their therapeutic benefits, have poor bioavailability due to their low water solubility and stability. Crude ginger extracts (CGEs) and 6-gingerol were individually encapsulated within NLs for in vitro activity assessment. In vitro evaluation of anti-proliferative and anti-inflammatory properties of encapsulated 6-gingerol and CGE was performed on healthy human periodontal ligament (PDL) fibroblasts and MDA-MB-231 breast cancer cells. Encapsulation efficiency and loading capacity of 6-gingerol reached 25.23% and 2.5%, respectively. NLs were found stable for up to 30 days at 4°C with a gradual load loss of up to 20%. In vitro cytotoxic effect of encapsulated 6-gingerol exceeded 70% in the MDA-MB-231 cell line, in a comparable manner with non-encapsulated 6-gingerol and CGE. The effect of CGE with an IC50 of 3.11 ± 0.39, 7.14 ± 0.80, and 0.82 ± 0.55 μM and encapsulated 6-gingerol on inhibiting IL-8 was evident, indicating its potential anti-inflammatory activity. Encapsulating 6-gingerol within NLs enhanced its stability and facilitated its biological activity. All compounds, including vitamin C, were equivalent at concentrations below 2 mg/mL, with a slight difference in antioxidant activity. The concentrations capable of inhibiting 50% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) substrate were comparable.

Role of the Solvent and Intramolecular Hydrogen Bonds in the Antioxidative Mechanism of Prenylisoflavone from Leaves of Vatairea guianensis

This work discusses the electron structure, antioxidative properties, and solvent contribution of two new antioxidant molecules discovered, named S10 and S11, extracted from a medicinal plant called Vatairea guianensis, found in the Amazon rain-forest. To gain a better understanding, a study using density functional theory coupled with the polarizable-continuum model and the standard 6-311++G(d,p) basis set was conducted. The results indicate that S10 has a higher antioxidant potential than S11, confirming the experimental expectations. In the gas phase, the hydrogen atom transfer route dominates the hydrogen scavenging procedure. However, in the water solvents, the antioxidant mechanism prefers the sequential proton loss electron transfer mechanism. Furthermore, the solvent plays a fundamental role in the antioxidant mechanism. The formation of an intramolecular OH···OCH3 hydrogen bond is crucial for accurately describing the hydrogen scavenging phenomenon, better aligning with the experimental data. The results suggest that the two isoflavones investigated are promising for the pharmacologic and food industries.

Nanoencapsulation of Ru(p-cymene) Complex Bearing Ginger-based Natural Product into Liposomal Nanoformulation to Improve Its Cellular Uptake and Antiproliferative Activity

The organometallic compounds are prospective candidates in the row of developing metallochemotherapeutics with the aim of overcoming the limitations of platinum drugs. In order to explore the anticancer properties of organometallic compounds with the natural medicines, two Ru(II)-p-cymene complexes containing the natural products, viz., 6-gingerol (6G) and benzylated-6-gingerdione (B-6GD) have been synthesized and characterized well. The phenolic group of the Ru(6G) complex facilitates its higher cell-free antioxidant activity than its analogue complex. Also, the same complex shows higher cytotoxicity toward A549 lung and HeLa-S3 cervical cancer cells than the Ru(B-6GD) complex but lower cytotoxicity toward A2058 metastatic melanoma cancer cells. Both complexes are shown to easily accumulate in melanoma cancer cells, and their degree of cytotoxicity in the same cells is found to be positively correlated with cell uptake. The cytotoxicity of complexes arises from their intracellular activity, mainly due to the induction of singlet oxygen production in cancer cells. The subcellular fractionation study shows that mitochondria and ER-Golgi membranes might be their predominant targets. Also, the mechanistic investigation revealed that Ru(B-6GD) induces caspase-dependent non-apoptotic cell death whereas Ru(6G) can induce caspase-independent non-apoptotic cell death. Furthermore, both complexes are found to moderately alter the adhesion properties of cancer cells, which is beneficial for antimetastatic treatment. Despite the potential pharmacological activity, Ru(6G) is encapsulated into polymer-supported liposomes to reduce its toxicity and further improve its anticancer potency. The π-conjugated yne-ene chain of polydiacetylene aids in the development of a stable nanoformulation, which achieved a slow release of the complex. Most importantly, the cancer cell uptake of the liposome-encapsulated Ru(6G) complex is 20 times enhanced and the total ROS formation in cancer cells is significantly increased compared to the non-encapsulated complex. However, the nanoformulation does not alter the antimetastatic potency of the encapsulated complex.

Spectroscopic Studies of CDPy Molecule in Different Protic and Aprotic Solvents and Investigation of Antioxidant Property

The properties of 3-Cyano-4, 6-Dimethyl-2-Pyridone (CDPy) were analyzed to study the antioxidant behavior. The UV-Visible absorption and fluorescence properties of CDPy have been studied in two protic (water and methanol) and two aprotic (acetonitrile and dimethyl sulfoxide) solvents. Its antioxidant properties were compared with well known antioxidant ascorbic acid. This compound, CDPy was found to exhibits moderate antioxidant properties. The experimental results were reproduced by theoretical density functional methods, which helped to understand the experimental result better.

Electron transfer in biologically important systems: Polycyclic aromatic hydrocarbons, DNA bases and free radicals

Occurrence of electron transfer was studied for different combinations of polycyclic aromatic hydrocarbons (PAHs) and DNA bases as electron donors or acceptors and free radicals only as electron acceptors. Geometries of all the molecules and radicals were optimized in aqueous medium employing the polarizable continuum model. Single electron transfer (SET) and sequential proton loss electron transfer mechanisms were investigated employing Gibbs free energies of the appropriate neutral, anionic and cationic species. Barrier energies involved in these phenomena were calculated using the Marcus theory. The SET barrier energies were found to be linearly correlated with [Formula: see text] (Electron affinities of acceptors – Ionization potentials of donors). SET barrier energies from the DNA bases to the PAHs follow the order Cy [Formula: see text] Th [Formula: see text] Ad [Formula: see text] Gu, whereas SET barrier energies from the PAHs to the DNA bases follow the order Gu [Formula: see text] Ad [Formula: see text] Th [Formula: see text] Cy. Thus, guanine, among the DNA bases, is the best electron donor to the PAHs and worst electron acceptor from the same.