Antioxidant, Anti-Inflammatory and Attenuating Intracellular Reactive Oxygen Species Activities of Nicotiana tabacum var. Virginia Leaf Extract Phytosomes and Shape Memory Gel Formulation.

Oxidative stress is one of the major causes of skin aging. In this study, the shape memory gels containing phytosomes were developed as a delivery system for Nicotiana tabacum var. Virginia fresh (VFL) and dry (VDL) leaf extracts. The extracts were loaded in the phytosomes by a solvent displacement method. The physical and chemical characteristics and stability of phytosomes were evaluated by dynamic light scattering and phytochemistry, respectively. The in vitro antioxidant activity and intracellular reactive oxygen species reduction of phytosomes and/or extracts were investigated by the DPPH and ABTS radical scavenging assays, FRAP assay, and DCFH-DA fluorescent probe. The cytotoxicity and anti-inflammatory activity of VDL and VFL phytosomes were studied by an MTT and a nitric oxide assay, respectively. Here, we first reported the total phenolic content in the dry leaf extract of N. tabacum var. Virginia was significantly greater than that of the fresh leaf extract. The HPLC analysis results revealed that VDL and VFL extracts contained 4.94 ± 0.04 and 3.13 ± 0.01 µg/mL of chlorogenic acid and 0.89 ± 0.00 and 0.24 ± 0.00 µg/mL of rutin, respectively. The phytosomes of the VDL and VFL extracts displayed stable size, polydispersity index, zeta potential values, and good chemical stability. VDL and VDL phytosomes showed higher phenolic and flavonoid contents which showed stronger DPPH and ABTS radical scavenging effects and reduced the intracellular ROS. The results suggested that the phenolic compounds are the main factor in their antioxidant activity. Both VDL and VFL phytosomes inhibited nitric oxide production induced by LPS, suggesting the anti-inflammatory activity of the phytosomes. The shape memory gel containing VDL and VFL phytosomes had good physical stability in terms of pH and viscosity. The VDL and VFL phytosomes dispersed in the shape memory gels can be considered as a promising therapeutic delivery system for protecting the skin from oxidation and reactive oxygen species.

Phytochemical, Antioxidant, Antihyaluronidase, Antityrosinase, and Antimicrobial Properties of Nicotiana tabacum L. Leaf Extracts.

Nicotiana tabacum L. (tobacco) is an important and valuable crop for the cigarette industry. However, cigarette cessation has been encouraged worldwide. Therefore, this study aimed to investigate the potential of N. tabacum leaf extract use in other industries besides cigarette production, especially cosmeceutical industries, which are of interest for increasing the value and widening the applications of N. tabacum. The leaves of N. tabacum var. Virginia and Turkish were extracted by maceration using 95% v/v ethanol or petroleum ether. The extracts were evaluated for their phytochemical compositions, antioxidant capacity, and anti-aging, antimelanogenic, and antimicrobial activities. The phytochemical screening of the extracts revealed terpenoids, steroids, alkaloids, tannins, and carbohydrates in all of the N. tabacum leaf extracts. The total phenolic content was detected to be the highest in the ethanolic extract of Virginia tobacco leaf, which had the most significantly potent antioxidant and antihyaluronidase activity (P < 0.05). On the contrary, the extracts from the Turkish variety demonstrated the most powerful antimicrobial activity against Staphylococcus aureus. Thus, ethanolic extracts of N. tabacum var. Virginia are suggested as good natural anti-aging ingredients with potent antioxidant and antihyaluronidase effects, whereas the leaf of N. tabacum var. Turkish is suggested as a good source of natural antimicrobial components, particularly for S. aureus inhibition. In summary, in addition to the cigarette industry, N. tabacum leaf could be a source of pharmaceutical and cosmeceutical compounds, particularly natural anti-aging and antimicrobial ingredients.