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.

Nicotine (NCT), administered in the form of a fast dissolving oral delivery system, can be a potential alternative to nicotine replacement therapy. NCT was extracted by maceration and acid-base extraction methods from Burley tobacco leaves with different stalk positions and extraction yield and NCT content were further determined. The extract with the highest nicotine content was selected for incorporation into a fast dissolving film formulation. The optimized film was evaluated for its physical and mechanical properties, in vitro disintegration, and drug release profile. The results demonstrated that the extract from the upper part of tobacco leaves using the acid-base extraction method had the highest amount of NCT. NCT fast dissolving film consisting of this extract as the active ingredient and HPMC E15 as a film polymer resulted in a homogeneous translucent film with a light brown color. The addition of NCT significantly affected the film properties in terms of weight, disintegration time, tensile strength, percentage elongation at break, and Young’s modulus values. The drug release of NCT fast dissolving film showed a rapid initial release of 80% within three minutes, and its kinetics followed the Higuchi matrix model. The results suggest that these NCT films can be employed in the development of NCT fast dissolving films for clinical use.

Clove oil (CO), an essential oil of Syzygium aromaticum, has been reported as an anesthetic for many fish species. However, its insoluble properties require a suitable delivery system for its application. In the present study, nanoformulations of CO as a nanoemulsion (CO-NE), a self-microemulsifying drug-delivery system (CO-SMEDDS), and a self-nanoemulsifying drug-delivery system (CO-SNEDDS) were prepared for delivering CO. Zebrafish were used as a fish model to investigate oil pathways. The result shows fluorescence spots of fluorescence-labeled CO accumulate on the gills, skin, and brain. All CO nanoformulations significantly increased penetration flux compared to CO ethanolic solution. Investigation of the anesthetic mechanism of action using a rat brain γ-aminobutyric acid subtype A (GABA_A) receptor-binding test demonstrates that CO and its major compound, eugenol, modulate [³H]muscimol binding. CO-NE exhibited a concentration-dependent binding activity with an EC₅₀ value of 175 µg/mL, significantly higher than CO solution in dimethyl sulfoxide. In conclusion, CO enters the fish through the skin and gills. The anesthetic mechanism of action of CO is based on modulation of [³H] muscimol binding to GABA_A receptors. Among three nanoformulations tested, CO-NE is the most effective at increasing permeability and enhancing the receptor-binding activity of the oil.

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 ( ). 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.

In this research, we aimed to assess antibacterial activity and develop oral care products from three natural plant extracts from the Thai highlands. The plants, including Camellia sinensis var. assamica, Zanthozylum limonella Alston, and Acorus calamus L., were extracted using two traditional extraction techniques: maceration and hydrodistillation methods. The extracts were characterized by percentage yield, total phenolic, and total flavonoid contents. Antibacterial activity against Staphylococcus aureus, which play a role in oral health and disease, was investigated. C. sinensis var. assamica extract had the highest content of phenolic acid (38.15 ± 4.12 mg GAE/g extract) and flavonoids (44.91 ± 2.76 mg QE/g extract). Interestingly, a combination of C. sinensis with Z. limonella and A. calamus provides a greater inhibitory effect against S. aureus. Furthermore, oral care products were prepared as a natural product mixture in two preparations: (i) oral ulcers gel and (ii) oral spray. Apart from antibacterial efficiency, volunteer satisfaction after the usage of oral care products containing traditional plant extracts was investigated via organoleptic evaluation. The findings of the volunteer surveys indicated positive feedback for both oral care products with high satisfaction levels. Hence, these oral care products could potentially be natural antimicrobial agents and can be further developed and applied for oral applications in the pharmaceutical and cosmetic industries.

Background/Objectives: Holy basil (Ocimum tenuiflorum L.) essential oil exhibits antioxidant, antimicrobial, and anesthetic activities, mainly due to eugenol, methyl eugenol, and β-caryophyllene. However, its clinical application is limited by poor water solubility, instability, and low bioavailability. This study developed and compared two delivery systems, self-nanoemulsifying drug delivery systems (SNEDDS) and microemulsions (ME), to enhance their stability and fish anesthetic efficacy. Methods: The optimized SNEDDS (25% basil oil, 8.33% coconut oil, 54.76% Tween 80, 11.91% PEG 400) and ME (12% basil oil, 32% Tween 80, 4% sorbitol, 12% ethanol, 40% water) were characterized for droplet size, PDI, zeta potential, pH, and viscosity. Stability was evaluated by monitoring droplet size and PDI over time and by determining the retention of eugenol, methyl eugenol, and β-caryophyllene after storage at 45 °C. Fish anesthetic efficacy was tested in koi carp (Cyprinus carpio var. koi). Results: SNEDDS maintained a small droplet size (~22.78 ± 1.99 nm) and low PDI (0.188 ± 0.088 at day 60), while ME showed significant size enlargement (up to 177.10 ± 47.50 nm) and high PDI (>0.5). After 90 days at 45 °C, SNEDDS retained 94.45% eugenol, 94.08% methyl eugenol, and 88.55% β-caryophyllene, while ME preserved 104.76%, 103.53%, and 94.47%, respectively. In vivo testing showed that SNEDDS achieved faster anesthesia (114.70 ± 24.80 s at 120 ppm) and shorter recovery (379.60 ± 15.61 s) than ME (134.90 ± 4.70 s; 473.80 ± 16.94 s). Ethanol failed to induce anesthesia at 40 ppm and performed poorly compared to SNEDDS and ME at other concentrations (p < 0.0001). Conclusions: SNEDDS demonstrated superior physical stability and fish anesthetic performance compared to ME. These findings support SNEDDS as a promising formulation for delivering holy basil essential oil in biomedical and aquaculture applications.