Protective Effects of Pinus halepensis Bark Extract and Nicotine on Cigarette Smoke-induced Oxidative Stress in Keratinocytes

Abstract

Background/Aim: Cigarette smoke (CS) is a major environmental health threat. The oxidative stress induced by CS on keratinocytes and the possible protective effect of nicotine, its receptor inhibitors, and Pinus halepensis bark extract in relation to known antioxidants were investigated. Materials and Methods: Primary mouse keratinocytes were exposed to cigarette smoke in the presence and absence of Pinus halepensis bark extract (1 μg/ml), rutin (50 μΜ) and ascorbic acid (250 μΜ), nicotine (1 μM) with or without mecamylamine (5 μM) and α-bungarotoxin (0.1 μΜ). Keratinocyte viability and oxidative stress were evaluated by MTT and fluorescence assays. Results: Pinus halepensis bark extract decreased the oxidative stress and increased the viability of keratinocytes, and moreover, these effects were more pronounced compared to the mixture of rutin and Lascorbic acid. Nicotine significantly enhanced the viability potentiation of the beneficial effect induced by Pinus halepensis bark extract. Mecamylamine and α-bungarotoxin showed no specific effect. Conclusion: Pinus halepensis bark extract in combination with nicotine may successfully reverse skin damage induced by cigarette smoke. Cigarette smoke (CS) is a global problem of our society and according to the World Health Organization "the tobacco epidemic is one of the biggest public health threats the world has ever faced, killing more than 8 million people a year" (1). The Lancet Commission on pollution and health characterized CS as more dangerous than AIDS, tuberculosis, and malaria (2). CS is associated with cardiovascular diseases, higher risk of skin diseases, such as squamous cell carcinoma and atopic dermatitis, and is connected with decreased wound healing rate (3-7). The skin is the most important target for the harmful effect of CS pollution. Both solid and gas products of CS contain aniline, N-nitrosodimethylamine, benzopyrenes, acrolein, formaldehyde, N-nitrosopyrrolidine that are considered to be toxic, causing serious oxidative damage (8). CS produces reactive oxygen and nitrogen species oxidizing important biomolecules such as DNA, proteins and lipids leading to tissue injury which is translated to enhanced inflammatory phenomena (9-14). One of the main constituents of CS is nicotine; it is an agonist of acetylcholine and acts on the epidermis via the keratinocyte nicotinic acetylcholine receptors (nAChRs) (15). nAChRs are large (290 kDa) pentameric transmembrane complexes, which are ligand-gated ion channels (LGICs) permeable to Na, K and Ca ions (16, 17). Nicotine activity is doubtful as it has been shown to exert both toxic and beneficial effects; it has been reported as neurotoxic and neuroprotectant (18), toxic to muscles and lung epithelium (19, 20), beneficial in colitis (21), while its potential activity on mitochondria apparently requires further investigation (22). Concerning inflammatory and wound healing processes, the effect of nicotine is considered rather negative, while topical nAchR antagonists have been shown to improve these negativ...

Assessment of natural antioxidants' effect on PDT cytotoxicity through fluorescence microscopy image analysis

“…Pinus is a well‐known source of antioxidants, mainly phenolic compounds 24 . Lately, the antimicrobial, antidiabetic, anti‐inflammatory, and cytotoxic properties of P. halepensis have been reported 25–28 . To the best of our knowledge, P. halepensis bark extract has not been studied before with prostate cancer or prostate cancer PDT.…”

“…24 Lately, the antimicrobial, antidiabetic, anti-inflammatory, and cytotoxic properties of P. halepensis have been reported. [25][26][27][28] To the best of our knowledge, P. halepensis bark extract has not been studied before with prostate cancer or prostate cancer PDT. Using a natural antioxidant agent derived from renewable natural biomass as a phytopharmaceutical for prostate cancer or as a promoter of PDT efficacy in prostate cancer would be an eco-friendly and sustainable approach.…”

Pinus thunbergii bark extract rich in flavonoids promotes hair growth in dorsal skin by regulating inflammatory cytokines and increasing growth factors in mice

“…For instance, a previous study demonstrated that oral ingestion of Pycnogenol ® protected against skin damage induced by UV irradiation, modulated skin pigmentation and enhanced skin barrier function and extracellular matrix homeostasis ( 33 ). In addition, in 2020, Pavlou et al ( 34 ) reported that the bark extract of Aleppo pine ( Pinus halepensis ) protected keratinocytes against cigarette smoke-induced oxidative stress. Of note, a recent study reported that Pinus thunbergii extract ameliorated lipopolysaccharide-induced acute inflammatory responses by regulating oxidative stress ( 35 ).…”

Cigarette smoke extract induces ferroptosis in human retinal pigment epithelial cells in Age-related macular degeneration

“…We prepared CSE using Longfeng Chengxiang cigarettes (carbon monoxide, 14 mg; nicotine, 1.2 mg; tar, 13 mg; Chongqing, China) as previously described [26][27][28][29][30] . Briefly, the steps are as follows: the smoke from the combustion of one cigarette was dissolved into 1 ml of DMEM/F12 using a modified 50-ml syringe as an actuating device.…”