Haouaouchi Fatma Zohra2026-09-102026-07-02https://dspace.univ-tebessa.dz/handle/123456789/415This thesis evaluates the efficacy of natural products derived from Juniperus phoenicea (JPH) and Juniperus oxycedrus L. (JOX) berries, collected in northeastern Algeria, in reducing the toxicity associated with cigarette smoke compounds. Using advanced extraction and analytical methods, the study assesses the bioactivity of essential oils and ethanolic extracts through both in vitro and in vivo models. Essential oils were extracted via hydrodistillation, while ethanolic extracts were prepared using ultrasound-assisted extraction (UAE) and conventional maceration. Chemical profiling by gas chromatography-mass spectrometry (GC-MS) and Liquid Chromatography-Electrospray Ionization- Tandem Mass Spectrometry (LC-ESI-MS/MS) identified major bioactive compounds including α- pinene, germacrene D, quinic acid, protocatechuic acid, and hesperidin. In vitro assays revealed that JOX essential oil (JOX-EO) reduced nicotine levels with an IC50 of 16.8 μg/mL through a novel rapid extraction method, surpassing JPH oil. Cytotoxicity testing on A549 lung cancer cells demonstrated potent, dose-dependent inhibition by JOX-EO (IC50 = 15.9 μg/mL), outperforming the chemotherapy drug etoposide. Antioxidant capacity, measured by DPPH, FRAP, CUPRAC, and nitric oxide (NO) scavenging assays, was highest in UAE ethanolic extracts, correlating with elevated phenolic and flavonoid content. Notably, the NO scavenging activity presented an inverse concentration-response, showing stronger inhibition at lower doses. UV-visible spectroscopy confirmed JOX-EO’s ability to degrade polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke. In vivo, subchronic cigarette smoke exposure in rats followed by JOX-EO treatment restored antioxidant enzymes (GST, CAT, GSH-Px) and reduced malondialdehyde (MDA) levels. Chronic exposure studies showed that JOX extracts and essential oil facilitated partial recovery of body weight, organ function, and biochemical markers (ALT, AST, LDH), improved inflammatory and lipid profiles, without affecting blood glucose levels. These results highlight JOX berries as a sustainable source of bioactive compounds with strong antioxidative, anticancer, and detoxifying properties, with extraction techniques significantly impacting their therapeutic potential. The findings support the development of JOX-based natural products for preventing and treating smoking related health hazards.enCigarette smoke toxicitynatural productsdetoxificationinhibition powerJuniperus oxycedrusEssential oilsEthanolic extracts Antioxidant activityand CytotoxicityThesis