Chemical Composition, Antibacterial Properties, and Anti-Enzymatic Effects of Eucalyptus Essential Oils Sourced from Tunisia

Antimicrobial, Herbicidal and pesticidal potential of Tunisian eucalyptus species: Chemoprofiling and biological evaluation

The Eucalyptus genus, characterized by its imposing stature and fragrant foliage, has been a source of fascination for humanity over the centuries. The focus of the present investigation was directed towards the essentials oils (EOs) of five Eucalyptus trees cultivated in Tunisia. The GC-MS analysis unveiled unique compositional profiles, a finding substantiated by both Hierarchical Clustering Analysis (HCA) and Principal Component Analysis (PCA) conducted on the leaves EOs. These analyses resulted in the formation of discrete HCA clades, delineating 23 significant components. Notably, the percentage of eucalyptol emerged as the pivotal factor demarcating the separation between three distinct groups. The statistical analysis revealed a dose-dependent relationship in both phytotoxicity evaluation and antibacterial activity. The EOs from Eucalyptus loxophleba and E. salubris exhibited the highest phytotoxicity, inhibiting radical elongation and germination of various seeds, especially Sinapis arvensis and Raphanus sativus. The antimicrobial assessment demonstrated significant inhibitory effects of the EOs on bacterial strains, with MIC values spanning from 14 to exceeding 50 mg/ml. The EOs also affected biofilm formation and cellular metabolism, displaying varied efficacy among different Eucalyptus species against some bacterial strains. The EOs exhibited selective inhibition against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-amylase, and α-glucosidase. E. campaspe EO showed the highest AChE activity, while E. loxophleba and E. salubris EOs were most potent toward α-amylase. E. loxophleba EO demonstrated notable activity against α-glucosidase. Overall, these findings provide important data about the diverse biological activities of Eucalyptus EOs, suggesting potential applications in agriculture, medicine, and pharmacy.

Phytochemical characterization and multifaceted bioactivity assessment of essential oil from Ptychotis verticillata Duby: Anti-diabetic, anti-tyrosinase, and anti-inflammatory activity

The aim of this study is to explore the pharmacological properties of the essential oil derived from Ptychotis verticillata Duby (PVEO), a medicinal plant native to Morocco, focusing on its antidiabetic, anti-tyrosinase, and anti-inflammatory effects. Additionally, the study aims to characterize the phytochemical composition of PVEO and evaluate its potential as a natural therapeutic alternative for various health conditions. To achieve this, phytochemical analysis was conducted using gas chromatography-mass spectrometry (GC-MS). Furthermore, in vitro assessments were conducted to investigate PVEO's antidiabetic activity by inhibiting α-amylase, xanthine oxidase, and α-glucosidase. Tests were also undertaken to evaluate the anti-inflammatory effect of PVEO on RAW 264.7 cells stimulated by lipopolysaccharide (LPS), as well as its efficacy as an anti-tyrosinase agent and its lipoxygenase inhibition activity. The results of the phytochemical analysis revealed that PVEO is rich in terpene compounds, with percentages of 40.35 % γ-terpinene, 22.40 % carvacrol, and 19.77 % β-cymene. Moreover, in vitro evaluations demonstrated that PVEO exhibits significant inhibitory activity against α-amylase, xanthine oxidase, and α-glucosidase, indicating promising antidiabetic, and anti-gout potential. Furthermore, PVEO showed significant anti-tyrosinase activity, with an IC50 of 27.39 ± 0.44 μg/mL, and remarkable lipoxygenase inhibition (87.33 ± 2.6 %), suggesting its candidacy for dermatoprotection. Additionally, PVEO displayed a dose-dependent capacity to attenuate the production of NO and PGE2, two inflammatory mediators implicated in various pathologies, without compromising cellular viability. The findings of this study provide a solid foundation for future research on natural therapies and the development of new drugs, highlighting the therapeutic potential of PVEO in the treatment of gout, diabetes, pigmentation disorders, and inflammation.

Fatty Acid Profiles and Biological Activities of the Vegetable Oils of Argania spinosa, Pinus halepensis and Pistacia atlantica Grown in Tunisia: A Preliminary Study

Several foods are used in both the nutraceutical and health sectors; vegetable oils, for example, can prevent the onset of numerous diseases. The properties of these oils are related to their chemical composition and primarily to the presence of fatty acids. The present work aimed to determine the chemical profiles of Argania spinosa, Pinus halepensis, and Pistacia altantica oils, used in traditional Tunisian foods, and to evaluate some biological properties. We evaluated their antioxidant, anti-enzymatic, antimicrobial, and anti-inflammatory properties. Linoleic acid was the main component of the three oils. P. atlantica oil showed more significant inhibitory activity against the enzymes studied than A. spinosa and P. halepensis. All three oils showed similar antioxidant and anti-inflammatory activity. Furthermore, A. spinosa and P. halepensis oils showed antibiofilm activity against P. aeruginosa, with 30-40% inhibition. These results focus on the possible use of these oils in the nutraceutical and healthcare sectors.