The Impact of Environmental Stress on the Secondary Metabolites and the Chemical Compositions of the Essential Oils from Some Medicinal Plants Used as Food Supplements

Abstract

This study aims to study the impact of environmental stresses on the chemical compositions of essential oils and the content of secondary metabolites of the plants most used by the rural population: Thymus vulgaris, Mentha pulégium and Rosmarinus officinalis. The results of the study indicate that the percentage of secondary metabolites increased in the second year when temperature and water pressure increased by 50%. Specifically, coumarin increased from 3.94% to 9.23%, saponins increased from 6.17% to 7.78%, tannins increased from 2.90% to 6.12%, alkaloids increased from 6.72% to 15.95%, and flavonoids increased from 7.42% to 12.90%. However, in the fourth year, the temperature continued to increase, and water availability decreased by 75%, leading to a decrease in the rate of secondary metabolites. Coumarin decreased from 9.22% to 6.15%, saponin decreased from 7.80% to 6.79%, tannin decreased from 6.11% to 4.16%, alkaloids decreased from 15.95% to 10.45%, and flavonoids decreased from 12.90% to 9.70%. Similar results were observed for the essential oil yield, which increased in year two from 3.57% to 3.84% and decreased in year four to 1.04%. The same pattern was observed for Mentha pulégium and Rosmarinus officinalis. The gas chromatography analysis of the three essential oil samples showed that the majority of the compounds of the three plants were modified under the conditions of climate change. For Mentha pulégium, pulegone was found to represent the highest proportion in sample two (73.3%), followed by sample one (71.1%), and finally, sample three (61.8%). For Rosmarinus officinalis, the majority of compounds were cineole and camphor, with cineole representing 36% in sample two, 45.89% in sample one, and 43.08% in sample three, and camphor representing 21.44% in sample two, 21.56% in sample three, and 17.44% in sample one. For Thymus vulgaris, the majority of the compounds were Thymol and Carvacrol, which underwent approximately the same modifications as the majority of compounds in the other two plants. The results indicate that environmental stresses can lead to significant changes in these compounds, which can affect the medicinal and aromatic properties of these plants. The findings of this study highlight the need for more research to understand the impacts of climate change on plant species and the potential implications for human health and well-being.

Analysis of Primary and Secondary Metabolites, Physical Properties, Antioxidant and Antidiabetic Activities, and Chemical Composition of Rosmarinus officinalis Essential Oils under Differential Water Stress Conditions

“…The plant material utilized in this study consisted of dried leaves that were subjected to shade drying. To extract the EO, approximately 100 g of the dried leaves underwent hydrodistillation using a Clevenger-type apparatus …”

“…To extract the EO, approximately 100 g of the dried leaves underwent hydrodistillation using a Clevenger-type apparatus. 26 2.4. Physical Properties.…”

Study of the Physiological Behavior of Some Plants in Response to Climate Change Conditions

“…The planting of the three sample sets was executed under varying levels of water stress for a year: 25% water stress for sample 1, 50% for sample 2, and 75% for sample 3. The study area encompasses 90 square meters, divided equally into three sections, each spanning 30 square meters [18].…”

“…Hydrodistillation is a method that employs water as a solvent to extract the volatile aromatic compounds, including essential oils, from the plant material. The design of the apparatus facilitates the separation of essential oils from the water and the subsequent collection of these valuable oils [18].…”

Carvacrol as a Stimulant of the Expression of Key Genes of the Ginsenoside Biosynthesis Pathway and Its Effect on the Production of Ginseng Saponins in Panax quinquefolium Hairy Root Cultures

“…Some of these metabolites may constitute a chemical barrier, while others demonstrate a function in signaling processes related to plant protection [1,2]. In addition, secondary metabolites, i.e., alkaloids, glycosides, phenolics (e.g., simple phenolics, coumarins, tannins, lignans, and flavonoids) saponins, terpenes, and essential oils, have therapeutic potential, showing multidirectional pharmacological activities [3,4]. Ginsenosides-triterpene saponins isolated from ginseng-are an example of PSM, whose biological activity has been confirmed by many studies.…”