Journal of Medicinal Plants Biotechnology

Abstract This study investigated the effect of different levels of charcoal obtained from acacia wood on some growth characteristics, essential oil content, and nutrient absorption of sage plants under cadmium stress. The experimental treatments included different levels of charcoal (0, 1, and 2% by weight) and cadmium stress at three levels of 0, 30, and 60 mg/kg of soil, which was factorial in the form of a completely randomized design with 4 replications in the research greenhouse of the Department of Horticultural Sciences, Faculty of Agriculture, Ferdowsi University of Mashhad. The results showed that increasing the concentration of cadmium caused a significant decrease in the growth of sage plants in terms of height, stem diameter, number of sub-branches, leaf area, number of leaves, biomass, and root growth. Cadmium stress also caused a decrease in essential oil content and the amount of nitrogen, phosphorus, and potassium elements, and increased iron, manganese, and cadmium in the aerial parts of the sage plant. The use of charcoal reduced the harmful effects of cadmium on growth by reducing the transfer of cadmium from roots to aerial organs and improving the absorption of nutrients. In plants treated with increasing charcoal concentration, the amount of essential oil in the flowering branches of sage significantly increased. The greatest effect of charcoal on morphological traits, percentage of essential oil, and concentration of nutrients was observed in the highest concentration used (2% by weight) and in plants under severe cadmium stress.

Abstract The genus Thymus is one of the plants with a Mediterranean distribution. This plant has about 350 species and in Iran there are 14 species of aromatic and perennial plants that grow in mountainous areas and have an important impact on treatment, health and various industries due to having more than 20 types of major known chemical compounds. The percentage of thyme essential oil varies between 0.8 and 1.4 and most of its components include phenolic compounds, monoterpenes and sesquiterpenes. Thymol is the main component of phenolic compounds in the thyme plant. Thyme leaves are used in food products and the plant's essential oils is used in various beverages and pharmaceutical, health and cosmetic industries. Thyme oil has properties such as antispasmodic, carminative, antifungal, antibacterial, disinfectant, anthelmintic, antirheumatic, expectorant, antioxidant, natural food preservative and delaying the aging of mammals. Thyme essential oil is one of the ten famous essential oils that has a special place in global trade. This study provides a general overview of scientific research and findings, especially the species and morphological and phytochemical diversity of the Thyme genus. So far, much research has been conducted on this genus, but due to the high diversity of species in this genus, as well as diverse climatic and ecological effects and numerous subspecies, there is no appropriate conclusion in this regard. It is hoped that by summarizing the findings of the researchers, a new horizon can be opened in the study of endemic species of Iran and high-yielding varieties worldwide.

Abstract An experiment was conducted to investigate the effects of water deficit stress (field capacity (FC), 50%, and 30% of FC) and foliar application of gamma-aminobutyric acid (GABA) and spermidine (control and 3 mg L⁻¹), as well as their combined application, on growth and selected physiological traits of basil. The highest plant biomass was observed under irrigation at FC + simultaneous foliar application of spermidine and GABA. The main effects of water deficit and foliar treatments significantly influenced chlorophyll, H2O2, malondialdehyde, proline, elemental content, and essential oil content of the plant. The highest chlorophyll a, calcium, magnesium, phosphorus, and potassium content were observed under irrigation at FC. Irrigation at FC and 50% FC significantly increased chlorophyll b and nitrogen contents. Irrigation at 30% FC resulted in elevated levels of H2O2, malondialdehyde, and proline accumulation. All three foliar treatments led to increased chlorophyll b, nitrogen and potassium contents. Simultaneous foliar application of both compounds contributed to a reduction in H2O2 and malondialdehyde levels, while enhancing chlorophyll a, proline, phenolic compounds, calcium, magnesium, phosphorus, and essential oil contents. Essential oil content was notably increased under irrigation at 50% FC. Sixteen constituents were identified in the basil essential oil, with methyl chavicol (38.42–42.38%) being the predominant compound, particularly prominent in the treatment combining irrigation at 30% FC with foliar application of both compounds. The results of the present study demonstrate the positive effect of concurrent application of both compounds on the evaluated physiological and biochemical traits of basil under water deficit conditions.

Abstract In light of the growing demand for medicinal plants and their increasing significance in global society, this study examined the essential oils composition and phenolic content in the flowers and leaves of Stachys schtschegleevi. Plant samples were collected from the Jolfa region, and the essential oils were extracted using a Clevenger apparatus. The chemical composition of the essential oils was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The results showed that the percentage of essential oil in the flower organs was 39% higher than in the leaves. Analysis of the essential oils identified 61 compounds in the flowers (98.39% of the total) and 49 compounds in the leaves (98.73% of the total). The dominant compounds in the flower organs were germacrene D (20.69%), α-cadinol (9.51%), α-muurolene (7.16%), n-hexadecanoic acid (5.93%), thymol (5.41%), spathulenol (4.77%), α-pinene (4.62%) and β-pinene (4%). The dominant compounds in Pulak leaf essential oil were found to be α-pinene (12.98%), germacrene D (11.92%), α-cadinol (7.9%), thymol (6.91%), n-hexadecanoic acid (4.82%), spathulenol (4.44%) and α-muurolene (4.22%). Evaluation of the phenolic compounds showed that the total phenol and flavonoid content in the flowers (81.8 and 3.5 mg/ g of dry extract, respectively) was higher than in the leaves (56.1 and 3 mg/g of dry extract, respectively). Therefore, due to its higher essential oil percentage and greater richness in phenolic compounds, the flower organ of Stachys schtschegleevi is considered more suitable than the leaf organ for industrial applications, particularly in the field of essential oil extraction.

Abstract The excessive and improper use of antimicrobial agents has led to the emergence of drug-resistant strains. Therefore, It necessitates the discovery and implementation of new sources to combat microbial pathogens. This study aimed to evaluate the antibacterial effect of ethanolic extract of Ziziphus spina-christi leaves against four bacteria; Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Corynebacterium glutamicum. Initial screening of the antibacterial activity of the extract was performed using the disk diffusion method. Subsequently, the minimum inhibitory concentration (MIC) was determined using the microdilution method, and the minimum bactericidal concentration (MBC) was identified through microbial culture. According to the results, the highest antibacterial effect of the leaf extract was observed against Corynebacterium glutamicum. The microdilution test showed that the MIC for all bacteria, except Escherichia coli, was 75 mg/mL. The lowest survival rate was observed in Corynebacterium glutamicum and Staphylococcus epidermidis. The MBC for these two bacteria was determined to be 150 mg/mL, while for Escherichia coli, it was 300 mg/mL. The findings of this research demonstrated that Ziziphus leaf extract has notable antibacterial activity, especially against the studied Gram-positive bacteria, and could be considered a natural source for developing of new antibacterial drugs.

Abstract Medicinal plants are recognized as significant sources of natural antioxidants due to their bioactive compounds, particularly phenolics and flavonoids, which have shown potential in the prevention and treatment of various diseases. These compounds are widely studied for their notable antioxidant, anti-inflammatory, and anticancer properties. The efficiency and profile of extracted phytochemicals are highly influenced by extraction parameters, including solvent type, solvent concentration, and extraction time. This study aimed to evaluate the effects of different extraction methods, namely maceration and ultrasound, along with solvent type and concentration (ethanol and methanol at 50% and 70%), and extraction durations (5 and 10 minutes), on the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity of extracts from Portulaca oleracea and the leaves and fruits of Ziziphus spina-christi. A factorial experiment was conducted based on a completely randomized design with two replications for statistical analysis. The results revealed that the highest phenolic content was obtained from P. oleracea extract using the maceration method with 70% methanol for 5 minutes. Similarly, the highest flavonoid content was observed in Z. spina-christi leaf extract under the same conditions. Regarding antioxidant activity, the most potent effect was recorded in the leaf extract of Z. spina-christi using 70% ethanol and an extraction time of 10 minutes. These findings highlight the importance of optimizing extraction conditions to enhance the recovery of beneficial bioactive compounds from medicinal plants, thereby improving the antioxidant potential of the resulting extracts.