Phytochemical constitutes and biological activities of essential oil extracted from irradiated caraway seeds (Carum carvi L.)

In Vitro Study to Evaluate the Best Conditions Highlighting the Antimicrobial Activity of Carum carvi Essential Oil on Human Pathogen Isolates in Formulations Against the Spread of Antibiotic Resistance

Background/Objectives: In recent years, antimicrobial resistance has become a major threat to global health, and scientific research aiming to identify new therapeutic resources is a priority. Essential oils (EOs), obtained from spices belonging to the culinary tradition, like Carum carvi essential oil (CC-EO), are of great interest for their antimicrobial activity, but the methods used to evaluate their efficacy need to be standardized. The aims of this work were to evaluate the following: (i) the best microbiological in vitro test; (ii) the best surfactant; and (iii) the best microbiological target of CC-EO and its method of administration. Methods: CC-EO quality was evaluated using gas chromatography-mass spectrometry. Antimicrobial susceptibility testing with drugs currently in use was performed. Antimicrobial effectiveness against 70 clinical strains belonging to S. aureus, E. coli, E. faecalis, K. pneumoniae, P. aeruginosa, S. pyogenes, and C. albicans was evaluated. Two microbial tests (broth microdilution tests and disk diffusion), generally used in routine clinical practice, were compared. To choose the best vehicle, Tween80, DMSO, and ethanol were evaluated. The antimicrobial efficacy of vapors was assessed using a microatmosphere test. Results: The broth microdilution test is confirmed as the best in evaluating the antimicrobial activity of EOs. The most suitable EOs vehicle for antimicrobial testing was Tween80. CC-EO and its vapors were effective against GRAM+ and C. albicans strains, both sensible and resistant, and ineffective against GRAM-. Conclusions: In the future, it may be possible to include CC-EO in topical or spray formulations for the treatment of GRAM+ and C. albicans infections.

Larvicidal and adulticidal activity of irradiated Thuja orientalis essential oil by gamma radiation for controlling Culexpipiens

Culex pipiens mosquitoes are the primary vector of the West Nile virus worldwide and have a wide distribution. To avoid the development of resistance in insect pests to conventional synthetic pesticides, there have been many attempts to study botanical pesticides. The increasing resistance of insect pests to synthetic pesticides is a threat to the diversity of ecosystems, which makes the study of botanical pesticides all the more important. The study aimed to determine the efficacy of Thuja orientalis essential oil irradiated with 1, 3 and 5 KGy compared to unirradiated T. orientalis as larvicidal agents against the third instar larvae of C. pipiens using six different concentrations (15, 20, 25, 30, 35 and 40 ppm) and as an adulticidal agent against approximately three-day-old female adults 0.2, 0.4, 0.6, 1 and 2%. The results generally showed that the irradiated essential oil with 5 KGy had the highest efficacy by LC50 (20.16 ppm) followed by essential oil irradiated with 3 and 1 KGy (LC50, 23.16 and 26.00 ppm, respectively) compared to unirradiated ones (LC50, 27.28 ppm) after 24 h from the exposure for the third instar larvae. The knockdown effect for adults increased significantly with higher concentrations of the oil, across different exposure times ranging from 5 to 60 min. The time to knock down 100% of mosquito population to Thuja orientalis essential oils at the highest concentration 2% were 20 min at 0, 1, and 3 KGy and 10 min at 5 KGy. Our results indicate that gamma irradiation of T. orientalis fruit improves the efficacy of their essential oil against Culex pipiens and the irradiated oil could be successfully used for management of these insects. The head capsule, antenna, and the last abdominal segments of the 3rd instar larvae exposed to the essential oil of unirradiated or irradiated Thuja orientalis unripe were examined by the scanning electron microscope (SEM).

Enhancing black mulberry storage with sodium caseinate and gum tragacanth edible films

A bright future lies ahead for the application of natural biocomposites in the food industry. In this research, edible biocomposite films were created using sodium caseinate (SC)-gum tragacanth (GT) and incorporating carum carvi seed essential oil (EO) as a nanoemulsion. Different ratios of oil were used as variables. The physical properties, structural morphology, mechanical characteristics, and thermal behavior of the films were evaluated. Furthermore, the preservative effects of these edible films were studied to prolong the shelf life of black mulberries over a period of 10 days at 4 °C. The findings indicated that the increase of EO content to the edible films resulted in a significant increase in thickness, tensile strength, opacity and water vapor permeability. Conversely, the elongation at break, water solubility and moisture content decreased with the rise in oil content up to 3.9%. Also the visual appearance and sensory evaluation of the fruits revealed that black mulberries covered with edible films containing 2.6 and 3.9% oil were more preferred compared to the other groups. The integration of caraway oil into the SC-GT biocomposite has been investigated for the first time, demonstrating that the resulting films are effective in prolonging the shelf life of black mulberries.

Design of three-component essential oil extract mixture from Cymbopogon flexuosus, Carum carvi, and Acorus calamus with enhanced antioxidant activity

The development of novel antioxidant compounds with high efficacy and low toxicity is of utmost importance in the medicine and food industries. Moreover, with increasing concerns about the safety of synthetic components, scientists are beginning to search for natural sources of antioxidants, especially essential oils (EOs). The combination of EOs may produce a higher scavenging profile than a single oil due to better chemical diversity in the mixture. Therefore, this exploratory study aims to assess the antioxidant activity of three EOs extracted from Cymbopogon flexuosus, Carum carvi, and Acorus calamus in individual and combined forms using the augmented-simplex design methodology. The in vitro antioxidant assays were performed using DPPH and ABTS radical scavenging approaches. The results of the Chromatography Gas-Mass spectrometry (CG-MS) characterization showed that citral (29.62%) and niral (27.32%) are the main components for C. flexuosus, while D-carvone (62.09%) and D-limonene (29.58%) are the most dominant substances in C. carvi. By contrast, β-asarone (69.11%) was identified as the principal component of A. calamus (30.2%). The individual EO exhibits variable scavenging activities against ABTS and DPPH radicals. These effects were enhanced through the mixture of the three EOs. The optimal antioxidant formulation consisted of 20% C. flexuosus, 53% C. carvi, and 27% A. calamus for DPPHIC50. Whereas 17% C. flexuosus, 43% C. carvi, and 40% A. calamus is the best combination leading to the highest scavenging activity against ABTS radical. These findings suggest a new research avenue for EOs combinations to be developed as novel natural formulations useful in food and biopharmaceutical products.

Effect of gamma rays on the essential oil and biochemical characteristics of the Satureja mutica Fisch & C. A. Mey

There are 16 species in the genus Satureja L. (Lamiaceae), of which 10 are native. This research aimed to investigate the effect of gamma rays and storage conditions and duration on the percentage and components of the essential oil and some biochemical characteristics of Satureja mutica Fisch & C.A. Mey at the Research Institute of Forests and Rangelands. Plants were collected at the full flowering stage and exposed to different doses of gamma rays (0, 2.5, 5, 7.5, and 10 kGy) at the Atomic Energy Organization, Iran. The samples were kept in a refrigerator (4 °C) and in the shade (25 ± 2 °C) for 0, 120, and 240 h. This experiment was performed in a completely randomized design. Essential oil extraction was done by water distillation for 2 h. The composition of their essential oil components was identified using GC and GC/MS. Some biochemical traits, including phenol content, antioxidant capacity, and carbohydrate content, were measured. The results indicated that irradiation on the percentage of essential oil showed a statistically significant difference. In addition, the interaction effect of irradiation × storage conditions, irradiation × duration of storage, on the percentage of essential oil was significant. According to a comparison of the means, 2.5 kGy irradiation produced the highest percentage of essential oil (0.4%); in contrast, a significant decrease was detected in components with 7.5 and 10 kGy irradiation. It was observed that the percentage of some essential oil compounds decreased with the gamma-ray intensity increase. 2.5 kGy of gamma rays and shade storage conditions for 240 h led to the highest content of p-cymene and carvacrol. Nevertheless, the highest thymol content was obtained under refrigeration conditions without irradiation. The maximum phenol content and antioxidant capacity were obtained when the plants were irradiated with 2.5 and 7.5 kGy gamma rays. However, the maximum carbohydrate rate was observed in non-irradiated plants. It was concluded that low-intensity gamma rays could improve the percentage of essential oil and main components like p-cymene and carvacrol in S. mutica Fisch & C.A. Mey.

Comparative Amino Acid Profile and Antioxidant Activity in Sixteen Plant Extracts from Transylvania, Romania

In addition to the naturopathic medicines based on the antiseptic, anti-inflammatory, anticancer, or antioxidant properties of plant extracts that have been capitalized upon through the pharmaceutical industry, the increasing interest of the food industry in this area requires potent new materials capable of supporting this market. This study aimed to evaluate the in vitro amino acid contents and antioxidant activities of ethanolic extracts from sixteen plants. Our results show high accumulated amino acid contents, mainly of proline, glutamic, and aspartic acid. The most consistent values of essential amino acids were isolated from T. officinale, U. dioica, C. majus, A. annua, and M. spicata. The results of the 2,2-diphenyl-1-pycrylhydrazyl (DPPH) radical scavenging assay indicate that R. officinalis was the most potent antioxidant, followed by four other extracts (in decreasing order): T. serpyllum, C. monogyna, S. officinalis, and M. koenigii. The network and principal component analyses found four natural groupings between samples based on DPPH free radical scavenging activity content. Each plant extracts' antioxidant action was discussed based on similar results found in the literature, and a lower capacity was observed for most species. An overall ranking of the analyzed plant species can be accomplished due to the range of experimental methods. The literature review revealed that these natural antioxidants represent the best side-effect-free alternatives to synthetic additives, especially in the food processing industry.

Effect of gamma radiation on the protective efficacy of Thuja orientalis essential oil on stored cowpea against Callosobruchus maculatus and Callosobruchus chinensis

PURPOSE

Cowpea is an essential pulse food in several regions throughout the world. Essential oil isolated from Thuja orientalis unripe fruits exposed to gamma radiation at dose levels of 0, 1, 3 and 5 kGy was evaluated as cowpea seed protectant against Callosobruchus maculatus and Callosobruchus chinensis.

MATERIALS AND METHODS

Cowpea seeds were treated with three rates of the oils from non-irradiated and irradiated fruits, 0.5, 1.5 and 3.0 g kg-1. Mortality of C. maculatus and C. chinensis adults after 3 and 7 days, progeny reduction and weight loss of cowpea seeds after 45 days were recorded for all treatments.

RESULTS

The pronounced mortality of C. maculatus adults was achieved at the highest rate 3.0 g kg-1 of the irradiated oil with 5 kGy (98.3%). While in the case C. chinensis, all tested application rates induced marked adult mortality and a complete mortality (100%) resulted at two application rates (0.5 and 1.5 g kg-1) of irradiated oil with 5 kGy and 3.0 g kg-1 after 7 days. Strong progeny suppression of C. maculatus and C. chinensis was resulted at the highest rate of 3.0 g kg-1 of irradiated oil with 5 kGy (11.3 ± 0.3) and (8.5 ± 3.8) after 45 days of treatment, respectively. High protection of cowpea seeds with weight loss 0.5 and 1.4% for C. maculatus and C. chinensis was achieved at 3.0 g kg-1 of irradiated oil dose of 5 kGy, respectively after 45 days.

CONCLUSIONS

Our results indicate that gamma irradiation of T. orientalis fruits improve the protective activity of their essential oil against C. maculatus and C. chinensis on stored cowpea seeds and the irradiated oil could be successfully used for management of these bruchid insects.