ABSTRACT
The exploration of new bioactive compounds from natural resources as alternatives to synthetic chemicals has recently attracted the attention of scientists and researchers. To our knowledge, the essential oil (EO) of Kickxia aegyptiaca has not yet been explored. Thus, the present study was designed to explore the EO chemical profile of K. aegyptiaca for the first time, as well as evaluate its antioxidant and antibacterial activities, particularly the extracts of this plant that have been reported to possess various biological activities. The EO was extracted from the aerial parts via hydrodistillation and then characterized by gas chromatography-mass spectrometry (GC-MS). The extracted EO was tested for its antioxidant activity via the reduction in the free radicals, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). In addition, the EO was tested as an antibacterial mediator against eight Gram-negative and Gram-positive bacterial isolates. Forty-three compounds were identified in the EO of K. aegyptiaca, with a predominance of terpenoids (75.46%). Oxygenated compounds were the main class, with oxygenated sesquiterpenes attaining 40.42% of the EO total mass, while the oxygenated monoterpenes comprised 29.82%. The major compounds were cuminic aldehyde (21.99%), caryophyllene oxide (17.34%), hexahydrofarnesyl acetone (11.74%), ar-turmerone (8.51%), aromadendrene oxide (3.74%), and humulene epoxide (2.70%). According to the IC50 data, the K. aegyptiaca EO revealed considerable antioxidant activity, with IC50 values of 30.48 mg L-1 and 35.01 mg L-1 for DPPH and ABTS, respectively. In addition, the EO of K. aegyptiaca showed more substantial antibacterial activity against Gram-positive bacterial isolates compared to Gram-negative. Based on the minimum inhibitory concentration (MIC), the EO showed the highest activity against Escherichia coli and Bacillus cereus, with an MIC value of 0.031 mg mL-1. The present study showed, for the first time, that the EO of K. aegyptiaca has more oxygenated compounds with substantial antioxidant and antibacterial activities. This activity could be attributed to the effect of the main compounds, either singular or synergistic. Thus, further studies are recommended to characterize the major compounds, either alone or in combination as antioxidants or antimicrobial agents, and evaluate their biosafety.
ABSTRACT
(1) Background: The demand for healthy and nutritious food is growing worldwide. Fermented dairy products are highly valued by consumers for their health benefits. Kefir is a fermented dairy product that brings many benefits to the consumer due to its antioxidant, anticancer, antidiabetic, antihypertensive and antimicrobial properties. Extracts from various plants in the form of volatile oils have a beneficial efct on consumer health. Following the research, their antioxidant and antimicrobial activities were demonstrated. (2) Methods: In the present study, the main purpose was to obtain a fermented dairy product with a high nutritional value;therefore, kefir, enriched with three types of volatile oils, namely, volatile mint oil, volatile fennel oil and volatile lavender oil, was made. The kefir samples obtained were sensory and texturally analyzed. The beneficial effect on health must also be studied in terms of the acceptability of these products by consumers from a sensory point of view. A non-numerical method based on several multi-personal approval criteria was used to interpret the results obtained in the sensory analysis. In the textural analysis, the consistency, cohesiveness and firmness of the kefir samples were analyzed. (3) Results: The samples enriched with volatile oils obtained superior results compared to the control sample in both conducted examinations. Kefir samples with volatile oils retained their sensory and textural characteristics for a longer time during storage. (4) Conclusions: The volatile oils added to kefir positively influenced the sensory and textural characteristics of the finished product.
ABSTRACT
Oral doses of certain essential oils may reduce symptoms of acute respiratory infections of viral origin. It is likely that the commercially available essential oil capsules Myrtol® (a mixture of essential oils of eucalyptus Eucalyptus globulus, sweet orange Citrus sinensis, myrtle Myrtus communis and lemon Citrus limonum) and Tavipec® (spike lavender Lavandula latifolia) could also provide mild to moderate symptom relief in patients with viral respiratory diseases. Myrtol® may also improve the course (duration and severity) of acute bronchitis of viral origin, in humans. Both products were well tolerated, with most of the mild to moderate side-effects affecting the gastrointestinal tract. This review found no research evidence describing the clinical effect of inhalation of essential oils for acute respiratory viral infections.
Clinical evidence from published clinical trials identified in this rapid review suggests that oral administration of blends of certain essential oils (EO) can reduce symptoms of acute respiratory infections of viral origin in humans, namely acute sinusitis and acute bronchitis.There is clinical evidence for orally administered Lavandula latifolia essential oil (Tavipec®) (n = 2) and a blend of essential oils of Eucalyptus globulus, Citrus sinensis, Myrtus communis and lemon Citrus limonum (Myrtol® and its successors GeloMyrtol® and GeloMyrtol®Forte) (n = 3) to reduce symptoms of acute sinusitis and acute bronchitis of viral origin(s) [[1], [2], [3], [4], [5]]. All five clinical trials relied mostly on (subjective) symptom scores to determine the treatment effect. Differences between treatment and placebo symptom scores in these clinical trials were statistically significant, although the differences in absolute numbers were small. Furthermore, clinical evidence suggests that Myrtol® is also able to improve the course (duration and severity) of acute bronchitis of viral origin, in humans [3,5].No clinical evidence was found on whether EO can also improve symptoms and/or course of other acute respiratory infections, like influenza or acute respiratory distress syndrome caused by viruses of the coronavirus class. Further clinical trials with these and other EO (or blends of EO), and other administration forms, like steam inhalation or personal inhalers, are warranted to further elucidate the potential of commonly available EOs in treating acute respiratory infections of viral origin, especially influenza and COVID-19.