Antioxidant and anti-inflammatory activities of essential oils: a short review

Chemical analysis and biological activities of Cupressus sempervirens var. horizontalis essential oils

CONTEXT

Safe and effective antioxidants are regarded as a cornerstone for the prevention and treatment of several types of disorders.

OBJECTIVE

The present study aimed to investigate the antioxidant and anti-glycation properties of branchlet and fruit oils of Cupressus sempervirens L. var. horizontalis (Mill.) Gord. (Cupressaceae).

MATERIALS AND METHODS

Essential oils were extracted from the branchlets and fruits of C. sempervirens var. horizontalis using the steam distillation method. A gas chromatography-mass spectrometry method was employed for the compositional analysis of essential oils. In order to evaluate antioxidant activities of oils at different concentrations (180, 220 and 260 μg mL(-1)), linoleic acid peroxidation test and peroxyl radical mediated hemolysis of red blood cells (RBC) assay were used. Linoleic acid peroxidation was monitored for 4 h and determined during each hour of incubation. Antiglycation effects of oils at 200, 400 and 600 μg mL(-1) were assessed using hemoglobin and insulin glycation assays.

RESULTS

Overall, 10 volatile components were identified, amounting for 88.2 and 93.2% of branchlet and fruit oils, respectively. α-Pinene and δ-3-carene were major components of both branchlet (46.2 and 22.7%) and fruit (59.2 and 14.9%) oils. Hemoglobin glycation was inhibited by both branchlet (44.8, 62.6 and 54.0% at 200, 400 and 600 μg mL(-1), respectively) and fruit (41.0, 62.8 and 48.5%) oils. As for the insulin glycation, inhibitory rates were 66.1, 69.2 and 73.8% for branchlet oil, and 80.0, 76.9 and 81.5% for fruit oil (at 200, 400 and 600 μg mL(-1), respectively). RBC hemolysis was also inhibited by both branchlet (49.9, 38.5 and 15.0% at 180, 220 and 260 μg mL(-1), respectively) and fruit (45.9, 38.6 and 25.0%) oil. Finally, the oils mitigated linoleic acid peroxidation which was peaked after 4 h for both branchlet (39.5, 35.6 and 53.4% at 180, 220 and 260 μg mL(-1), respectively) and fruit (47.5, 58.6 and 59.8%) oil.

CONCLUSIONS

The present findings suggest that essential oils obtained from the branchlets and fruits of C. sempervirens var. horizontalis possess antioxidant and, in particular, antiglycation properties. These activities may find implication in the prevention of diabetic and cardiovascular complications. However, further investigations are required to justify the traditional medical applications of the plant.

A review on anti-inflammatory activity of monoterpenes

Faced with the need to find new anti-inflammatory agents, great effort has been expended on the development of drugs for the treatment of inflammation. This disorder reduces the quality of life and overall average productivity, causing huge financial losses. In this review the anti-inflammatory activity of 32 bioactive monoterpenes found in essential oils is discussed. The data demonstrate the pharmacological potential of this group of natural chemicals to act as anti-inflammatory drugs.

Methods for the evaluation of the protective efficacy of sunscreen products

The objective of the present investigation was to examine the utilization of optical and spectroscopic methods for the noninvasive characterization of Anthelios XL Fluide Extreme (SPF 50+), an exemplary sunscreen, concerning its homogeneity of distribution on the skin, its spectroscopic properties and its overall protective efficacy. The homogeneity of the distribution of the sunscreen on the skin was investigated with a multiphoton tomography microscope. Additionally, the sum transmission spectrum was determined using tape stripping and spectroscopic measurements. The results revealed a very homogeneous distribution of the sunscreen on the skin surface and also in the deep furrows. The sum transmission spectrum reflects a high protective efficacy of the sunscreen in both the UVA and UVB ranges. The sunscreen Anthelios XL Fluide Extreme (SPF 50+) generates a comfortable feeling on the skin and can be easily distributed. The presented optical methods have been shown to be suitable to investigate the overall protective efficacy of sunscreen products objectively, noninvasively and quickly.

Corn silk (Stigma maydis) in healthcare: a phytochemical and pharmacological review

Corn silk (Stigma maydis) is an important herb used traditionally by the Chinese, and Native Americans to treat many diseases. It is also used as traditional medicine in many parts of the world such as Turkey, United States and France. Its potential antioxidant and healthcare applications as diuretic agent, in hyperglycemia reduction, as anti-depressant and anti-fatigue use have been claimed in several reports. Other uses of corn silk include teas and supplements to treat urinary related problems. The potential use is very much related to its properties and mechanism of action of its plant's bioactive constituents such as flavonoids and terpenoids. As such, this review will cover the research findings on the potential applications of corn silk in healthcare which include its phytochemical and pharmacological activities. In addition, the botanical description and its toxicological studies are also included.

Anti-acetylcholinesterase and antioxidant activity of essential oils from Hedychium gardnerianum Sheppard ex Ker-Gawl

Acetylcholinesterase inhibition, antioxidant and cytotoxic activities of Hedychium gardnerianum leaf essential oils from S. Miguel Island were determined. All the oils inhibited acetylcholinesterase, with IC₅₀ values of approximately 1 mg/mL, showing no statistical differences between collection sites. Three oils presented mixed inhibition, whilst one was almost truly competitive. This activity can be attributed to the presence of sesquiterpenes, which constituted more than 60% of the composition of the oils. Regarding the antioxidant activity as measured by the DPPH method, all the oils presented activities similar to reference compounds, although with statistical differences between collection sites. Cytotoxicity measured using Artemia salina classified these oils as moderately toxic, with LC₅₀ values ranging from 300 to 500 µg/mL. These results indicate a possible application of these oils in aromatherapy as coadjuvants in the treatment of cognitive diseases such as Alzheimer, since they may contribute to increase acetylcholine in cholinergic neurons and simultaneously fight deleterious oxidations responsible by neurological degeneration.

Coping with antibiotic resistance: combining nanoparticles with antibiotics and other antimicrobial agents

The worldwide escalation of bacterial resistance to conventional medical antibiotics is a serious concern for modern medicine. High prevalence of multidrug-resistant bacteria among bacteria-based infections decreases effectiveness of current treatments and causes thousands of deaths. New improvements in present methods and novel strategies are urgently needed to cope with this problem. Owing to their antibacterial activities, metallic nanoparticles represent an effective solution for overcoming bacterial resistance. However, metallic nanoparticles are toxic, which causes restrictions in their use. Recent studies have shown that combining nanoparticles with antibiotics not only reduces the toxicity of both agents towards human cells by decreasing the requirement for high dosages but also enhances their bactericidal properties. Combining antibiotics with nanoparticles also restores their ability to destroy bacteria that have acquired resistance to them. Furthermore, nanoparticles tagged with antibiotics have been shown to increase the concentration of antibiotics at the site of bacterium-antibiotic interaction, and to facilitate binding of antibiotics to bacteria. Likewise, combining nanoparticles with antimicrobial peptides and essential oils generates genuine synergy against bacterial resistance. In this article, we aim to summarize recent studies on interactions between nanoparticles and antibiotics, as well as other antibacterial agents to formulate new prospects for future studies. Based on the promising data that demonstrated the synergistic effects of antimicrobial agents with nanoparticles, we believe that this combination is a potential candidate for more research into treatments for antibiotic-resistant bacteria.

Chemical compositions and anti-influenza activities of essential oils from Mosla dianthera

ETHNOPHARMACOLOGICAL RELEVANCE

Mosla dianthera as an aromatic herb is used in folk medicine for the treatment of cough, colds, fever, bronchitis, nasal congestion and headache.

AIM OF THE STUDY

To characterize chemical compositions and to evaluate the anti-influenza effects of essential oils of M. dianthera (MDEO) in influenza virus A (IVA) infected mice.

MATERIALS AND METHODS

MDEO was obtained by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC-MS). ICR mice were treated with MDEO for 5 consecutive days at doses of 90-360 mg/kg after post-infected. Levels of Serum IL-4 and IFN-γ were assayed by ELISA. Levels of MOD, SOD, TAOC and GSH-Px in lung tissue were determined by colorimetric method.

RESULTS

GC-MS analysis revealed the presence of 29 components that account for 97.74% of phenolic sesquiterpenes and aromatic compounds. The major compounds were elemicin (16.51%), thymol (14.77%), β-caryophyllene (14.49%), iso-elemicin (9.22%), asarone (6.09%) and α-caryophyllene (5.26%). It had significant effects on decreasing lung viral titers, inhibiting pneumonia, reducing levels of serum IFN-γ and IL-4, and enhancing antioxidant activity in the lung tissue of IVA infected mice.

CONCLUSIONS

MPE could exhibit therapeutical effects in IVA infected mice as a suppressor of IVA replication and inflammatory mediators and a promoter of antioxidant potentials. Therefore, MDEO could provide a safe and effective therapeutic candidate for treatment of influenza and its subsequent viral pneumonia.

Anti-inflammatory Activity of Pistacia lentiscus Essential Oil: Involvement of IL-6 and TNF-α

The topical anti-inflammatory activity of essential oil of Pistacia lentiscus L. was studied using carrageenan induced rat paw edema and cotton pellet induced granuloma. The effect on serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in rats inserted with cotton pellet was also investigated. On topical application, the oil exhibited a significant decrease in paw edema. The oil also inhibited cotton pellet-induced granuloma, and reduced serum TNF-α and IL-6. It can be concluded that the essential oil of Pistacia lentiscus reduces leukocyte migration to the damaged tissue and exhibits anti-inflammatory activity.

Antioxidant and antiacetylcholinesterase activities of some commercial essential oils and their major compounds

The commercial essential oils of Citrus aurantium L., Cupressus sempervirens L., Eucalyptus globulus Labill., Foeniculum vulgare Mill. and Thymus vulgaris L., isolated by steam distillation by a company of Morocco were evaluated in terms of in vitro antioxidant activity through several methods. In vitro acetylcholinesterase inhibitory activity was also determined. Citrus limon (L.) Burm. f. oil was also studied, but it was obtained by peel expression. The best antioxidant was T. vulgaris oil, independent of the method used, mainly due to the presence of the phenolic monoterpenes thymol and carvacrol, which when studied as single compounds also presented the best activities. Concerning the acetylcholinesterase inhibition activity, E. globulus was the most effective. Nevertheless its main components 1,8-cineole and limonene were not the most active, a feature that corresponded to δ-3-carene.