Analgesic and antiinflammatory activities of the essential oil from Artemisia sieberi Besser

In Vitro Anti-Inflammatory Activity of Cotula anthemoides Essential Oil and In Silico Molecular Docking of Its Bioactives

The genus Cotula (Asteraceae) comprises about 80 species, amongst them Cotula anthemoides L. It is a wild plant growing in Egypt that possesses many traditional uses as a headache, colic, and chest cold remedy. In our study, the chemical composition of C. anthemoides essential oils was analyzed using GC-MS spectroscopy. Sixteen components of leave and stem oils and thirteen components of flower oils were characterized. The main components in both essential oil parts were camphor (88.79% and 86.45%) and trans-thujone (5.14% and 10.40%) in the leaves and stems and the flowers, respectively. The anti-inflammatory activity of the oils in lipopolysaccharide-stimulated RAW 264.7 macrophage cells was evaluated. The flower oil showed its predominant effect in the amelioration of proinflammatory cytokines and tumor necrosis factor-α, as well as cyclooxygenase-2. The bornyl acetate showed the highest affinity for the cyclooxygenase-2 receptor, while compound cis-p-menth-2-ene-1-ol had the best affinity for the tumor necrosis factor receptor, according to the results of molecular docking. In addition, the molecule cis-β-farnesene showed promising dual affinity for both studied receptors. Our findings show that essential oils from C. anthemoides have anti-inflammatory properties through their control over the generation of inflammatory mediators. These findings suggest that C. anthemoides essential oils could lead to the discovery of novel sources of anti-inflammatory treatments.

Total phenolic, flavonoid contents, and biological activities of stem extracts of Astragalus spinosus (Forssk.) Muschl. grown in Northern Border Province, Saudi Arabia

Background and objective

Genus Astragalus belongs to the family Fabaceae and is one among the largest genera consisting of around 3000 species. The plants have been used traditionally in treatment of various ailments in folklore. The study was planned to assess the analgesic and inflammatory activity of Astragulus spinosus (Forssk.) Muschl extract of the stem.

Materials and methods

Course powder of stems of Astragulus spinosus was extracted using chloroform and methanol as solvents. Folin ciocalteu method was employed for determination of the phenolic acid content. Aluminum chloride colorimetric procedure was followed for estimating the flavonoid content. Both chloroform and methanolic extracts at 250 and 500 mg/kg, were tested for the analgesic activity, however, only methanolic extract was selected for anti-inflammatory property based on the results of analgesic activity. The analgesic effect was executed on male rats by the hot plate model. The anti-inflammatory effect was studied in the carrageenan rat paw edema model. The experimental information was interpreted statistically using one-way ANOVA and p < 0.05 was used to express importance of the results.

Results

The total phenolics of the methanol extract was 420 µg and that of chloroform extract was 265 µgwhile total flavonoid content in terms of quercetin was found to be 68 µg and 17.5 µg for methanol and chloroform extract respectively. Only methanolic extract exhibited significant (p < 0.001) analgesic activity by elevating the pain threshold starting from 15 min. The methanolic extract inhibited (p < 0.001) the edema in carrageenan induced model. The performance of higher dose (500 mg/kg) was better with reference to lower dose (250 mg/kg).

Conclusion

Outcome of the results show that the methanolic stem extracts exhibited significant analgesic and anti-inflammatory-like activity with reference to chloroform extract. Credit of which is given to flavonoids and phenolic content present in the methanolic extract. However, more research is suggested to establish the safety and effectiveness of the herbal drug to manage diseased states including pain and inflammation.

Supercritical fluid extraction of four aromatic herbs and assessment of the volatile compositions, bioactive compounds, antibacterial, and anti-biofilm activity

Artemisia arborescens, Artemisia abyssinica, Pulicaria jaubertii, and Pulicaria petiolaris are fragrant herbs traditionally used in medication and as a food seasoning. To date, there are no studies on the use of supercritical fluids extraction with carbon dioxide (SFE-CO₂) on these plants. This study evaluates and compares total phenolic content (TPC), antioxidant activity by DPPH^• and ABTS^•+, antibacterial, and anti-biofilm activities of SFE-CO₂ extracts. Extraction was done by SFE-CO₂ with 10% ethanol as a co-solvent. A. abyssinica extract had the highest extraction yield (8.9% ± 0.41). The GC/MS analysis of volatile compounds identified 307, 265, 213, and 201compounds in A. abyssinica, A. arborescens, P. jaubertii, and P. petiolaris, respectively. The P. jaubertii extract had the highest TPC (662.46 ± 50.93 mg gallic acid equivalent/g dry extract), antioxidant activity (58.98% ± 0.20), and antioxidant capacity (71.78 ± 1.84 mg Trolox equivalent/g dry extract). The A. abyssinica and P. jaubertii extracts had significantly higher antimicrobial activity and were more effective against Gram-positive bacteria. B. subtilis was the most sensitive bacterium. P. aeruginosa was the most resistant bacterium. P. jaubertii extract had the optimum MIC and MBC (0.4 mg/ml) against B. subtilis. All SFE-CO₂ extracts were effective as an anti-biofilm formation for all tested bacteria at 1/2 MIC. Meanwhile, P. jaubertii and P. petiolaris extracts were effective anti-biofilm for most tested bacteria at 1/16 MIC. Overall, the results indicated that the SFE-CO₂ extracts of these plants are good sources of TPC, antioxidants, and antibacterial, and they have promising applications in the industrial fields.

Efficacy of Essential Oils in Pain: A Systematic Review and Meta-Analysis of Preclinical Evidence

Background: The demand for essential oils (EOs) has been steadily growing over the years. This is mirrored by a substantial increase in research concerned with EOs also in the field of inflammatory and neuropathic pain. The purpose of this present systematic review and meta-analysis is to investigate the preclinical evidence in favor of the working hypothesis of the analgesic properties of EOs, elucidating whether there is a consistent rational basis for translation into clinical settings.

Methods: A literature search has been conducted on databases relevant for medical scientific literature, i.e., PubMed/MEDLINE, Scopus, and Web of Science from database inception until November 2, 2020, following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) criteria for systematic reviews and meta-analyses.

Results: The search was conducted in order to answer the following PICOS (participants/population, interventions, comparisons, outcomes, and study design) question: are EOs efficacious in reducing acute nociceptive pain and/or neuropathic pain in mice experimental models? The search retrieved 2,491 records, leaving 954 studies to screen after the removal of duplicates. The title and abstract of all 954 studies were screened, which left 127 records to evaluate in full text. Of these, 30 articles were eligible for inclusion.

Conclusion: Most studies (27) assessed the analgesic properties of EOs on acute nociceptive pain models, e.g. the acetic acid writhings test, the formalin test, and the hot plate test. Unfortunately, efficacy in neuropathic pain models, which are a more suitable model for human conditions of chronic pain, had fewer results (only three studies). Moreover, some methodologies raised concerns in terms of the risk of bias. Therefore, EOs with proven efficacy in both types of pain were corroborated by methodologically consistent studies, like the EO of bergamot, which should be studied in clinical trials to enhance the translational impact of preclinical modeling on clinical pain research.