(Caprifoliaceae) essential oil

This work aimed to investigate the chemical composition, antioxidant activity, antinociceptive effect, and wound healing activity of the Lonicera caprifolium L. flower essential oil (LCEO). Linalool (16.42%), d-limonene (9.99%), and α-cadinol (10.65%) were the most prevalent components of the LCEO. The LCEO revealed moderate DPPH and ABTS radical-scavenging activity. LCEO exhibited potent antinociceptive activity in acetic acid-induced writhing and hot plate-induced pain model; LCEO reduced 73.88 ± 2.78% of writhing and significantly increased pain withdrawal latency in the mice, respectively. The LCEO also presented a potent wound healing effect, with 98.08 ± 1.37% wound closure on the 12th day of treatment. The results of the study demonstrate antioxidant and wound healing potential with antinociceptive effect. To the best of our knowledge, this is the first report on the bioactivities of L. caprifolium L. essential oil.

The Antioxidant and Prebiotic Activities of Mixtures Honey/Biomimetic NaDES and Polyphenols Show Differences between Honeysuckle and Raspberry Extracts

In our previous research, we demonstrated that honey and its biomimetic natural deep eutectic solvent (NaDES) modulate the antioxidant activity (AOA) of the raspberry extract (RE). In this study, we evaluated the AOA behaviour of the mixture honey/NaDES-honeysuckle (Lonicera caprifolium, LFL) extract and compared it with the mixture honey/NaDES-RE. These two extracts have similar major flavonoids and hydroxycinnamic acid compounds but differ in their total content and the presence of anthocyanins in RE. Therefore, it was of interest to see if the modulation of the LFL polyphenols by honey/NaDES was similar to that of RE. We also evaluated the prebiotic activity of these mixtures and individual components on Limosilactobacillus reuteri DSM 20016. Although honey/NaDES modulated the AOA of both extracts, from synergism to antagonism, the modulation was different between the two extracts for some AOA activities. Honey/NaDES mixtures enriched with LFL and RE did not show significant differences in bacterial growth stimulation. However, at a concentration of 45 mg/mL, the honey -LFL mixture exhibited a higher effect compared to the honey-RE mixture. The antioxidant and prebiotic properties of mixtures between honey and polyphenol-rich extracts are determined by multiple interactions in complex chemical systems.

Honeysuckle essential oil as a potential source of ecofriendly larvicides for mosquito control

BACKGROUND

Some plant essential oils have insecticidal properties against mosquitoes and can be harnessed as ecofriendly tools for mosquito control. We conducted bioassays to determine the toxicity of Italian honeysuckle (Lonicera caprifolium) essential oil and its fractions against larvae of the yellow fever mosquito, Aedes aegypti.

RESULTS

Sixteen constituents were identified in honeysuckle essential oil compared to 15, 15, 15, and 11 constituents in fractions A, B, C, and E, respectively. The chemical constituents for fraction D were not determined due to lack of enough fraction sample. The two major constituents identified were patchouli alcohol (29.3%) and 6-acetyl-1,1,2,4,4,7-hexamethyltetralin (20.6%) in whole essential oil, alpha-bulnesene (27.6%) and 6-acetyl-1,1,2,4,4,7-hexamethyltetralin (23.2%) in fraction A, unknown chemical (47.3%) and diethyl phthalate (19.5%) in fraction B, unknown chemical (38.3%) and diethyl phthalate (23.2%) in fraction C, and patchouli alcohol (58.7%) and diethyl phthalate (20.5%) in fraction E. The LC₅₀ for whole essential oil was 34.4 ppm and significantly higher than 20.6, 19.7, 18.6, and 17.7 ppm for fractions B, C, D, and E, respectively. In contrast, fraction A was inactive. At 50 ppm, all individual constituents tested were less toxic than the whole essential oil with exception of patchouli alcohol, which caused 100% mortality.

CONCLUSION

These findings suggest that patchouli alcohol is one of the chemical constituents responsible for bioactivity of honeysuckle essential oil and some of its fractions. The findings also demonstrate that honey suckle essential oil and its fractions can be exploited as a source of ecofriendly larvicides for mosquito control. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.