Eleutherococcus senticosus (Araliaceae) Leaf Morpho-Anatomy, Essential Oil Composition, and Its Biological Activity Against Aedes aegypti (Diptera: Culicidae)

Abstract

The roots of Eleutherococcus senticosus (Rupr. & Maxim.) Maxim., a well-known medicinal plant from Eastern Asia, are used worldwide for their known beneficial medicinal properties. Recently, the leaves have been used as an alternative to the roots. The present study was aimed at exploring the leaf essential oil as a potential source of compounds for mosquito management. Gas chromatography/mass spectrometry analysis of the leaf essential oil revealed 87 compounds, constituting 95.2% of the oil. α-Bisabolol (26.46%), β-caryophyllene (7.45%), germacrene D (6.87%), β-bisabolene (4.95%), and α-humulene (3.50%) were five of the major constituents. The essential oil was subjected to biting deterrence and repellent activity against mosquito Aedes aegypti. The biting deterrence of the oil produced a proportion not biting (PNB) value of 0.62 at 10 µg/cm2 as compared with 0.86 of control DEET (N,N-diethyl-3-methylbenzamide) at a standard dose of 25 nmol/cm2. Among individually selected compounds present in the oil (α-bisabolol, β-caryophyllene, α-humulene, and caryophyllene oxide), only α-bisabolol produced a PNB value of 0.80, equivalent to DEET at 25 nmol/cm2, whereas the others were not repellent. The artificial mixture (AMES-1) of these four selected compounds produced a relatively high PNB value of 0.80. The repellent activity measured by minimum effective dosage (MED) for α-bisabolol and α-humulene produced MED values of 0.094 and 0.104 mg/cm2, respectively, as compared with 0.023 mg/cm2 of DEET. The leaf essential oil, the artificial mixture (AMES-1), and other binary and tertiary combinations of major compounds showed no repellent activity. In addition, morpho-anatomical features of the leaf are provided for correct identification of the species.

Root growth of Eleuthero (Eleutherococcus senticosus [Rupr. & Maxim.] Maxim.) seedlings cultured with chitosan oligosaccharide addition under different light spectra

“…Therefore, taking seedlings as materials, Eleuthero was more sensitive to light spectra in root growth than most of the tree species in current studies. Because root is one of the main organs with abundant pharmacological compounds for Eleuthero seedlings (Sun et al, 2011;Zhai et al, 2017), the LED lighting with the spectrum of 43.8%R/47%G/9.2%B can be considered for use with the purpose of promoting fine root elongation in this species.…”

“…Eleuthero naturally distributes as a long-lived shrub in broad-leaved and mixed broadleaf-conifer forests. Underground organs of Eleuthero contain multiple antioxidants and pharmacological ingredients (Zhai et al, 2017). However, the over-exploitation of Eleuthero has almost wiped out its natural reserves in Northeast China (Zhai et al, 2017).…”

“…Underground organs of Eleuthero contain multiple antioxidants and pharmacological ingredients (Zhai et al, 2017). However, the over-exploitation of Eleuthero has almost wiped out its natural reserves in Northeast China (Zhai et al, 2017). Climate change has also contributed to the shift and decline of its natural distribution (Wan et al, 2016;Guo et al, 2019).…”

Pharmacological effects of Eleutherococcus senticosus on the neurological disorders

“…Its leaves have hairy veins and 6 or 7 pairs of secondary veins; the upper surface of the leaflet is rough, dark green, with coarse hairs on the veins, while the lower is light green and the veins are short and soft. Its petioles attain 3–10 cm and are finely prickly, while the petiole of a leaflet (0.60–1.22 cm) usually has brownish pubescence (Zhai et al, 2017). Its solitary or 2–6 umbels together form an organized panicle, inflorescence terminal, 2–4 cm in diameter.…”

Characterization of botanical origin of selected popular purple Eleutherococcus tea grown in Yunnan province of China and quantification of Its anthocyanins using spectrophotometric method

“…Maxim. However, morphologically characteristic (Figure 1) showed purple Eleutherococcus had branches glabrous, usually with a coarsely recurved spine, while Eleutherococcus senticosus had branches with dense to scattered, slensder, terete, bristlelike prichles (http:// www.iplant.cn/frps) (Zhai et al, 2017). Therefore, the origin of purple Eleutherococcus still needs to be further determined.…”