3'-Demethoxy-6-O-Demethylisoguaiacin and Norisoguaiacin Nematocidal Lignans from Artemisia cina against Haemonchus contortus Infective Larvae

Artemisia cina is a plant used in traditional Chinese medicine as a remedy for parasitic diseases. This study describes the isolation and chemical characterization of anthelmintic compounds of A. cina against Haemonchus contortus infective larvae (L₃) through lethal testing. Previously, three extracts-n-hexane (HexAc), ethyl acetate (EtOAc) and methanol (MeOAc)-were evaluated at concentrations of 4 to 0.5 mg/mL, resulting in the HexAc extract with the greatest effect of 76.6% mortality of the larvae at 4 mg/mL. Then, this was chemically fractioned by polarity, obtaining seven fractions (C1F1-C1F7), and, when evaluated at concentrations from 2 to 0.25 mg/mL, the 2 mg/mL C1F5 fraction produced an effect against the nematode H. contortus of 100% mortality of the larvae. Thus, this fraction was fractionated again by column chromatography, obtaining twelve subfractions (C2F1-C2F12) which were evaluated from 1 to 0.125 mg/mL, with the C2F5 subfraction causing a nematicidal effect of 100% mortality. NMR analysis of one (¹H, ¹³C and DEPT) and two dimensions (COSY, HSQC and HMBC) and mass spectrometry of this fraction allowed us to identify the mixture of 3'-demethoxy-6-O-demethylisoguaiacin and norisoguaiacin. Therefore, it can be assumed that the mixture of these compounds is responsible for the anthelmintic effect. These results indicate that A. cina containing anthelmintic compounds and might be used as an antiparasitic drug against H. contortus.

An Artemisia cina n-hexane extract reduces the Haemonchus contortus and Teladorsagia circumcincta fecal egg count in naturally infected periparturient goats

The objective of this study was to evaluate an n-hexane extract of Artemisia cina (Acn-h) as a natural anthelmintic treatment for periparturient goats naturally infected with the nematodes Haemonchus contortus and Teladorsagia circumcincta. A total of 200 periparturient Alpine and Nubian goats were used. Deworming criteria were based on the following parameters: fecal egg account (epg), ocular mucosa color (OMC), and body condition (BC). A previous analysis using coprocultures of the flock revealed the presence of H. contortus (80%) and T. circumcincta (20%). The Acn-h contained two new compounds identified by mass spectrometry data as isoguaiacin and norisoguaiacin at 284.14 and 315 m/z. The lethal effects of Acn-h at 0.5, 1, 2, and 4 mg/mL on H. contortus adult stages were 31.6, 66.5, 81.3, and 86.9%, respectively (p < 0.05), showing similar efficacy at 2 and 4 mg/mL with albendazole (positive control group). Then, two experimental groups, with 100 goats in peripartum in each, were distributed randomly and treated at day 0 as follows: group 1 = 4 mg/kg of Acn-h as single oral dose, and group 2 = control group, treated with water (as a placebo). The epg, OMC, and BC parameters were recorded at 0 (periparturient period), 7 (birth period), and 23 (postpartum) days and analyzed using a completely randomized design with Duncan's test for comparison of means and analysis of variance. The following epg reductions were recorded in the Acn-h-treated group as follows: 20.1 ± 34.4 and 31.7 ± 38.2% at days 7 and 23 compared to the control group. During the whole experiment, no significant differences in OMC or BC were observed in relation to the control group, excepting at day 23 (p < 0.05) for BC in the group treated with A. cina. Thus, Acn-h can be a useful natural alternative tool for the control of the nematodes H. contortus and T. circumcincta in periparturient goat flocks.

In Vitro Nematocidal Effect and Anthelmintic Activity of Artemisia cina Against Haemonchus contortus in Gerbils and Relative Expression of Hc29 Gene in Transitional Larvae (L3-L4)

PURPOSE

(1) To assess the in vitro activity of Artemisia cina against Haemonchus contortus L₃ (HcL₃) and in transitional (L₃-L₄) larvae (HcTrL₃-L₄); (2) to quantify the relative expression of the Hc29 gene in HcTrL₃-L₄ exposed to the A. cina n-hexane extract; and (3) to assess the anthelmintic activity (AA) of the A. cina organic extracts in gerbils artificially infected with H. contortus (HcArt/inf/gerbs).

METHODS

The in vitro assay was carried out in 96-well microtitration plates. The following A. cina extracts: ethyl acetate (Ac-EtOAcEx), n-hexane (Ac-n-HexEx), and methanol (Ac-MethEx) were assessed at 1 and 2 mg/mL against HcL₃ and HcTrL₃-L₄ at 24 h exposure. Relative expression of the Hc29 gene in HcTrL₃-L₄ was obtained by RT-PCR. For assessing the AA, six groups of five HcArt/inf/gerbs were used. Groups were treated orally with 4 mg/kg BW of A. cina extracts. Five days after treatment, the gerbils were necropsied and nematodes counted.

RESULTS

The highest in vitro activities (75 and 82.6%) were shown by Ac-n-HexEx at 1 and 2 mg/mL, respectively. For HcTrL₃-L₄ the highest in vitro activities (69 and 23%) were shown by Ac-n-HexEx and isoguaiacine at 0.625 mg/mL, respectively. Also, upregulation of H. contortus Hc29 gene by 13- and 80-fold (p < 0.01) was observed on the HcTrL₃-L₄ stage after exposure to Ac-n-HexEx extract and isoguaiacine at 0.078 mg/mL, respectively. Reduction percentage was 100% in HcArt/inf/gerbs treated with Ac-n-HexEx.

CONCLUSIONS

We conclude that the Ac-n-HexEx and isoguaiacine compound had anthelmintic efficacy against H. contortus and L₃ and HcTrL₃-L₄.

Pharmacological Evaluation of Artemisia cina Crude CO2 Subcritical Extract after the Removal of Santonin by Means of High Speed Countercurrent Chromatography

Artemisia species are highly important due to their economic significance as medicines, fodder and food. Artemisia cina is an endemic species to Kazakhstan. In folk medicine, water extract of A. cina was used in the treatment of bronchial asthma while the alcohol extract has larvicidal and antituberculosis activity. The most common and most extensively studied compound from this species is the terpenoid santonin. The toxicity of this compound occurs at the doses of 60 mg for children and 200 mg for adults causing among other issues xanthopsia, leading to blindness. Having this in mind, the main idea of this work was to remove santonin from the crude extract and to check if the santonin-free extract would still be of any pharmacological importance. A CO₂ subcritical extract was chromatographed using high-speed countercurrent chromatography (HSCCC) for the removal of santonin. The santonin-free CO₂ subcritical extract (SFCO₂E) as well as the isolated compound pectolinarigenin, a flavonoid, were assessed for their pharmacological actions. From the results obtained we can safely suggest that HSCCC is an efficient methodology to completely remove santonin from the CO₂ subcritical extract. It was also possible to observe promising antinociceptive and anti–inflammatory activities for both SFCO₂E and pectolinarigenin at concentrations that can justify the production of a phytomedicine with this endemic plant from Kazakhstan.