Bisbenzylisoquinoline Alkaloids of Cissampelos Sympodialis With in Vitro Antiviral Activity Against Zika Virus.

In search of new antiviral compounds against Zika virus we conducted a bioassay-guided fractionation of bisbenzyilisoquinoline alkaloids isolated from Cissampelos sympodialis (Menispermaceae), a medicinal plant species endemic to Brazil. Six subfractions were obtained from a tertiary alkaloidal fraction of the rhizomes (TAFrz) using preparative high-performance liquid chromatography. All the subfractions were tested against Zika virus-infected Vero cells as the cellular model to evaluate cytotoxicity and antiviral effective concentrations. The results showed that three of the six TAFrz subfractions tested were active. The most active ones were the subfraction 6 (that consisted of the alkaloids methylwarifteine and warifteine present as a mixture at a ratio of 8.8:1.2 respectively) and the subfraction 5, that was later identified as warifteine, the major tertiary alkaloid of this species. Warifteine was able to significantly reduce virus titer in Zika virus-infected Vero cells with an IC50 of 2.2 µg/ml and this effect was selective (selectivity index, SI = 68.3). Subfraction 6 had an IC50 = 3.5 µg/ml and was more cytotoxic than pure warifteine, with SI = 6.14. Fraction 5 and fraction 6 were more potent in decreasing the viral titer of Zika virus-infected Vero cells than 6-methylmercaptopurine riboside (IC50 = 24.5 µg/ml and SI = 11.9), a mercaptopurine riboside with ZIKV antiviral activity used as a positive control. Our data demonstrate that alkaloids of the bisbenzylisoquinoline type may be explored as new antiviral agents or as an useful pharmacophore for investigating ZIKV antiviral activity.

Bisbenzylisoquinoline alkaloids of Cissampelos sympodialis with antiviral activity against dengue virus.

A number of bisbenzyilisoquinoline alkaloids have been previously isolated from Cissampelos sympodialis (Menispermaceae). The tertiary alkaloid fraction of the rhizomes (TAFrz) was prepared and the major alkaloid warifteine was isolated. Five TAFrz subfractions in addition to warifteine were tested against Dengue virus (DENV). We then used an epithelial (Vero) cell line to evaluate the cytotoxicity and effective concentrations of the samples against DENV. All TAFrz subfractions were active, but subfraction 6 (a mixture of the alkaloids methylwarifteine and warifteine) in particular showed a promising antiviral effect against DENV-2 with an IC50 of 2.00 µg/mL and a selectivity index (SI) of 10.74. Warifteine was the second most active sample and had an IC50 of 8.13 µg/mL and SI = 10.94. The antiviral activity of the samples compared favorably with that of 6-methylmercaptopurine riboside (IC50 = 7.31 µg/mL and SI = 11.8). These results suggest that bisbenzylisoquinoline alkaloids may prove interesting leading antiviral compounds.

Studies with Cissampelos sympodialis: the search towards the scientific validation of a traditional Brazilian medicine used for the treatment of asthma

The paper is a review of the literature on the ethnobotanical, chemical and pharmacological aspects of the species Cissampelos sympodialis Eichler, Menispermaceae, in order to assess its potential for the treatment of asthma. The aqueous infusion from the leaves of this Brazilian plant is used in the traditional medicine for the treatment of respiratory conditions, including colds, bronchitis and asthma. A multidisciplinary approach has led to the elucidation of the main chemical biomarkers and of the mechanism of action of the extract and its isolated constituents in animal models of inflammation and asthma. A comprehensive review of the literature on the species and its related chemical constituents was conducted using Pubmed, Web of Sciences, Lilacs, SciFinder, as well as conference proceedings. Retrieved literature data demonstrates that the aqueous fraction of the ethanolic extract from the leaves exerts an immunomodulatory activity in different animal models of asthma. This include an increase in the levels of anti-inflammatory cytokines, a decrease in the production of antigen-specific immunoglobulin, a decrease in mucus production and deposition in the airways, and a direct bronchodilator activity. These preclinical results clearly demonstrate the potential of this species for the treatment of asthma and points to the need for well-designed clinical trials to finally validate the traditional use of this herbal medicine.