In Vitro Assessment of Plants Growing in Cuba Belonging to Solanaceae Family Against Leishmania amazonensis

Therapeutic Potential of Bioactive Compounds from Brugmansia suaveolens Bercht. & J. Presl

Brugmansia suaveolens Bercht. & J. Presl has been widely used due to the presence of different bioactive compounds. This review summarizes the latest advances and perspectives of the B. suaveolens plant species; it is a systematic literature review on aspects of botany, traditional uses, phytochemistry, pharmacology, and toxicology as therapeutic potential. In addition, 120 compounds are described, including alkaloids, flavonoids, terpenoids, steroids, amino acids, aromatics, and aliphatics. As for the therapeutic potential, it is described in extracts and compounds in the antitumor, anti-inflammatory, antioxidant, antimicrobial, antispasmodic, anticoagulant, and analgesic aspects, as well as the effects on the central nervous system. The toxicity of the genus stands out, especially the potential for organ toxicity. Therefore, this review evidenced the knowledge related to the traditional use based on the scientific research of Brugmansia suaveolens, highlighting an overview of bioactive compounds and biological and toxicological activities in order to provide a scientific basis for future studies on the value of this species for the development of new natural products.

Review on the genus Brugmansia: Traditional usage, phytochemistry, pharmacology, and toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Brugmansia belongs to the Solanaceae family and contains approximately 7-8 species distributed in America, Europe, Africa, and Asia. The genus Brugmansia plants are used in the traditional medicine of different parts of the world for the treatment of inflammations, rheumatic arthritis, wounds, skin infections, headache, asthma, colic, aches, and so on.

AIM OF THE REVIEW

To the best of our knowledge, this is the first review study that focuses on the phytochemistry, pharmacology, toxicity, and traditional uses of Brugmansia species in order to understand the link between the traditional uses, phytochemistry, and modern therapeutic uses, and provide a scientific fundamental for further research in the phytochemical and pharmacological activities of their species.

MATERIALS AND METHODS

The information reported in this study was retrieved from the scientific database such as ScienceDirect, PubMed, Springer, CNKI, Wiley, Google Scholar, and Baidu Scholar, up until May 2020. The key search word was "Brugmansia." Additionally, information was derived by search on the reference lists of included articles and Ph.D. dissertations.

RESULTS

As traditional uses, Brugmansia species are used against a wide range of diseases such as body pain, inflammatory conditions, skin infection, wound, and other diseases. Also, these species are used as a hallucinogen, protection from evil, and magical rituals. Phytochemical investigations have led to reporting approximately 189 chemical compounds in this genus. Among these components, tropane alkaloids, terpenes, and flavonoids are the most representative components of Brugmansia species. The plant extracts and chemical constituents of Brugmansia species exhibit a broad spectrum of biological and pharmacological activities, including anti-inflammatory, cytotoxic, antioxidant, antibacterial, antispasmodic, anti-asthmatic, antinociceptive, antiprotozoal activities, and so on.

CONCLUSION

This review summarized and analyzed the information of traditional uses, phytochemical, pharmacological activities, and toxicity of the genus Brugmansia plants, which show their species have interesting chemical constituents with different biological activities. The traditional uses of some species from this genus have been estimated by pharmacological activities, such as the anti-inflammatory, antispasmodic, antiasthma, antinociceptive, anti-addictive, and antiprotozoal activity. However, the traditional uses of many species have not been confirmed, also the secondary metabolites of the many species have not yet been determined and have never been pharmacologically estimated. Considerably more research is needed to assert the ethnopharmacological uses, determine the chemical constituents, toxicity, and pharmacological activities of the genus Brugmansia species. The present review will be helpful for further research in the phytochemistry and pharmacology of Brugmansia species.

In-Vitro Evaluation of 52 Commercially-Available Essential Oils Against Leishmania amazonensis

Leishmaniasis is a neglected tropical disease caused by members of the Leishmania genus of parasitic protozoa that cause different clinical manifestations of the disease. Current treatment options for the cutaneous disease are limited due to severe side effects, poor efficacy, limited availability or accessibility, and developing resistance. Essential oils may provide low cost and readily available treatment options for leishmaniasis. In-vitro screening of a collection of 52 commercially available essential oils has been carried out against promastigotes of Leishmania amazonensis. In addition, cytotoxicity has been determined for the essential oils against mouse peritoneal macrophages in order to determine selectivity. Promising essential oils were further screened against intracellular L. amazonensis amastigotes. Three essential oils showed notable antileishmanial activities: frankincense (Boswellia spp.), coriander (Coriandrum sativum L.), and wintergreen (Gualtheria fragrantissima Wall.) with IC₅₀ values against the amastigotes of 22.1 ± 4.2, 19.1 ± 0.7, and 22.2 ± 3.5 μg/mL and a selectivity of 2, 7, and 6, respectively. These essential oils could be explored as topical treatment options for cutaneous leishmaniasis.

In vitro activity and mode of action of phenolic compounds on Leishmania donovani

BACKGROUND

Leishmaniasis is a disease caused by the protozoan parasite, Leishmania. The disease remains a global threat to public health requiring effective chemotherapy for control and treatment. In this study, the effect of some selected phenolic compounds on Leishmania donovani was investigated. The compounds were screened for their anti-leishmanial activities against promastigote and intracellular amastigote forms of Leishmania donovani.

METHODOLOGY/PRINCIPAL FINDINGS

The dose dependent effect and cytotoxicity of the compounds were determined by the MTT assay. Flow cytometry was used to determine the effect of the compounds on the cell cycle. Parasite morphological analysis was done by microscopy and growth kinetic studies were conducted by culturing cells and counting at 24 hours intervals over 120 hours. The cellular levels of iron in promastigotes treated with compounds was determined by atomic absorption spectroscopy and the effect of compounds on the expression of iron dependent enzymes was investigated using RT-qPCR. The IC50 of the compounds ranged from 16.34 μM to 198 μM compared to amphotericin B and deferoxamine controls. Rosmarinic acid and apigenin were the most effective against the promastigote and the intracellular amastigote forms. Selectivity indexes (SI) of rosmarinic acid and apigenin were 15.03 and 10.45 respectively for promastigotes while the SI of 12.70 and 5.21 respectively was obtained for intracellular amastigotes. Morphologically, 70% of rosmarinic acid treated promastigotes showed rounded morphology similar to the deferoxamine control. About 30% of cells treated with apigenin showed distorted cell membrane. Rosmarinic acid and apigenin induced cell arrest in the G0/G1 phase in promastigotes. Elevated intracellular iron levels were observed in promastigotes when parasites were treated with rosmarinic acid and this correlated with the level of expression of iron dependent genes.

CONCLUSIONS/SIGNIFICANCE

The data suggests that rosmarinic acid exerts its anti-leishmanial effect via iron chelation resulting in variable morphological changes and cell cycle arrest.

Efficacy of Four Solanum spp. Extracts in an Animal Model of Cutaneous Leishmaniasis

Background: Leishmaniasis is a complex protozoa disease caused by Leishmania genus (Trypanosomatidae family). Currently, there have been renewed interests worldwide in plants as pharmaceutical agents. In this study, the in vivo efficacy of Solanum spp. is assessed in an L. amazonensis BALB/c mice model for experimental cutaneous leishmaniasis. Methods: Animals were infected with 5 × 10⁶ metacyclic promastigotes and 30-day post-infection, a treatment with 30 mg/kg of Solanum extracts or Glucantime^® (GTM) was applied intralesionally every four days to complete 5 doses. Results: Neither death nor loss of weight higher than 10% was observed. All the tested extracts were able to control the infection, compared with the infected and untreated group. Solanum havanense Jacq. extract showed the highest efficacy and was superior (p < 0.05) to GTM. Solanum myriacanthum Dunal., S. nudum Dunal. and S. seaforthianum Andr. extracts demonstrated a similar effect (p > 0.05) to GTM. An increase of IFN-γ (p < 0.05) was displayed only by animals treated with S. nudum compared to the group treated with a vehicle, while no differences (p > 0.05) were observed for IL-12. Conclusions:In vivo effects of Solanum extracts were demonstrated, suggesting that this genus could be further explored as a new antileishmanial alternative.