Anti-malarial activity and HS-SPME-GC-MS chemical profiling of Plinia cerrocampanensis leaf essential oil

Plinia cerrocampanensis is an endemic plant of Panama. The leaf essential oil of this plant has shown antibacterial activity. However, anti-malarial activity and chemical profiling by HS-SPME-GC-MS of this essential oil have not been reported before. Anti-malarial activity of the essential oil (EO) was evaluated in vitro against chloroquine-sensitive HB3 and chloroquine-resistant W2 strains of Plasmodium falciparum. Synergistic effect of chloroquine and the EO on parasite growth was evaluated by calculating the combination index. A methodology involving headspace solid phase microextraction and gas chromatography-mPlinia cerrocampanensis is an endemic plant of Panama. The leaf essential oil of this plant has shown antibacterial activity. However, anti-malarial activity and chemical profiling by HS-SPME-GC-MS of this essential oil have not been reported before. Anti-malarial activity of the essential oil (EO) was evaluated in vitro against chloroquine-sensitive HB3 and chloroquine-resistant W2 strains of Plasmodium falciparum. Synergistic effect of chloroquine and the EO on parasite growth was evaluated by calculating the combination index. A methodology involving headspace solid phase microextraction and gas chromatography-

Anti-malarial activity and HS-SPME-GC-MS chemical profiling of Plinia cerrocampanensis leaf essential oil

Plinia cerrocampanensis is an endemic plant of Panama. The leaf essential oil of this plant has shown antibacterial activity. However, anti-malarial activity and chemical profiling by HS-SPME-GC-MS of this essential oil have not been reported before. Anti-malarial activity of the essential oil (EO) was evaluated in vitro against chloroquine-sensitive HB3 and chloroquine-resistant W2 strains of Plasmodium falciparum. Synergistic effect of chloroquine and the EO on parasite growth was evaluated by calculating the combination index. A methodology involving headspace solid phase microextraction and gas chromatography-mPlinia cerrocampanensis is an endemic plant of Panama. The leaf essential oil of this plant has shown antibacterial activity. However, anti-malarial activity and chemical profiling by HS-SPME-GC-MS of this essential oil have not been reported before. Anti-malarial activity of the essential oil (EO) was evaluated in vitro against chloroquine-sensitive HB3 and chloroquine-resistant W2 strains of Plasmodium falciparum. Synergistic effect of chloroquine and the EO on parasite growth was evaluated by calculating the combination index. A methodology involving headspace solid phase microextraction and gas chromatography-

Automated Synchronization of P. falciparum using a Temperature Cycling Incubator

As malaria keeps affecting millions of lives every year, research based in culture of Plasmodium falciparum in vitro needs to be efficient and accurate. The development of better techniques and methodologies for the growth and maintenance of the parasites can save money, time, and lead to more trustable results. It has been observed, first in patients and then in the laboratory, that the malaria falciparum parasites growth is affected by high temperatures. This trait can be used with laboratory cultures to synchronize and maintain the parasites in the same stage of their cell cycle. This harmony of stages is very desirable for the purpose of conducting metabolomic, proteomic and transcriptome analysis as well as for drug screening. Most scientists in the field of malaria use chemicals (usually sorbitol) that kill certain stages of the parasite to obtain synchronization, but this latter method does not last long and the parasites thus treated should not be used for assays immediately after the treatment, due to the toxic effects that might have been infringed in the culture. A temperature cycling incubator (TCI) was acquired in our laboratory and it was used to test the synchronization of the multidrug resistant W2 and chloroquine resistant 7G8 strains, commonly used in our bioassays where they and their synchronization constitute essential tools for our drug discovery program. We followed the protocol designed by Haynes and Moch in 2002 and we made a comparison of the effectiveness of each of the two methods, chemical and temperature based. Our results show W2 synchronization by temperature cycling, with the help of an initial use of 0.3 M alanine, to last more than two months while a tight synchronization with the use of 5% sorbitol was lost as rapidly as in one week. Sorbitol could also be used with the TCI for synchronization with good results. However, 7G8 could not be efficiently synchronized with temperature cycling using the same program as that of W2.As malaria keeps affecting millions of lives every year, research based in culture of Plasmodium falciparum in vitro needs to be efficient and accurate. The development of better techniques and methodologies for the growth and maintenance of the parasites can save money, time, and lead to more trustable results. It has been observed, first in patients and then in the laboratory, that the malaria falciparum parasites growth is affected by high temperatures. This trait can be used with laboratory cultures to synchronize and maintain the parasites in the same stage of their cell cycle. This harmony of stages is very desirable for the purpose of conducting metabolomic, proteomic and transcriptome analysis as well as for drug screening. Most scientists in the field of malaria use chemicals (usually sorbitol) that kill certain stages of the parasite to obtain synchronization, but this latter method does not last long and the parasites thus treated should not be used for assays immediately after the treatment, due to the toxic effects that might have been infringed in the culture. A temperature cycling incubator (TCI) was acquired in our laboratory and it was used to test the synchronization of the multidrug resistant W2 and chloroquine resistant 7G8 strains, commonly used in our bioassays where they and their synchronization constitute essential tools for our drug discovery program. We followed the protocol designed by Haynes and Moch in 2002 and we made a comparison of the effectiveness of each of the two methods, chemical and temperature based. Our results show W2 synchronization by temperature cycling, with the help of an initial use of 0.3 M alanine, to last more than two months while a tight synchronization with the use of 5% sorbitol was lost as rapidly as in one week. Sorbitol could also be used with the TCI for synchronization with good results. However, 7G8 could not be efficiently synchronized with temperature cycling using the same program as that of W2

Sequestration and cyanobacterial diet preferences in the opisthobranch molluscs Dolabrifera nicaraguana and Stylocheilus rickettsi

A multidisciplinary approach was used to assess chemical ecological dietary interactions between marine organisms as a tool to isolate novel ecologically relevant compounds with biotechnological potential. First, laboratory-based feeding preference assays of the sea hare Dolabrifera nicaraguana (previously known as D. dolabrifera), an anaspidean mollusc, were conducted by simultaneously offering six food options collected from nearby tidal pools in the Coiba National Park in the Tropical Eastern Pacific of Panama. An evaluation of preferred dietary repertoire revealed D. nicaraguana significantly preferred cf. Lyngbya sp. over the cyanobacterium Symploca sp., green alga Chaetomorpha sp., and red alga Spyridia sp. A no-choice feeding assay using cf. Lyngbya sp. or green alga Cladophora sp. supported this finding. Secondly, we conducted bioactivity-guided fractionation using the preferred food source of D. nicaraguana, the ‘hair-like” cf. Lyngbya sp. from which we also isolated and elucidated two new depsipeptide compounds, veraguamide M (1) and veraguamide N (2). Veraguamides M (1) and N (2) showed in vitro activity toward the malaria-causing parasite Plasmodium falciparum with GI50 values of 4.2 and 4.3 mM, respectively, and therapeutic windows of 7.0–8.0 (based on moderate cytotoxicities to mammalian Vero cells with GI50 values of 29.3 and 34.1 mM, respectively). Veraguamide N (2) was also active against Leishmania donovani, the causative agent of visceral leishmaniasis, with a GI50 value of 6.9 mM. We then evaluated sequestration of these new compounds by D. nicaraguana used in the feeding assays and found trace amounts of the dietary sequestered compounds. Finally, we evaluated sequestration of these new compounds by the sea hare Stylocheilus rickettsi (previously known as S. striatus) that were grazing on the cf. Lyngbya sp. used in the feeding assays and found both to be sequestered. This study is the first example whereby compounds with significant activity against tropical parasites have been found in both the sea hare S. rickettsi and its cyanobacterial food source. These results suggest that chemical ecological studies involving sea hares and cyanobacteria continue to provide a diverse source of bioactive compounds with biotechnological potential

Analysis of the antiparasitic and anticancer activity of the coconut palm (Cocos nucifera L. ARECACEAE) from the natural reserve of Punta Patiño, Darién.

Cocos nucifera (C. nucifera) (the coconut palm tree) has been traditionally used to fight a number of human diseases, but only a few studies have tested its components against parasites such as those that cause malaria. In this study, C. nucifera samples were collected from a private natural reserve in Punta Patiño, Darien, Panama. The husk, leaves, pulp, and milk of C. nucifera were extracted and evaluated against the parasites that cause Chagas' disease or American trypanosomiasis (Trypanosoma cruzi), leishmaniasis (Leishmania donovani) and malaria (Plasmodium falciparum), as well as against a line of breast cancer cells. While there was no activity in the rest of the tests, five and fifteen-minute aqueous decoctions of leaves showed antiplasmodial activity at 10% v/v concentration. Removal of some HPLC fractions resulted in loss of activity, pointing to the presence of synergy between the components of the decoction. Chemical molecules were separated and identified using an ultra-performance liquid chromatography (UPLC) approach coupled to tandem mass spectrometry (LC-MS/MS) using atmospheric pressure chemical ionization quadrupole-time of flight mass spectrometry (APCI-Q-TOF-MS) and molecular networking analysis, revealing the presence of compounds including polyphenol, flavone, sterol, fatty acid and chlorophyll families, among others