Eight extremophile plants from Tunisia were screened to find natural products with benefits in human health.These plants were collected in different areas in Tunisia. Their methanolic extracts were evaluated for their total phenolic content and for their antiradical (DPPH), antimicrobial (on 35 bacteria and one yeast), antiviral (hepatitis C virus, HCV) and cytotoxic activity (against WI38 and J774 cell lines). The most active species were subjected to a bioguided fractionation.The screening revealed promising activity for four plants, but two species have both antiradical and antimicrobial activity: Juncus maritimus and Limonium virgatum. The rhizomes extract of J. maritimus showed the highest activity against HCV, a selective antibacterial activity against Streptococcus dysgalactiae, and a moderate antiradical activity which is due to luteolin isolated in one step by centrifugal partition chromatography. The stems' and leaves' extracts of L. virgatum were rich in polyphenols responsible for the antiradical activity. Also, Limonium extracts showed an antibacterial activity with a broad spectrum.Extremophile plants have proven to be a promising source for bioactive metabolites. They have a powerful antioxidant system highly influenced by biotic and abiotic factors and the ability to produce secondary metabolites with antimicrobial activity.
Duroia macrophylla Huber (Rubiaceae) is a tropical tree, known as “puruí”, which occurs in the Amazon region. The study of the methnolic extract led to the isolation of the indolic alkaloids 9-methoxyajmalicine and 10-methoxyajmalicine (cabucine) which were identified by NMR and MS data analyses. The methanolic extract was toxic against Artemia salina (IC50=40µg/mL).
Abstract Traditional practitioners commonly use plant crude extracts to treat various diseases in patients with symptoms that can be seen during enterovirus infections. In this study, the antienteroviral activity of medicinal plants from the Republic of Congo has been evaluated in vitro. Through an ethnopharmacological approach, seven plants grouped into six families were identified. Aqueous and organic extracts of various organs from these plants were prepared. The organic extracts at subcytotoxic concentrations did not inhibit the cytopathic effect (CPE) induced by coxsackievirus (CV)B1‐5, CVA6, poliovirus type 1, and enterovirus 71. The aqueous extract of Syzygium brazzavillense, but not those of other plants, inhibited the CPE induced by CVB3 and CVB4 at 30 µg/mL (CC 50 ; 2800 µg/mL, IC 50 ; 0.8 µg/mL) and by CVB2 and poliovirus type 1 at higher concentrations. When aqueous extract of this plant was mixed with CVB4, the replication of the virus was inhibited. In conclusion, aqueous extracts of Syzygium brazzavillense can inhibit the infection with CVB4 and other enteroviruses in vitro. The present ethnopharmacological investigation helped to identify a plant with potential properties useful to combat enterovirus infections.
Abstract This study was performed on all Eryngium species growing in Tunisia in order to evaluate their intra and interspecies variabilities and to investigate their biological activities. These species are used in traditional medicine, and literature about the phytochemical investigations of most of them is scarce. Antimicrobial and light‐enhanced activities were tested against multiresistant microorganisms and extended spectrum beta‐lactamase producing bacteria (ESBL). All studied species showed antimicrobial effect with several MIC values lower than 70 μg/ml. Tested Eryngium species have proven to be a promising source of photoactive compounds, while light‐enhanced activity offers an alternative for the inactivation of pathogenic microorganisms which is currently subjected to a great interest. This is the first report of this activity in genus Eryngium . A significant improvement of antimicrobial activity with UV irradiation was observed, mainly for E. dichotomum , E. ilicifolium and E. triquetrum . Cytotoxicity, studied for the first time for the most species, was evaluated against cancer (J774) and non‐cancer (WI38) human cell lines. Chemical composition of volatile compounds presented in the most active crude extracts (petroleum ether extracts) of the aerial parts was investigated using GC/MS analysis and was submitted to statistical analyses. It revealed their high content of bioactive phytochemicals, particularly oxygenated sesquiterpenes like spathulenol, ledol and α ‐bisabolol but also hydrocarbon sesquiterpenes such as β ‐bisabolene and copaene, as well as polyacetylene derivatives such as falcarinol. Statistical analyses permitted to evaluate the interrelations between all Tunisian Eryngium species.
Microdesmis keayana J. Léonard and Microdesmis puberula Hook f. are two common species from the central African forest used in traditional medicine. The roots of both are used to remedy sexual dysfunction and the leaves are used against malaria [1], gastrointestinal parasites and various infections [2]. These two perennial shrubs belong to the Pandaceae family which has not been greatly explored. Recent studies on M. keayana have shown the roots to have hypotensive, antioxidant properties and stimulating effects on sexual behaviour in male rats. They have also revealed that polyamines such as the spermidine or spermine derivatives contained in the hydromethanolic extract are involved in these biological activities. Previous phytochemical works led to the isolation and identification of nitrogenous compounds as a 6-hydroxyquinoline-4-carboxamide, three N 1,N 5,N 10-tris(4-hydroxycinnamoyl)spermidines and a N 1,N 5,N 15-tris(4-hydroxycinnamoyl)spermine from hydromethanolic root extract of M. keayana [3,4]. In the continuation of our study on Microdesmis genus, the methanolic root extracts of M. keayana and M. puberula were investigated. The ESI-MS2 technique with specific NMR analysis of hydrolysed products made it possible to identify N 1,N 5,N 15-tris(p-coumaroyl)spermine, N 1-feruloyl, N 5,N 15-di(p-coumaroyl)spermine and
Abstract High prevalence of parasitic or bacterial infectious diseases in some world areas is due to multiple reasons, including a lack of an appropriate health policy, challenging logistics and poverty. The support to research and development of new medicines to fight infectious diseases is one of the sustainable development goals promoted by World Health Organization (WHO). In this sense, the traditional medicinal knowledge substantiated by ethnopharmacology is a valuable starting point for drug discovery. This work aims at the scientific validation of the traditional use of Piper species (“ Cordoncillos” ) as firsthand anti-infectious medicines. For this purpose, we adapted a computational statistical model to correlate the LCMS chemical profiles of 54 extracts from 19 Piper species to their corresponding anti-infectious assay results based on 37 microbial or parasites strains. We mainly identified two groups of bioactive compounds (called features as they are considered at the analytical level and are not formally isolated). Group 1 is composed of 11 features being highly correlated to an inhibiting activity on 21 bacteria (principally Gram-positive strains), one fungus ( C. albicans ), and one parasite ( Trypanosoma brucei gambiense ). The group 2 is composed of 9 features having a clear selectivity on Leishmania (all strains, both axenic and intramacrophagic). Bioactive features in group 1 were identified principally in the extracts of Piper strigosum and P. xanthostachyum . In group 2, bioactive features were distributed in the extracts of 14 Piper species. This multiplexed approach provided a broad picture of the metabolome as well as a map of compounds putatively associated to bioactivity. To our knowledge, the implementation of this type of metabolomics tools aimed at identifying bioactive compounds has not been used so far.
