In vitro anthelmintic activity ofMelia azedarach naturalized in Argentina

In vitro anthelmintic activity of active compounds of the fringed rue Ruta chalepensis against dairy ewe gastrointestinal nematodes

Infections by gastrointestinal nematodes negatively affect small ruminant health and at the same time cause substantial economic losses worldwide. Because resistance to conventional anthelmintic compounds is growing, target studies evaluating the effectiveness of alternative ingredients of botanical origin on gastrointestinal nematodes are needed. In this study, we evaluated the in vitro anthelmintic activity of Ruta chalepensis L. extracts on the third-stage larvae of sheep gastrointestinal nematodes. A methanol extract showed the highest anthelmintic activity, with an EC50 = 0.10 ± 0.06 mg/ml after 96 h, while the essential oil had an EC50 = 1.45 ± 1.22 mg/ml after 48 h. Moreover, three secondary metabolites of the essential oil, i.e. 2-decanone, 2-nonanone and 2-undecanone, showed EC50 values of 0.07 ± 0.06, 0.25 ± 0.29 and 0.88 ± 0.73 mg/ml at 24 h, respectively. The present study indicated that the R. chalepensis methanol extract, the essential oil and its metabolites 2-decanone, 2-nonanone and 2-undecanone showed promising anthelmintic activity on gastrointestinal nematodes.

Limonoids from Melia azedarach Fruits as Inhibitors of Flaviviruses and Mycobacterium tubercolosis

The biological diversity of nature is the source of a wide range of bioactive molecules. The natural products, either as pure compounds or as standardized plant extracts, have been a successful source of inspiration for the development of new drugs. The present work was carried out to investigate the cytotoxicity, antiviral and antimycobacterial activity of the methanol extract and of four identified limonoids from the fruits of Melia azedarach (Meliaceae). The extract and purified limonoids were tested in cell-based assays for antiviral activity against representatives of ssRNA, dsRNA and dsDNA viruses and against Mycobacterium tuberculosis. Very interestingly, 3-α-tigloyl-melianol and melianone showed a potent antiviral activity (EC₅₀ in the range of 3–11μM) against three important human pathogens, belonging to Flaviviridae family, West Nile virus, Dengue virus and Yellow Fever virus. Mode of action studies demonstrated that title compounds were inhibitors of West Nile virus only when added during the infection, acting as inhibitors of the entry or of a very early event of life cycle. Furthermore, 3-α-tigloyl-melianol and methyl kulonate showed interesting antimycobacterial activity (with MIC values of 29 and 70 μM respectively). The limonoids are typically lipophilic compounds present in the fruits of Melia azeradach. They are known as cytotoxic compounds against different cancer cell lines, while their potential as antiviral and antibacterial was poorly investigated. Our studies show that they may serve as a good starting point for the development of novel drugs for the treatment of infections by Flaviviruses and Mycobacterium tuberculosis, for which there is a continued need.

In vitro screening of compounds against laboratory and field isolates of human hookworm reveals quantitative differences in anthelmintic susceptibility

A panel of 80 compounds was screened for anthelmintic activity against a laboratory strain of Ancylostoma ceylanicum and field isolates of hookworm obtained from school children in the Kintampo North District of the Brong Ahafo Region of Ghana. Although the laboratory strain of A. ceylanicum was more susceptible to the compounds tested than the field isolates of hookworm, a twofold increase in compound concentration resulted in comparable egg hatch percent inhibition for select compounds. These data provide evidence that the efficacy of anthelmintic compounds may be species-dependent and that field and laboratory strains of hookworm differ in their sensitivities to the anthelmintics tested. These data also suggest that both compound concentration and hookworm species must be considered when screening to identify novel anthelmintic compounds.

nematicidal carboxylic acids and aldehydes from Melia azedarach fruits

Melia azedarach is a species gaining scientific interest mostly concerning its range of biological activities against agricultural target pests. The nematicidal melia methanol extract (MME) obtained from the fruits, acting against the phytonematode Meloidogyne incognita , is herein reported to contain hexadecanoic, acetic, and hexanoic acids as well as furfural, 5-hydroxymethylfurfural, 5-methylfurfural, and furfurol. All compounds were tested individually for nematicidal activity against the nematode second-stage juveniles, in paralysis experiments. The nematicidal activity was studied both after nematodes' immersion in treatment solutions and after exposure to test substance vapors. Clear dose and time response relationships were established at the dose ranges of 31.2-500 and 1-100 μg/mL, concerning the aldehydes and carboxylic acids, respectively, implementing analogous predominance of nematicidal activity. Nevertheless, no synergistic effects were observed in respective mixture interaction bioassays among furfural, 5-hydroxymethylfurfural, 5-methylfurfural, and furfurol. Furfural was the most active bionematicidal compound reported herein for the first time as a natural constituent of M. azedarach.