Inhibition of seed germination, toxicity on Artemia salina and phytochemical prospecting with from Cuban plants as indicator of antitumo activity

Abstract

Cuba has a high biodiversity and many plants are widely known and used in folk medicine and for commercial manufacturing of phytomedicines. However, many plants have not been studied for their pharmacological properties, particularly endemic plants. Two simple, inexpensive and rapid biological assays, inhibition of germination of tomato and lettuce seeds and toxicity on the brine shrimp A. salina, have been evaluated as prescreens for possible antitumor activity. Extracts of six plant species collected in Havana, Cuba were subjected to the brine shrimp lethality test and inhibition of seed germination in order to detect potential sources of novel cytotoxic and cytostatic antitumor compounds, respectively. The larvicidal activity, based on the percentage of larval mortality, was evaluated after 24 h exposure to the treatments. In the case of inhibition of seed germination the readings were made 48 h after exposure. Semi-quantitative phytochemical prospecting was done by color and precipitation reactions for chemical functional groups. All species tested showed some cytotoxic and cytostatic effects. Two extracts showed high cytotoxicity in the Artemia salina test, the methanol extract from flowers of Tithonia diversifolia (TD) with IC50 (Inhibitory concentration 50) or LD50 (Lethal doses 50) of 1.14 µg/mL and methanol extract of stems from Castela lucida (CL) with LD50 of 0.052 µg/mL. However, the more promising species was the Tabebuia hypoleuca (TH) with cytostatic effect superior of 65% and good cytotoxic effect with the leaf extract, with the prominent compound classes’ triterpenes, tannins, phenols, and alkaloids. Keywords: Cuban plants; cytotoxic; Artemia salina; cytostatic; seed germination; chemical compounds

Antifungal Potential, Mechanism of Action, and Toxicity of 1,4-Naphthoquinone Derivatives

“…Germination inhibition assay in tomato and arugula seeds: For tomato seeds, the protocol as proposed by Sánchez Perera et al [16] was used with modifications as follows. In Petri dishes containing sterile filter paper, five seeds each were covered with different concentrations of 2-3-DBNQ naphthoquinone (0 -800 µg/mL) diluted in 10% DMSO and sterile distilled water with a final volume of 3 mL.…”