Cytotoxic activity of extracts from Tecoma species and isolated lignans

Abstract A phytochemical study of Tecoma genus (Bignoniaceae) was accomplished by antitumor activity of ethanolic extracts. Species of this genus are composed of small shrubs often used as ornamental plants. The Tecoma stans species is used in folk medicine for different purposes. Recent work shows in vitro anticancer activity against human breast cancer. The ethanolic extracts from leaves and trunks of Tecoma casneifolia, T. garrocha, T. stans var. angustata and T. stans var. stans were tested in vitro. The assays used were against line tumor cells by the MTT method and the most active extracts were further studied. In this way, the ethanolic extract from T. stans var. stans trunks presented the higher cytotoxicity against the tumor cell lines studied (CC50 0.02 to 0.55 µg/ml) when compared to the other extracts tested (CC50 0.08 to 200.0 µg/ml). Accordingly, this extract was selected for chromatographic fractionation from which five known lignans were isolated. Further, paulownin, paulownin acetate, sesamin, olivil and cycloolivil were identified using 13C and 1H NMR, IR, UV and spectroscopy and spectrometric MS techniques. These isolated compounds were tested and exhibited CC50 ranging from 13.01 to100.0 µg/ml which is superior to the ethanolic extract of trunk of T. stans

Evaluation of Some Vitamins and Macro-Nutrients Composition of Ethanolic Extract of Tecoma stans and Costus afer Leaves

Aim:This study aims to determine the presence of some vitamins and minerals in both T. stansand C. aferleaves.Materials and Methods:Composition of some vitamins and minerals of ethanolic extract of T. stansand C. aferleaves wereevaluated andcollected at Malabo Campus, University of Calabar, Calabar and from Eman-Uruan local government area, Akwa IbomState, Nigeria respectively.The parameters investigated were determined using standard biochemical methods. Results:The leaves contained a variety of vitamins (A, D, E, B complex and C) with vitamin E-(276.33.±3.28mg/100g) for Tecoma stansand (265.67±5.49mg/100g)for Costus afer.T. stansrecorded higher concentration in mg/100 l for the determined vitamins except for vitamin D, whose concentration for C. afer(0.09±0.01mg/100g) was higher than the value (0.07±0.01mg/100g) for T. stansthough it was significant. T. stansis significantly different [p=0.05] from C. aferfor vitamins A and C respectively.The mineral compositions of T. stansand C. aferleaves contain considerable amount of Potassium (3.27 ± 0.009mg/l) and (4.63±0.09mg/l), Magnesium (26.03 ± 0.009mg/l) and (89.83±0.91?mg/l), Sodium (5.27 ± 0.078mg/l) and (16.23±0.12?mg/l), Calcium (25.33 ± 0.88mg/l) and (82.00±1.53?mg/l), Phosphorus (2.27±0.09mg/l) and (1.63±0.09?mg/l), respectively.C. afercontained significant (p <0.05) higher concentration of Mg, Ca, K and Na compared to T. stans.This indicates the tendency of T. stansand C. aferto be able to control osmotic balance, essential for bone formation, lower blood pressure and also act a source of antioxidant vitamins and minerals.Conclusion:The presence of these vitamins and minerals in both T. stansand C. aferleaves in this leafy vegetables supports the use of these leaves for food and ethnomedicinal purposes in Nigeria and parts of the world where they are cultivated.

Antioxidant and cytotoxic activity of Tecoma stans against lung cancer cell line (A549)

ABSTRACT Human have been constantly using plants and plant products to overcome many diseases. The antioxidant property of the plant sources is studied to obtain an efficacious drug against cancer. The objectives of the present study is to evaluate the antioxidant and cytotoxic activity of the Tecoma stans extracts against lung cancer cell line in comparison with vincristine drug. The antioxidant activity was studied using the standard DPPH assay and the cytotoxic activity using MTT assay. DPPH assay results show that methanolic extract of T. stans in higher concentration show better antioxidant potential than the standard L-ascorbic acid. They exhibited strong antioxidant potential at 20 µg/mL concentration. The absorbance at 517 nm showed that in the range of 0.201-0.0203 compared to that of absorbance of ascorbic acid at 0.023.Cytotoxic activity was studied using MTT assay which showed that the increase in concentration of extract increases the cell death. At 100µg/mL concentration there is an increased cytotoxic activity, i.e., 99% of cell inhibition. The results of antioxidant and anticancerous activity may be positively correlated.

Interaction of temperature and light on seed germination in Tecoma stans L. Juss. ex Kunth (Bignoniaceae)

The effects of the temperature and light on the control of seeds germination in Tecoma stans was studied in the present work. The influence of constant temperatures from 10 to 45ºC, with 5ºC intervals, under the white light and darkness were tested. The optimum temperature for the germination of the seeds was between 25 and 30ºC, for both the light and the dark treatments. The maximal germination was reached in the range of 15 to 35ºC under the light and of 20 to 40ºC in the darkness. The seeds showed highest synchronization of the germination near the optimal temperature. The germination in the field was tested under the two light conditions. The highest percent of germination occurred under the direct sunlight (86.1%) than under the canopy (69%). However, under the canopy, the seedling presented 1.5% of the recruitment, while under the direct sunlight, 96.9 %. Results showed that T. stans seeds germinated well in the open areas with the occurrence of high seedling recruitment indicating the invasion potential of the species in such light conditions.

Os efeitos da temperatura e da luz na germinação de Tecoma stans foram determinados no presente trabalho. Foram testadas temperaturas constantes de 10 a 45ºC, com intervalos de 5ºC, sob luz branca e escuro. Verificou-se que a temperatura ótima para a germinação da espécie está entre 25 e 30ºC, tanto na luz como no escuro, já o intervalo de máxima germinabilidade está entre 15 e 35ºC na luz e 20 e 40ºC no escuro. Suas sementes apresentaram uma maior sincronização da germinação próxima à temperatura ótima. A germinação de sementes de Tecoma stans em condições naturais foi testada sob radiação solar direta e na sombra de vegetação. A maior porcentagem de emergência ocorreu no ambiente de sol (86,1%), porém com menor velocidade em relação à sombra, embora na sombra também ocorreu a emergência, mas em menor proporção (69%). Entretanto, o índice de recrutamento na sombra foi de 1,5% enquanto a pleno sol foi de 96,9%. Estes resultados indicam que as sementes de Tecoma stans germinam e recrutam suas plântulas em ambientes abertos confirmando o potencial invasor da espécie.