Studies on extracts of Argentinean plants: cytotoxic tumoral activity per se and as photosensitizers in photodynamic of cancer

BATLLE A; MAMONE L; CASAS A; RODRIGUEZ L; DI VENOSA G

In the hope of going over the present Clinical PD and PDT". A Symposium Book in "Pacifichem 2010"

Sankeisha Co., Ltd

Lugar: Nagoya; Año: 2011; p. 4 - 22

Photodynamic Therapy (PDT) and Photodiagnosis (PD) can be used for the treatment and diagnosis of tumors and other non-tumoral diseases. PDT is based on combining the use of a photosensitiser (PS), light and oxygen. There are several PSs, among them there exist some natural products, obtained from plants. Our aim has been to investigate extracts, obtained from autochthonous plants, looking for new PSs and to evaluate their cytotoxic properties per se. Next, we plan to purify the photoactive compound, determine its chemical structure and attempt its synthesis. Extracts from 40 plant species have been studied. Time exposure to tumour cells was 24h. It was found that exposure of the murine tumour line LM2 to the methanol extracts of 10 µg/ml of Combretum fruticosum and 50 µg/ml of Scutia buxifolia leaves and irradiation with light doses of 0.073 J/cm2 and 0.019 J/cm2, respectively, induced 50% death. Methanol extracts from 0.01 mg/ml of Iochroma australe and 0.025 mg/ml of Jacaranda mimosifalia flowers and 0.08 mg/ml of Collaea argentina leaves as well as aqueous extracts from 0.1 mg/ml of Solanum verbacifolium flowers, were inducing 50% death in LM2 cells. Treatment of human mammary tumour cell line HB4a-Ras with around 50 µg/ml of Iochroma austrae and Solanum verbacifolium flowers, also induced 50% death. Exposure of the murine tumour line LM3 to 50 µg/ml of crude methanol extracts of Collaea argentina and Macfadyena unguis cati, induced 50% death, irradiating with 0.43 J/cm2 for C. argentina and 0.53 J/cm2 for M. unguis cati respectively. Irradiations have been performed using a last generation 630 nm Lumiia Laser, the first prototype developed in Argentina. Comparative studies with this Laser and others we had been using, were done, showing that Lumiia Laser, is very easy and friendly to use, portable, more powerful and far more economic than other similar equipments.