L’ananas est supérieur à la chimio 5-FU (5-fluouracil)

Une équipe de chercheurs et scientiques on publié dans la revue Planta Medica les résultats d’extraits d’annas comme étant supérieurs à l’agent cytotoxique 5-fluorauracil in vivo (i.e., expérimentation animale, voir l’étude ci-dessous). La chimio 5-FU est un poison non seulement pour les cellules cancéreuses, mais aussi pour toutes les autres cellules humaines qui se divisent rapidement (par ex, les cellules immunitaires, les cellules des cheveux, des intestins etc), vu que le mécanisme d’action de cette drogue cible et inhibe la synthèse RNA et ses enzymes de reproduction. A contrario,  les molécules naturelles comme les enzymes bromelaines des ananas sont généralement dotées d’une cytotoxicité sélective,  poussant les cellules handicapées comme les cellules cancéreuses à s’éliminer d’elle memes (via le mécanisme de l’apoptose), tout en gardant l’ensemble des autres cellules intact.  Pire, la chimio cytotoxique a tendance à renforcer la chimio-résistance ainsi que les cellules cancéreuses souches, lesquelles deviennent encore plus agressives, tout en profitant pour se disperser au travers du corps, nonobstant une certain réduction tumorale de l’excroissance primaire.

Attribution photo :  Creative Commons  et Wikipedia

Planta Med. 2007 Oct;73(13):1377-83. Epub 2007 Sep 24.

In vivo antitumoral activity of stem pineapple (Ananas comosus) bromelain.
Báez R1, Lopes MT, Salas CE, Hernández M.

Abstract

Stem bromelain (EC 3.4.22.32) is a major cysteine proteinase, isolated from pineapple ( Ananas comosus) stem. Its main medicinal use is recognized as digestive, in vaccine formulation, antitumoral and skin debrider for the treatment of burns. To verify the identity of the principle in stem fractions responsible for the antitumoral effect, we isolated bromelain to probe its pharmacological effects. The isolated bromelain was obtained from stems of adult pineapple plants by buffered aqueous extraction and cationic chromatography. The homogeneity of bromelain was confirmed by reverse phase HPLC, SDS-PAGE and N-terminal sequencing. The in vivo antitumoral/antileukemic activity was evaluated using the following panel of tumor lines: P-388 leukemia, sarcoma (S-37), Ehrlich ascitic tumor (EAT), Lewis lung carcinoma (LLC), MB-F10 melanoma and ADC-755 mammary adenocarcinoma. Intraperitoneal administration of bromelain (1, 12.5, 25 mg/kg), began 24 h after tumor cell inoculation in experiments in which 5-fluorouracil (5-FU, 20 mg/kg) was used as positive control. The antitumoral activity was assessed by the survival increase (% survival index) following various treatments. With the exception of MB-F10 melanoma, all other tumor-bearing animals had a significantly increased survival index after bromelain treatment. The largest increase ( approximately 318 %) was attained in mice bearing EAT ascites and receiving 12.5 mg/kg of bromelain. This antitumoral effect was superior to that of 5-FU, whose survival index was approximately 263 %, relative to the untreated control. Bromelain significantly reduced the number of lung metastasis induced by LLC transplantation, as observed with 5-FU. The antitumoral activity of bromelain against S-37 and EAT, which are tumor models sensitive to immune system mediators, and the unchanged tumor progression in the metastatic model suggests that the antimetastatic action results from a mechanism independent of the primary antitumoral effect.

Copyright:  Centre Pyrénéen de Bien-Etre Holistique

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