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Francis V Defeudis

Publications and source records attributed to Francis V Defeudis.

2 recordsLinked to original sources

Bilobalide and neuroprotection.

In vivo studies have indicated that systemically administered bilobalide, a sesquiterpene trilactone constituent of Ginkgo biloba leaf extracts, can reduce cerebral edema produced by triethyltin, decrease cortical infarct volume in certain stroke models, and reduce cerebral ischemia. In vitro and ex vivo studies indicate that bilobalide has multiple mechanisms of action that may be associated with neuroprotection, including its preservation of mitochondrial ATP synthesis, its inhibition of apoptotic damage induced by staurosporine or by serum-free medium, its suppression of hypoxia-induced membrane deterioration in the brain, and its actions of increasing the expression of the mitochondrial DNA-encoded COX III subunit of cytochrome c oxidase and the ND1 subunit of NADH dehydrogenase. As multiple modes of action may apply to bilobalide, it could be useful in developing therapy for disorders involving cerebral ischemia and neurodegeneration.

Animals↗

Cancer-related overexpression of the peripheral-type benzodiazepine receptor and cytostatic anticancer effects of Ginkgo biloba extract (EGb 761).

The peripheral-type benzodiazepine receptor (PBR) is an 18-kDa high affinity drug- and cholesterol-binding protein that is involved in various cell functions, including cell proliferation and apoptosis. PBR was shown to be overexpressed in certain types of malignant human tumors and cancer cell lines, correlating with enhanced tumorigenicity and cell proliferation rates. The present study was conducted in order to further define the role of PBR in cancer and to extend our recent findings regarding the possible anticancer effects of the standardized Ginkgo biloba extract EGb 761. Treatment with EGb 761 decreased PBR mRNA levels and inhibited the proliferation of breast, glioma and hepatocarcinoma cell lines, further corroborating our previous contention that its mechanism of action is through the modification of PBR expression. In vivo treatment with Ginkgo biloba extract led to dose-dependent decreases in xenograft growth of both MDA-MB-231 breast cancer and U-87 glioma cell lines in nude mice, although the effects were not maintained after 50 days of treatment in the latter. The results obtained in MDA-MB-231 xenografts indicated pronounced inhibition of tumor growth, verified by MRI imaging. These results were obtained using a modified experimental protocol where the animals were treated with the extract before cell inoculation. Although an exact role for PBR in relation to the initiation and progression of various types of cancer remains to be defined, our results indicate that PBR overexpression in certain cancer cells is related to an aggressive phenotype. Since EGb 761 treatment opposes this aggressive phenotype by decreasing PBR overexpression, it could be useful in preventing or treating cancer invasiveness and metastasis.

Animals↗