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Matti Narkia

Mechanisms of Berberine (Natural Yellow 18)-Induced Mitochondrial Dysfunction: Interact... - 0 views

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    Mechanisms of berberine (natural yellow 18)-induced mitochondrial dysfunction: interaction with the adenine nucleotide translocator. Pereira CV, Machado NG, Oliveira PJ. Toxicol Sci. 2008 Oct;105(2):408-17. Epub 2008 Jul 3. PMID: 18599498 doi: 10.1124/jpet.107.128017 The data from the present work appear to show that berberine also presents some degree of toxicity to "nontumor" systems, which should be carefully understood. ANT inhibition in nontumor cells by berberine would be responsible for a decrease in energy production and could also result in MPT induction. To the best of our knowledge, no full toxicity assessment exists for berberine in humans, although its use in several commercially available supplements suggests that the compound may present a relatively wide safety interval. In fact, a study with patients with congestive heart failure treated with 1.2 g/day of oral berberine revealed low toxicity and resulted into an average plasma concentration of 0.11 mg/l which would translate into 0.3µM (Zeng and Zeng, 1999Go). Repeated cumulative treatments, alternative forms of formulation (e.g., topical application vs. injection) or more importantly, active mitochondrial accumulation due to its positive charge would be expected to increase its concentration in cells into the range of concentrations used in this study. Empirical data from nontraditional medicines plus the use of extensive clinical assays would allow the use of berberine as a promising antimelanoma agent while maintaining its safety for humans. In radial/vertical forms of melanoma, a possible topical application of berberine would also be possible, thus minimizing side effects on other organs. In conclusion, the present work identifies the ANT as an important target for berberine, with clear relevance for its proposed antitumor effects.
Matti Narkia

Sloan-Kettering - Garlic - 0 views

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    Derived from the bulb or clove of the plant. Garlic is used as a spice and to treat hyperlipidemia, hypertension, atherosclerosis, cancer, and infections. Processing can have a substantial effect on the chemical content in garlic; the volatile oil components are sensitive to heat and certain enzymes are acid-labile. Several oral garlic formulations are available, and clinical studies have addressed a variety of the proposed claims. Placebo-controlled trials on the cholesterol lowering effect of garlic yielded mixed results (16) (17) (18) (21) (22) (26). Studies evaluating the antithrombotic effects repeatedly have shown modest reduction in platelet aggregation, but varying levels of fibrinolytic activity. Research shows mixed effects with regard to reductions in blood glucose, blood pressure, or risk of cardiovascular disease (23). Frequently reported adverse events include bad breath, headache, fatigue, GI upset, diarrhea, sweating, and possible hypoglycemia (9). Because garlic is known to decrease platelet aggregation and potentially elevate the INR, it should not be used with anticoagulants or in patients with platelet dysfunction (15). Garlic appears to induce cytochrome p450 3A4 and may enhance metabolism of many medications (e.g. cyclosporin and saquinavir) (12). An analysis of several case-control studies in Europe suggests an inverse association between garlic consumption and risk of common cancers (25).
Matti Narkia

Mitochondrially Targeted Effects of Berberine [Natural Yellow 18, 5,6-dihydro-9,10-dime... - 0 views

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    Mitochondrially targeted effects of berberine [Natural Yellow 18, 5,6-dihydro-9,10-dimethoxybenzo(g)-1,3-benzodioxolo(5,6-a) quinolizinium] on K1735-M2 mouse melanoma cells: comparison with direct effects on isolated mitochondrial fractions. Pereira GC, Branco AF, Matos JA, Pereira SL, Parke D, Perkins EL, Serafim TL, Sardão VA, Santos MS, Moreno AJ, Holy J, Oliveira PJ. J Pharmacol Exp Ther. 2007 Nov;323(2):636-49. Epub 2007 Aug 17. PMID: 17704354 doi: 10.1124/jpet.107.128017 The present work shows that berberine is accumulated by mitochondria of a mouse melanoma cell line, leading to mitochondrial fragmentation and dysfunction, accompanied by decreased cellular energy charge. When the effect was compared with the results obtained on isolated mitochondrial fractions, it is observed that regardless of the system used, berberine is toxic for mitochondria. One major limitation of the present study (as in many others) is the lack of knowledge of the real concentration of berberine that reaches mitochondria in intact cells. Although we do not possess data regarding this aspect, it is wise to speculate that mitochondrial berberine concentrations will be much higher than in the bulk cytosol due to electrophoretic accumulation. We believe that the range of berberine concentrations accumulated by mitochondria in intact cells is within the range of concentrations used on isolated mitochondrial fractions in the present study. The present work not only provides insights on the mechanism by which berberine interferes with tumor cell proliferation, demonstrating previously unknown effects on mitochondrial physiology, but also raises a note of caution on the use of berberine as a nontoxic "natural" over-the-counter medication.
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