Mitochondrial Proanthocyanidin-Tuning: Fruit & Seed Extracts from Grapes Cheer Up Tired Mitochondria.

Image 1: Grapes - mitochondrial super food.

While I am still not sold on the idea that the unfortunate and unhealthy fate of being a fat slob is in your genes, it is a commonly accepted scientific fact that lifestyle factors (and thus epigenetics) contribute to obesity related mitochondrial dysfunctions. Defective cellular powerplants, on the other hand, make it increasingly difficult to lose weight and may be one of the major causes of the weight(re-)gain the majority of dieters experience after ardeous weeks of (un-)successful calories-in-vs-calories-out dieting.

The results of two very studies published in the latest issue Journal of the American Chemical Society (Kang. 2011) and the Journal of Food and Chemical Toxicology (Arola. 2011) indicate that both the proanthocyanidins from grapeseeds, as well as the mixture of bioactive substances from whole red grapes may ameliorate the impairment in oxidative capacity and decrease the oxidative stress due to the increased superoxide dismutase (SOD) production in defective mitochondria. Thusly "tuned" mitochondria could not only use energy more effectively, the experimentally established negative correlation of metabolic waste products and insulin sensitivity (more "waster" = more SOD = less insulin sensitivity) would suggests that the restoration and optimization of mitochondrial function turn could trigger a whole cascade of beneficial health effects which improve metabolic health and facilitate weight loss.

Luis Arola and his colleagues from the Departament de Bioquímica i Biotecnologia at the Universitat Rovira i Virgili in Tarragona, Spain, investigated the effects supplementation of Zucker obese rats (commonly used model for type II diabetes and the metabolic syndrome) with 35mg/kg grape seed extract [GSPE; human equivalent: 5.7mg/kg; 454mg for an 80kg human] for 6 weeks had on the skeletal muscle energy metabolism of the animals.

Note: If you intend to buy a similar extract you want to know the exact proanthocyanidin composition. For the extract in the study the ratio of mono to polymers was as follows: monomers (21.3%), dimers (17.4%), trimers (16.3%), tetramers (13.3%) and oligomers (5-1391 units) (31.7%).

In that, it is interesting to note, that the scientists based their hypothesis that GSPE would exert beneficial effects on the metabolically deranged rodents, on previous observations in healthy male Wistar rats, where the proanthocyanidin content of GSPE increased the activity of key enzymes of energy metabolism in muscle and brown adipose tissue five hours after oral administration. Contrary to what has been observed in those healthy animals, however,

chronic GSPE administration decreased citrate synthase activity [which had been increased by GSPE administration in healthy rats], the amount  of oxidative phosphorylation complexes I and II, and Nrf1 gene expression, without any effects on the mitochondrial
oxidative capacity.

The scientists argue that this decrease of citrate synthase may be related to "a lower mitochondrial density in the [gastromenicus] muscle" of the GSPE treated rats; at first sight, a highly undesirable effect, which - and this was confirmed by gene essays - was yet not mediated by apoptosis, i.e. cell-death, due to a pro-apoptotic activity of GSPE - such stress-related phenomena have been observed with high doses of resveratrol (Pan. 2008) or the green tea polyphenol EGCG (Weinreb. 2003; Quanungo. 2005) in cancer cells. Though, whatever the reasons for the reduced critrate synthase, the initially step of the energy production in the Krebs cycle, may be, the

high-resolution respirometry results, using a combination of carnitine and palmitoyl-CoA as substrates, revealed that proanthocyanidins caused higher state 2 respiration levels [which in turn suggests] an improvement in fatty acid transport into the mitochondria and/or an increased capacity for fatty acid oxidation by beta-oxidation.

Coupled with the observed increase in pyruvate influx into the crebs cycle and the anti-inflammatory effect derived from the 163% increase in the cyclooxygenase (COX) to citrate synthase activity (cf. figure 1) this effect may have (over-)accomodate the potential reduction in the number of mitochondria; despite a small decline in triglycerides, it could yet not completely inhibit the slight, yet statistical significant weight gain (7.4%) in the GSPE group, which in itself was the consequence of a 15.1% increase in food intake.

Figure 1: Citrate synthase (CS) and COX/citrate synthase ratio (primary axis), ATPase/CS ratio (secondary axis) in Zucker obese rats after 8 weeks of GSPE supplementation at 36mg/kg (data adapted from Arola. 2011)

In view of the beneficial effects of exercise training on mitochodrial biogenensis (e.g. Balakrishnan. 2010), it goes without saying that athletes and dieters, alike, could benefit from the addition of GSPE to a reasonably planned weight training regime. While the GSPE will ramp up mitochondrial efficiency (as indicated by the increase in ATPase/CS increase, cf. fig. 1), the resistance training will add new mitochondria to the trained muscle - or as Carl Lenore would have it: You build metabolic currency, while practicing currency revaluation at the same time; better than any building loan contract, isn't it ;-)

Figure 2: Effect of 8 weeks on control, high fat and high fat RISC (resveratrol, genistein and carnitine) supplemented diets on fat pad weight of mice (data adapted from Kang. 2011)

If that ain't not enough and you got further funds to spend on supplements, you may literally take the RISC and add some isoflavones, and l-carnitine to the mix. And although I am convinced that the resulting mixture was quite aptly (yet certainly unconsciously) labeled RISC (R is from resveratrol from red grape extract, IS is from isoflavone and C is from L-carnitine), due to its soy isoflavone content, Jong Song Kang (Kang. 2011) and his/her (?) co-workers were able to show that 400 mg/kg or 800 mg/kg of the mixture of resveratrol, genistein and l-carnitine fed to mice at a ratio of 4:1:2.5...

substantially inhibited high-fat diet (HFD)-induced increase in body weight in a dose-dependent manner in C57BL/6 mice; [decreased] the amount of subcutaneous and mesenteric fat [...] significantly [and] significantly increased the plasma level of high density
lipoprotein cholesterol without affecting the level of low density lipoprotein
cholesterol and triglycerides.

The 'RISCy' treatment also reduced lipid accumulation in the livers of the high-fat-fed mice and returned the elevated plasma levels of glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase into the normal range.

Did you know? Grapes are not the only food rich in proanthocyanidins, pistacios are also a dietary source of ligomer/polymer proanthocyanidin fractions and have shown to exert anti-inflammatory effects on macrophages (immune cells) only, very recently (Gentil. 2011). The proanthocyanidin content of wine and sparkling wine, on the other hand, depends on its origin and, as a study by Jardao et al. on the polyphenol and proanthocyanidin content of Portugues wines suggests, vineyard (Jardao. 2010). While the highest concentrations were in the range of 55-130mg/L the majority of samples taken from wines from Portuguese sparkling wines from Bairrada contained no proanthocyanidin, at all.

In view of the results from the RISC trial, it could be speculated that l-carnitine (write-up for Amino Acids for Super Human Series coming soon!) was the rate limiting factor in the Arola study and additional supplementation of the "fat-carrying amino acid" at what would correspond to 133mg/kg (low dose RISC) or 266mg/kg(high dose RISC) for the mice, 66mg/kg or 133mg/kg for rats and 11mg/kg or 22mg/kg for humans (i.e. 870mg or 1649mg of l-carnitine for an 80kg human being / take in at least 3 doses divided across the day) would eventually turn the 5.7mg/kg of grape seed extract into a true "fat burner"... and if this does not work, I'd suggest the addition of resveratrol (dose in the RISC trial would correspond to 17mg/kg /low dose or 34mg/kg high dose in human beings) and carnitine. In view of the highly devious effects of genistein on both the male, as well as female endocrine system I would pass on the soy-isoflavone if your hormonal health is dear to your heart - the slight decreases in fat accumulation (cf. fig.2) certainly ain't worth it. Ah,... and I do not have to remind you of the importance of complementary restiance training, do I?