Sunday, April 14, 2013

Fighting to Stay Lean? These 20+ Anti-Obesity Agents Have the Potential to Inhibit Fat Gain Right at the Cellular Level

No, none of the 20 agents in the list below is going to do the work for you, but they could help you "conserve" the results, keep you lean on a bulk and/or avoid the hazardous Yoyo effect when you go off a die.
It's actually normal that the introduction is the last part of an article I write. What's special about today's SuppVersity article is thus not that I write the introduction at the end, but that I did not really know what I would be writing here, when I set out to compile the unsorted (but not chaotic) list of potential anti-obesity agents below. All of them act by pathway(s) you as a SuppVersity reader will have read about before, most prominently AMPK, and the peroxisome proliferator receptors (PPARs), of which the blockade of the obesogenic PPAR-gamma pathway, which is the main working principle of CLA turned out to be the go-to explanation for the ability of these agents to block both the differentiation of adipocytes and the storage of triglycerides in existing fat cells.

20 more or less proven anti-obesity agents for the weekend

As you are about to see, the list, which was never intended to be complete, got pretty and I guess I could add a couple of additional items, if I spent more time digging. In order not to steal your and waste more of my precious time on this sunny (finally!) Sunday, I did yet decide to call it a day, when I hit the 20-items mark. Now it's up to you to invest some of your sunny Sunday time, to read up on the details. 
  • On a side note: The "holy" vitamin D does the exact opposite, if you incubate preadipocytes with 25(OH)D(3) this will lead to a significant increase in the active 1,25(OH)(2)D(3) and enhanced adipogenesis in primary mouse. Reason enough for a group of Thai researchers to conclcude that "vitamin D status may [actually] regulate human adipose tissue growth and remodeling." (Nimitphong . 2012)
    Vitamin A - Retinoic acid upregulates the expression of the adipogenesis inhibitors Pref-1, Sox9, and Kruppel-like factor 2 (KLF2) to "suppress adipogenesis in vivo and that the activity significantly contributes to the ability of the hormone to counteract diet-induced obesity." (Berry. 2012) Previous studies have also shown that all-trans-retionic acid directly increases the activity of PPARbeta/delta and so that Berry & Noy conclude "RA may be a uniquely efficacious agent in the therapy and prevention of the metabolic syndrome." (Berry. 2009) Similar results have been reported and conclusions have been drawn by Brun et al. and Sagara et al. (Brun. 2012; Sagara. 2013). Finally, Hisada et al report that - just like testosterone (learn more) - retinoic acid ensures that mesenchymal stem cells (MSCs) become osteoblasts (bone precursor cells), not fat cells (Hisada. 2013).
  • Bromocriptine - If you do know it at all, then probably for it's ability to decrease the "milk hormone" prolaction. If you take a look at the broad spectrum of physiological effects of prolactin, the effect it has on the mammalian mammary gland is really negligible. A recent study from the Department of Biotechnology at the Daegu University in The Republic of Korea does now suggest that the inhibition of adipogenesis (formation of new fat cells) and lipogenesis (storage of lipids in existing fat cells) via decreased expressions of the adipogenic activators Pparα, Pparγ, and Cebpα, as well as major lipogenic target genes, including Me1, Acc1, 6Pgd, Fasn, and Prkaa1 is one of these "auxiliary functions" (Mukherjee. 2013)
  • EC also boosts erectile performance and testosterone (learn more)
    Ecklonia cava (EC) - or rather the dioxinodehydroeckol (DHE) molecules that are contained in this type of brown seaweed "exert[s] its anti-adipogenic effect on adipocyte differentiation through the activation and modulation of the AMPK signaling pathway" (Kim. 2010a). As a SuppVersity reader, you will be aware that this effect has been confirmed in in-vivo studies, later on (learn more).

    What's probably Interestingly DHE is not the only anti-adipogenic agent in brown sea algae, Fucoidan, a sulfated polysaccharide from brown seaweeds has likewise been reported to affect the development of adipocytes. In 2010, Kim et al. were able to show that it targets the MAPK kinase pathway by inhibiting the the expression of both early CCAAT-enhancer-binding proteins alpha (C/EBPalpha) and peroxisome proliferator-activated receptors gamma (PPARgamma), as well as the late activating protein 2 (aP2) adipogenic transcription factors (Kim. 2010b).
  • Curcumin - While you my get the impression there was nothing curcumin cannot do (learn more), I am not whether the anti-PPAR gamma effects of curcumin are a result of it's anti-inflammatory effects or not... be that as it may, Lee et al. have demonstrated in 2009 already that the stimulatory effect curcumin exerts on the AMPK expression of adipocytes results in a down-regulation of PPAR-gamma in 3T3-L1 adipocytes (Lee. 2009).
  • Resveratrol - Similar popularity, similar "cures it all" status and similar effects on AMPK and downstream PPAR-gamma expression in 3T3-L1 adipocytes... actually I would not need another bulletin point for resveratrol which acts by the exact same pathway(s) s curcumin to inhibit fat cell differentiation (Chen. 2011)
  • Creatine RT by Athletic Edge Nutrition; contains a cousin of ASL and is supposed to be another "super creatine" -  True or False? The 2011 SuppVersity article has the answer (read it!).
    Artemisia sacrorum Ledeb. (ASL) - Extracts from the small shrub have been used in Oriental Medicine for centuries, in 2011 Yuan et al. were able to show that ASL "down-regulate[s] the adipogenesis-related gene expression of the sterol regulatory element-binding protein 1c (SREBP1c) and its target genes, such as fatty acid synthase (FAS), stearoyl-CoA desaturase 1 (SCD1) and glycerol-3-phosphate acyltransferase (GPAT) in a concentration-dependent manner" (Yuan. 2011) The effects are meediated by a reduced expression of the peroxisome proliferator-activated receptor γ (PPARγ) and of the CCAAT/enhancer binding protein-α (C/EBPα), both of which are key transcription factors in adipogenesis.

    With the concomitant reduction in adipocyte fatty acid binding protein (aP2) gene expression, ASL is another potential anti-obesity agent of which Yuan et al. propose that it works its  anti-adipogenic magic via AMPK activation. In view of the fact that the same is true for the fat accumulation in human liver cells, it could serve a viable tool "in the prevention of serious diseases such as fatty liver and type-2 diabetic mellitus" (Yuan. 2010). Related increases in fatty acid oxidation have been observed in a rodent study by Hong later in 2009 with another variety of Aertemisia, namely Artemesia Capillaris (Hong. 2010). The human equivalent dosage in this trial wast 8mg/kg of the ethyl acetate fraction of the shrub.
  • Phosphorylated glucosamine - While you will probably remember that large doses of regular glucosamine have been associated with insulin resistance (see previous installment of "True Or False"), it's phosphorylated variety glucosamine-6-phosphat (PGlc), Kong et al. synthesized using methanesulfonic acid, phosphorus pentoxide (P(2)O(5)), NH(2)NH(2) and DMF "significantly reduced lipid accumulation during adipocyte differentiation and induced down-regulation of peroxisome proliferator-activated receptor-gamma, sterol regulatory element binding protein 1 and CCAAT/enhancer binding protein-alpha in a dose-dependent manner." (Kong. 2010)
    Phosphorylated glucosamine works (like most of the anti-obesity agents, including the well-known conjugated linoleic acid by reducing the expression of PPAR-gamma (left). It's dose-dependent effects are yet not restricted to the peroxisome proliferator receptor, but affect the pro-adipogenic genes C/EBP-alpha and SREBP1, as well (right; Kong. 2010)
    What's also worth mentioning is that the in-vitro study from the Marine Bioprocess Research Center at the Pukyong National University in South Korea also revealed that PGcl also hampered the maturation of pre-adipocytes by down-regulating adipocyte-specific gene promoters such as adipocyte fatty acid binding protein, fatty acid synthase, lipoprotein lipase and leptin. In conjunction "[t]hese results suggest that the inhibitory effect of PGlc on adipocyte differentiation might be mediated through the down-regulation of adipogenic transcription factors, such as peroxisome proliferator-activated receptor-gamma, sterol regulatory element binding protein 1 and CCAAT/enhancer binding protein-alpha, which are related to the downstream adipocyte-specific gene promoters" (Kong. 2010) 
  • Add. reads: "Temporary +100kcal/Day Cold Thermogenesis Response W/ Exotic Ginger Extract" (more) "250-1000mg of Freeze-Dried Ginger Reduce Visceral Fat Even When Rodents Are Fed an Obesogenic High Fat Diet" (more).
    6-gingerol (6G) - The active ingredient in ginger has just been shown to block the obesity effects of the anti-diabetes med rosiglitazone (Tzeng. 2013). It does so by blocking the PPAR-gamma mediated effects of the "store the superfluous energy as body fat"-drug and was thus able to suppress the oil droplet accumulation and reduce the sizes of the droplets in the course rosiglitazone(RSG)-induced adipocyte differentiation in 3T3-L1 cells. Since it also blunted the increased levels of mRNA and protein in adipocyte-specific fatty acid binding protein 4 and fatty acid synthase induced by RGZ, it can be expected that 6G will not only inhibit the accrual of new, but also the (re-)filling of existing fat cells. 
  • Piperine and capsaicin - In view of the fact that piperine is a "quasi-cousins" of 6-gingerol, it is actually not really surprising that it shares similar effects on the expression of PPAR-gamma (Park. 2012). It is therefore not surprising that the third member of this spicy triumvirate, i.e. capsaicin, shares the exact same PPAR-gamma reducing effects (Joo. 2010).
  • Berberin - Contrary to many other items on the list, berberin's anti-PPAR-gamma effects are actually pretty well-known. There is ample evidence from in-vitro (Huang. 2006; Liu. 2009) and in-vivo (Lee. 2006) evidence that it blunts fat gain by increasing the catabolism of high energy intermediates, upregulating AMPK, modulating the expression of the GATA-2 and 3 gene and reducing the expression of (you guessed it) PPAR-gamma (Hu. 2009).
    Table 1: Berberine content of various commercially available supplements (Brown 2008)
    Berberine has also been shown to improve endothelial function in man (Wang. 2009) and promote the "longevity and mitochondrial health gene" SIRT1 in obesity ridden, insulin resistant skeletal muscle (Gomes. 2012).
  • Ginsenosides (spec. ginsenoside Rg3) - Just like ginereol (see above) ginsenoside Rg3 has been shown to block the adipogenic effects of the anditiabetic drug rosiglitazone via an AMPK/PPAR-gamma dependent pathway (Hwang. 2009). It may be worth mentioning that at least the effect triglyceride storage was not dose-dependent. Once  a threshold amount of 40µM was reached, the adipocytes that were incubated with Rg3 did not "lose" any additional triglycerides, when the dosage was increased to 80µM.
  • On a side note: Although promoted in the same health and longevity circles as CAPE, the hailed "telomerase lengthener" Astraglaus is a PPAR-gamma promoter and will thus "enhance the accumulation of lipid drops, and increase the terminal differentiation of preadipocytes" (Liu. 2007)
    Caffeic acid phenethyl ester (CAPE) - You've heard about the anti-inflammatory, muscle protective ability of this compound from bee propolis only recently (go back). In addition to being a potent anti-inflammatory, the natural phenolic compound that's also found in a variety of plants, has also been found to block the conversion of mouse fibroblasts into fat cells (Juman. 2010). As for most of the other agents the effects of CAPE appear to be mediated by a reduction inperoxisome proliferator-activated receptor (PPAR) gamma and CCAAT/enhancer-binding protein (C/EBPalpha) and concomittant reduction isn fatty acid synthetase and the expression of adipocyte-specific fatty acid binding protein (aP2). 
  • Lysimachia foenum-graecum (LFE) - LFE is a Chinese herb and well-known anti-inflammatory from Oriental Medicine. The anti-obesity effect of L. foenum-graecum extract was first discovered by Seo et al., when they simply screened a whole host of potential natural agents for their anti-adipogenic effects. In 2011 the researchers found that "LFE blocked the differentiation of 3T3-L1 preadipocyte in a dose-dependent manner with an IC50 of 2.5 μg/ml". The underlying mechanism which has also been observed in an in-vivo rodent study with 100 mg/kg/day, are - how else could it be - mediated by the inhibition of PPARγ and C/EBPα expression.
    Effects of the administration of an lysimachia foenum-graecum ethanol extract on lipid and glucose metabolism and adipokine signalling in mice on an obesogenic diet (Seo. 2011)
    Moreover, LFE stimulated fatty acid oxidation in an AMPK-dependent manner, greatly improved serum levels of obesity-related biomarkers such as glucose, triglycerides, and adipocytokines leptin, adiponectin, and resistin and lead to an effective decrease in total body weight gain in mice who received 30, 100, and 300 mg/kg/day of an Lysimachia foenum-graecum ethanol extract (50:6; LFE) in addition to their obesogenic high fat diet (see figure above). The mice in the HFD + LFE group did simply have lower body weights, they also had a reduced amount of adipose tissues especially within the metabolically active and highly unhealthy abdominal subcutaneous, epididymal, and perirenal adipose tissue.
  • Photos of the lean (A and D), HFD-fed (B and E) and HFD-fed + SRLE supplemented (C and F) mice in the Thounaojam study (2011).
    Sida rhomboidea. Roxb leaf extract (SRLE) - SRLE does only sound like the stuff many supplement companies used after the ban of mua huang (natural source of ephedrine). It is however a different variety of Sida (Batyάlaka, Sida cordifolia)... well, at least it is from the same family which lacks the CNS stimulating activity of mua huang. With its ability to prevent high fat diet (HFD) induced visceral adiposity by down-regulation of PPARγ2 and leptin gene expression it could in fact work synergistically with ephedrine, though. After all the HED of the 24% w/w water extract Thounaojam et al. used to prevent the obesogenic effects of a hypercaloric high fat diet in their rodent study amounts to no more than ~40mg/kg and since SRLE has been shown to be non-toxic up to 3g/kg (in mice; HED ~240mg/kg) it would be interesting to see studies that probe whether it works in humans (Thounaojam. 2011).
  • SH21B is an anti-obesity composition composed of seven herbs: Scutellaria baicalensis Georgi, Prunus armeniaca Maxim, Ephedra sinica Stapf, Acorus gramineus Soland, Typha orientalis Presl, Polygala tenuifolia Willd and Nelumbo nucifera Gaertner (active ingredients; see figure below) that has been used for the treatment of obesity in traditional medical clinics in Korea and has recently been shown to decrease the expression of major transcription factors of the adipogenesis pathway and result in the down-regulation of lipid metabolizing enzymes involved in the transport, uptake and synthesis of lipids - unfortunatedly, only in vitro (Lee. 2009)
    Effects of SH21B on fat droplet formation in 3T3-L1 cells (top) and size of adipocytes in adipose tissue. (bottom), as well as active ingredients in SH21B (based on Lee. 2009)
    As you can see in the stains from the adipose tissue of the above, the effects are clearly mediated by both an inhibition of the maturation of preadipocytes (top) and the inhibition of fat storage... now you tell me the world needs "new" anti-obesity agents!? I mean, it's quite obvious that the Koreans knew all along what keeps you lean ;-)
  • Lactobacillus plantarum KY1032 cell extract - Before you begin to jubilee about the triumph march of probiotics, let me tell you this: I am not sure how on earth the remnants of a gut bacterium are supposed to reach your adipocyte tissue in a healthy individual without a leaky gut. Against that background I am not sure, whether it is even necessary to mention that Park et al. observed in 2011 that a cell exctract of the KY1032 strain of lactobacilli is another compound that can down-regulate the expression of peroxisome proliferator-activated receptor-γ2, CCAAT/enhancer binding protein-α, fatty acid synthase, and adipocyte-fatty acid binding protein and thus blunt fat gains in vitro... ah, now I wrote it down, so I'll just leave it here ;-) 
  • Irvingia gabonensis seed extract - Likewise not a newcomer to the supplement the African / Southeast Asian tree, respectively an extract from its seeds has been shown to dose-dependently decrease the expression of PPAR-gamma in murine adipose cells in the petri dish in a 2008 study by scientists from  Faculty of Science, University of Yaoundé in Cameroon and the Wake Forest University School of Medicine in Winston-Salem, USA (Oben. 2008).
The in-vitro study shows, CAF may inhibit fat storage, but it does not "squeeze" the fat out of the cells (data based on Kim. 2012)
  • Citrus aurantium falvenoids (CAF)- Despite the fact that most of you will probably have realized in N=1 experiments that citrus aurantium is a supplemental non-starter as a fatburner. It has (in-vitro) the ability to reduce the epxression of C/EBPβ and subsequently inhibit the activation of PPARγ and C/EBPα. So unless you have taken tons of pure CAF supplements during your last bulk, it is no wonder that you did not realize any effect from the fat burner you bought last summer. After all you are not storing any fat when you are dieting anyway... and I guess you have been dieting, when you took that product, right?

    Apropos dieting, the data in the figure on the right also shows that citrus aurantium, alone, won't help with that. After all it lacks the ability to increase LPL and thus the release of free fatty acids from the triglyceride stores in your fat stores.
  • Silibinin (from milk thistle) - You will probably have heard that milk thistle can help replenish the antioxidative defenses of your liver and thus prevent all sorts of systemic toxicities (learn more). At least in-vitro silibinin (aka silybin), the major active ingredient in silymarin, can also prevent the accumulation of triglycerides in existing, as well as the formation / maturation of future adipocytes. From a mechanistic point of view, the effect is mediated by the usual suspects respectively their downregulation (CAAT/enhancer binding protein-alpha, fatty acid synthase, sterol response element binding protein 1c, adipocyte-specific lipid binding protein, peroxisome proliferator-activated receptor gamma and lipoprotein lipase; cf. Ka. 2009).
  • Stem bromelain (SBM) - Just as so many of the previously mentioned agents, SBM, a specific member of the bromelain family you may know as "pineapple enzyme", is by no means a "new kid on the anti-fatloss block". Rather than that it has been used for centuries in traditional medicine as - guess what? - an anti-obesity agent. Now, I would never suggest that all TCM medicines work, but for stem bromelain it does at least seem as if the in-vitro studies, Dave et al. conducted about a year ago would support the notion that the ingestion of respective supplements can in fact exert beneficial effects on the accumulation of body fat (Dave. 2012).
    Illustration of the mechanism and selected downstream effects of stem bromelain (SBM) on fat cells in the petri dish (compiled based on data from Dave. 2012)
    At the molecular level, SBM targets the same adipogenesic genes as (almost all) of the previous agents. What's interesting though, is the fact that the scsientists also found that "SBM's ability to repress PPARγ expression seems to stem from its ability to inhibit Akt and augment the TNFα pathway." (Dave. 2012) In other words, it's the increase in "bad" TNF-alpha and the decrease in the purportedly muscle, but in fact simply "mass building" Akt-TSC2-mTORC1 pathway that entails the apoptosis (controlled cell death) of mature adipocytes and lipolysis.
With the stem bromelain this comprehensive, but by no means all-encompassing list of "proven" (mostly only in vitro) anti-adipogenic agents, has come full circle. After all, Dave et al. point out that their data would indicate that stem bromelain, together with all-trans retinoic-acid (atRA), which is a metabolite of vitamin A, the first item on our list "may be a potent modulator of obesity by repressing the PPARγ-regulated adipogenesis pathway at all stages and by augmenting TNFα-induced lipolysis and apoptosis in mature adipocytes." (Dave. 2010).

It's not just beyond the scope of this article, but - in the majority of the cases simply not known - whether or not the TNFα increase is an integral part of the anti-obesity effects of all of the aforementioned compounds. As far as the inhibition of PPAR-gamma is concerned things are different, though. With PPAR-gamma being the central "fat storage" switch, its deactivation and the entailing blockade of adipocyte differentiation, pre-adipocyte maturation and triglyceride storage is currently probably the most effective anti-obesity  mechanism we know. A mechanism that is way more fundamental than the diet-induced and stimulant / alpha/beta-agaonist (caffeine, ephedra, clenbuterol, yohimine) supported emptying of existing adipocyte triglyceride stores.

I know it's not popular, but in the case of vitamin D we already have evidence of it's obesity promoting effects (read more). It's straight forward experimental evidence, much contrary to the epidemiological guesswork on the basis of which people are popping vitamin D pills, these days.
Keep in mind: Most of the data is derived from in-vitro studies. Few compounds do have actual evidence from rodent studies and the number of substances that showed beneficial effects in human studies is even smaller.

Nevertheless, the above list harbors a number of compounds which could be of great interest for the lean physical culturist, for whom (at least physique-wise) stuff like vitamin D (note: the effects could be dose-dependent with benefits at low, and detrimental effects at high levels), astragalus and the rest of the healthy, but pro-adipogenic agents that can help obese individuals to stash away the tons of sugar and fat floating through their arteries are of little use.

Against that background I want to close this post with a warning, or I should say a reminder of the the fact that the effects of PPAR-gamma are physiologically important (e.g. prevention of lipotoxicity, Medina-Gomez. 2007) and go beyond "just making you fat" in how it would be worth striving to suppress it altogether is thus questionable (suggested read: CLA Destroys Body Fat). Since for all of the previously discussed agents that have in-vivo data to support their efficacy have postivite, not negative "side effects" (think of curcumin, gingerol, ginseng, etc.), it is yet unlikely that the use of reasonable amounts of one or a stack of many of them is going to harm you.

Just keep in mind: The goal should be to keep the PPAR-gamma activity in check, not to annihilate it. Consequently you should not and cannot expect to be able to "eat whatever you want and still stay lean" by supplementing with any of the agents above. On the other hand, they can hardly be even less useful than the vast majority of currently available arsenal of OTC "fat burners" ;-)

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