Review

Isohumulones from hops (Humulus lupulus) and their potential role inmedical nutrition therapy

Jeffrey S. Bland a,*, Deanna Minich b, Robert Lerman b, Gary Darland b, Joseph Lamb b,Matthew Tripp b, Neile Grayson a

aKinDex Pharmaceuticals, Seattle, Washington, USAbConsultant Scientist, Seattle, Washington, USA

A R T I C L E I N F O

Article history:Received 22 January 2015Received in revised form 27 February 2015Accepted 3 March 2015Available online 9 March 2015

Keywords:HopsIsohumulonesMetabolic inflammationInsulin resistance

A B S T R A C T

The lipophilic extracts of the common hops (Humulus lupulus) contain compounds that are readilymodified to the family of isohumulones (e.g., iso-alpha acids). The isohumulones have been found toreduce metabolic inflammation and insulin resistance, and positively impact dyslipidemia and obesity.These effects are consistent across studies in multiple cell lines, animal model systems and humanintervention trials. Mechanistic work has demonstrated that these isohumulones have a uniquepleiotropic mechanism of action which is consistent with their demonstrated safety and range ofphysiological effects. It is suggested from this extensive body of work that specific isohumulones may beimportant bioactive agents for the application in medical nutrition therapy in the support of diseasesassociated with chronic inflammation and insulin resistance.ã 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND

license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Contents

1. Influence of hops isohumulones (iso-alpha acids) on inflammation and insulin sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472. Bioavailability and metabolism of isohumulones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493. Effects of hops isohumulones on insulin sensitivity and metabolic syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494. Influence of the hops-derived isohumulones on obesity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

The past two decades have witnessed a global explosion in theprevalence of non-communicable, non-infectious chronic diseasessuch as type 2 diabetes, coronary heart disease, autoimmunediseases, and dementia [1]. All of these diseases have been found tobe associated with a physiological state of chronic inflammationdefined as low-grade inflammation orchestrated bymetabolic cellsin response to specific immune activating signals [2], the origin ofwhich is complex but has been found to be related to diet, lifestyleand environmental factors [3]. The recent PREDIMED study hasdemonstrated that a Mediterranean diet rich in fruit andvegetables, whole grains, nuts and virgin olive oil has a beneficialinfluence on lowering the incidence of heart disease and reducingchronic metabolic inflammation [4–8].

[TD$INLINE]

This association between specific dietary components and thereduction in incidence of non-communicable chronic diseases

* Corresponding author. Tel.: +1 2069222912.E-mail address: jeffbland@kindexpharmaceuticals.com (J.S. Bland).

http://dx.doi.org/10.1016/j.phanu.2015.03.0012213-4344/ã 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

PharmaNutrition 3 (2015) 46–52

Contents lists available at ScienceDirect

PharmaNutrition

journal homepage: www.elsevier .com/ locate /phanu

raises the question as to themechanistic role that specific diets andtheir component nutrients have on chronic diseases associatedwith metabolic inflammation. It is well known that food iscomposed of a complex matrix of the macronutrients protein,carbohydrate and fat that exist in many different chemical andphysical forms depending on the type of foods and their method ofpreparation that are included in the diet. Beyond these nutrients,however, vitamins, minerals, essential fatty acids, phytochemicalsand conditionally essential nutrients such as taurine, lipoic acid,coenzyme Q10, and carnitine all play roles in the modulation ofphysiological function.

Micronutrients and phytonutrients have been found to influ-ence physiology through the following cellular interactions [9,10]:

� B-vitamins serve as cofactors to specific enzymes that regulatemetabolism.

� Minerals serve as cofactors that regulate enzyme activities.� Fat soluble vitamins A and D have been demonstrated toinfluence genetic expression as well as non-genomic effects.

� Essential amino acids such as phenylalanine, tyrosine andtryptophan serve as precursors to neurotransmitters.

� Phytochemicals can serve as agents that modulate intercellularsignal transduction and genetic expression.

Over the past decade phytochemicals have been identified thatinfluence metabolism, signal transduction and genetic expressionthrough a number of specific mechanisms that include [11–15]:

� Nuclear transcription factor regulation.� Epigenetic regulation.� Response element influence.� Mitochondrial redox regulation.� Enzyme inhibition.� Precursor to cellular mediators.� Post-translational protein modification.

Howitz and Sinclair have suggested that the role of phyto-chemicals in influencing mammalian physiology is through ahormetic effect (i.e., low dose beneficial modulatory effect) onsignal transduction and genetic expression that reduces cellularstress response as described in Fig. 1 [16].

1. Influence of hops isohumulones (iso-alpha acids) oninflammation and insulin sensitivity

One of the interesting families of phytochemicals in terms oftheir influence on cellular disturbances associated with metabolicinflammation and insulin resistance as reviewed by Van Cleemputet al. are the lipophilic isohumulones (e.g., iso-alpha acids) derivedfrom the common hops, Humulus lupulus [17].

The resin glands or strobiles of the female hop plantbiosynthesize several hundred different phytochemicals. Thehumulones or alpha acids represent one major class of lipophilicagents produced by the female plant, and have been used asbittering agents in the production of beer for centuries. In thebrewing of beer, the heating process involved in the developmentof the wort can isomerize the cyclohexadienone structure of thehumulones to the cyclopentadienone structure of the isohumu-lones as shown in Fig. 2. The degree of isomerization and theamount of bitter flavor produced by the addition of hops is highlydependent on the length of time the hops are boiled.

Yajima et al. were the first group to report the influence thatisohumulones have in both cellular and animal models of insulinresistance [18]. Their published study included the results of asmall double blind, placebo controlled pilot trial in diabetichumans demonstrating a significant reduction in fasting bloodglucose and hemoglobin A1c after 8 weeks of intervention in theisohumulone treated group versus the control group. Subsequentstudies reported by this Japanese group indicated that thehops-derived isohumulones reduced elevated triglycerides asso-ciated with insulin resistance, and raised HDL cholesterol levelswhile reducing liver fat stores in diabetic animal models [19,20]. Ina companion study this same group reported that the administra-tion of isohumulones prevented high fat diet-induced obesity inthe C57BL/6N mouse model [21]. Nozawa et al. also reported thatdietary supplementation with isohumulones was found to reducethe production of the proinflammatory prostaglandin E2 in the ratcolon suggesting a tissue-specific anti-inflammtory effect [22].

In 2005 Tripp reported the unique antiinflammatory potentialand putative mechanism of action of the isohumulones [23,24].Babish et al. screened 208 chemically characterized phytochemicalextracts for antiinflammatory and antidiabetic activity and foundthat the iso-alpha acids derived from hops and proanthocyanidins

[(Fig._1)TD$FIG]

Fig. 1. Influence of various phytochemicals on cellular stress response [16].

J.S. Bland et al. / PharmaNutrition 3 (2015) 46–52 47

from Acacia nilotica were among the most active naturalcompounds influencing both inflammation and insulin signalingpathways [25]. Indeed, a synergistic relationship between theisohumulones derived from hops and A. nilotica- derivedproanthocyanidins was observed at specific ratios and mayrepresent an example of how combination of specific phytochem-icals can have a hormetic influence on cellular physiology [26].

Hougee et al. have described the influence of lipophilic hops-extracts on the reduction of zymosan-induced arthritis in themouse model [27]. Minich and Bland discuss the role of the hopsisohumulones and other phytochemicals on signal transductionassociated with regulation of the insulin and inflammationmetabolic network [28].

The isohumulones are the major constituents of modified hopextracts which is an approved food additive in the United States forthe use as bittering agents in beer [29]. The chemical structures ofthe cis and trans isomers of the three classes of isohumulonestermed n, co and ad are as shown:

[TD$INLINE]

The isohumulones have been found effective in reducinginflammatory arthritis in both animal models and open labeland controlled human intervention trials in individuals with thepain and inflammation associated with osteoarthritis to improvesymptoms as determined by the use of the WOMAC validatedosteoarthritis screening questionnaire [30,31].

The safety of the hops-derived isohumulones as contrasted tothe standard non-steroidal anti-inflammatory medications isrelated to the unique antiinflammatory mechanism of action ofthe isohumulones. Hall et al. have demonstrated that theisohumulones are not a direct inhibitor of the proinflammatoryenzyme cyclooxygenase 2, but rather they reduce the nucleartranslocation of the transcription factor NFkB selectively inimmune activated macrophages [32]. The isohumulones reducethe abundance of the inducible cyclooxygenase 2 in the immune

activated cells without adversely influencing cyclooxygenase2 expression in other cells such as the gastrointestinal mucosawhere this enzyme is important for maintaining healthy function.It was shown by Hall et al. in the AGS human gastric mucosal cellline that the isohumulones do not have an adverse effect oncyclooxygenase function whereas the common non-steroidalantiinflammatories aspirin, ibuprofen, indomethacin and nap-roxen increase the risk to gastrointestinal pathology due to theirinhibition of cyclooxygenase function [33]. In human interventiontrials the isohumulone pharmacophore had no effect on the level offecal calprotectin, a measure of gastric inflammation, whenadministered orally, whereas naproxen in the same subjects in acrossover trial resulted in a significant increase in fecal calprotectin[33,34].

Mechanistic studies executed by Konda et al. demonstrated thatthe isohumulones had a dose dependent impact on both NFkBnuclear translocation and nitric oxide production in LPS stimulatedRAW 264.7 murine macrophages as shown in Fig. 3 indicating thatthe anti-inflammatory effect of the isohumulones was a result ofdecreased inflammatory gene expression [35].

[(Fig._2)TD$FIG]

Fig. 2. Isomerization of hops humulone to isohumulone in the brewing of beer.

[(Fig._3)TD$FIG]

Fig. 3. Influence of the hops-derived RIAA on NFkB and nitric oxide synthaseactivity [35].

48 J.S. Bland et al. / PharmaNutrition 3 (2015) 46–52

Desai et al. demonstrated that the isohumulone derivativeTHIAA attenuates the TNF-alpha activated inflammation andmatrix metalloproteinase-9 expression in human monocyticTHP-1 cells as well as their adherence to human aortic endothelialcells [36]. These observations suggest that THIAA may havebeneficial effects for the prevention of cardiovascular diseases byameliorating inflammation and subsequent plaque destabilization,which are hallmarks of atherosclerosis. Desai et al. have alsoreported that the THIAA derivative from hops was capable ofreducing the inflammatory processes associated with an animalmodel of rheumatoid arthritis by showing a reduction in swelling,prevention of cartilage destruction, and reduction in bonedestruction [36].

2. Bioavailability and metabolism of isohumulones

Cattoor et al. evaluated the bioavailability of the isohumulonesin New Zealandwhite rabbits andwell as in Caco-2 cellmonolayersto investigate epithelial transport. The bioavailability of theisohumulones was determined through the differential pharma-cokinetics of an oral versus intravenously administered dose. Theisohumulones were found to be efficiently transported across thegastrointestinalmucosa resulting in approximately 30% absorptionof an oral dose within 4h after administration [37,38].

When the isohumulones were incubated with rabbit hepaticmicrosomes it was found that they were rapidly metabolized to avariety of oxidation products principally characterized as humu-linic acids and allosio-alpha-acids which are water soluble andreadily excreted [39].

In studies with Dahl salt-sensitive hypertensive rats it wasfound that when they were fed a diet supplemented withisohumulones that there was a marked reduction observed inrenal injury, proteinuria and blood pressure. It was also found thatglomerulosclerosis and interstitial fibrosis scores were significant-ly decreased. The authors suggest that the exposure to isohumu-lones and their metabolites may help prevent the progression ofrenal injury caused by hypertension [40].

3. Effects of hops isohumulones on insulin sensitivity andmetabolic syndrome

Over the past decade the interrelationship between theinflammatory and insulin signaling pathways has been elucidated[41]. In vitro assays with murine 3T3L1 adipocytes as well diabeticanimal models indicated that the antiinflammatory effects of theisohumulones were associated with the improvement in insulinsignaling [42,43]. Obara et al. reported the results of a study ofninety-four subjects with prediabetes whowere randomly dividedinto four groups and engaged in a 12 week double blind dose-finding study to evaluate the impact of ingestion of 16, 32, or 48mgof isohumulones per day versus placebo [44]. After treatment thefasting blood glucose was decreased in the 32 and 48mg groups,but did not change in the placebo group. The hemoglobin A1c wasalso significantly decreased in the 48mg group versus the placebo.There was also a significant decrease in body mass index (BMI) inthe 48mg group as compared with placebo.

In a 12 week, diet controlled intervention trial in patients withmetabolic syndrome and dyslipidemia it was found that a medicalfood supplemented program containing isohumulones and Acaciaanthocyandins resulted in a clinical improvement in all thebiomarkers associated with insulin resistance [45]. In a largermulti-centered, diet controlled study in women with insulinresistance and metabolic syndrome Jones et al. found that anisohumulone and anthocyanidin containing medical food admin-istered along with a low glycemic load, Mediterranean dietdecreased atherogenic lipoproteins and lipoprotein (a) and

oxidized low density lipoprotein more effectively than the lowglycemic load, Mediterranean diet alone [46].

Lerman et al. reported that in women and men with metabolicsyndrome, insulin resistance and dyslipidemia that interventionwith the medical food containing the hops-derived isohumulonesand A. nilotica anthocyanidins along with a low glycemic load,Mediterranean style diet resulted in significantly better outcome inreduction of all the clinical features of metabolic syndrome than ina matched group of subjects who received the low glycemic load,Mediterranean diet alone [47].

4. Influence of the hops-derived isohumulones on obesity

Sumiyoshi and Kimura reported that extracts of hops(H. lupulus) were found to inhibit obesity in mice fed a high fatdiet over a long-term period [48]. They proposed that specific hopextracts might be useful for preventing obesity and glucoseintolerance caused by a high fat diet.

In examining the influence of isohumulones on obesity, Kondaet al. reported that a specific molecule synthesized from theisohumulone THIAA mixture had the ability to improve insulinsignaling and obesity in both the diet-induced obesity mousemodel of type 2 diabetes and the Zucker diabetic fatty rat model[49]. This study demonstrated that the isohumulone pharmaco-phore represents itself as a privileged structure that influencesadipocyte physiology and adiposity.

Vroegriik et al. demonstrated that the hops-derived isohumu-lone mixture when administered in a high-fat fed mouse model ofdiabetes for 5–14 weeks resulted in a significantly lower meanweight than the control animals or those treated with the insulinsensitizing drug rosiglitazone even though calorie consumptionwas equal in all three groups as shown in Fig. 4 [50].

In metabolic chamber studies they found that the isohumu-lones increased thermogenic responsiveness and resting energyexpenditure in the animals suggesting that the isohumulonesincrease lipid metabolism.

[(Fig._4)TD$FIG]

Fig. 4. Effect of the isohumulonemixture (Meta060) and rosiglitazone interventionon obesity in the high fat fed diabetic mouse model [50].

J.S. Bland et al. / PharmaNutrition 3 (2015) 46–52 49

These observations that the isohumulones are associated withimproved lipid metabolism, improved insulin sensitivity and thereduction in metabolic inflammation raises the question as to amechanistic explanation for these varied influences on metabolicdisturbance. Everard et al. have provided a novel potentialexplanation for the various influences that the isohumuloneshave on these multiple physiological endpoints [51]. Theyevaluated the influence of isohumulones in the high-fat fedmouse model of diabetes on insulin sensitivity, serum triglycer-ides, inflammation and obesity. Their data confirmed previousstudies that demonstrated the ability of the isohumulones toimprove insulin action and its relationship to the regulation ofpost-prandial serum glucose, and the reduction of triglyceridesand obesity.

Beyond these observations, however, Cani et al. demonstratedthat the isohumulones were capable of reducing post-prandialendotoxemia. There is now considerable evidence that high fatdiets create alteration in gut mucosal permeability and activationof the enteric immune system that initiates metabolic inflamma-tion and insulin resistance [52–54]. This state of chronicpostprandial endotoxemia in turn results in systemic crosstalkamong the intestinal microbiota, circulating macrophages andmonocytes, adipocytes and skeletal muscle that creates a bluntingof insulin sensitivity and reduced lipid metabolism [55,56].Characteristics of postprandial endotoxemia include an increasein serum lipopolysaccharides derived from the outer cellularmembrane of intestinal gram negative bacteria and the proin-flammatory cytokines TNF-alpha and interleukin-6 [57]. The workof Cani et al. demonstrated in the diet-induced obesity mousemodel that the administration of isohumulones resulted in a trendtoward a statistically significant reduction of plasma lipopolysac-charides, however the reduction in postprandial serum levels ofinterleukin-6 and tumor necrosis factor alpha did reach statisticalsignificance [51].

It is known that the high fat diet increases gastrointestinalmucosal permeability through the alteration in integrity of thetight junction proteins, occludin and zonulin, which then

contributes to the increased absorption of LPS and activation ofthe enteric immune system [58,59]. As is shown in Fig. 5, Cani et al.demonstrated that the administration of isohumulones improvedzonulin and occludin mRNA expression in the gastrointestinalmucosa in the high-fat fed obese mouse model which is consistentwith improved gastrointestinal mucosal integrity and a reducedabsorption of LPS [51].

These data suggest that isohumulonesmay reduce the activationof specific pattern recognition receptors on target tissues suchas thegastrointestinalmucosal cells thereby reducing the triggering of theproinflammatory immune responsewhich is associatedwith insulinresistance, dyslipidemia, and obesity [60,61].

5. Conclusion

The lipophilic family of isohumulones derived from a modifiedhops extract have been found to have a unique ability to modulatethe metabolic disturbances that result in chronic metabolicinflammation. These effects have been demonstrated consistentlyamong various cell lines, animal model systems and humanintervention trials. The isohumulones improve insulin resistanceand dyslipidemia in humans. They have also been shown to reducesystemic inflammation, increase lipid metabolism and reduceadiposity in high fat-fed animal models. Lastly they have beenshown to reduce post-prandial endotoxemia while improvinggastrointestinalmucosal integrity during high fat feeding in animalmodels. These characteristics of this class of molecules indicatethat the isohumulones position themselves as potentially useful asbioactive substances for inclusion in medical nutrition therapiesfor the management of chronic diseases associated with metabolicinflammation related diabesity [62]. The emerging understandingof the physiological effects of the isohumulones suggests that theyhave a pleiotropic network influence on metabolism. As Barabasihas recently commented “network effects increasingly affect allaspects of biologic andmedical research, fromdiseasemechanismsto drug discovery. It is only amatter of time until these advances inunderstanding will start to affect medical practice, making theemergence of a new field that may be aptly called networkmedicine” [63]. The isohumulones represent a family of moleculesthat maywell find applications in medical nutrition therapy due totheir unique pleiotropic influences on the chronic diseasesassociated with metabolic inflammation.

References

[1] Woolf SH, Aron L, editors. U.S. health in international perspective: shorterlives, poorer health. Washington, D.C: NRC and IOM, National AcademiesPress; 2013

[2] Strissel KJ, Denis GV, Nikolajczyk BS. Immune regulators of inflammation inobesity-associated type 2 diabetes and coronary artery disease. Curr OpinEndocrinol Diabetes Obes 2014;21(5):330–8, doi:http://dx.doi.org/10.1097/MED.0000000000000085. 25106001.

[3] Olden K, Lin YS, Gruber D, Sonawane B. Epigenome: biosensor of cumulativeexposure to chemical and nonchemical stressors related to environmentaljustice. Am J Public Health 2014;104(10):1816–24, doi:http://dx.doi.org/10.2105/AJPH.2014.302130. 25122010.

[4] Estruch R, Ros E, Salas-Salvad J, Covas MI, Corella D, Aros F, et al. Primaryprevention of cardiovascular disease with a Mediterranean diet. N Engl J Med2013;368(14):1279–90, doi:http://dx.doi.org/10.1056/NEJMoa1200303.23432189.

[5] De Lorgeril M. Mediterranean diet and cardiovascular disease: historicalperspective and latest evidence. Curr Atheroscler Rep 2013;15(12):370, doi:http://dx.doi.org/10.1007/s11883-013-0370-4. 24105622.

[6] Chiva-Blanch G, Badimon L, Estruch R. Latest evidence of the effects of theMediterranean diet in prevention of cardiovascular disease. Curr AtherosclerRep 2014;16(10):446, doi:http://dx.doi.org/10.1007/s11883-014-0446-9.25115436.

[7] Casas R, Sacanella E, Urpi-Sarda M, Chiva-Blanch G, Ros E, Martinez-GonzalezMA, et al. The effects of the Mediterranean diet on biomarkers of vascular wallinflammation and plaque vulnerability in subjects with high risk for cardio-vascular disease. A randomized trial. PLoS One 20149(6), doi:http://dx.doi.org/10.1371/journal.pone.0100084. 24925270

[(Fig._5)TD$FIG]

Fig. 5. Influence of isohumulones (Meta) on gastrointestinal mucosal occludin andzonulin mRNA in the high fat fed obese mouse model [51].

50 J.S. Bland et al. / PharmaNutrition 3 (2015) 46–52

[8] Ruiz-Canela M, Estruch R, Corella D, Salas-Salvadó J, Martínez-González MA.Association of Mediterranean diet with peripheral artery disease: the PRE-DIMED randomized trial. JAMA 2014;311(4):415–7, doi:http://dx.doi.org/10.1001/jama.2013.280618. 24449321.

[9] Kaur B, Henry J. Micronutrient status in type 2 diabetes: a review. Adv FoodNutr Res 2014;71:55–100, doi:http://dx.doi.org/10.1016/B978-0-12-800270-4.00002-X. 24484939.

[10] Ames BN, Elson-Schwab I, Silver EA. High-dose vitamin therapy stimulatesvariant enzymes with decreased coenzyme binding affinity (increased Km):relevance to genetic disease and polymorphisms. Am J Clin Nutr 2002;75(4):616–58. 11916749.

[11] González-Castejón M, Rodriguez-Casado A. Dietary phytochemicals and theirpotential effects on obesity: a review. Pharmacol Res 2011;64(5):438–55, doi:http://dx.doi.org/10.1016/j.phrs.2011.07.004. 21798349.

[12] Anuradha CV. Phytochemicals targeting genes relevant for type 2 diabetes. CanJ Physiol Pharmacol 2013;91(6):397–411, doi:http://dx.doi.org/10.1139/cjpp-2012-0350. 23745945.

[13] Malireddy S, Kotha SR, Secor JD, Gurney TO, Abbott JL, Maulik G, et al. Phy-tochemical antioxidants modulate mammalian cellular epigenome: implica-tions in health and disease. Antioxid Redox Signaling 2012;17(2):327–9, doi:http://dx.doi.org/10.1089/ars.2012.4600. 22404530.

[14] Shankar S, Kumar D, Srivastava RK. Epigenetic modifications by dietaryphytochemicals: implications for personalized nutrition. Pharmacol Ther2013;138(1):1–17, doi:http://dx.doi.org/10.1016/j.pharmthera.2012.11.002.23159372.

[15] Khuda-Bukhsh AR, Das S, Saha SK. Molecular approaches toward targetedcancer prevention with some food plants and their products: inflammatoryand other signal pathways. Nutr Cancer 2014;66(2):194–205, doi:http://dx.doi.org/10.1080/01635581.2014.864420. 24377653.

[16] Howitz KT, Sinclair DA. Xenohormesis: sensing the chemical cues of otherspecies. Cell 2008;133(3):387–91, doi:http://dx.doi.org/10.1016/j.cell.2008.04.019. 18455976.

[17] Van Cleemput M, Cattoor K, De Bosscher K, Haegeman G, De Keukeleire D,Heyerick A. Hops (Humulus lupulus)-derived bitter acids as multipotent bio-active compounds. J Nat Prod 2009;72(6):1220–30, doi:http://dx.doi.org/10.1021/np800740m. 19476340.

[18] Yajima H, Ikeshima E, Shiraki M, Kanaya T, Fujiwara D, Odai H, et al. Iso-humulones, bitter acids derived from hops, activate both peroxisome pro-liferator-activated receptor alpha and gamma and reduce insulin resistance. JBiol Chem 2004;279(32):33456–62, doi:http://dx.doi.org/10.1074/jbc.M403456200. 15178687.

[19] Miura Y, Hosono M, Oyamada C, Odai H, Oikawa S, Kondo K. Dietary iso-humulones, the bitter components of beer, raise plasma HDL-cholesterollevels and reduce liver cholesterol and triacylglycerol contents similar toPPARa activations in C57BL/6 mice. Br J Nutr 2005;93(4):559–67. 15946420.

[20] Shimura M, Hasumi A, Minato T, Hosono M, Miura Y, Mizutani S, et al. Iso-humulones modulate blood lipid status through the activation of PPAR alpha.Biochim Biophys Acta 2005;1736(1):51–60, doi:http://dx.doi.org/10.1016/j.bbalip.2005.06.008. 16099209.

[21] Yajima H, Noguchi T, Ikeshima E, Shiraki M, Kanaya T, Tsuboyama-Kasaoka N,et al. Prevention of diet-induced obesity by dietary isomerized hop extractcontaining isohumulones, in rodents. Int J Obes (Lond) 2005;29(8):991–7, doi:http://dx.doi.org/10.1038/sj.ijo.0802965. 15852044.

[22] Nozawa H, Nakao W, Zhao F, Kondo K. Dietary supplement of isohumulonesinhibits the formation of aberrant crypt foci with a concomitant decrease inprostaglandin E2 level in rat colon. Mol Nutr Food Res 2005;49(8):772–8, doi:http://dx.doi.org/10.1002/mnfr.200500027. 15968705.

[23] Tripp ML, Darland G, Lerman R, Lukaczer D, Bland J. Hop and modified hopextracts have potent in vitro anti-inflammatory properties. Acta Hort2005;668:217–27.

[24] Tripp ML, Konda VR, Darland G, Desai A, Chang J-I, Carroll BJ, et al. Rho-iso-alpha acids and tetrahydro-iso-acids are selective protein kinase inhibitorswhich potently reduce inflammation in macrophages in vitro and in thecollagen-induced rheumatoid arthritis model in vivo. Arch Hort2009;848:221–34.

[25] Babish JG, Pacioretty LM, Bland JS, Minich DM, Hu J, Tripp ML. Antidiabeticscreening of commercial botanical products in 3T3-L1 adipocytes and db/dbmice. J Med Food 2010;13(3):535–47, doi:http://dx.doi.org/10.1089/jmf.2009.0110. 20521979.

[26] Tripp ML, Darland G, Konda VR, Pacioretty LM, Chang J, Bland JS, et al. Op-timized mixture of hops rho iso-alpha acids-rich extract and acacia proan-thocyanidins-rich extract reduces insulin resistance in 3T3-L1 adipocytes andimproves glucose and insulin control in db/db mice. Nutr Res Pract 2012;6(5):405–13, doi:http://dx.doi.org/10.4162/nrp.2012.6.5.405.

[27] Hougee S, Faber J, Sanders A, Berg WB, Garssen J, Smit HF, et al. Selectiveinhibition of COX-2 by a standardized CO2 extract of Humulus lupulus in vitroand its activity in a mouse model of zymosan-induced arthritis. Planta Med2006;72(3):228–33, doi:http://dx.doi.org/10.1055/s-2005-916212. 16534727.

[28] Minich DM, Bland JS. Dietary management of the metabolic syndrome beyondmacronutrients. Nutr. Rev. 2008;66(8):429–44, doi:http://dx.doi.org/10.1111/j.1753-4887.2008.00075.x. 18667004.

[29] United States Federal Food and Drug Code of Federal Regulations, 21 CFR Ch.1(04.01.03 ed.).

[30] Lukaczer D, Darland G, TrippM, LIska D, Lerman RH, Schiltz B, et al. A pilot trialevaluating Meta050, a proprietary combination of reduced iso-alpha acids,rosemary extract and oleanolic acid in patientswith arthritis and fibromyalgia.

Phytother Res 2005;19(10):864–9, doi:http://dx.doi.org/10.1002/ptr.1709.16261517.

[31] Minich DM, Bland JS, Katke J, DarlandG, Hall A, Lerman RH, et al. Clinical safetyand efficacy of NG440: a novel combination of rho iso-alpha acids from hops,rosemary, and oleanolic acid for inflammatory conditions. Can J PhysiolPharmacol 2007;85(9):872–83, doi:http://dx.doi.org/10.1139/Y07-055.18066133.

[32] Hall AJ, Babish JG, Darland GK, Carroll BJ, Konda VR, Lerman RH, et al. Safety,efficacy and anti-inflammatory activity of rho iso-alpha-acids from hops.Phytochemistry 2008;69(7):1534–47, doi:http://dx.doi.org/10.1016/j.phy-tochem.2008.02.001. 18358504.

[33] Hall AJ, Tripp M, Howell T, Darland G, Bland JS, Babish JG. Gastricmucosal cell model for estimating relative gastrointestinal toxicity of non-steroidal anti-inflammatory drugs. Prostaglandins Leukot Essent Fatty Acids2006;75(1):9–17, doi:http://dx.doi.org/10.1016/j.plefa.2006.04.006.16806870.

[34] Konda VR, Desai A, Darland G, Bland JS, Tripp ML. Rho iso-alpha acidsfrom hops inhibit the GSK-3/NF-kappaB pathway and reduce inflammatorymarkers associated with bone and cartilage degradation. J Inflamm (Lond)2009;6:26–32, doi:http://dx.doi.org/10.1186/1476-9255-6-26. 19712471.

[35] Konda VR, Desai A, Darland G, Bland JS, Tripp ML. Meta060 inhibits osteo-clastogenesis and matrix metalloproteinases in vitro and reduces bone andcartilage degradation in a mouse model of rheumatoid arthritis. ArthritisRheum 2010;62(6):1683–92, doi:http://dx.doi.org/10.1002/art.27441.20201075.

[36] Desai A, Darland G, Bland JS, Tripp ML, Konda VR. META060 attenuates TNF-a-activated inflammation, endothelial-monocyte interactions, and matrixmetalloproteinase-9 expression, and inhibits NF-kB and AP-1 in THP-1 monocytes. Atherosclerosis 2012;223(1):130–6, doi:http://dx.doi.org/10.1016/j.atherosclerosis.2012.05.004. 22658256.

[37] Cattoor K, Bracke M, Deforce D, De Keukeleire D, Heyerick A. Transport of hopbitter acids across intestinal Caco-2 cell monolayers. J Agric Food Chem2010;58(7):4132–40, doi:http://dx.doi.org/10.1021/jf904079h. 20329731.

[38] Cattoor K, Remon JP, Boussery K, Van Bocxlaer J, Bracke M, De Keukeleire D,et al. Bioavailability of hop-derived iso-alpha-acids and reduced derivatives.Food Funct 2011;2(7):412–22, doi:http://dx.doi.org/10.1039/c1fo10009b.21894329.

[39] Cattoor K, Dresel M, De Bock L, Boussery K, Van Bocxlaer J, Remon JP, et al.Metabolism of hop-derived bitter acids. J Agric Food Chem 2013;61(33):7916–24, doi:http://dx.doi.org/10.1021/jf300018s. 23898921.

[40] Namikoshi T, Tomita N, Fujimoto S, Haruna Y, Ohzeki M, Komai N, et al.Isohumulones derived from hops ameliorate renal injury via an anti-oxidativeeffect in dahl salt-sensitive rats. Hypertens Res 2007;30(2):175–84, doi:http://dx.doi.org/10.1291/hypres.30.175.

[41] ParkMH, KimDH, Lee EK, KimND, ImDS, Lee J, et al. Age-related inflammationand insulin resistance: a review of their intricate interdependency. ArchPharm Res 2014;37(12):1507–14, doi:http://dx.doi.org/10.1007/s12272-014-0474-6. 25239110.

[42] Minich DM, Lerman RH, Darland G, Babish JG, Pacioretty LM, Bland JS, et al.Hops and acacia phytochemicals decreased lipotoxicity in 3T3-L1 adipocytes,db/dbmice, and individuals withmetabolic syndrome. J Nutr Metab 2010, doi:http://dx.doi.org/10.1155/2010/467316. 20721358

[43] Tripp ML, Darland G, Konda VR, Pacioretty LM, Chang JL, Bland JS, et al. Op-timized mixture of hops rho iso-alpha acids-rich extract and Acacia proan-thocyanidins-rich extract reduces insulin resistance in 3T3-L1 adipocytes andimproves glucose and insulin control in db/db mice. Nutr Res Pract 2012;6(5):405–13, doi:http://dx.doi.org/10.4162/nrp.2012.6.5.405. 23198019.

[44] Obara K, Mizutani M, Hitomi Y, Yajima H, Kondo K. Isohumulones, the bittercomponent of beer, improve hyperglycemia and decrease body fat in Japanesesubjects with prediabetes. Clin Nutr 2009;28(3):278–84, doi:http://dx.doi.org/10.1016/j.clnu.2009.03.012. 19395131.

[45] Lerman RH, Minich DM, Darland G, Lamb JJ, Schiltz B, Babish JG, et al. En-hancement of a modified Mediterranean-style, low glycemic load dietwith specific phytochemicals improves cardiometabolic risk factors in sub-jects with metabolic syndrome and hypercholesterolemia in a randomizedtrial. Nutr Metab 2008;5(1):29–37, doi:http://dx.doi.org/10.1186/1743-7075-5-29.

[46] Jones JL, Fernandez ML, McIntosh MS, Najm W, Calle MC, Kalynych C, et al. AMediterranean-style low-glycemic-load diet improves variables of metabolicsyndrome in women, and addition of a phytochemical-rich medical foodenhances benefits on lipoprotein metabolism. J Clin Lipidol 2011;5(3):188–96,doi:http://dx.doi.org/10.1016/j.jacl.2011.03.002. 21600524.

[47] Lerman RH,Minich DM, Darland G, Lamb JJ, Chang JL, Hsi A, et al. Subjects withelevated LDL cholesterol and metabolic syndrome benefit from supplemen-tation with soy protein, phytosterols, hops rho iso-alpha acids, and Acacianilotica proanthocyanidins. J Clin Lipidol 2010;4(1):59–68, doi:http://dx.doi.org/10.1016/j.jacl.2009.11.002. 21122628.

[48] Sumiyoshi M, Kimura Y. Hop (Humulus lupulus L.) extract inhibits obesity inmice fed a high-fat diet over the long term. Br J Nutr 2013;109(01):162–72, doi:http://dx.doi.org/10.1017/S000711451200061X.

[49] Konda VR, Desai A, Darland G, Grayson N, Bland JS. KDT501, a derivative fromhops, normalizes glucose metabolism and body weight in rodent models ofdiabetes. PLoS One 2014;9(1):e87848, doi:http://dx.doi.org/10.1371/journal.pone.0087848. 24498211.

[50] Vroegrijk IO, van Diepen JA, van den Berg SA, Romijn JA, Havekes LM, van DijkKW, et al. META060 protects against diet-induced obesity and insulin resis-

J.S. Bland et al. / PharmaNutrition 3 (2015) 46–52 51

tance in a high-fat-diet fed mouse. Nutrition 2013;29(1):276–83, doi:http://dx.doi.org/10.1016/j.nut.2012.05.004. 22985971.

[51] Everard A, Geurts L, Van Roye M, Delzenne NM, Cani PD. Tetrahydroiso-alpha acids from hops improve glucose homeostasis and reduce bodyweight gain and metabolic endotoxemia in high-fat diet-fed mice. PLoS One2012;7(3):e33858, doi:http://dx.doi.org/10.1371/journal.pone.0033858.22470484.

[52] Festi D, Schiumerini R, Eusebi LH, Marasco G, Taddia M, Colecchia A. Gutmicrobiota and metabolic syndrome. World J Gastroenterol 2014;20(43):16079–94, doi:http://dx.doi.org/10.3748/wjg.v20.i43.16079. 25473159.

[53] Moreno-Indias I, Cardona F, Tinahones FJ, Queipo-OrtuñoMI. Impact of the gutmicrobiota on the development of obesity and type 2 diabetes mellitus. FrontMicrobiol 2014;5:190–5, doi:http://dx.doi.org/10.3389/fmicb.2014.00190.24808896.

[54] Tilg H, Moschen AR. Microbiota and diabetes: an evolving relationship. Gut2014;63(9):1513–21, doi:http://dx.doi.org/10.1136/gutjnl-2014-306928.24833634.

[55] Bleau C, Karelis AD, St-Pierre DH, Lamontagne L. Crosstalk between intestinalmicrobiota, adipose tissue and skeletal muscle as an early event in systemiclow-grade inflammation and the development of obesity and diabetes. Dia-betes Metab Res Rev 2014;31:342–8.

[56] Kwon H, Pessin JE. Adipokines mediate inflammation and insulin resistance.Front Endocrinol 2013;4:71–6, doi:http://dx.doi.org/10.3389/fendo.2013.00071. 23781214.

[57] Xiao S, Zhao L. Gut microbiota-based translational biomarkers to preventmetabolic syndrome via nutritional modulation. FEMSMicrobiol Ecol 2014;87(2):303–14, doi:http://dx.doi.org/10.1111/1574-6941.12250. 24219358.

[58] Sapone A, de Magistris L, Pietzak M, Clemente MG, Tripathi A, Cucca F, et al.Zonulin upregulation is associatedwith increased gut permeability in subjectswith type 1 diabetes and their relatives. Diabetes 2006;55(5):1443–9, doi:http://dx.doi.org/10.2337/db05-1593. 16644703.

[59] Assimakopoulos SF, Tsamandas AC, Tsiaoussis GI, Karatza E, Triantos C, VagianosCE, et al. Altered intestinal tight junctions’ expression in patients with livercirrhosis: a pathogenetic mechanism of intestinal hyperpermeability. Eur J ClinInvest 2012;42(4):439–46, doi:http://dx.doi.org/10.1111/j.1365-2362.2011.02609.x. 22023490.

[60] ParkMH, KimDH, Lee EK, KimND, ImDS, Lee J, et al. Age-related inflammationand insulin resistance: a review of their intricate interdependency. Arch.Pharm Res 2014;37(12):1507–14, doi:http://dx.doi.org/10.1007/s12272-014-0474-6. 25239110.

[61] Kwon H, Pessin JE. Adipokines mediate inflammation and insulin resistance.Front Endocrinol 2013;4:71–8, doi:http://dx.doi.org/10.3389/fendo.2013.00071. 23781214.

[62] Kral JG. Diabesity: palliating, curing or preventing the dysmetabolic diathesis.Maturitas 2014;77(3):243–8, doi:http://dx.doi.org/10.1016/j.matur-itas.2013.12.004. 24439056.

[63] Barabási A-L. Networkmedicine–from obesity to the “diseasome”. N Engl J Med2007;357(4):404–7, doi:http://dx.doi.org/10.1056/NEJMe078114. 17652657.

52 J.S. Bland et al. / PharmaNutrition 3 (2015) 46–52