PRESS RELEASE |

EFFECT OF CITRUS AND POMEGRANATE BIOACTIVES ON ENERGY AND VITALITY: A REVIEW OF EVIDENCE AND ACTIFUL, A PROMISING COMPLEX FOR ACTIVE LIVING AND VITALITY

J.Zolotarjova, Bioactor

With advancing age, it is well-documented that significant physiological changes occur, such as a reduction in body energy levels and vitality. Bioactives derived from citrus and pomegranate have been shown to exert favorable effects on blood flow and energy systems, and could represent a novel, potent natural complex for supporting and maintaining active living and vitality. However, the concentration of flavonoids naturally occurring in citrus fruit depends on a multitude of factors (citrus species, harvest date, etc.), making it challenging to ensure sufficient flavonoid intake from fruit juices, in order to achieve beneficial systemic health effects. Therefore, Actiful, an all-natural, stimulant-free, highly bioavailable citrus and pomegranate complex, containing an optimal enantiomer configuration and standardized active flavonoid and nitrate content, could be a promising delivery strategy for enhancing energy and vitality in middle age and older populations. Actiful comprises of a clinically tested orange extract that has been shown to improve both blood flow for a better oxygen delivery to muscle cells and enhance mitochondrial efficiency for a higher energy (ATP) output. Actiful is further augmented with pomegranate as a clinically tested nitrate source to boost NO production. Together, this complex is optimized for a fast uptake of the most bioactive flavonoids and NO substrate. Actiful provides a full-circle effect by systemically activating the oxygen pump and improving mitochondrial respiration. Overall, this leads to a significant improvement in peak force output, required for starting exercise (e.g. walking, sports, or other physical activity) and in endurance, necessary for staying active throughout the day.

1.Introduction

Energy metabolism is the principal, continuous driving force for every function within the human body. Largely, energy metabolism plays an imperative role in the basic maintenance of homeostasis and repair processes (e.g. circulation, respiration), digestion, and the performance of daily and more intensive physical activities. It has been widely recognized that over a lifespan, the body’s cells and systems undergo considerable physiological, degenerative changes and weakening of function.1,2 Consequently, an ensuing reduction in energy levels and vitality is commonly associated with advancing age. Conjointly, physical activity levels have been documented to progressively decline with a concomitant loss of muscle strength, muscle mass, and endurance capacity.3 The World Health Organization (WHO) reported that in European regions, approximately 66% of adults 55-69 years of age and 75% of those over 70 seldom or never partake in exercise.4 While a reduction in activity levels can profoundly impact energy metabolism, deterioration in mitochondrial function with age can cause cells to lose their energy-producing capabilities.3 To potentially prevent and combat such aforementioned health consequences, maintaining and reinforcing daily physical activity and adequate nutrition can serve as integral support for energy systems and overall vitality.1 Moreover, once an individual in mid-age engages in more physical activity, vitality levels will increase and encourage such persons to maintain an active lifestyle.

2.Key Drivers for Vitality: Mood, Blood Flow, and Energy

Over recent years there has been an emerging consumer interest in natural, stimulant-free ingredients and products for promoting a healthy, active lifestyle. This is especially relevant due to the foreseeing rise in ageing populations and the desire to stay active longer. The main drivers supporting vitality are enhanced mood, blood flow, and more efficient energy (ATP) production.

2.1 Mood Enhancement

Mood is an intangible component of the vitality equation. Presently, there is strong evidence for the influence of caffeine intake on boosting energy levels. Caffeine is conventionally consumed through coffee, caffeinated carbohydrate containing beverages, or energy drinks. However, for middle age and older populations (55+), caffeine is a stimulant that can pose a heightened health risk by adversely affecting sleep patterns, increasing irritability, and inducing dehydration, as caffeine is a known diuretic. Hence, caffeine is not believed to be the most optimal solution for enhancing vitality.

2.2 Blood Flow Enhancement

A healthy vascular system is critical for supporting active living and vitality. A healthy blood circulation is able to efficiently distribute more oxygen and nutrients to muscle cells. Through movement and a diet abundant in fresh fruits and vegetables, the production of nitric oxide (NO), a key signaling molecule throughout the body and a potent vasodilator, can be augmented. NO synthesis can be increased by more substrate provision (e.g. nitrate) and through the activation of the prime enzyme for NO synthesis, endothelial nitric oxide synthase (eNOS). Furthermore, increased NO production will lead to the relaxation of the smooth muscles and widening of blood vessels. Subsequently, this induces vasodilation and enhances blood flow to muscle tissue.5 Ultimately, oxygen delivery supports mitochondrial activity through a greater supply of protons, which power the phosphorylation of ADP into ATP.

 2.3 Mitochondrial Efficiency

Mitochondria are regarded as the ‘energy powerhouse of the cell’ and are organelles found in most eukaryotic cells, responsible for the conversion of oxygen molecules and nutrients into the chief source of intracellular energy, adenosine triphosphate (ATP), during aerobic cellular respiration. To improve the rate of cellular respiration for greater energy availability, it is essential that sufficient oxygen supply is present. Oxygen is the terminal electron acceptor within the electron transport chain and can facilitate ATP synthesis from nutrients. Typically, mitochondrial efficiency is co-determined by the amount of proton-leakage, which accounts for 20-25% in energy losses or mitochondrial oxygen consumption.6

3. Promising Results with Flavonoids on Blood Flow and Energy

Promisingly, flavonoids derived from citrus and pomegranate fruits, which are recognized natural components of the Mediterranean Diet, have shown in recent studies to have vitality promoting properties by exerting favorable effects on blood flow and energy systems.7 Citrus fruits are a powerful source of flavonoids.8 Flavonoids are a large group of polyphenolic substances naturally occurring in plant secondary metabolites responsible for fruit coloration. A modest long-term intake of a flavonoid-rich diet rich has been shown to have health-protective benefits.7 Particularly, increasing evidence corroborates the vasodilatory capacity of citrus flavonoids and their ability to improve the efficiency of energy production at the mitochondrial level. Also, the European Food Safety Authority (EFSA) has provided supporting information on citrus flavonoids and the potential maintenance of a healthy venous circulation.9

3.1 Effect of Citrus Flavonoids and Pomegranate Derivatives on Blood Flow

Citrus flavonoids and pomegranate derivatives have notable vasoprotective effects that were observed in in vivo studies.

A popular beverage, orange juice, with elevated citrus flavonoid concentrations, has been investigated in a four-week human intervention study (N=24) among healthy moderately overweight men, whereby a positive effect (P<0.05) on postprandial endothelium-dependent microvascular reactivity after orange juice consumption (500 ml, containing on average 292 mg of Hesperetin-7-O-rutinoside) was observed.10 Notably, these effects on vascular function corresponded with plasma concentrations of flavonoids. The likely mechanism underlying improved endothelial function was attributed to eNOS activation. Similarly, a recently published randomized, controlled, double-masked, crossover study (2017) has evaluated the acute impact of flavanone containing 240 ml beverages (orange juice: 128.9 mg; flavanone-rich orange juice: 272.1 mg; homogenized whole orange: 452.8 mg) on postprandial (double meal including 81 g of fat) vascular function among middle-aged healthy men (N=28).11 All flavanone interventions were able to attenuate temporary impairments in flow-mediated dilation (FMD) caused by the sequential high-fat meal (7h post intake, P<0.05), due to probable actions of citrus flavanone metabolites on NO. As most individuals remain in a post-prandial state throughout the day, inducing such transient vascular changes through the daily intake of citrus flavonoids, may impart long-term beneficial effects on vascular health.11

Collectively, these in vivo findings provide compelling evidence for the potential of citrus flavonoids to enhance eNOS activity and NO synthesis, allowing the body to better adapt to situations requiring rapid vasodilation. Importantly, orange juice has a reputation for being a ‘health drink’, but alarmingly, this beverage has one of the highest sugar contents, closely following soda. Also, orange juice does not contain a standardized content of active flavonoids, making it a less than ideal solution for older populations.

Similar to citrus, pomegranate can exert favorable effects on vascular function. Next to beetroot, pomegranate fruit (Punica granatum) is amongst the chief potent natural sources of nitrate and flavonoid antioxidants.12 The effects of a five-week atherogenic diet supplemented with pomegranate juice on the biological actions of NO and arterial function were examined in obese Zucker rats.13 Plasma nitrate and nitrite levels were significantly increased by pomegranate juice intake (P<0.05) along with vascular reactivity, eNOS expression, and thus, NO production.

Particularly, pomegranate concentrate contains antioxidants that are also capable of protecting NO against oxidative destruction, thus enhancing the biological actions of NO.14 Additionally, not only can NO production and blood flow be increased through eNOS activation, but also, through an NOS-independent pathway whereby circulating nitrate is reduced to nitrite in the mouth, by bacteria. Nitrite enters the systemic circulation and is reduced in the blood and tissues to NO. This pathway is heightened under physiological hypoxia (reduced oxygen), which is vital for NO formation during exercise.12 Given the foregoing, it seems advantageous to administer standardized flavonoids and pomegranate concentrate in the form of a beverage or ready-to-drink (RTD) powder formulation.

3.2 Effect of Citrus Flavonoids on Energy/Mitochondrial Efficiency

Citrus flavonoids may be able to enhance the efficiency of oxygen usage and energy production at the mitochondrial level.

Mitochondrial Proton Leakage

During mitochondrial respiration, an electrochemical gradient or proton motive force is created through the transportation of protons from the mitochondrial matrix into the intermembrane space.3 The proton motive force shuttles protons back into the matrix through ATP synthase, driving ATP synthesis. However, through proton leakage, almost 20-25% of protons may move back into the mitochondrial matrix, bypassing the ATP synthase, and reducing the ability to generate most of the cell’s ATP supply.6,15 Notably, citrus flavonoids may potentially reduce proton leakage (H+), thereby increasing ATP production.

Radical Scavenging Activity and Mitochondrial Efficiency

It is well-recognized that mitochondrial respiration is not a 100% effectual process, and not all oxygen may be converted into water. This can cause low levels of reactive oxygen species (ROS) to form during muscle contractions. Low-to-moderate levels of ROS and cellular oxidative stress may actually be beneficial for controlling cell signaling pathways, but higher levels induced during heavier activity, can augment structural damage to cells (oxidative stress) and decrease the removal of excess radial species. Such consequences reduce mitochondrial efficiency and impair exercise performance.

A study by Ghanim et al.16 discerned that citrus flavonoids present in orange juice can prevent postprandial ROS production and diminish oxidative stress, which may improve NO bioavailability and endothelial function. Ultimately, this can have a considerable latter effect on energy systems. Citrus flavonoids have direct radical scavenging activities and are able to neutralize ROS, for example superoxide anions, hydroxyl radicals, peroxynitrite, and nitric oxide radicals.17 Additionally, a 12-week daily intake of 450 mg of active flavonoids may be able to increase total antioxidant capacity (TAC, µM Trolox) by 13%.18 Thus, a higher antioxidant capacity may be able to potentially attenuate the damaging effects of ROS.

In essence, available data on citrus flavonoids corroborates their role in scavenging excess ROS during oxidative stress. This may be applicable to exercise-induced oxidative stress and the possible prevention of muscle damage and energy loss.

3.3 Effects of Citrus Flavonoids/Pomegranate on Exercise Performance

No prior published human studies conducted on citrus flavonoid intake and exercise performance were found. An animal study performed by de Oliveira et al. has investigated the effects of four-week hesperetin-7-O-rutinoside supplementation (100 mg/kg body mass) with continuous and interval swimming on oxidative stress markers (TBARS and DPPH) in rats.19 Markedly, the rats allocated to the interval swimming group had an observed 60% increase in lipid peroxidation. This suggests that the intensity of exercise fostered greater oxidative stress, but an intake of citrus flavonoids was able to mitigate these effects.

In 2016, a study was conducted to investigate the consumption of natural pomegranate juice supplementation (POMj) on exercise performance and delayed responses of muscle soreness.20 Elite weightlifters (N=9) consumed 1500 ml of POMj or placebo three times daily, 48 hours proceeding two weightlifting-training sessions (250 ml x 6 times with 8 hour intervals in between). Additionally, one hour before the training sessions, an additional 500 ml of POMj or placebo was consumed. Individuals allocated to the POMj group demonstrated higher total and maximal weight lifted amounts (+8.30%) in comparison to the placebo group (P<0.05). Furthermore, a significant 13.4% improvement in DOMS (delayed onset muscle soreness) of the knee extensors (P<0.01) was observed with POMj ingestion. These favorable effects of natural pomegranate juice on exercise performance is corroborated by previous findings from a study that evaluated the acute intake of 1000 mg of pomegranate extract.12 Pomegranate’s superior nitrate and polyphenol content was able to increase NO production and enhance exercise performance.

In essence, these studies provide a novel insight into citrus flavonoids and pomegranate concentrate and derivatives and their promise to enhance energy and exercise performance.

4. Actiful, a promising complex targeting energy and vitality

Actiful is an all-natural, stimulant-free, citrus and pomegranate complex containing 450 mg of citrus flavonoids delivered through a low daily dose of 700 mg. Notably, 85% of these citrus flavonoids are standardized to consist of the most active 2S enantiomer. Actiful also provides more NO substrate through pomegranate’s naturally high nitrate content. This complex is specifically designed to stimulate a greater blood flow and enhance short- and long-term energy to support active living.

4.1 Bioavailability

Bioavailability plays an important role in the physiological significance of citrus flavonoid intake on human health. Systemic health effects of citrus flavonoids are highly dependent upon enantiomer configuration.21 Prominently, unprocessed citrus fruit contains elevated concentrations of the most biologically active 2S form of hesperitin-7-O-rutinoside. Contrastingly, typical citrus flavonoid extracts contain high levels of the least active 2R configuration and are commercially available as a racemic mixture of both stereoisomers, limiting their efficacy as a health ingredient.21 Moreover, standard citrus flavonoid extracts have been shown to exhibit low solubility, resulting in an even more reduced bioavailability and bioactivity in the body.22 To overcome these deficiencies, a specific novel formulation, Actiful, containing a standardized citrus flavonoid content whereby at least 85% of these flavonoids consist of the active 2S-enantiomer, was developed to maximize the absorption of bioactive metabolites. Markedly, a pharmacokinetic study has revealed over a 50% greater bioavailability 24 hours post-intake of a 500 mg Citrus sinensis formulation with 450 mg of active flavonoids predominantly rich in 2S-enantiomer composition in comparison to a 500 mg standard citrus extract.21 This suggests that the abundance of active flavonoids in Actiful may elicit greater bioactivity and stronger favorable health effects as with standard citrus flavonoid extracts.

4.2 Blood flow-FMD study

A six-week randomized, placebo-controlled, double-blind, parallel-group study (2016) examined the effects of a daily dose of 450 mg of active flavonoids extracted from Citrus sinensis or a placebo on blood flow and endothelial function in a sub-group population of 48 healthy individuals (70% of total study population) with a baseline FMD ≥ 3 (mean age 50±14 years, mean BMI 29.1±2.8 kg/m2 ).23 After inducing temporary endothelial dysfunction through the consumption of a high-fat meal, an intake of 450 mg of active flavonoids were shown to attenuate the postprandial impairment of FMD two hours post-intake (P=0.05).

This finding provides support for the promising role of Actiful in increasing blood flow (FMD) and preserving endothelial function in a mid-age population (55+). With enhanced FMD, arteries are more flexible and better able to adapt to changes in blood flow for example, during physical activity when muscles require a greater supply of nutrients and oxygen.

 

4.3 Energy-exercise performance study

Furthermore, a four-week randomized, placebo-controlled, double-blind clinical study was conducted in order to investigate the effects of a daily dose of 450 mg of active flavonoids extracted from Citrus sinensis or maltodextrin (placebo) on power output (watts) and oxygen consumption in 39 regularly active individuals (mean age 22.9±2.0 years, mean BMI 21.8±1.88 kg/m2).24 At baseline and follow-up after four weeks of supplementation, power output and oxygen consumption were measured during a 10-minute full exhaustion ergometer cycling trial. Individuals allocated to the group ingesting 450 mg of flavonoids had a significant 5% increase in mean power output as compared to the placebo group (P=0.032). Consumption of this flavonoid formulation was shown to affect both aerobic and anaerobic energy systems, demonstrating a sharp increase in anaerobic derived power at the start of exercise, followed by a higher sustained aerobic power throughout the 10-minute trial. This outcome is also highly applicable to daily activities such as, walking, running, and cycling, which require contribution from dual energy systems.

A prime determinant of aerobic performance is the balance between oxygen consumption and power output. At follow-up, in the intervention group, there was a significant eight-fold decrease in VO2/W ratio (oxygen consumption/power ratio) (2.62%) relative to the placebo group (0.30%) (P=0.001). This signifies that more watts could be generated per unit of oxygen, reflecting an improved efficiency of oxygen usage during mitochondrial respiration.

Additionally, a stratified analysis within the intervention group illustrated that those who exercise less than six hours per week experienced more improvement in power (7.5%) than individuals that exercise more than six hours per week (5.13%). This outcome provides vital implications for the target group for Actiful, comprising of active individuals looking to boost energy levels to support and maintain an active lifestyle.

Notably, this was the first study known to exclusively investigate the effect of citrus flavonoids on exercise performance in human subjects. Products that have a direct effect on mitochondria are of great interest as mitochondria are one of the key regulators of longevity.2 Thus, the active flavonoids contained in Actiful can augment the efficiency of energy production at the mitochondrial level, supporting vitality.

5. Discussion

Recent evidence provides compelling support for the great potential of citrus flavonoids in combination with pomegranate-derived nitrate and their ability to exert favorable effects on blood flow and mitochondrial efficiency. To maximize the impact on human health, it is vital that citrus flavonoid formulations predominantly contain an optimal enantiomer composition to ensure superior bioavailability and bioactivity. Collectively, available data reflect a promising potential for Actiful, an all-natural citrus and pomegranate complex with superior bioavailability. Bioactives in this complex have been shown to beneficially affect vasodilation and subsequently, blood flow, as well as, elicit a direct effect on mitochondrial function through improving the efficiency of oxygen usage for the synthesis of ATP. Thus, Actiful may have a potent and lasting effect on daily activities and exercise performance during both the moment of peak performance and endurance phases of activity. As a novel ingredient that can wholly target energy and vitality, Actiful delivers the ultimate support for active living.

References

  1. Amarya S, Singh K, Sabharwal M. Changes during aging and their association with malnutrition. JCGG 2015;6:78-84.
  2. Bratic I, Trifunovic A. Mitochondrial energy metabolism and ageing. Biochim Biophys Acta 2010;1797:961-7.
  3. Payne BA, Chinnery PF. Mitochondrial dysfunction in aging: much progress but many unresolved questions. Biochim Biophys Acta 2015;1847:1347-53.
  4. World Health Organization (WHO) Europe, Active ageing: physical activity promotion in elderly, (2017).
  5. Zhao Y, Vanhoutte PM, Leung SW. Vascular nitric oxide: beyond eNOS. J Pharmacol Sci 2015;129:83-94.
  6. Porter C, Hurren N, Sidossis L, Elisabet B. The impact of aging on mitochondrial proton leaks in human skeletal muscle (1159.9). The FASEB Journal 2014;28:1159.9.
  7. Del Rio D, Rodriguez-Mateos A, Spencer JP, Tognolini M, Borges G, Crozier A. Dietary (poly)phenolics in human health: structures, bioavailability, and evidence of protective effects against chronic diseases. Antioxid Redox Signal 2013;18:1818-92.
  8. Tripoli E, La Guardia M, Giammanco S, Di Majo D, Giammanco M. Citrus flavonoids: molecular structure, biological activity and nutritional properties: a review. Food Chem 2007;104:466-79.
  9. European Food Safety Authority (EFSA) scientific opinion on the substantiation of health claims register on nutrition and health claims. EFSA Journal 2011;9:2082.
  10. Morand C, Dubray C, Milenkovic D, Lioger D, Martin JF, Scalbert A, et al. Hesperidin contributes to the vascular protective effects of orange juice: a randomized crossover study in healthy volunteers. Am J Clin Nutr 2011;93:73-80.
  11. Rendeiro C, Dong H, Saunders C, Harkness L, Blaze M, Hou Y, et al. Flavanone-rich citrus beverages counteract the transient decline in postprandial endothelial function in humans: a randomised, controlled, double-masked, cross-over intervention study. Br J Nutr 2017;116:1999-2010.
  12. Trexler ET, Smith-Ryan AE, Melvin MN, Roelofs EJ, Wingfield HL. Effects of pomegranate extract on blood flow and running time to exhaustion. Appl Physiol Nutr Metab. 2014;39:1038-42.
  13. de Nigris F, Balestrieri ML, Williams-Ignarro S, D’Armiento FP, Fiorito C, Ignarro LJ, et al. The influence of pomegranate fruit extract in comparison to regular pomegranate juice and seed oil on nitric oxide and arterial function in obese Zucker rats. Nitric Oxide 2007;17:50-4.
  14. Ignarro LJ, Byrns RE, Sumi D, de Nigris F, Napoli C. Pomegranate juice protects nitric oxide against oxidative destruction and enhances the biological actions of nitric oxide. Nitric Oxide 2006;15:93-102.
  15. Rolfe D, Brand MD. Contribution of mitochondrial proton leak to skeletal muscle respiration and to standard metabolic. Am J Physiol Cell Physiol 1996;271:C1380-89.
  16. Ghanim H, Sia CL, Upadhyay M, Korzeniewski K, Viswanathan P, Abuaysheh S, et al. Orange juice neutralizes the proinflammatory effect of a high-fat, high-carbohydrate meal and prevents endotoxin increase and Toll-like receptor expression. Am J Clin Nutr 2010;91:940-9.
  17. Parhiz H, Roohbakhsh A, Soltani F, Rezaee R, Iranshahi M. Antioxidant and anti-inflammatory properties of the citrus flavonoids hesperidin and hesperetin: an updated review of their molecular mechanisms and experimental methods. Phytother Res 2015;29:323-31.
  18. BioActor internal study data.
  19. de Oliveira DM, Dourado GK, Cesar TB. Hesperidin associated with continuous and interval swimming improved biochemical and oxidative biomarkers in rats. J Int Soc Sports Nutr 2013;10:27.
  20. Ammar A, Turki M, Chtourou H, Hammouda O, Trabelsi K, Kallel C, et al. Pomegranate supplementation accelerates recovery of muscle damage and soreness and inflammatory markers after a weightlifting training session. PLoS One 2016;11:e0160305.
  21. Possemiers S, Balter L, Fallais S. A novel polyphenol extract improves endothelial

function and bioavailability: an extract from sweet orange. Agro Food Industry Hi Tech 2015;26:6-10.

  1. Brand W, Shao J, Hoek-van den Hil EF, van Elk KN, Spenklink B, de Haan LH, et al. Stereoselective conjugation, transport and bioactivity if s- and R-hesperetin enantiomers in vitro. J Agric Food Chem 2010;58:6119-25.
  2. Salden BN, Troost FJ, de Groot E, Stevens YR, Garcés-Rimn M, Possemiers S, et al. Randomized clinical trial on the efficacy of hesperidin 2s on validated cardiovascular biomarkers in healthy overweight individuals. Am J Clin Nutr 2016;104:1523-533.
  3. InnoSportLab Papendal study report- internal data (2015).