Scientific and regulatory aspects of nutraceutical products in the United States

The safety, efficacy and pharmaceutical quality of male enhancement nutraceuticals bought online: Truth versus claim

OBJECTIVE

Nutraceutical products are widely used for their claimed therapeutic benefits. However, falsified or adulterated nutraceuticals present a major health threat to consumers. This study investigates the pharmaceutical quality, safety and anti-inflammatory effects of six male enhancement nutraceuticals that claim to be 100% natural.

METHODS

Three batches of six male enhancement products were tested to detect the presence and levels of adulterants via high-performance liquid chromatography (HPLC). The pharmaceutical quality of the selected nutraceuticals was tested with near infrared spectroscopy (NIR) and SeDeM. The cytotoxic effects of these products on HepG2 cells were determined through cell proliferation (XTT) and lactate dehydrogenase (LDH) cytotoxicity assays. Lastly, the in vitro inflammatory effects of these products were investigated using murine J774 macrophages through cytokine release analysis.

RESULTS

HPLC analysis detected the presence of sildenafil citrate, a vasodilator, and the active ingredient in Viagra and Revatio, in all batches of the products we analyzed. Amount of sildenafil citrate ranged from 0.45 mg to 51.85 mg among different batches. NIR assessment showed inter- and intra-batch heterogeneity in product composition. Results of the XTT and LDH assays showed significant cytotoxic effects of the analyzed products. XTT analysis revealed that the viability of HepG2 treated with tested products varied from 27.57% to 41.43%. Interestingly, the male enhancement products also showed anti-inflammatory effects.

CONCLUSION

Despite their labeling as 100% natural, all products tested in this study contained levels of sildenafil citrate, which was not reported on the packaging. There was a lack of pharmaceutical uniformity among products of the same batch and across different batches. Additionally, the products we tested had cytotoxic effects. These study findings highlight the adulteration, poor quality and hazard of these nutraceuticals. Therefore, strict regulation of these products and standardization of the definition of nutraceuticals are urgently needed. Further, these falsely advertised products should be withdrawn from the market due to potential adverse effects on the health of their consumers.

The filling of powdered herbs into two-piece hard capsules using hydrogenated cotton seed oil as lubricant

The aim of this work was to investigate the plug formation and filling properties of powdered herbal leaves using hydrogenated cotton seed oil as an alternative lubricant. In a first step, unlubricated and lubricated herbal powders were studied on a small scale using a plug simulator, and low-force compression physics and parameterization techniques were used to narrow down the range in which the optimum amount of lubricant required would be found. In a second step these results were complemented with investigations into the flow properties of the powders based on packing (tapping) experiments to establish the final optimum lubricant concentration. Finally, capsule filling of the optimum formulations was undertaken using an instrumented tamp filling machine. This work has shown that hydrogenated cotton seed oil can be used advantageously for the lubrication of herbal leaf powders. Stickiness as observed with magnesium stearate did not occur, and the optimum lubricant concentration was found to be less than that required for magnesium stearate. In this work, lubricant concentrations of 1% or less hydrogenated cotton seed oil were required to fill herbal powders into capsules on the instrumented tamp-filling machine. It was found that in principle all powders could be filled successfully, but that for some powders the use of higher compression settings was disadvantageous. Relationships between the particle size distributions of the powders, their flow and consolidation as well as their filling properties could be identified by multivariate statistical analysis. The work has demonstrated that a combination of the identification of plug formation and powder flow properties is helpful in establishing the optimum lubricant concentration required using a small quantity of powder and a powder plug simulator. On an automated tamp-filling machine, these optimum formulations produced satisfactory capsules in terms of coefficient of fill weight variability and capsule weight.

Biological properties of curcumin-cellular and molecular mechanisms of action

Curcuminoids, a group of phenolic compounds isolated from the roots of Curcuma longa (Zingiberaceae), exhibit a variety of beneficial effects on health and on events that help in preventing certain diseases. A vast majority of these studies were carried out with curcumin (diferuloyl methane), which is a major curcuminoid. The most detailed studies using curcumin include anti-inflammatory, antioxidant, anticarcinogenic, antiviral, and antiinfectious activities. In addition, the wound healing and detoxifying properties of curcumin have also received considerable attention. As a result of extensive research on the therapeutic properties of curcumin, some understanding on the cellular, molecular, and biochemical mechanism of action of curcumin is emerging. These findings are summarized in this review.

Enzyme inhibition and protein-binding action of the procyanidin-rich french maritime pine bark extract, pycnogenol: effect on xanthine oxidase

Pycnogenol, an extract from French maritime pine bark (PBE), is a complex mixture of bioflavonoids with reported protective effects against disease. PBE is an effective scavenger of reactive oxygen species, and its main constituents are procyanidins of various chain lengths. To find out the biochemical basis of action of PBE on enzyme activity, involvement of its redox activity and direct binding to the enzyme in its subsequent action on enzyme activity have been investigated. PBE dose-dependently inhibited the activities of xanthine oxidase, xanthine dehydrogenase, horseradish peroxidase, and lipoxygenase, but it did not affect the activities of glucose oxidase, ascorbate oxidase, or elastase. To characterize the mechanism of PBE action, studies were focused on xanthine oxidase and glucose oxidase. Under non-denaturing conditions, PBE changed the electrophoretic mobility of xanthine oxidase but not of glucose oxidase. Gel filtration chromatography confirmed higher molecular weight complexes of xanthine oxidase and xanthine dehydrogenase in the presence of PBE. It was found that hydrophobic bonding might be the dominant mode of interaction between PBE and xanthine oxidase. The importance of the binding in the effect of PBE on enzyme activity was supported by the observation that PBE binds to and inhibits catalase, but not superoxide dismutase. However, no correlation was found between superoxide/hydroxyl radical scavenging activity and the inhibitory effect on xanthine oxidase activity of PBE, various purified flavonoids, or other complex mixtures of bioflavonoids. The results indicate that PBE selectively inhibits xanthine oxidase through binding to the enzyme rather than by the redox activity.

Ferulic acid excretion as a marker of consumption of a French maritime pine (Pinus maritima) bark extract

French maritime pine (Pinus maritima) bark extract (PBE) is a polyphenol-rich food supplement patented under the name of Pycnogenol and known to have strong antioxidant activity and different beneficial effects on human health. Although its biological properties have begun to be extensively studied both in vitro, in laboratory animals and more recently in humans, little is known about its bioavailability. The present study investigated the urinary excretion of free and conjugated ferulic acid, present in quantitatively detectable amounts in PBE, after oral PBE administration to human subjects. Eleven healthy adult subjects (4 women and 7men) consumed either a single dose (200 mg PBE) or two doses of PBE (100 and 200 mg, respectively) within a 48-h interval. Two days before the oral administration of PBE and during the urine sample collection period volunteers adhered to a diet low in polyphenols. Aliquots of all urine production were collected over 24 h. Free and conjugated ferulic acid was assessed in urine by HPLC using diode array detection. A close association between the dietary intake of PBE and the urinary excretion of ferulic acid was detected. Moreover, the results indicate that a considerable proportion of ferulic acid is excreted as glucuronide or sulfate after PBE consumption, varying over the range 2 to 20% between individuals. The kinetics of excretion associated with the administration of 100 mg PBE was quite similar to that obtained after 200 mg PBE. A a biphasic trend was evident in a number of subjects. All subjects studied here displayed a significant, although variable level of excretion of ferulic acid after supplementation with PBE, Thus, the data provide evidence that at least a part of the phenolic components of PBE are absorbed, metabolized, and eliminated by humans.

Nutritional and Health Benefits of Inulin and Oligofructose. Proceedings of a conference. Bethesda, Maryland, USA. May 18-19, 1998

Statements about the ability of selected foods to reduce the risk of diseases and to enhance the quality of life continue to captivate, and at times polarize, opinions. Interests in these "functional" foods and their active components are being propelled by increasing health care cost, recent legislative events and mounting scientific evidence. Increasingly, scientists are being asked to clarify the precise role that foods have in maintaining and promoting health. Accepting this movement as an opportunity to "optimize nutrition" rather than as a way in which to endorse good or bad foods or as a marketing gimmick will surely make it more acceptable to many scientists. However, the response to functional foods depends on several factors, including genetics, physiologic state and the composition of the entire diet. Although evaluation of the benefits or risks of foods normally does not entail the same extensive examination as that required of drugs, this does not negate the need for sound scientific information for making recommendations to the consumer. Identification of sensitive and reliable biomarkers will be key to adequate assessment of the true effect of foods and their components. Inulin and oligofructose are components of the diet that deserve added attention for their potential health benefits. Evidence that oligofructose and inulin alter several biomarkers, including gastrointestinal transit time, experimentally induced neoplasia and colonic microflora, suggests that these nondigestible carbohydrates are naturally occurring dietary constituents that may improve the quality of life and increase disease resistance in both humans and animals.