Ray A. Matulka

The safety of PolyGlycopleX® (PGX®) as shown in a 90-day rodent feeding study

BackgroundThis study was designed to evaluate the safety of PolyGlycopleX® (PGX®), a novel viscous dietary polysaccharide (fiber), when administered to Sprague Dawley® rats in the diet for 90 days.MethodsGroups of ten male and ten female rats each consumed PGX mixed in the diet at levels of 0, 1.25, 2.5 or 5.0% for 90 days, then evaluated for toxicological effects on parameters that included neuromotor activity, body weight, clinical chemistry, urinalysis, hematology, and histopathology.ResultsMean body weight, mean feed consumption and food efficiency in the treated groups were generally comparable to controls for both male and female rats. No changes were noted in neuromotor behavior, and histopathological analysis revealed no significant changes between treated and control animals. There were no differences in mean organ weight, organ-to-body weight or organ-to-brain weight values between controls and treated animals. Decreased red blood cell count occurred in the high dose males and increases in aspartate and alanine aminotransferase enzyme levels and triglycerides, while significant decreases in serum sodium, potassium and chloride concentrations were observed in the females fed 5.0% PGX. However, the decreased mineral concentrations may be the result of significantly increased urinary volume in both males and females at the high dose, with a concomitant decrease in urinary specific gravity (males and females) and protein concentration (females). These results were within historical control values, did not correlate with any histopathological changes, and were not considered adverse.ConclusionThe results indicate a no observed adverse effect level (NOAEL) for PGX at 5.0% of the diet, corresponding to an average daily intake of 3219 and 3799 mg/kg bw/day in male and female rats, respectively.

Naturally Occurring Food Toxins

Although many foods contain toxins as a naturally-occurring constituent or, are formed as the result of handling or processing, the incidence of adverse reactions to food is relatively low. The low incidence of adverse effects is the result of some pragmatic solutions by the US Food and Drug Administration (FDA) and other regulatory agencies through the creative use of specifications, action levels, tolerances, warning labels and prohibitions. Manufacturers have also played a role by setting limits on certain substances and developing mitigation procedures for process-induced toxins. Regardless of measures taken by regulators and food producers to protect consumers from natural food toxins, consumption of small levels of these materials is unavoidable. Although the risk for toxicity due to consumption of food toxins is fairly low, there is always the possibility of toxicity due to contamination, overconsumption, allergy or an unpredictable idiosyncratic response. The purpose of this review is to provide a toxicological and regulatory overview of some of the toxins present in some commonly consumed foods, and where possible, discuss the steps that have been taken to reduce consumer exposure, many of which are possible because of the unique process of food regulation in the United States.

Safety studies conducted on a proprietary high-purity aloe vera inner leaf fillet preparation, Qmatrix

The aloe vera plant has a long history of safe use for oral and topical applications. This publication describes safety studies conducted on a proprietary high-purity aloe vera inner leaf fillet preparation, Qmatrix. In a 13-week study in rats, Qmatrix was administered via gavage at 0, 500, 1000 and 2000 mg/kg body weight (bw)/day. There were no significant changes in food or water consumption, body weight, serum biochemistry or hematology at any of the doses tested. Sporadic, significant increases were observed in some of the measured urinalysis parameters; however, these variations were not treatment-related, as most were observed only in one sex, not dose-dependent and within historical control values. Organ weights were unaffected, except for a statistically significant, though not dose-dependent, increase in absolute and relative weights of the right kidney in males at 500 and 2000 mg/kg bw/day, respectively. Histopathological analysis revealed no abnormal signs. Qmatrix was non-mutagenic in an Ames test and a chromosomal aberration test at concentrations up to 10,000 microg/plate, and in an in vivo bone marrow micronucleus test at doses up to 5000 mg/kg bw/day. Based on these results, Qmatrix is not genotoxic in vitro or in vivo and; has an oral NOAEL greater than 2000 mg/kg bw/day following 90 days of oral exposure.

Developmental and Reproductive Effects of SE5-OH: An Equol-Rich Soy-Based Ingredient

Consumption of the isoflavones daidzein, genistein, glycitein, and their structural analogues is generally considered beneficial to human health. Equol is not found in soy, but is converted from daidzein by human gut bacterial flora. Research indicates that between 30–50% of the population is capable of converting daidzein to equol; therefore, there has been recent development of a new equol-rich functional food that relies on bacterial conversion of daidzein to equol under strictly controlled conditions. Therefore, a new equol-rich soy product (SE5-OH) has been developed, based on the bacterial conversion of daidzein; and its reproductive and developmental toxicity has been evaluated in a two-generation study and a developmental toxicity study with Sprague-Dawley rats at dose levels of 200, 1000, and 2000 mg/kg/day by gavage. SE5-OH contains approximately 0.65% equol, 0.024% daidzein, 0.022% genistein, and 0.30% glycitein. From the reproductive study, the no-observed-adverse-effect-level (NOAEL) for SE5-OH determined for both male and female rats is 1000 mg/kg/day (6.5 mg equol/kg/day). In the developmental toxicity phase of the study, no effects by SE5-OH were found in the embryo-fetus at any of the doses tested. The NOAEL for developmental effects of SE5-OH is 2000 mg/kg/day (13 mg equol/kg/day).

Safety evaluation of Whole Algalin Protein (WAP) from Chlorella protothecoides.

Microalgae such as Chlorella spp., were once consumed as traditional human foods; now they are being developed as ingredients for modern diets. Whole Algalin Protein (WAP) from dried milled Chlorella protothecoides was evaluated for dietary safety in a 13-week feeding trial in rodents with genotoxic potential evaluated using in vitro and in vivo assays and the likelihood of food allergy potential evaluated via human repeat-insult patch test (HRIPT). In the subchronic study, rats consumed feed containing 0, 25,000, 50,000 or 100,000 ppm WAP for 92-93 days. No treatment-related mortalities or effects in general condition, body weight, food consumption, ophthalmology, urinalysis, hematology, clinical chemistry, gross pathology, organ weights, and histopathology occurred. Several endpoints exhibited statistically significant effects, but none was dose-related. The no-observed-adverse-effect level (NOAEL) was based on the highest WAP concentration consumed by the rats and was equivalent to 4805 mg/kg/day in males and 5518 mg/kg/day in females. No mutagenicity occurred in Salmonella typhimurium or Escherichia coli tester strains (≤5000 μg/plate WAP) with or without mutagenic activation. No clastogenic response occurred in bone marrow from mice administered a single oral dose (2000 mg/kg WAP). Skin sensitization was not induced by WAP via HRIPT, indicating little potential for food allergy.

Safety evaluation of a high lipid Whole Algalin Flour (WAF) from Chlorella protothecoides.

Microalgae such as Chlorella spp. have a long history of use in human food. A high lipid Whole Algalin Flour (WAF) composed of dried milled Chlorella protothecoides was evaluated for subchronic toxicity and genotoxic potential. Likelihood of food allergy potential was also evaluated by human repeat-insult patch test. In the subchronic study, rats were fed dietary levels of 25,000, 50,000 or 100,000 ppm WAF in feed for 93-94 days. No mortalities occurred. No treatment-related effects were identified for general condition, body weight, food consumption, ophthalmology, urinalysis, hematology, clinical chemistry, gross pathology, organ weights, and histopathology. Although statistically significant effects were noted for several endpoints, none was test-substance related. The no-observed-adverse-effect level (NOAEL) for WAF was based on consumption of the 100,000 ppm diet, the highest dietary concentration tested, and was 4807 mg/kg bw/d in male rats and 5366 mg/kg bw/d in female rats. Additionally, WAF (≤ 5000 μg/plate) was not mutagenic in Salmonella typhimurium or Escherichia coli tester strains nor did WAF induce a clastogenic response in bone marrow from mice given a single oral dose (2000 mg/kg bw). Further, WAF did not elicit skin sensitization in a repeat-insult dermal patch test which indicates little potential for food allergy.

Lack of toxicity by medium chain triglycerides (MCT) in canines during a 90-day feeding study

Dietary fats in food are natural energy sources to animals and are included in the American Association of Feed Control Officials (AAFCO) manual as a requirement for dog food. Medium chain triglycerides are comprised of a glycerol backbone esterified to medium chain length (8-12 carbon) fatty acids (FA) and, in the context of this report, are all saturated FA. Unlike esterified long chain (>12 carbons) FA (long chain triglycerides or LCT), MCT are lower in caloric value, and are eliminated from the body more quickly than LCT. The objective of this study was to determine the safety of MCT when fed to beagles for 90 days at levels of 0%, 5%, 10%, and 15% MCT added to conventional feed. The beagles were monitored for signs of toxicity by clinical observations, body weight measurements, food consumption level, physical examinations, hematology and serum chemistry, ophthalmic examinations, and urinalysis. There were no signs of toxic effects observed in any of the animals that were related to feed, and the animal viability was 100% at the end of the study. Some animals exhibited significant increased blood urea nitrogen, potassium and cholesterol levels in the 10% and 15% MCT-fed groups. Also, in the same groups with elevated nitrogen, there were concomitant reductions in total blood protein and urine volumes. These changes in serum chemistry may be the result of protein sparing effects due to the high levels of MCT intake, and are not deemed to be pathological in nature. Animals receiving 15% MCT in feed had lower levels of food intake due to palatability issues. From the other examination parameters, there were no significant changes noted between groups receiving MCT and vehicle feed. No safety concerns were noted at any dose level, although an issue with palatability precluded identifying 15% as the highest dose level tested.

Safety evaluation of oleic-rich triglyceride oil produced by a heterotrophic microalgal fermentation process

Numbers of macro- and microalgae have been used as food sources in various cultures for centuries. Several microalgae are currently being developed as modern food ingredients. The dietary safety of oleic-rich microalgal oil produced using a heterotrophic fermentation process was assessed in a 13-week feeding trial in rats with genotoxic potential evaluated using in vitro and in vivo assays. In the genotoxicity assays, the test oil was not mutagenic in Salmonella typhimurium or Escherichia coli tester strains (⩽5000μg/plate) with or without metabolic activation. Further, no clastogenic response occurred in chromosome aberration assays in the bone marrow of mice administered a single intraperitoneal dose (2000mg/kg). In the subchronic study, rats consumed feed containing 0, 25,000, 50,000 or 100,000ppm oleic-rich oil for 90days. No treatment-related mortalities or adverse effects occurred in general condition, body weight, food consumption, ophthalmology, urinalysis, hematology, clinical chemistry, gross pathology, organ weights or histopathology. Although several endpoints exhibited statistically significant effects, none were dose-related or considered adverse. Taking all studies into consideration, the NOAEL for the oleic-rich oil was 100,000ppm, the highest concentration tested and equivalent to dietary NOAELs of 5200mg/kg bw/day and 6419mg/kg bw/day in male and female rats, respectively.

Two new nontoxic, non-pathogenic strains of Sphingomonas elodea for gellan gum production.

Two new strains of Sphingomonas elodea (designated as PHP1 and PBAD1) were tested for toxicity and pathogenicity in healthy Sprague-Dawley CD(®) IGS rats in separate studies. In each study, twelve rats/sex were administered ≥10(8) viable cells/rat by oral gavage, and four untreated rats/sex served as controls. Blood, feces, and selected organs/tissues collected at various times over the course of the 22 day study were evaluated for the presence of PHP1 or PBAD1 (depending on the study) by a validated method, to determine the potential for survival, propagation, or infectivity of PHP1 and PBAD1 cells in the rat. No mortalities, test substance-related changes in clinical or macroscopic findings, body weight or body weight gain were observed in treated animals compared with controls, indicating a lack of toxicity. PHP1 or PBAD1 were not detected in the tissue, fecal or fluid samples collected from treated animals. Therefore, neither PHP1 nor PBAD1 were pathogenic or acutely toxic under the conditions of the studies.

Pre-clinical in vitro and in vivo safety evaluation of bovine whey derived osteopontin, Lacprodan® OPN-10.

Lacprodan® OPN-10 is a proprietary whey-based protein product that contains bovine-derived osteopontin (OPN), found in human milk and other bodily tissues. In vitro genotoxicity tests conducted according to accepted guidelines at up to 5000μg/plate OPN failed to induce genetic mutations in Salmonella typhimurium strains and Escherichia coli strain and did not induce chromosomal aberrations or cytotoxicity in human lymphocytes. Administration of an acute dose of Lacprodan® OPN-10 (2300mg/kg body weight) to male and female mice did not induce chromosomal damage or mitotic apparatus damage to erythroblasts from bone marrow. Lacprodan® OPN-10 was evaluated in a 13-week oral toxicity study in which rats were fed diets containing 0.5%, 1.0% and 2.0% Lacprodan® OPN-10. No test-article-related clinical observations or toxicological effects on body or organ weights, food consumption, ophthalmic effects, locomotor activity, hematology, clinical chemistry, urinalysis, or pathology were identified. In a teratogenicity study, administration of Lacprodan® OPN-10 up to 2500mg/kgbw/day via gavage to pregnant rats had no effect on dams or pups. The No Observed Adverse Effect Level (NOAEL) for Lacprodan® OPN-10 in the 13-week toxicity study was 2.0% of the diet (equivalent to 1208mg/kgbw/day in male rats and 1272mg/kgbw/day in female rats).