Gelatin Ingestion Research Articles

Quantitative analysis of cyclic prolyl-hydroxyproline in human plasma after ingestion of gelatin and gelatin hydrolysates

Quantitative analysis of cyclic prolyl-hydroxyproline in human plasma after ingestion of gelatin and gelatin hydrolysates

Comparison of gelatin and low-molecular weight gelatin hydrolysate ingestion on hydroxyproline (Hyp), Pro-Hyp and Hyp-Gly concentrations in human blood

This study showed that gelatin ingestion significantly increased prolyl-hydroxyproline (Pro-Hyp) levels in plasma of 9 subjects, with maximum concentrations of 15.5 ± 3.0 nmol/mL 2 h post-ingestion. Hydroxyprolyl-glycine (Hyp-Gly) concentrations were significantly increased and reached a maximal level of 2.3 ± 0.5 nmol/mL 1 h post-ingestion of gelatin. A low molecular weight gelatin hydrolysate (LMW-GH) significantly enhanced concentrations of both peptides, while gelatin hydrolysate ingestion did not significantly enhance the maximum concentration and area under the plasma concentration–time curve (AUC) of Hyp-Gly relative to gelatin. The absorption of free Hyp following gelatin ingestion (94.4 ± 16.4 nmol/mL) was significantly lower relative to GH (150.9 ± 15.3 nmol/mL) and LMW-GH (169.1 ± 32.5 nmol/mL). The present study is the first report demonstrating that Hyp-containing peptides are elevated to μM levels in human plasma after gelatin ingestion. These results suggested that gelatin is useful as a functional food as effectively as GH.

Collagen-Derived Di-Peptide, Prolylhydroxyproline (Pro-Hyp): A New Low Molecular Weight Growth-Initiating Factor for Specific Fibroblasts Associated With Wound Healing.

Many cells and soluble factors are involved in the wound healing process, which can be divided into inflammatory, proliferative, and remodeling phases. Fibroblasts play a crucial role in wound healing, especially during the proliferative phase, and show heterogeneity depending on lineage, tissue distribution, and extent of differentiation. Fibroblasts from tissue stem cells rather than from healthy tissues infiltrate wounds and proliferate. Some fibroblasts in the wound healing site express the mesenchymal stem cell marker, p75NTR. In the cell culture system, fibroblasts attached to collagen fibrils stop growing, even in the presence of protein growth factors, thus mimicking the quiescent nature of fibroblasts in healthy tissues. Fibroblasts in wound healing sites proliferate and are surrounded by collagen fibrils. These facts indicate presence of new growth-initiating factor for fibroblasts attached to collagen fibrils at the wound healing site, where the collagen-derived peptide, prolyl-hydroxyproline (Pro-Hyp), is generated. Pro-Hyp triggers the growth of p75NTR-positive fibroblasts cultured on collagen gel but not p75NTR-negative fibroblasts. Thus, Pro-Hyp is a low molecular weight growth-initiating factor for specific fibroblasts that is involved in the wound healing process. Pro-Hyp is also supplied to tissues by oral administration of gelatin or collagen hydrolysate. Thus, supplementation of gelatin or collagen hydrolysate has therapeutic potential for chronic wounds. Animal studies and human clinical trials have demonstrated that the ingestion of gelatin or collagen hydrolysate enhances the healing of pressure ulcers in animals and humans and improves delayed wound healing in diabetic animals. Therefore, the low molecular weight fibroblast growth-initiating factor, Pro-Hyp, plays a significant role in wound healing and has therapeutic potential for chronic wounds.

Determination of bioavailability and identification of collagen peptide in blood after oral ingestion of gelatin.

Gelatin has long been widely used in foods, pharmaceuticals, cosmetics, and other products. However, there are few reports on its bioavailability and bioavailable forms. In this study, the bioavailability of gelatin was indirectly evaluated by the determining the bioavailability of total hydroxyproline in gelatin using a pharmacokinetic method after oral administration to rats. The relative and absolute bioavailability of gelatin were 74.12% and 85.97%, respectively. The amino acid profile of plasma indicated that 41.91% of the digested gelatin was absorbed from the intestine in the form of peptide, and there was a good linear correlation between the absorbed amount of an amino acid and its content in gelatin (R(2) = 0.9566). Moreover, 17 types of collagen peptide were purified by multi-step chromatography and identified with ultra-performance liquid chromatography-electrospray ionisation-mass spectrometry. Gelatin had high oral bioavailability. Nearly half of digested gelatin was absorbed from the intestine in the form of various collagen peptides.

Effects of amla extract and collagen peptide on UVB-induced photoaging in hairless mice

Amla (Emblica officinalis Gaertn.) is a rich dietary source of vitamin C, minerals and amino acids, and also contains a wide variety of phenolic compounds. Amla has also been used as a principal constituent of many preparations of Ayurved, the Indian system of traditional medicine. Gelatin hydrolysate, also known as collagen peptide as a functional ingredient, is obtained from animal hide or fish scales. Ingestion of gelatin or collagen peptide affects various functions of the body, including bone, the achilles tendon, and skin. However, there are few data on the effects of amla extract and collagen peptide on photoaging in vivo. In the present study, therefore, we administered amla extract and/or collagen peptide to hairless mice that were repeatedly exposed of UVB irradiation, and examined the resulting effects on photoaging. Amla extract and collagen peptide suppressed the formation of 8-OHdG-positive cells and epidermal hyperplasia, and controlled skin hydration, thus reducing skin wrinkle formation in the mice. Collagen peptide, but not amla extract, also enhanced the production of collagen. We demonstrated that amla extract and collagen peptide exerted an additive effect in ameliorating skin dehydration and wrinkle formation, suggesting that they were able to attenuate photoaging effectively in UVB-irradiated hairless mice.

Complementary foods for appetite suppression

New diet strategies are needed to aid with weight loss and adherence to energy‐restricted diets. This study examined the appetite suppression and antiglycemic effects of two novel foods: algae and gelatin. In a double‐blind, randomized, crossover study, 15 healthy individuals (7 M, 8 F; 28±7y, BMI 26.1±5.6kg/m2) consumed an isocaloric breakfast meal under three treatments separated by 1–2 wk: control (buttered bagel, juice); algae (algae [4g protein] enriched butter, bagel, juice); and gelatin (gelatin [4g protein] enriched butter, bagel, juice). Five blood samples (0, 30, 60, 90, 120 min postprandial) were collected and analyzed for glucose. Hunger was assessed using a 100mm visual analog scale. Food and beverage consumption for the remainder of the day was recorded. Neither algae nor gelatin altered postprandial glycemia or perceptions of hunger up to 2 h post‐ingestion. However, there was a marked decrease (300–400 kcal) in subsequent 24 h energy consumption in the gelatin group when compared to the algae (p=0.01) or control (p=0.07) groups. These data suggest that gelatin ingestion may be associated with appetite suppression over a 24 h period. Supported by ASU Graduate and Professional Student AssociationGrant Funding Source: Graduate and Professional Student Association, Arizona State University

The Effects of Protein Ingestion on GH Concentrations in Visceral Obesity

Growth hormone (GH), a hormone originating from the anterior pituitary gland, is an important regulator of metabolism and body composition. Low GH secretion is associated with features of the metabolic syndrome, in particular increased visceral body fat and decreased lean body mass. It has been shown that GH release can be promoted by ingestion of protein, in particular gelatin protein. The question remains; is the GH-promoting effect of gelatin protein also present in a population with blunted GH response, such as visceral obesity? 8 lean women (age: 23+/-3 years, BMI: 21.6+/-2.0 kg/m (2)) and 8 visceral obese women (age: 28+/-7 years, BMI: 33.8+/-5.5 kg/m (2)) were compared with regard to their 5-h GH response after oral ingestion of gelatin protein (0.6 g protein per kg bodyweight), placebo (water), or injection of growth hormone releasing hormone (GHRH) (1 mu/kg body weight), in a randomized crossover design. GH response after placebo, gelatin protein, or GHRH was higher in lean subjects than in visceral obese subjects (p<0.05). Ingestion of gelatin protein increased GH response compared with placebo in both visceral obese (182.1+/-81.6 microg/l.5 h vs. 28.4+/-29.8 microg/l.5 h) and lean (631.7+/-144.2 microg/l.5 h vs. 241.0+/-196.8 microg/l.5 h) subjects (p<0.05). GH response after ingestion of gelatin protein in visceral obese did not differ from that in lean, placebo-treated subjects (p=0.45). GH concentrations after GHRH injection correlated significantly with GH concentrations after gelatin ingestion (AUC; r=0.71, p<0.01, Peak; r=0.81, p<0.01). Further research is needed to investigate if gelatin protein is able to improve metabolic abnormalities in hyposomatotropism in the long term or to investigate the relevance of protein as diagnostic tool in hyposomatotropism.

The effects of dietary protein on the somatotropic axis: a comparison of soy, gelatin, α-lactalbumin and milk

Growth hormone (GH) is an important regulator of growth and body composition. It has been shown that GH release can be promoted by administration of various amino acids (AAs), such as arginine and lysine, that are present in soy protein. We previously showed that oral ingestion of soy protein stimulates the GH release, it is not known however to which extent other proteins stimulate the GH secretion. Ingestion of soy protein (soy), gelatin protein (gelatin), alpha-lactalbumin protein (alpha-lactalbumin) and milk protein (milk) were compared on their GH-stimulating capacity. After oral ingestion of protein (0.6 g protein per kg bodyweight), blood was sampled every 20 min for 5 h to analyze GH, AA, insulin and glucose concentrations. The study was performed in eight healthy women (aged 19-26 years; body mass index 19-26 kg/m(2)) in a randomized, single blind, placebo-controlled crossover design. GH responses were more increased after ingestion of gelatine (8.2+/-1.1 microg/l) compared with ingestion of soy, alpha-lactalbumin and milk (5.0+/-0.8, 4.5+/-0.6 and 6.4+/-1.0 microg/l, respectively) (P<0.05). After ingestion of each protein, GH responses were higher compared with placebo ingestion (P<0.05). Simultaneously ingestion of gelatin resulted in the highest serum-arginine concentrations (ARG) compared with after ingestion of the other proteins (P<0.05). Insulin as well as glucose concentrations were not different after ingestion of the various proteins (P<0.05). The GH-promoting activity of protein depends on the protein source, in that, gelatin protein is the most potent GH stimulator. Arginine may be the responsible AA in the GH-promoting effect of gelatin, although each protein may have its own specific AA-spectrum involved in the stimulation of the somatotropic axis.

Gelatin intake increases the atheroma formation in apoE knock out mice

The effect of gelatin ingestion on cholesterol metabolism and on atheroma formation was evaluated in both wild type ( n=14) and apoprotein E (apoE) knock out (apoE −/−) ( n=20) C57BL/6 7-week-old mice. Animals were fed a cholesterol-free isoproteic semi-purified diet containing 20% of casein (control diet) or 10% of casein plus 10% of gelatin (gel diet) for 8 weeks. In wild type mice, dietary gelatin caused a reduction in the serum triacylglycerols levels associated with an increase in the fecal excretion. No difference in blood cholesterol was seen at the sixth week of experiment. At the eighth week of experiment, there was a modest but significant reduction of serum total and high density lipoprotein (HDL) cholesterol in apoE −/− mice fed on gel diet compared to the control. Total cholesterol/HDL cholesterol ratio was 2-fold higher in the gel group than that seen in the control group (14.39 and 7.84, respectively). Histological analyzes showed a 2.2-fold increase in the dimension of the atherosclerotic plaques in the proximal aorta in apoE −/− mice fed on a gel diet compared to those fed on a control diet. The gel diet also promoted a reduction in the fecal excretion of bile acids. Hepatic cholesterol was similar in both groups. In conclusion, although gelatin reduced total serum cholesterol, this reduction was associated to a decrease of HDL cholesterol and consequent increase of total cholesterol/HDL cholesterol ratio, resulting in an acceleration of atherogenesis.

The insulin and glucose responses to meals of glucose plus various proteins in type II diabetic subjects

We previously have shown that ingested beef protein is just as potent as glucose in stimulating a rise in insulin concentration in type II diabetic patients. A synergistic effect was seen when given with glucose. Therefore, we considered it important to determine if other common dietary proteins also strongly stimulate an increase in insulin concentration when given with glucose. Seventeen type II (non-insulin-dependent) untreated diabetic subjects were given single breakfast meals consisting of 50 g glucose, or 50 g glucose plus 25 g protein in the form of lean beef, turkey, gelatin, egg white, cottage cheese, fish, or soy. The peripheral plasma concentrations of glucose, insulin, glucagon, alpha amino nitrogen, urea nitrogen, free fatty acids, and triglycerides were measured. Following ingestion of the meals containing protein, the plasma insulin concentration was increased further and remained elevated longer compared with the meal containing glucose alone. The relative area under the insulin response curve was greatest following ingestion of the meal containing cottage cheese (360%) and was least with egg white (190%) compared with that following glucose alone (100%). The glucose response was diminished following ingestion of the meals containing protein with the exception of the egg white meals. The peripheral glucagon concentration was decreased following ingestion of glucose alone and increased following all the meals containing protein. The alpha amino nitrogen concentration varied considerably. It was decreased after glucose alone, was unchanged after egg white ingestion, and was greatest after ingestion of gelatin. The free fatty acid concentration decrease was 4- to 8-fold greater after the ingestion of protein with glucose compared with ingestion of glucose alone.

Amino Acids in Postprandial Gut Contents of Man

The objective of the investigation was to determine the free amino acids in the lower duodenum of man 1.5 hours after ingestion of food. The 4 types of test meals consisted of lean beef, gelatin, eggs or milk. Subjects were 5 healthy males 21 to 64 years of age. Molar ratios of amino acids in the doudenal contents were different from those derivable from hydrolysis of the test meal proteins in vitro. For example, after gelatin ingestion, the amount of tryptophan present was as great as when the complete proteins of eggs and milk were ingested. It is concluded that large quantities of endogenous protein enter the duodenum of man during digestion and are mixed with ingested protein. On hydrolysis, this protein mixture yields an amino acid mixture for absorption which is quite different from that provided by the ingested protein alone.

The Significance of Gelatin Tolerance in Malabsorptive States

Summary The determination of peptide hydroxyproline in the serum and urine after gelatin ingestion has been found to be of value in the in vivo assessment of proteolytic activity. Normal individuals demonstrated rapid absorption and excretion of peptide hydroxyproline. In contrast, delayed serum and urinary peptide hydroxyproline peak values were found in two patients with severe pancreatic insufficiency. In addition, depressed serum glycine, proline, and alanine levels were noted in these patients after gelatin ingestion. Therapy with Cotazym and with Cotazym plus sodium bicarbonate was dramatically effective, restoring the peptide hydroxyproline levels to normal values. A patient with untreated adult celiac disease had a low absolute increase in urinary hydroxyproline after gelatin ingestion, as well as an elevated and delayed peptide hydroxyproline level in the serum. Patients with treated celiac disease demonstrated rapid absorption and excretion of hydroxyproline peptides.

An oral gelatin-xylose test for estimating pancreatic proteolytic activity

An oral gelatin-xylose test is proposed as a practical test for pancreatic proteolytic activity. The principal function of the xylose test is to support the adequacy of small-bowel absorption and thus allow for the more confident interpretation of protein digestion. It was found that, following gelatin ingestion, the normal adult increases his urinary total hydroxyproline excretion by a mean of 7.7 mg./hr. Values falling below 3.3 mg./hr. after a test meal are considered abnormal. A practical short testing period in children is feasible because of the rapid renal clearance of the absorbed hydroxyproline peptides. These peptides are the principal form of urinary hydroxyproline.

Further studies in the use of gelatin in the treatment of brittle nails.

Introduction Recently two of us reported on the treatment of the brittle nail with gelatin. 1 This study raised several questions requiring further investigation. Among these were the following: (1) the duration of the effect after ingestion of gelatin has been stopped; (2) which clinical conditions and pathological states of the nails respond to gelatin intake; (3) the mechanism of the effect of gelatin on nails. It was felt also that an attempt should be made to correlate other physiological changes in pathological nails. Specifically, the concept that blood levels of calcium, phosphorus, and/or the basal metabolic rate in pathological nails are disturbed, was challenged. This idea seems to have established itself firmly on the medical mind, in spite of the work of Kile 2 and others. A recent query on brittleness in nails was answered by giving calcium deficiency 3 as the usual cause. The