Efficacy of polyglucosamine for weight loss-confirmed in a randomized double-blind, placebo-controlled clinical investigation

A Randomized Double-Blind Placebo-Controlled Clinical Study to Evaluate the Effect on the Weight of a Medical Device with Polyglucosamine L112 in a Group of Overweight and Obese Subjects

BACKGROUND

Overweight and obesity have reached epidemic proportions and safe treatments are needed to heal these diseases.

OBJECTIVE

The objective of this study is to examine the activity of a medical device based on polyglucosamine polymers (PG) on body weight (BW) reduction, insulin resistance, and the serum levels of fat-soluble vitamins and glucosamine.

METHODS

A double-blind placebo-controlled interventional study comparing PG and a placebo (PL) was conducted. One hundred and fifty overweight or obese cases were treated, divided into two groups for a period of 90 days at the dosage of 3 g/day.

RESULTS

One hundred and nineteen cases (58 with PG and 61 with PL, respectively) concluded the treatment. PG was more effective than the PL on the reduction of BW and insulin resistance. No modification of fat-soluble vitamins (Vit A, E, D3, K1) and glucosamine levels was shown. Total cholesterol levels were significantly more reduced in the PG group compared to the PL group as it was for subjects with a BW decrease of >5%.

CONCLUSIONS

PG acts as a safe medical device, is not absorbed, and binds lipids in the upper gastrointestinal tract, reducing their availability, with a significant activity on the reduction of BW, insulin resistance, and cholesterol levels without the modification of fat-soluble vitamins.

Efficacy of dietary supplements containing isolated organic compounds for weight loss: a systematic review and meta-analysis of randomised placebo-controlled trials

BACKGROUND/OBJECTIVES

A systematic review with meta-analysis was conducted to synthesise evidence on the efficacy of dietary supplements containing isolated organic compounds for weight loss.

SUBJECTS/METHODS

Four electronic databases (Medline, Embase, Web of Science, Cinahl) were searched until December 2019. Sixty-seven randomised placebo-controlled trials of dietary supplements containing isolated organic compounds for weight loss were included. Meta-analyses were conducted for chitosan, glucomannan, conjugated linoleic acid and fructans, comparing mean weight difference post-intervention between participants receiving the dietary supplement or placebo.

RESULTS

Statistically significant weight differences compared to placebo were observed for chitosan (-1.84 kg; 95% confidence interval [CI] -2.79, -0.88; p < 0.01), glucomannan (-1.27 kg; 95%CI -2.45, -0.09; p = 0.04), and conjugated linoleic acid (-1.08 kg; 95%CI -1.61, -0.55; p < 0.01). None met our threshold for clinical significance (≥2.5 kg). There was no statistically significant effect on weight for fructans compared to placebo (p = 0.24). For dietary supplements with an inadequate number of trials for meta-analysis, a statistically and borderline clinically significant weight difference compared to placebo was found for modified cellulose, manno-oligosaccharides (in males), blood orange juice extract, and three multiple-ingredient dietary supplements. These were only reported in one trial of each. Thus, more evidence is needed before recommending them for weight loss.

CONCLUSIONS

While some dietary supplements containing isolated organic compounds warrant further investigation to determine efficacy and safety, there is currently insufficient evidence to recommend any of these dietary supplements for weight loss.

A Systematic Review of the European Rapid Alert System for Food and Feed: Tendencies in Illegal Food Supplements for Weight Loss

Background: Slimming products represent a dynamically growing group of food supplements worldwide. The efficacy of safely usable natural ingredients is usually below consumers' expectations. Certain manufacturers add unauthorized or prohibited ingredients to weight loss supplements in order to increase their efficacy. Hence, many of these products are adulterated and may pose a risk to the consumers' health. Aims: The aim of our work was to give an overview on natural ingredients used in slimming products, to summarize the frequently used synthetic adulterants and also to assess the trends of adulterated and illegal food supplements in the European Union based on the warnings of the Rapid Alert System for Food and Feed (RASFF) in the time period of 1988-2019. Methods: Reports between 1988-2019 were extracted from the RASFF portal on January 1, 2020. Each entry was individually reviewed. Results: 2,559 records of food supplements with quality problems were identified in the RASFF, several of which [319 (12,5%)] were marketed to facilitate weight loss. 202 (63,3%) contained unapproved, synthetic drug ingredients. The major adulterant (113 of 319, 35.4%) was DNP (2,4-dinitrophenol), whereas sibutramine was the second most frequent adulterant agent (69 products, 21,6%) between 1988 and 2019. Conclusion: The number of approved medicines for the indication of weight loss is relatively low and their efficacy (and also that of the natural ingredients) is limited. Therefore, a significant number of weight loss supplements is adulterated to satisfy patients' expectations. Hence, these products may cause serious adverse effects in sensitive patients.

Effect of Polyglucosamine on Weight Loss and Metabolic Parameters in Overweight and Obesity: A Systemic Review and Meta-Analysis

The use of dietary supplements for weight loss has gained significant momentum. Polyglucosamine, a chitosan derivative, is a dietary supplement increasingly used for weight loss. In this meta-analysis, we systematically summarized and quantified the key findings of four randomized, placebo-controlled clinical trials examining the effects of polyglucosamine supplementation and caloric restriction, and physical activity on body weight, body mass index (BMI), and waist circumference in subjects with overweight and obesity. The control group was set with a physical activity from 6–7 MET-h/week activity and up to 21 MET-h/week activity with caloric restriction. Compliance in the latter trials was reported via a follow-up questionnaire with the individual participants. The analysis included 399 subjects followed for a period ranging from 12 weeks to one year. Subjects’ age ranged from 21–75 years, BMI from 26–45 kg/m², and all were white European or Caucasian in ethnicity. The meta-analyzed mean differences for random effects showed that polyglucosamine supplementation improves weight loss by −1.78 kg [−2.78, −0.79], BMI by −1.52 kg/m² [−3.58, 0.54], and improves waist circumference reduction by −1.45 cm [−2.77, −0.12]. In conclusion, the use of polyglucosamine supplementation in conjunction with lifestyle behavioral therapies can be effective for weight reduction. Further studies are needed to examine the long-term effects of polyglucosamine supplementation on weight loss and other metabolic parameters

Regular Consumption of Lipigo® Promotes the Reduction of Body Weight and Improves the Rebound Effect of Obese People Undergo a Comprehensive Weight Loss Program

Obesity is a global public health problem. Objective: To evaluate the effect of the regular consumption of the product Lipigo^® on body weight and rebound effect on overweight/obese subjects undergoing a comprehensive weight loss program. Methods: A randomized, parallel, double-blind, placebo-controlled clinical trial was conducted with male and female subjects presenting a BMI 25–39.9 kg/m². All subjects underwent a comprehensive weight loss program (WLP) for 12 weeks, which included an individualized hypocaloric diet, physical activity recommendations, nutritional education seminars, and three times a day consumption of the product Lipigo^® or Placebo. After-WLP, subjects continued the treatment for 9 months to assess rebound effect. Body weight (BW), BMI, and body composition were measured at the beginning and the end of the WLP, and in the follow-up. Results: A total of 120 subjects (85% women) 49.0 ± 9.5 years old and with a BW of 81.57 ± 13.26 kg (BMI 31.19 ± 3.44 kg/m²) were randomized and 73 subjects finished the study. At the end of the WLP, there was a tendency toward reduced BW (p = 0.093), BMI (p = 0.063), and WC (p = 0.059) in the treated group. However, subjects with obesity type 1 (OB1) from the treated group significantly reduced body weight (−5.27 ± 2.75 vs. −3.08 ± 1.73 kg; p = 0.017) and BMI (−1.99 ± 1.08 vs. −1.09 ± 0.55 kg/m²; p = 0.01) compared with placebo. They also presented a minor rebound effect after 9 months with product consumption (−4.19 ± 3.61 vs. −1.44 ± 2.51 kg; p = 0.026), minor BMI (−1.61 ± 1.43 vs. −0.52 ± 0.96 kg/m²; p = 0.025) and tended to have less fat-mass (−3.44 ± 2.46 vs. −1.44 ± 3.29 kg; p = 0.080) compared with placebo. Conclusions: The regular consumption of the product Lipigo^® promotes the reduction of body weight and reduces the rebound effect of obese people after 52 weeks (12 months), mainly in obesity type 1, who undergo a comprehensive weight loss program.

Persister Cells Resuscitate Using Membrane Sensors that Activate Chemotaxis, Lower cAMP Levels, and Revive Ribosomes

Persistence, the stress-tolerant state, is arguably the most vital phenotype since nearly all cells experience nutrient stress, which causes a sub-population to become dormant. However, how persister cells wake to reconstitute infections is not understood well. Here, using single-cell observations, we determined that Escherichia coli persister cells resuscitate primarily when presented with specific carbon sources, rather than spontaneously. In addition, we found that the mechanism of persister cell waking is through sensing nutrients by chemotaxis and phosphotransferase membrane proteins. Furthermore, nutrient transport reduces the level of secondary messenger cAMP through enzyme IIA; this reduction in cAMP levels leads to ribosome resuscitation and rescue. Resuscitating cells also immediately commence chemotaxis toward nutrients, although flagellar motion is not required for waking. Hence, persister cells wake by perceiving nutrients via membrane receptors that relay the signal to ribosomes via the secondary messenger cAMP, and persisters wake and utilize chemotaxis to acquire nutrients.

Nutritionist and obesity: brief overview on efficacy, safety, and drug interactions of the main weight-loss dietary supplements

Over the past 20 years the use of dietary supplements as adjuvant therapy for weight loss gained growing favor among consumers and dietician-nutritionists, with the subsequent astounding increase in health costs. Despite the reassuring label of natural remedy for losing weight, dietary supplements contain a wide variety of ingredients on which available information is rather scanty and scientifically incomplete. Currently, there is little evidence that weight-loss supplements offer effective aids to reduce weight and meet criteria for recommended use. Robust, randomized, placebo-controlled studies to provide clear-cut scientific evidence of their efficacy and potential side effects in clinical practice are still lacking. Understanding the evidence for the efficacy, safety, and quality of these supplements among nutritionists and physicians is critical to counsel patients appropriately, especially considering the risk of serious adverse effects and interference with concomitant therapies. Detailed information on the efficacy and safety of the most commonly used weight-loss dietary supplements has been recently published by the National Institutes of Health (NIH). However, in this report the thorny issue that may result from drug interactions with weight-loss dietary supplements has been not sufficiently addressed. The aim of this review was to provide a synthetic, evidence-based report on efficacy and safety of the most commonly used ingredients in dietary supplements marketed for weight loss, particularly focusing on their possible drug interactions.

A Meta-Analysis on Randomised Controlled Clinical Trials Evaluating the Effect of the Dietary Supplement Chitosan on Weight Loss, Lipid Parameters and Blood Pressure

Background and objectives: Erratic results have been published concerning the influence of the dietary supplement chitosan used as a complementary remedy to decrease the body weight of overweight and obese people. The published articles mention as secondary possible benefits of usage of chitosan the improvement of blood pressure and serum lipids status. We performed a meta-analysis evaluating body weight, body mass index, total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides, systolic and diastolic blood pressure among overweight and obese patients. Materials and Methods: Searching MEDLINE, Cochrane up to December 2017 on clinical trials that have assessed the influence of chitosan used as a dietary supplement on overweight and obese patients. An additional study was identified in the References section of another meta-analysis. A total of 14 randomised control trials (RCT) were used to assess the effect on body weight, serum lipids and blood pressure. Results: The usage of chitosan as a dietary supplement up to 52 weeks seems to slightly reduce the body weight (-1.01 kg, 95% CI: -1.67 to -0.34). Considering the other parameters studied, the most significant improvement was observed in systolic and diastolic blood pressure: -2.68 mm Hg (95% CI: -4.19 to -1.18) and -2.14 mm Hg (95% CI: -4.14 to -0.14) in favour of chitosan versus a placebo. Conclusions: Based on the meta-analysis realized with 14 RCT we concluded that the usage of chitosan as a dietary supplement can lead to a slight short- and medium-term effect on weight loss and to the improvement of serum lipid profile and cardiovascular factors.

Protective Effect of Chitosan Oligosaccharides Against Cyclophosphamide-Induced Immunosuppression and Irradiation Injury in Mice

Chitosan oligosaccharides (COS), hydrolyzed products of chitosan, was found to display various biological activities. Herein, we assessed the immunostimulatory activity of COS both in in vitro and in vivo studies. In vitro cytotoxicity studies to murine macrophage RAW264.7 revealed that COS is safe even at the maximum tested concentration of 1000 μg/mL. It also stimulates the production of nitric oxide (NO) and tumor necrosis factor (TNF-α) and enhances the phagocytosis in COS-stimulated RAW264.7. We have shown that the COS could significantly (P < 0.05) restore the reduced immune organs indices, phagocytic index, lymphocyte proliferation, natural killer cell activity, and antioxidant enzyme activities in a cyclophosphamide-induced immunosuppressed mice model. COS can also improve the survival rate in irradiation injury mice and significantly (P < 0.05) increased the spleen indices and up-regulates the CD4+/CD8+ ratio in splenocytes. In sum, the aforementioned results suggest that COS might has the potential to be used as an immunostimulatory agent in patients with immune dysfunctions or be a model for functional food development.

PRACTICAL APPLICATION

COS might has the potential to be used as an immunostimulatory agent in patients with immune dysfunctions or be a model for functional food development.

Long-Term Treatment of Overweight and Obesity with Polyglucosamine (PG L112): Randomized Study Compared with Placebo in Subjects after Caloric Restriction

Background: Short-term treatment of overweight and obesity with polyglucosamine (PG) was found to be more effective than placebo and orlistat in double-blind clinical studies. Objective: The aim of the study was to compare the efficacy of long-term (12-mo) treatment of weight loss with PG and placebo (PL). Methods: This was a double-blind randomized study in 100 participants of both sexes with a body mass index (in kg/m2) >30 to <35. One group of 50 participants was treated for 1 y with PG at 1.6 g/d and a similar group received PL. PG is a combination of low-molecular-weight chitosan with organic acids. Participants were instructed to reduce their caloric intake by 10% and increase the physical activity level by 9 metabolic equivalent task hours/wk. Dietary compliance was checked every 3 mo by using a weekly questionnaire [food intake assessment (FIA)] based on 25 different food servings. Body weight (BW), waist circumference (WC), blood pressure (BP), glucose, lipids, and high-sensitivity C-reactive protein (hs-CRP) were also monitored. Results: Ninety-seven participants completed the study (49 in the PG group, 48 in the PL group). The decrease in calories was similar in both groups, as was the change in number of food servings (P > 0.05, ANOVA). Decreases in BW and WC were 8.0 kg and 10.2 cm, respectively, in the PL group, whereas they were 12.1 kg and 13.3 cm in the PG group (P < 0.001, ANOVA). The decrease in BP, plasma lipids, glucose, and hs-CRP was more evident in the group treated with PG (P < 0.05, ANOVA). The intake of lipids was found to correlate directly with hs-CRP, with the exception of extra-virgin olive oil. Conclusions: PG was found to be more effective than PL in reducing BW, WC, glucose, BP, plasma lipids, and hs-CRP in moderately obese individuals undergoing a 10% caloric reduction and a slight increase in physical activity. Dietary monitoring with the use of an FIA was an effective tool in supporting dietary compliance. This trial was registered at clinicaltrials.gov as U111111292405 (WHO).

Randomised, double-blind, clinical investigation to compare orlistat 60 milligram and a customized polyglucosamine, two treatment methods for the management of overweight and obesity

BACKGROUND

The efficacy of a non-prescription drug to support weight loss programs has yet to be compared. This clinical trial investigates the comparability of orlistat 60 milligram (mg) and polyglucosamine.

METHODS

Sixty-four overweight or obese subjects were included in a two-center double-blind study. One center was in Germany [center 1] and the other was in Italy [center 2]. The subjects (26 in center 1 and 38 in center 2) were recommended to follow a calorie deficit of about 2000 kilojoules/day and to increase their physical activity to 3 metabolic equivalent hours (MET h)/day. In both centers, subjects were randomized to receive polyglucosamine (2 tablets x 2) or orlistat (1 capsule x 3) for a period of 12 weeks. Weight loss was considered as a main variable together with the reduction of 5 per cent (%) of body weight (5R). Body Mass Index (BMI) and waist circumference (WC) were taken as secondary variables.

RESULTS

A significant difference in weight loss between the two groups was shown, 6.7 ± 3.14 kilogram (kg) in group polyglucosamine versus 4.8 ± 2.24 kg in group orlistat (t test p < 0.05) respectively; BMI and WC reduction were also more consistent with polyglucosamine treatment than with orlistat treatment (t test p < 0.05). No significant difference was found in the number of subjects who achieved 5R (70% for polyglucosamine and 55% for orlistat group; chi square p > 0.05). The administration of polyglucosamine following energy restriction and increase in physical activity reduces body weight, BMI and WC more efficiently than orlistat.

CONCLUSIONS

Even though both groups were instructed to adopt a calorie restricted diet together with increased physical activity an additional weight loss in the polyglucosamine group of 1.6 kilogram (kg) compared to the orlistat group (6.2 ± 3.46 versus 4.6 ± 2.36 kg) in both centers was seen despite the higher consumption of carbohydrates in Italy (center 2). A typical Italian diet is usually high in carbohydrate content whereas Germans tend to consume meals with higher fat content. This leads to the assumption that polyglucosamine limits both fat and carbohydrate absorption which would explain the comparable effective weight reduction in the Italian participants.

TRIAL REGISTRATION

Trial registration at ClinicalTrials.gov NCT02529631, registered on Aug 19, 2015 retrospectively registered.

Chitosan oligosaccharide: Biological activities and potential therapeutic applications

Chitosan oligosaccharide (COS) is an oligomer of β-(1➔4)-linked d-glucosamine. COS can be prepared from the deacetylation and hydrolysis of chitin, which is commonly found in the exoskeletons of arthropods and insects and the cell walls of fungi. COS is water soluble, non-cytotoxic, readily absorbed through the intestine and mainly excreted in the urine. Of particular importance, COS and its derivatives have been demonstrated to possess several biological activities including anti-inflammation, immunostimulation, anti-tumor, anti-obesity, anti-hypertension, anti-Alzheimer's disease, tissue regeneration promotion, drug and DNA delivery enhancement, anti-microbial, anti-oxidation and calcium-absorption enhancement. The mechanisms of actions of COS have been found to involve the modulation of several important pathways including the suppression of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPK) and the activation of AMP-activated protein kinase (AMPK). This review summarizes the current knowledge of the preparation methods, pharmacokinetic profiles, biological activities, potential therapeutic applications and safety profiles of COS and its derivatives. In addition, future research directions are discussed.

A single oral dose of a polyglucosamine influences the bioavailability of [9-(14)C]-Oleic acid in adult female Göttingen minipigs

Background

Worldwide obesity has nearly doubled since 1980 and is a leading risk for global deaths, profoundly affecting morbidity, mortality, health-care costs, and professional and personal quality of life. Treatment of obesity and its consequences include lifestyle intervention, pharmacotherapy, and bariatric surgery. Polyglucosamines have been proposed as an alternative strategy for treating obesity, by reducing the amount of absorbed fat through interaction with dietary fat through various mechanisms. The objective of this study is to investigate the influence of polyglucosamine on the bioavailability of the model compound [9-¹⁴C]-oleic acid in female Göttingen minipigs.

Method

The study consisted of two treatment groups, each consisting of six adult female Göttingen minipigs with a catheterized vena jugularis to enable frequent blood sampling. One group served as the untreated group (control) and the other group was pre-treated with 2 tablets of 500 mg formoline L112. After 30 min, all animals were dosed orally with [9-¹⁴C]-oleic acid. Excreta and blood samples were collected for analysis of radioactivity from 48 h pre-dose up to 144 h post-dosing. At sacrifice, the liver and contents of the gastrointestinal tract were collected for radioanalysis.

Results

Upon treatment with polyglucosamine (formoline L112), the T_max of [¹⁴C]-oleic acid in plasma was shifted from 4 to 16 h, and the C_max decreased significantly from 14.1 μg/g to 3.3 μg/g. In addition, upon treatment with polyglucosamine the internal exposure to [¹⁴C]-oleic acid as reflected by the area under the curve during the 0–12 h post-dose time interval (AUC_0-12h), is significantly decreased to 32.9 % of the plasma value of [¹⁴C]-oleic acid in untreated animals. Even up to 24 h post-dose, the AUC_0-24h is significantly decreased to 50.7 % of the plasma value in untreated animals and this significant effect is prolonged up to 60 h post-dose.

Conclusions

This study shows that treatment with polyglucosamine (formoline L112) reduces (as judged by C_max & AUC) and delays (as judged by T_max) fat absorption from the gastrointestinal tract into the systemic circulation and limits peak exposure to free fatty acids which may contribute to a more beneficial condition in overweight humans.

Single-blind, placebo controlled randomised clinical study of chitosan for body weight reduction

Background

Chitosan is a dietary fibre which acts by reducing fat absorption and thus used as a means for controlling weight. Weight loss clinical trial outcomes, however, have contradictory results regarding its efficacy. The primary objective of the present study was to evaluate the efficacy and safety of a chitosan from fungal origin in treatment of excess weight in the absence of dietary restrictions.

Methods

A phase IV, randomised, multicentre, single-blind, placebo-controlled, clinical study was conducted by administering chitosan capsules (500 mg, five/day) and indistinguishable placebo capsules as daily supplements to 96 overweight and obese subjects for 90 days. The study participants were divided in 2:1 ratio to receive either chitosan (n = 64) or placebo (n = 32). Efficacy was assessed by measuring body weight, body composition parameters, anthropometric measurements, HbA1C level and lipid profile at day 45 and day 90. Also, short form-36 quality of life (QoL) questionnaire was assessed to evaluate improvement in life-style and dietary habits were recorded for calorie intake. Safety was assessed by evaluating safety parameters and monitoring adverse events.

Results

The mean changes in body weight were -1.78 ± 1.37 kg and -3.10 ± 1.95 kg at day 45 and day 90 respectively in chitosan group which were significantly different (p < 0.0001) as compared to placebo. BMI was decreased by10.91 fold compared to placebo after 90 day administration. In concert with this, there was also reduction in body composition and anthropometric parameters together with improvement in QoL score. Chitosan was also able to reduce HbA1C levels (below 6 %) in subjects who had initial higher values. The mean caloric intake shows that there was no change in dietary habits of subjects in both groups. Lipid levels were unaffected and all adverse events were mild in nature and unrelated to study treatment.

Conclusion

Chitosan from fungal origin was able to reduce the mean body weight up to 3 kg during the 90 day study period. Together with this, there was also improvement in body composition, anthropometric parameters and HbA1C, reflecting overall benefits for the overweight individuals. Additionally, there was also improvement in QoL score. It was safe and well tolerated by all subjects.

Trial registration

CTRI/2014/08/004901.