Peripheral neuropathy due to dinitrophenol used for weight loss: something old, something new

Determination of 12 anti-obesity drugs in human plasma by a 96-well protein precipitation plate using HPLC-MS

A 96-well protein precipitation plate combined with HPLC-MS/MS was developed for the determination of 12 anti-obesity drugs in human plasma; the detection method showed high throughout and high sensitivity with suitable recovery.

The synthesis of conjugated microporous polymers via nucleophilic substitution of hydroquinone with cyanuric chloride and hexachlorocyclotriphosphazene for sensing to 2,4-dinitrophenol and 2,4,6-trinitrophenol

Hydroquinone is an electron-rich connector similar in structure to DNP and TNP. Two hydroquinone-based conjugated microporous polymers have excellent fluorescence sensing performance for DNP and TNP, respectively.

2,4 dinitrophenol: It's not just for men

BACKGROUND

2,4 dinitrophenol (DNP) is an organic compound which causes thermogenesis resulting in fat burning and weight loss. Although not licensed for human consumption, the globalised access to and information about this compound on the internet has prompted a renewed interest in DNP making it readily available to purchase online.  Studies into user experiences remain scarce and much of the previous literature has focused on DNP use in male dominated bodybuilding communities. While online accounts of female DNP use are plentiful, this group are under researched.

METHOD

Ten online forums containing female discussion of DNP were identified and 440 threads subjected to a thematic analysis. Semi structured interviews were conducted with four forum moderators (all men) and one woman who reported use of DNP.

RESULTS

The findings highlighted diverse motivations for why women use DNP as well as differences in experiences, dosing regimens, willingness to take risks and adverse effects. Many women reported using online forums to seek advice and trusted the information they received. However, much of the discussion and protocols for use online is perpetuated by and geared towards men, with DNP seen as a 'hard core' drug that is not suitable for women. Female DNP use was frequently stigmatised because the potential risks were seen to be at odds with women's roles as mothers and caregivers. Women who used DNP were often ignored, ridiculed or seen as novice users, while men were viewed as the DNP experts.

CONCLUSION

This study provides an overview of female experiences of DNP use. There is a growing body of evidence as to the harms associated with this compound and there are no guaranteed 'safe' regimens that can be advocated for any potential user. Users equate deaths or ill harms from DNP with incorrect dosing or insufficient knowledge of the impact of the drug on the body. This leads women to incorrectly assume that if they are not suffering ill effects they are using DNP safely. Of key concern from this study is that within a vacuum of harm reduction advice, women are reported to be accepting DNP advice circulating in male-dominated forums and adopting the protocols of male bodybuilders with potentially fatal consequences. Furthermore, women using DNP are doing so without any 'real world' support, gender sensitive treatment pathways or interventions in place.

Being in control? A thematic content analysis of 14 in-depth interviews with 2,4-dinitrophenol users

BACKGROUND

2,4-Dinitrophenol (2,4-DNP) is a compound with multiple industrial purposes. Currently unlicensed for human consumption, it is used by the gym-going population for drastic, short-term body fat loss. Nonetheless, physiological mechanisms can lead to potentially fatal hyperthermia. Reported fatal incidents have caused concern and highlighted the need for intervention. Understanding decision-making leading to 2,4-DNP use alongside the perceived outgroup attitudes is vital to forming effective harm minimisation policies targeting current and potential users. First-hand accounts from this elusive population are scarce.

METHODS

Fourteen novel and experienced users (13 male, 1 female) were recruited via "snowballing" techniques. Semi-structured interviews were conducted, comprising 28 questions. Thematic content analysis was conducted using 37 codes.

RESULTS

Four characteristic themes emerged: 1. Users considered the Internet to be a crucial multifunctional resource directly impacting their 2,4-DNP use. 2. Users "respected" 2,4-DNP, proactively taking harm reduction measures. 3. Attitudinal polarisation towards 2,4-DNP within the gym-going community was consistent in all accounts. 4. Users perceived outgroup populations to have inherently negative attitudes towards their use. These themes fell under the all-encompassing theme of "being in control".

CONCLUSION

For the first time, this study offers a rich detail of attitudes toward 2,4-DNP use by giving a collective voice to users. The element of control over every aspect of the users' life appears to be a significant contributor to the successful risk-management of 2,4-DNP use. In the absence of an established safe upper limit and effective regulatory control, education is critical to harm minimisation.

Evaluation of efficacy of resin hemoperfusion in patients with acute 2,4-dinitrophenol poisoning by dynamic monitoring of plasma toxin concentration

OBJECTIVE

The intoxications caused by 2,4-dinitrophenol (2,4-DNP), even death, have been frequently reported in recent years. This study aims to investigate the dynamic changes of plasma toxin concentration and explore the clinical value of resin hemoperfusion (HP) in the treatment of patients with acute 2,4-DNP poisoning.

METHODS

We reported 16 cases of acute 2,4-DNP poisoning through occupational exposure due to ignoring the risk of poisoning. The blood samples were collected from the 14 survivors. According to the different treatments of resin HP, the survivors were divided into routine HP (n=5) and intensive HP (n=9) groups. Ultra high performance liquid chromatography/ tandem mass spectroscopy (UPLC-MS/MS) was used to detect the 2,4-DNP concentration in plasma in this study.

RESULTS

The 14 survivors recovered very well after treatment. The initial plasma 2,4-DNP concentrations (C1) of survivors ranged from 0.25 to 41.88 µg/ml (mean (12.56±13.93) µg/ml). A positive correlation existed between initial plasma 2,4-DNP concentration (C1) and temperature. The elimination of 2,4-DNP was slow and persistent, and the total clearance rates of plasma toxin from the 1st to 3rd day (R3), the 3rd to 7th day (R3-7), and the 1st to 7th day (R7), were only (53.03±14.04)%, (55.25±10.50)%, and (78.29±10.22)%, respectively. The plasma toxin was cleared up to 25 d after poisoning in most of the patients. The R3, R3-7, and R7 in the intensive HP group were all apparently higher than those in the routine HP group, with statistical significance (P<0.05). Simultaneously, the elimination half-life (t1/2) of 2,4-DNP in the intensive HP group was apparently shorter than that in the routine HP group, with statistical significance (P<0.05).

CONCLUSIONS

The clinicians should be aware of this slow and persistent process in the elimination of plasma 2,4-DNP. Higher initial plasma toxin concentration resulted in a more severe fever for the patient. According to the limited data, longer and more frequent resin HP may accelerate to eliminate the poison.

The cellular and molecular progression of mitochondrial dysfunction induced by 2,4-dinitrophenol in developing zebrafish embryos

The etiology of mitochondrial disease is poorly understood. Furthermore, treatment options are limited, and diagnostic methods often lack the sensitivity to detect disease in its early stages. Disrupted oxidative phosphorylation (OXPHOS) that inhibits ATP production is a common phenotype of mitochondrial disorders that can be induced in zebrafish by exposure to 2,4-dinitrophenol (DNP), a FDA-banned weight-loss agent and EPA-regulated environmental toxicant, traditionally used in research labs as an uncoupler of OXPHOS. Despite the DNP-induced OXPHOS inhibition we observed using in vivo respirometry, the development of the DNP-treated and control zebrafish were largely similar during the first half of embryogenesis. During this period, DNP-treated embryos induced gene expression of mitochondrial and nuclear genes that stimulated the production of new mitochondria and increased glycolysis to yield normal levels of ATP. DNP-treated embryos were incapable of sustaining this mitochondrial biogenic response past mid-embryogenesis, as shown by significantly lowered ATP production and ATP levels, decreased gene expression, and the onset of developmental defects. Examining neural tissues commonly affected by mitochondrial disease, we found that DNP exposure also inhibited motor neuron axon arbor outgrowth and the proper formation of the retina. We observed and quantified the molecular and physiological progression of mitochondrial dysfunction during development with this new model of OXPHOS dysfunction, which has great potential for use in diagnostics and therapies for mitochondrial disease.

The unrelenting fall of the pharmacological treatment of obesity

Nowadays pharmacological therapy to limit obesity has reached a critical stage: not only have Authorities limited the use of antiobesity drugs due to their proven inefficacy and dangerous side effects, but bariatric surgery has delivered better results. At present, when the number of obese subjects is growing exponentially worldwide and more and more pathological mechanisms inducing fat accumulation have been discovered, no drugs are available to help patients and physicians to limit one the most dreadful causes of death. Following the failures of promising drugs as sibutramine and rimonabant, many companies stopped to invest in the field of obesity pharmacotherapy. At the same time, leading Authorities have started to require more solid evidence before providing authorization for these drugs to enter the market. This review aims at revising the failed promises of antiobesity drugs and describing the few potential future candidates in order to shed some light in the still uncertain field of antiobesity drugs. It also provides a critical contribution to the ongoing debate among scientists, clinicians, patients and Authorities on the possibility to treat obesity with pharmacological drugs.

Kidney hypoxia, attributable to increased oxygen consumption, induces nephropathy independently of hyperglycemia and oxidative stress

Diabetic nephropathy is strongly associated with both increased oxidative stress and kidney tissue hypoxia. The increased oxidative stress causes increased kidney oxygen consumption resulting in kidney tissue hypoxia. To date, it has been difficult to determine the role of kidney hypoxia, per se, for the development of nephropathy. We tested the hypothesis that kidney hypoxia, without confounding factors such as hyperglycemia or elevated oxidative stress, results in nephropathy. To induce kidney hypoxia, dinitrophenol (30 mg per day per kg bodyweight by gavage), a mitochondrial uncoupler that increases oxygen consumption and causes kidney hypoxia, was administered for 30 consecutive days to rats. Thereafter, glomerular filtration rate, renal blood flow, kidney oxygen consumption, kidney oxygen tension, kidney concentrations of glucose and glycogen, markers of oxidative stress, urinary protein excretion, and histological findings were determined and compared with vehicle-treated controls. Dinitrophenol did not affect arterial blood pressure, renal blood flow, glomerular filtration rate, blood glucose, or markers of oxidative stress but increased kidney oxygen consumption, and reduced cortical and medullary concentrations of glucose and glycogen, and resulted in intrarenal tissue hypoxia. Furthermore, dinitrophenol treatment increased urinary protein excretion, kidney vimentin expression, and infiltration of inflammatory cells. In conclusion, increased mitochondrial oxygen consumption results in kidney hypoxia and subsequent nephropathy. Importantly, these results demonstrate that kidney tissue hypoxia, per se, without confounding hyperglycemia or oxidative stress, may be sufficient to initiate the development of nephropathy and therefore demonstrate a new interventional target for treating kidney disease.