Histologic response to injected phosphatidylcholine in fat tissue: experimental study in a new rabbit model

Promoting Effect of Choline-Phosphate Cytidylyltransferase Gene (pcyt-1) on Departure of Pinewood Nematode from Monochamus alternatus

In order to study the key gene in internal causes of pinewood nematode (PWN), Bursaphelenchus xylophilus, a departure from its vector beetle, Monochamus alternatus, we collected PWNs extracted from newly emerged M. alternatus and beetles 7 days after emergence. The total RNAs of the two groups of PWNs were extracted, transcriptomes sequencing was performed, and gene expression differences between the two groups of PWN were analyzed. It was found that the expression of the choline-phosphate cytidylyltransferase gene (pcyt-1) was markedly up-regulated. After inhibition of pcyt-1 expression by RNA interference, the rate of lipid degradation in PWN decreased significantly, and the motility of PWN also decreased significantly. The analysis identified that phosphatidylcholine could promote the emulsification and degradation of neutral lipid granules in PWN, which provides sufficient energy for PWN departure from M. alternatus. The up-regulation of the gene pcyt-1 is an important internal factor for PWN departure from its vector.

The Role of Fat Reducing Agents on Adipocyte Death and Adipose Tissue Inflammation

Deoxycholic Acid (DCA), which is an FDA-approved compound for the reduction of submental fat, has evolved through an unanticipated and surprising sequence of events. Initially, it was used as a solvent for Phosphatidylcholine (PDC), which was thought to promote lipolysis, but it was later proven to be the bioactive component of the formula and is currently widely used as Kybella. It has also been used off-label to treat other types of fat deposits like lipomas, HIV lipodystrophy, and excess orbital fat. Despite widespread clinical use, there has been no consensus clarifying the mechanisms of DCA and PDC alone or in combination. Furthermore, despite PDC's removal from the FDA-approved formula, some studies do suggest it plays an important role in fat reduction. To provide some clarity, we conducted a PubMed search and reviewed 41 articles using a comprehensive list of terms in three main categories, using the AND operator: 1) Phosphatidylcholines 2) Deoxycholic Acid, and 3) Lipoma. We isolated articles that studied PDC, DCA, and a PDC/DCA compound using cell biology, molecular and genetic techniques. We divided relevant articles into those that studied these components using histologic techniques and those that utilized specific cell death and lipolysis measurement techniques. Most morphologic studies indicated that PDC/DCA, DCA, and PDC, all induce some type of cell death with accompanying inflammation and fibrosis. Most morphologic studies also suggest that PDC/DCA and DCA alone are non-selective for adipocytes. Biochemical studies describing PDC and DCA alone indicate that DCA acts as a detergent and rapidly induces necrosis while PDC induces TNF-α release, apoptosis, and subsequent enzymatic lipolysis after at least 24 hours. Additional papers have suggested a synergistic effect between the two compounds. Our review integrates the findings of this growing body of literature into a proposed mechanism of fat reduction and provides direction for further studies.

Injection Lipolysis: A Systematic Review of Literature and Our Experience with a Combination of Phosphatidylcholine and Deoxycholate over a Period of 14 Years in 1269 Patients of Indian and South East Asian Origin

Background

Phosphatidylcholine and deoxycholate (PC-DC) injections have been used as nonsurgical alternatives to liposuction. DC as a constituent for lipolysis has recently been approved by the US Food and Drug Administration.

Aim

PC and DC have independently been used in lipolysis. We hereby present a systematic review of literature on injection lipolysis and share our experience of using DC in combination with PC for injection lipolysis. We have retrospectively evaluated the effects of PC-DC treatments in varied age groups, both sexes, and over different target areas.

Materials and Methods

This study spans over 14 years wherein 1269 patients of different age groups and sex were treated with injection lipolysis with PC-DC combination. The PC-DC cocktail injection was given to all patients for an average four sessions every 4 weeks, and the results were assessed after 8 weeks from the last session.

Results

The effects were best appreciated over the face (malar, jawline, and submental areas) and upper arm, whereas average effect was observed on the thighs and around the knees. We have also used lipolysis as a primary modality as well as a touch-up modality following liposuction. The results are better appreciated in primary lipolysis. The need for follow-up sessions (1-2 sessions) of lipolysis and the quantification of results in subsequent sessions reveal that maximal improvement is achieved in the first session.

Conclusion

PC-DC cocktail used for lipolysis as a local administration is effective for reducing unwanted fat. It shows great efficacy in treating localized fat, especially over the face and bra roll in the women of younger age group (20-30 years).

Injection of phosphatidylcholine and deoxycholic acid regulates gene expression of lipolysis-related factors, pro-inflammatory cytokines, and hormones on mouse fat tissue

Injection of phosphatidylcholine (PC) and deoxycholic acid (DA) preparation is widely used as an alternative to liposuction for the reduction of subcutaneous fat. Nevertheless, its physiological effects and mechanism of action are not yet fully understood. In this report, PC and deoxycholic acid (DA) were respectively injected into adipose tissue. PC decreased tissue mass on day 7, but DA did not. On the other hand, a decrement of DNA mass was observed only in DA-injected tissue on day 7. Both PC and DA reduced the mRNA expression of adipose tissue hormones, such as adiponectin, leptin, and resistin. In lipolysis-related gene expression profiles, PC increased hormone-sensitive lipase (HSL) transcription and decreased the expression other lipases, perilipin, and the lipogenic marker peroxisome proliferator-activated receptor-γ (PPARγ); DA treatment diminished them all, including HSL. Meanwhile, the gene expression of pro-inflammatory cytokines and a chemokine was greatly elevated in both PC-injected and DA-injected adipose tissue. Microscopic observation showed that PC induced lipolysis with mild PMN infiltration on day 7. However, DA treatment did not induce lipolysis but induced much amount of PMN infiltration. In conclusion, PC alone might induce lipolysis in adipose tissue, whereas DC alone might induce tissue damage.

The effect of phosphatidylcholine and deoxycholate compound injections to the localized adipose tissue: an experimental study with a murine model

Background

Phosphatidylcholine (PPC) and deoxycholate (DCA) compound has been recently used for the purpose of partial lipolysis and is valued for its efficacy and lower invasiveness compared to liposuction and dermolipectomy used previously. In this article, the authors discuss the efficacy of the PPC dissolved in DCA via an experimental rat study model, along with suggesting a useful animal experimental model for the study of adipose tissue and lipolysis.

Methods

Bilateral inguinal fat pads of an experimental rat were elevated with the deep inferior epigastric vessel as the sole vascular pedicle. Normal saline was injected on one side as a control group and a PPC and DCA compound was injected on the other side. After 4 days, the rats were euthanized for microscopic tissue examination. The pathology was scored by a semiquantitative system in 4 categories: normal fat amount, fat necrosis, inflammatory activity, and stage of fibrosis. A Wilcoxon signed-rank test powered by SPSS packet program was used for statistical analysis and to determine significance.

Results

Microscopic examination was performed on the obtained samples, and the experimental data of all four categories showed significant histologic differences compared to the control group. All of the data also showed statistical significance by the Wilcoxon signedrank test (P<0.01).

Conclusions

In the inguinal fat pad rat model, the control group and the experimental group had a differed significantly in the amount of normal fat tissue, inflammation, necrosis, and fibrosis. We recommend the rat inguinal fat pad model used in this study, as it is likely to be useful in related research.

[Injection lipolysis]

A new treatment variation in the spectrum of aesthetic medicine has been investigated worldwide since 2004: so-called injection lipolysis. Advances in knowledge regarding the efficacy and mechanism of action have been achieved especially in Germany because most users are found in Germany when compared on an international level. The reason for this is that the combination of phosphatidylcholine and deoxycholic acid as active substances has been approved for i.v. treatment of fat embolisms. It is thus readily available, but the subcutaneous injection of the drug Lipostabil N® is considered as off-label use. Meanwhile injection lipolysis has become an integral component for many in the practice of aesthetic medicine. The international association of physicians performing lipolysis in the so-called NETWORK-Lipolysis (with more than 2,000 members worldwide) has in particular called for the development of internationally recognized treatment standards and protocols. When the indication for its use adheres to strict criteria and the physicians applying the method have participated in intensive training, subcutaneous injection of phosphatidylcholine/deoxycholic acid represents a meaningful addition to the scope of minimally invasive aesthetic medicine.

Phosphatidylcholine as a constituent in the colonic mucosal barrier--physiological and clinical relevance

Phosphatidylcholine (PC) is an important constituent of the gastrointestinal tract. PC molecules are not only important in intestinal cell membranes but also receiving increasing attention as protective agents in the gastrointestinal barrier. They are largely responsible for establishing the hydrophobic surface of the colon. Decreased phospholipids in colonic mucus could be linked to the pathogenesis of ulcerative colitis, a chronic inflammatory bowel disease. Clinical studies revealed that therapeutic addition of PC to the colonic mucus of these patients alleviated the inflammatory activity. This positive role is still elusive, however, we hypothesized that luminal PC has two possible functions: first, it is essential for surface hydrophobicity, and second, it is integrated into the plasma membrane of enterocytes and it modulates the signaling state of the mucosa. The membrane structure and lipid composition of cells is a regulatory component of the inflammatory signaling pathways. In this perspective, we will shortly summarize what is known about the localization and protective properties of PC in the colonic mucosa before turning to its evident medical importance. We will discuss how PC contributes to our understanding of the pathogenesis of ulcerative colitis and how reinforcing the luminal phospholipid monolayer can be used as a therapeutic concept in humans.

Randomized double-blind clinical trial of subcutaneously injected deoxycholate versus a phosphatidylcholine-deoxycholate combination for the reduction of submental fat

BACKGROUND

Subcutaneous injections consisting of the detergent, sodium deoxycholate, alone or in combination with the phospholipid, phosphatidylcholine, have been reported to reduce adipose tissue. The role of phosphatidylcholine remains unclear.

OBJECTIVE

To evaluate the safety profile and efficacy of subcutaneously injected deoxycholate alone compared with a conventionally utilized mixture of phosphatidylcholine/deoxycholate in patients with undesirable accumulations of submental fat.

METHODS

This was a single center, randomized, double-blind exploratory study. A total of 42 subjects were enrolled; 28 were injected into the submental fat with 1 mL of deoxycholate or phosphatidylcholine/deoxycholate, and 14 received 2 mL per treatment. Subjects received up to 5 treatments every four weeks, and completed a home diary and post-treatment self-assessment. Clinicians blinded to treatment performed injections, physical examination, and photographic evaluation.

RESULTS

Photographic assessment of 32 of the 42 enrolled patients revealed modest changes in submental profiles after a median of 5 deoxycholate or 4 phosphatidylcholine/deoxycholate treatments. Mean degree of improvement (0=none, 1=mild, 2=moderate, 3=significant) was 0.8 (+/-0.9) for deoxycholate and 0.6 (+/-0.5) for phosphatidylcholine/deoxycholate, with a median improvement of 0.5 (range, 0-3) for both groups. The incidence of correct before:after photographic sequence assignments was similar. There were no notable differences on physical examination, incidence, duration, and severity of adverse events (most commonly edema, erythema, pain, and burning) or subject self-assessment of fat loss, skin tightening, chin profile, and overall performance between the treatments.

CONCLUSION

Under the conditions employed, injections of deoxycholate or phosphatidylcholine/deoxycholate into the submental fat produced minimal aesthetic improvement overall. No apparent differences in efficacy or adverse events were observed with the inclusion of phosphatidylcholine. Enhanced neck profiles in several subjects demonstrate a proof of concept that warrants further study utilizing a validated, submental profile grading scale and methods to optimize dose and technique.

A new method to quantify the effect after subcutaneous injection of lipolytic substances

BACKGROUND

Increasing numbers of patients request lipolytic injection therapy for aesthetic indications. However, only the clinical results of these therapies have been published to date. In most cases, pre- and postprocedure photographs and measurements have been presented. As with every other medical procedure, it is necessary to ensure that the results of lipolytic injections are quantified on an objective and scientific basis with comparable data.

METHODS

In the past, the size of fat tissue could not be measured properly with conventional ultrasound systems. High-resolution, real-time three-dimensional (RT-3D) ultrasound is a fairly new method for measuring the volume of tissue. Therefore, this study aimed to measure the interscapular fat bodies of New Zealand rabbits before and after lipolytic therapy with Lipostabil, phosphatidycholine and orciprenalin (Alupent).

RESULTS

The ultrasound-controlled injection of the lipolytic substances into the interscapular fat body ensured a precise injection. The RT-3D ultrasound data were compared with the magnetic resonance imaging (MRI) measurements performed at the same time. The greatest decrease in volume, up to 44%, was measured with orciprenalin (Alupent). There was a significant correlation between the data from ultrasound imaging and MRI.

CONCLUSION

The data suggest that RT-3D ultrasound imaging could be a simple and fast method for proving the effects on volume size after lipolytic procedures. Of the three investigated substances, orciprenalin (Alupent) showed the highest lipolytic effect in our animal model.

Tissue-toxic effects of phosphatidylcholine/deoxycholate after subcutaneous injection for fat dissolution in rats and a human volunteer

BACKGROUND

The safety of the lipodissolution procedure for the cosmetic treatment of fat is unknown.

OBJECTIVES

The objective was to determine the subcutaneous tissue effects of phosphatidylcholine solubilized with deoxycholate (PC/DC) in rats and a human volunteer.

METHODS

Rats were treated subcutaneously three times with 50, 300, or 600 microL of PC/DC formula on the abdomen in a chronic study (30 days). A human volunteer undergoing elective liposuction was similarly treated. Cell membrane lysis, cell viability, and histologic status were determined on fresh biopsies of subcutaneous fat from the injection sites.

RESULTS

PC/DC dose-dependently reduced membrane integrity and cell viability. Histologic alterations induced by PC/DC included fibroplasia, bandlike fibrosis in the region of the cutaneous muscle, and partial muscle loss. The highest dose caused widespread fat necrosis, fat cyst formation, and necrotic changes of the walls of small blood vessels. Histologic sections of subcutaneous tissue from the human volunteer showed dose-dependent panniculitis, fat cysts, and vessel necrosis. DC (2.5%), tested for comparison in the rat, exerted membrane and histologic effects similar to those of PC/DC. Solvent controls caused negligible alterations.

CONCLUSIONS

Injection lipolysis with PC/DC causes tissue fibrosis and necrosis of adipose and vascular tissues in rat and man, making the long-term safety of PC/DC for nonsurgical treatment of subcutaneous fat deposits uncertain.