Lotus leaf extract and L-carnitine influence different processes during the adipocyte life cycle

Advances in the pharmacological effects and mechanisms of Nelumbo nucifera gaertn. Extract nuciferine

ETHNOPHARMACOLOGIC RELEVANCE

The leaves of Nelumbo nucifera Gaertn. Are recorded in the earliest written documentation of traditional Chinese medicinal as "Ben Cao Gang Mu", a medicinal herb for blood clotting, dysentery and dizziness. Nuciferine, one of N. nucifera Gaertn. leaf extracts, has been shown to possess several pharmacological properties, including but not limited to ameliorating hyperlipidemia, stimulating insulin secretion, inducing vasodilation, reducing blood pressure, and demonstrating anti-arrhythmic properties.

AIM OF THE STUDY

In light of the latest research findings on nuciferine, this article provides a comprehensive overview of its chemical properties, pharmacological activities, and the underlying regulatory mechanisms. It aims to serve as a dependable reference for further investigations into the pharmacological effects and mechanisms of nuciferine.

MATERIALS AND METHODS

Use Google Scholar, Scifinder, PubMed, Springer, Elsevier, Wiley, Web of Science and other online database search to collect the literature on extraction, separation, structural analysis and pharmacological activity of nuciferine published before November 2023. The key words are "extraction", "isolation", "purification" and "pharmacological action" and "nuciferine".

RESULTS

Nuciferine has been widely used in the treatment of ameliorating hyperlipidemia and lose weight, Nuciferine is a monomeric aporphine alkaloid extracted from the leaves of the plant Nymphaea caerulea and Nelumbo nucifera Gaertn. Nuciferine has pharmacological activities such as relaxing smooth muscles, improving hyperlipidemia, stimulating insulin secretion, vasodilation, inducing hypotension, antiarrhythmic effects, and antimicrobial and anti-HIV activities. These pharmacological properties lay a foundation for the treatment of tumors, inflammation, hyperglycemia, lipid-lowering and weight-loss, oxidative stress and other diseases with nuciferine.

CONCLUSION

Nuciferine has been clinically used to treat hyperlipidemia and aid in weight loss due to its effects on lipid levels, insulin secretion, vasodilation, blood pressure reduction, anti-tumor properties, and immune enhancement. However, other potential benefits of nuciferine have not yet been fully explored in clinical practice. Future research should delve deeper into its molecular structure, toxicity, side effects, and clinical pharmacology to uncover its full range of effects and pave the way for its safe and expanded clinical use.

β-Hydroxyphosphocarnitine modifies fibrosis, steatosis and improves liver function in non-alcoholic steatohepatitis induced in rats

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a chronic disease characterized by inflammation, steatosis, and liver fibrosis. The liver is particularly affected by alterations in lipid metabolism. Our aim was to evaluate the effect of β-hydroxyphosphocarnitine (β-HPC) on NASH induced in rats.

METHODS

NASH was produced via the ad libitum daily chronic administration of a fructose solution (400 kcal) for 9 weeks, an oral dose of fat solution (16 kcal) for 7 weeks and a subcutaneous injection of CCl₄ (30%) two times a week for 2 weeks to Wistar rats. To evaluate the effect of β-HPC, a dose of 100 mg/kg was administered perorally for 4 weeks and its biochemical and hepatic effects on rats with NASH were analyzed. Serum levels of glucose, triglycerides, cholesterol, and liver enzymes were quantified. Histological changes were evaluated on slices stained with H&E, trichromic and PAS. Glycogen content was measured in liver samples. α-SMA and SREBP-1 immunopositive cells were identified in liver tissue.

RESULTS

NASH was characterized by elevated triglycerides, elevated liver damage enzymes, and the presence of necrosis, inflammation, steatosis, and fibrosis. Significant amounts of glycogen were found, along with α-SMA positive cells in fibrosis areas. The over-expression of SREBP-1 in cytoplasm and nuclei was evident. Animals with NASH treated with β-HPC showed a significant reduction in inflammation, necrosis, and glycogen content in the liver. A reduction in α-SMA and SREBP-1 immunopositive cells correlated with a significant reduction in the degree of fibrosis and steatosis found in liver tissue. β-HPC reduced the levels of ALP and GGT, and significantly reduced triglyceride levels. Animals treated with β-HPC did not show any alterations in liver enzyme function.

CONCLUSIONS

Our research shows that β-HPC can improve liver function and morphology in the case of NASH induced in rats, suggesting β-HPC could be potentially used in the treatment of NASH.

Fat reducing effects of Nelumbo nucifera leaf extract in overweight patients

The leaf of Nelumbo nucifera (Family Nelumbonaceae) has been widely included in the diet of Chinese people from the time of the Min Dynasty. In this study, a randomized double-blind trial (n = 60) was performed to determine the effects of extract from sun dried Nelumbo nucifera leaves (NnEx), which included quercetin-3-glucuronide (Q3GA) as the main components, in overweight patients (24 kg/m²<body mass index < 28 kg/m²) during 12 weeks. For both men and women, compared with those in the non-intervention control groups, the whole body fat was significantly decreased after NnEx ingestion, and men also significantly reduced visceral fat and waist circumference after NnEx ingestion compared with those in the control group.

Discovery of eight alkaloids with D1 and D2 antagonist activity in leaves of Nelumbo nucifera Gaertn. Using FLIPR assays

ETHNOPHARMACOLOGICAL RELEVANCE

Dopamine receptors are long-standing primary targets in the treatment of mental diseases and there is growing evidence that suggests relationships between obesity and the dopamine system, especially dopamine D1 and D2 receptors. Leaves of Nelumbo nucifera Gaertn. (lotus leaves) have been medically used for helping long-term maintenance of weight loss. Whether and how components of lotus leaves function through the dopamine receptors remains unclear.

AIM OF THE STUDY

This work aimed to discover dopamine receptor-active alkaloids isolated from the lotus leaves, to evaluate their potencies and to analyze their structure activity relationship.

MATERIALS AND METHODS

Dried lotus leaves were prepared and total extract was divided into alkaloids and flavones. Eight alkaloids were separated and characterized by a combination of high-performance liquid chromatography, quadrupole time-of-flight mass spectrometry and nuclear magnetic resonance, and assayed by a fluorometric imaging plate reader platform. Human embryonic kidney 239 cell lines expressing dopamine D1, D2 and serotonin 2A (5-HT2A) receptors, respectively, were cultured and used in the assay.

RESULTS

Alkaloids in the lotus leaves were the bioactive phytochemicals and inhibited dopamine from accessing the D1 and D2 receptors. All eight compounds functioned as D1-receptor antagonists and except N-nornuciferine, seven alkaloids functioned as D2-receptor antagonists. (S)-coclaurine and (R)-coclaurine are optical isomers and antagonized both D1 and D2 with equivalent potencies, suggesting that the optical rotation of the methylene linker in the monobenzyl isoquinoline backbone did not influence their activity. Among the eight alkaloids, O-nornuciferine was the potent antagonist to both receptors (the lowest IC₅₀ values, D1: 2.09 ± 0.65 μM and D2: 1.14 ± 0.10 μM) while N-nornuciferine was found to be the least potent as it moderately antagonized D1 and was inactive on D2. O-nornuciferine was also a 5-HT2A antagonist (IC₅₀~20 μM) while N-nornuciferine had no activity. These hinted the importance of a methyl group attached to the nitrogen atom in the aporphine backbone. Armepavine showed a nearly 10-fold selectivity to D2.

CONCLUSIONS

In this work, eight alkaloids were isolated from the leaves of Nelumbo nucifera Gaertn. and assayed on the D1 and D2 receptors. They were D1/D2 antagonists with IC₅₀ values in the mid- to low-micromolar range and O-nornuciferine was the most potent alkaloid among the eight. This family of alkaloids was biochemically evaluated on the dopamine receptors by the same platform for the first time.

Comparative Analysis of Chemical Constituents in Different Parts of Lotus by UPLC and QToF-MS

Six parts of lotus (seeds, leaves, plumule, stamens, receptacles and rhizome nodes) are herbal medicines that are listed in the Chinese Pharmacopoeia. Their indications and functions have been confirmed by a long history of clinical practice. To fully understand the material basis of clinical applications, UPLC-QToF-MS combined with the UNIFI platform and multivariate statistical analysis was used in this study. As a result, a total of 171 compounds were detected and characterized from the six parts, and 23 robust biomarkers were discovered. The method can be used as a standard protocol for the direct identification and prediction of the six parts of lotus. Meanwhile, these discoveries are valuable for improving the quality control method of herbal medicines. Most importantly, this was the first time that alkaloids were detected in the stamen, and terpenoids were detected in the cored seed. The stamen is a noteworthy part because it contains the greatest diversity of flavonoids and terpenoids, but research on the stamen is rather limited.

Nuciferine Inhibited the Differentiation and Lipid Accumulation of 3T3-L1 Preadipocytes by Regulating the Expression of Lipogenic Genes and Adipokines

Purposes: Nuciferine, a main aporphine alkaloid component found in lotus leaf (Nelumbo nucifera), has been demonstrated to possess the property of reducing fat mass and alleviating dyslipidemia in vivo. The purpose of this study is to explore the effects of nuciferine on the proliferation and differentiation of 3T3-L1 cells and further investigate the possible underlying molecular mechanisms.

Methods: 3T3-L1 preadipocytes were treated with 0∼20 μM nuciferine for 24∼120 h, the cell viability was assessed using CCK8. 3T3-L1 preadipocytes and human primary preadipocytes were then induced differentiation and the effects of nuciferine on the lipid metabolism in differentiating and fully differentiated adipocytes were observed by the methods of intracellular triglyceride (TG) assay, Oil Red O staining, RT-qPCR and western blot. Transient transfection and dual luciferase reporter gene methods were used to assess the effects of nuciferine on FAS promoter activities.

Results: Nuciferine inhibited the proliferation of 3T3-L1 preadipocytes in a dose- and time-dependent manner. 20 μM nuciferine significantly attenuated lipid accumulation and reduced intracellular TG contents by 47.2, 59.9 and 55.4% on the third, sixth and ninth day of preadipocytes differentiation, respectively (all p < 0.05). Moreover, the mRNA levels of PPARγ, C/EBPα, C/EBPβ, FAS, ACC, HSL and ATGL were notably decreased by 39.2∼92.5% in differentiating preadipocytes when treated with 5∼20 μM nuciferine (all p < 0.05). In fully differentiated adipocytes treated with 20 μM nuciferine for 48 h, the mRNA levels of FAS, ACC and SREBP1 were remarkably downregulated by 22.6∼45.2% compared with the controls (0 μM) (all p < 0.05), whereas the expression of adipokines FGF21 and ZAG were notably promoted by nuciferine. Similarly, in fully differentiated human primary adipocytes, the mRNA levels of FAS, ACC, SREBP1 were decreased and the expression of FGF21 and ZAG were elevated after treated with nuciferine (all p < 0.05). Further mechanism studies showed that 2.5∼20 μM nuciferine significantly decreased FAS promoter activities in 3T3-L1 preadipocytes.

Conclusion: Nuciferine inhibited the proliferation and differentiation of 3T3-L1 preadipocytes. The inhibitory effects of nuciferine on adipogenesis might be due to the downregulation of PPARγ, C/EBPα and C/EBPβ, which led to the reduction of intracellular lipid accumulation in 3T3-L1 cells and by downregulating the expression of critical lipogenic enzymes, especially of FAS, which was achieved by inhibiting the FAS promoter activities. Besides, nuciferine promoted the expression of adipokines in fully differentiated adipocytes.

Lipid-Lowering Effects of Lotus Leaf Alcoholic Extract on Serum, Hepatopancreas, and Muscle of Juvenile Grass Carp via Gene Expression

Compared with wild grass carp (Ctenopharyngodon idellus), intensively cultured fish displayed disordered lipid metabolism, showing excess lipid deposition in the hepatopancreas and muscle. Lotus leaf prevents fat accumulation in humans and may have similar effects on fish. This study explored the regulatory mechanisms by which the dietary addition of an alcoholic extract of lotus leaf (AELL) reduced lipid deposition in the hepatopancreas and muscle of juvenile grass carp. The fish (average initial weight: 34.00 ± 0.40 g) were fed four experimental diets containing different AELL levels (0, 0.07, 0.14, and 0.21%) for 8 weeks. Serum components, lipid droplet size, triacylglycerol (TAG) content, enzymatic activities, and mRNA levels of genes related to lipid metabolism in the hepatopancreas and muscle were analyzed. The results show that dietary AELL supplementation significantly reduced the TAG content and lipid droplet area in the histological sections as well as the fatty acid synthase (FAS) activity in both the hepatopancreas and muscle but enhanced the activities of lipoprotein lipase (LPL) and carnitine palmitoyltransferase I (CPT1) in both tissues. In addition, dietary AELL supplementation decreased the mRNA expression of genes involved in fatty acid uptake (cd36, fatp1/fatp4/fatp6, fabp10/fabp11, acsl1/acsl4) and de novo lipid synthesis (pgd, g6pd, and fasn) as well as the transcription factors pparg and srebf1 in the hepatopancreas and muscle but increased the mRNA levels of genes relating to lipid catabolism (cpt1a, lipe, pnpla2, lpl), lipid transportation (apob), and the transcription factor ppara in both tissues. In conclusion, dietary AELL supplementation reduced lipid accumulation in the hepatopancreas and muscle by affecting the gene expression of proteins with known effects on lipid metabolism in juvenile grass carp.

Co-administration of nuciferine reduces the concentration of metformin in liver via differential inhibition of hepatic drug transporter OCT1 and MATE1

Nuciferine (NF), one of the main and effective components in Nelumbo nucifera Gaertn. leaf extracts, is a promising drug candidate for the treatment of obesity-related diseases, while metformin is a first line therapeutic drug for type 2 diabetes mellitus. Since nuciferine and metformin are likely to be co-administered, the aim of the present study was to evaluate whether co-administration of nuciferine would influence the liver (target tissue) distribution and the anti-diabetic effect of metformin by inhibiting hepatic organic cation transporter 1 (OCT1) and multidrug and toxin extrusion 1 (MATE1). The data demonstrated that nuciferine significantly reduced metformin accumulation in MDCK cells stably expressing human OCT1 (MDCK-hOCT1) or hMATE1 (MDCK-hMATE1), and primary cultured mouse hepatocytes. Furthermore, the presence of nuciferine in the basal compartment caused a concentration-dependent reduction of intracellular metformin accumulation in MDCK-hOCT1/hMATE1 cell monolayers. Compared with the metformin treatment-alone group, co-administration of nuciferine (40 mg/kg) markedly reduced the metformin concentration in mouse livers at 30 and 60 min after a single oral dose of metformin (200 mg/kg), and subsequently impaired the glucose-lowering effect of metformin (200 mg/kg), but the glucose-lowering effect became no different at 90 and 120 min. Therefore, nuciferine influenced the liver concentration and glucose-lowering effect of metformin only for a period of time after dose, administration of nuciferine and metformin with an interval might prevent the drug-drug interaction mediated by OCT1 and MATE1.

Identify super quality markers from prototype-based pharmacokinetic markers of Tangzhiqing tablet (TZQ) based on in vitro dissolution/ permeation and in vivo absorption correlations

BACKGROUND

A quality marker (Q-marker) is defined as an inherent chemical compound that is used for the quality control of a drug. Its biological activities are closely related to safety and therapeutic effects. Generally, a multiple-component herbal medicine may have many Q-markers. We therefore proposed a concept of "super Q-marker" satisfying both the criterion of Q-markers and PK-markers to be used in more effective quality control of herbal medicine.

PURPOSE

The first aim was to find suitable prototype-based PK-markers from Tangzhiqing tablets (TZQ), a Chinese patent medicine. Then super Q-markers were expected to be identified from the prototype-based PK-markers based on an in vitro-in vivo correlation study.

METHODS

Potentially eligible prototype-based PK-markers were identified in a single- and multiple-dose pharmacokinetic study on TZQ in 30 healthy volunteers. The in vitro dissolution and permeation profiles of the prototype-based PK-markers of TZQ were evaluated by the physiologically-based drug dissolution/absorption simulating system (DDASS). An in vitro-in vivo correlation analysis was conducted between the dissolution/permeation behaviors in DDASS and the actual absorption profiles in human to test the transferability and traceability of the promising super Q-markers for TZQ.

RESULTS

In human, plasma paeoniflorin and nuciferine as prototype-based PK-markers exhibited the appropriate pharmacokinetic properties, including dose-dependent systemic exposure (AUC, C_max) and a proper elimination half-life (1∼3h). In DDASS, it was predicted that paeoniflorin and nuciferine are highly permeable but the absorption rates are primarily limited by the dissolution rates. Moreover, the established in vitro-in vivo correlations of paeoniflorin and nuciferine were in support of the super Q-markers features.

CONCLUSION

Paeoniflorin and nuciferine are identified as the super Q-markers from the prototype-based PK-markers of TZQ based on findings from a combination of in vitro, in vivo, and in vitro-in vivo correlation studies. This method is practical for optimal identification of qualified Q-markers, thus helping improve the quality control of herbal medicines.

Lotus Leaf Aqueous Extract Reduces Visceral Fat Mass and Ameliorates Insulin Resistance in HFD-Induced Obese Rats by Regulating PPARγ2 Expression

Objectives: Lotus leaf is a kind of traditional Chinese medicine. We aimed to explore the effects of lotus leaf aqueous extract (LLAE) on peroxisome proliferative activated receptor γ2 (PPARγ2) expression in preadipocytes and adipocytes and further investigate its effects on high fat diet (HFD)-induced obese rats.

Methods: pGL3-Enhancer-PPARγ2 (625 bp)-Luc plasmid, a luciferase reporter gene expression plasmid containing PPARγ2 promoter, was stably transfected into 3T3-L1 preadipocytes. PPARγ2 promoter activities were determined by assaying the luciferase activities. Then PPARγ2 promoter activities in preadipocytes and PPARγ2 mRNA levels in human subcutaneous adipocytes were measured after the administration with LLAE. Additionally, the effects of LLAE on body weight, fat mass, glucose and lipid metabolism and the expression of PPARγ2, insulin receptor substrate 1 and glucose transporter 4 (GLUT4) in visceral adipose tissue (VAT) were measured in HFD-induced obese rats treated with low or high dose [0.5 or 3.0 g crude drug/(kg.d)] LLAE for 6 weeks.

Results: Ten μg/ml LLAE significantly increased the luciferase activities in 3T3-L1 cells and the stimulatory action reached 2.51 folds of controls when LLAE was 1000 μg/ml (P < 0.01). After treating 3T3-L1 cells with 100 μg/ml LLAE, the stimulatory role peaked at 32 h where it was 2.58 folds of controls (P < 0.01). Besides, 100 μg/ml LLAE significantly increased PPARγ2 mRNA levels in human adipocytes to 1.91 folds of controls (P < 0.01). In HFD-induced obese rats, administration with both low and high dose LLAE notably reduced visceral fat mass by 45.5 and 58.4%, respectively, and significantly decreased fasting serum insulin levels (P < 0.05). The high dose LLAE also significantly decreased homeostasis model assessment of insulin resistance in obese rats (P < 0.05). Furthermore, the mRNA levels of PPARγ2 and GLUT4 in VAT of obese rats were significantly increased when compared with control rats, and were notably suppressed by LLAE intervention for 6 weeks (P < 0.05).

Conclusion: LLAE significantly reduces visceral fat mass and ameliorates insulin resistance in HFD-induced obese rats. These beneficial effects of LLAE may associate with its role in stimulating PPARγ2 expression in preadipocytes and subcutaneous adipocytes and suppressing PPARγ2 and GLUT4 expression in VAT.

Alcoholic Extract of Lotus Leaves Improves Lipid Profile in Rats with HIV Protease Inhibitor-induced Dyslipidaemia

OBJECTIVE

To examine the effect of the alcoholic extract of lotus leaves (AELL) on antiretroviral treatment-induced dyslipidaemia in a rat model.

METHODS

Lotus leaves were extracted by 95% ethanol. Seventy male Sprague-Dawley rats were given lopinavir/ritonavir for six weeks. At week 0 and 6, sera were collected for measurement of total cholesterol (TC) and triglyceride (TG). Rats meeting the criteria for dyslipidaemia were assigned to four groups and received once daily for another four weeks lopinavir/ritonavir (group A), lopinavir/ritonavir plus 0.52 g/kg AELL (group B), lopinavir/ritonavir plus 0.26 g/kg AELL (group C), or lopinavir/ritonavir plus 0.13 g/kg AELL (group D), respectively. At weeks 8 and 10, blood samples were collected again for measurement of TC or TG.

RESULTS

Both TC and TG increased over time in group A during the observation period (weeks 6 to 10), however, TC and TG decreased in group B, and TG declined in group C. Neither TC nor TG could be reduced to a level near baseline.

CONCLUSION

Alcoholic extract of lotus leaves may have the potential to treat dyslipidaemia related to highly active antiretroviral therapy, but may not be potent enough to reduce TC or TG concentrations to goal levels when used alone.

Effects of potato and lotus leaf extract intake on body composition and blood lipid concentration

[Purpose]

The purpose of this study was to investigate the effects of potato and lotus leaf extract intake on body composition, abdominal fat, and blood lipid concentration in female university students.

[Methods]

A total of 19 female university students participated in this 8-week study, and they were randomly assigned into 2 groups; potato and lotus leaf extract (skinny-line) administered group (SKG, n =9) and placebo group (PG, n = 10). The main results of the present study are presented below.

[Results]

1) Body mass index, and percent body fat and abdominal fat in students of the SKG showed a decreasing tendency without significant interaction, 2) total cholesterol (TC), triglyceride (TG), and low density lipoprotein (LDL-C) in students of the SKG showed an averagely decreasing tendency and there was a significant interaction of TC only, 3) high density lipoprotein (HDL-C) in students of the SKG showed an increasing tendency without significant interaction, and 4) Z-score of fatness testing interaction in group × repetition did not show a significant interaction; however, there was a significant interaction of TC in group × repetition. Based on these results, 8-week intake of potato and lotus leaf extract had a positive effect of lowering TC. On the other hand, it had no significant effect on other types of lipids and percent body fat changes.

[Conclusion]

There was a positive tendency of blood lipids in students of the SKG and it seems that potato and lotus leaf extract intake might prevent obesity and improve obesity related syndromes.

A sensitive liquid chromatography-tandem mass spectrometry method for pharmacokinetics and tissue distribution of nuciferine in rats

Nuciferine is an important drug candidate for the treatment of obesity-related diseases. However, few investigations have been conducted about the pharmacokinetics and tissue distribution of nuciferine to better understand its behavior and action mechanism in vivo. Thus, a sensitive and reliable liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) method was established and validated for the quantification of nuciferine in rat plasma and tissue samples. The validated method was successfully applied to the pharmacokinetic and tissue distribution study of nuciferine in rats. One-compartmental pharmacokinetic parameters indicated that nuciferine had rapid distribution, extensive tissue uptake, and poor absorption into systemic circulation. The values of absolute bioavailability were (3.8±1.4)%, (4.2±1.3)% and (3.9±1.0)% after oral administration of 2.0, 5.0 and 10.0mg/kg nuciferine and intravenous administration of 0.2mg/kg nuciferine in rats. The results of the tissue distribution study suggested that nuciferine was distributed into the brain, liver and adipose tissue after intravenous administration. In conclusion, the present study may provide a material basis for study of the pharmacological action of nuciferine in the treatment of obesity, and meaningful insights into further study on dosage modification.

Plant natural products as an anti-lipid droplets accumulation agent

Recently people often suffer from unhealthy energy metabolism balance as they tend to take more energy than required. Normally, excess energy taken in is converted into triglyceride and stored in adipocyte as lipid droplets. Recent studies have suggested that irregular accumulation of triglyceride in adipocyte might be a cause of many metabolic diseases. Thus, the awareness of the detrimental effects on health of excessive lipid droplets accumulation (LDA) has urged the development or finding of drugs to counter this effect, including those from botanical origins. This review summarized recent progress in this field from the viewpoint of crude drug studies with references to their anti-LDA activity. Possible mechanisms involved in their anti-LDA effect and isolations of the relevant bioactive compounds were also discussed.

Effect of Nelumbo nucifera Petal Extracts on Lipase, Adipogenesis, Adipolysis, and Central Receptors of Obesity

N. nucifera is one among the important medicinal plants assessed for its antiobesity action in various preclinical models. The present study was aimed at investigating the antiobesity effect of methanol and successive water extracts of petals of N. nucifera by studying its effect on adipogenesis, adipolysis, lipase, serotonin (5-HT_2C), cannabinoid (CNR₂), melanocyte concentrating hormone (MCHR₁), and melanocortin (MC₄R) receptors. Both methanol and successive water extracts of N. nucifera petals had an effect on inhibition of lipid storage in adipocytes and on increasing lipolysis. N. nucifera petal methanol extract exhibited the concentration-dependent inhibitory effect on lipase activity with an IC₅₀ value of 47 µg/mL. N. nucifera petal extracts showed evident agonist and antagonist activity towards 5-HT_2C and CNR₂ receptors, respectively, while it showed no effect towards MCHR₁ and MC₄R receptors. Overall, methanol extract of N. nucifera petals showed better activity than successive water extract.

Topically applied L-carnitine effectively reduces sebum secretion in human skin

BACKGROUND

  Oily skin condition is caused by an excessive sebaceous gland activity, resulting in an overproduction of sebum, giving the skin an undesired shiny, oily appearance.

AIMS

  To identify an active substance that reduces sebum production in human sebaceous glands by regulating fat metabolism in a natural way.

PATIENTS/METHODS

  The effects of L-carnitine on β-oxidation and intracellular lipid content were investigated in vitro using the human sebaceous cell line SZ95. Penetration experiments utilizing pig skin as a model system were performed with a cosmetic formulation containing radioactively labeled L-carnitine. To determine the in vivo effects, a vehicle-controlled, randomized study was carried out using a cosmetic formulation containing 2%l-carnitine for 3 weeks. Sebum production was investigated utilizing the lipid-absorbent Sebutape(®).

RESULTS

  SZ95 cells treated with 0.5% or 1% L-carnitine demonstrated a significant concentration-dependent increase in β-oxidation compared to control cells. Following the treatment with L-carnitine, intracellular lipid concentrations decreased significantly in a dose-dependent manner compared with untreated control cells. In skin penetration experiments, topically applied L-carnitine reached the dermis. In addition, topical in vivo application of a formulation containing 2% L-carnitine for 3 weeks significantly decreased the sebum secretion rate compared to the treatment with vehicle.

CONCLUSIONS

  Our results show that the treatment of human sebocytes with L-carnitine significantly augments β-oxidation and significantly decreases intracellular lipid content in human sebocytes. Topically applied L-carnitine is bioavailable and leads to a significant sebum reduction in vivo. In conclusion, L-carnitine represents a valuable compound, produced naturally within the body, for the topical treatment of oily skin in humans.

Propionyl-L-carnitine corrects metabolic and cardiovascular alterations in diet-induced obese mice and improves liver respiratory chain activity

AIMS

Obesity is a primary contributor to acquired insulin resistance leading to the development of type 2 diabetes and cardiovascular alterations. The carnitine derivate, propionyl-L-carnitine (PLC), plays a key role in energy control. Our aim was to evaluate metabolic and cardiovascular effects of PLC in diet-induced obese mice.

METHODS

C57BL/6 mice were fed a high-fat diet for 9 weeks and then divided into two groups, receiving either free- (vehicle-HF) or PLC-supplemented water (200 mg/kg/day) during 4 additional weeks. Standard diet-fed animals were used as lean controls (vehicle-ST). Body weight and food intake were monitored. Glucose and insulin tolerance tests were assessed, as well as the HOMA(IR), the serum lipid profile, the hepatic and muscular mitochondrial activity and the tissue nitric oxide (NO) liberation. Systolic blood pressure, cardiac and endothelial functions were also evaluated.

RESULTS

Vehicle-HF displayed a greater increase of body weight compared to vehicle-ST that was completely reversed by PLC treatment without affecting food intake. PLC improved the insulin-resistant state and reversed the increased total cholesterol but not the increase in free fatty acid, triglyceride and HDL/LDL ratio induced by high-fat diet. Vehicle-HF exhibited a reduced cardiac output/body weight ratio, endothelial dysfunction and tissue decrease of NO production, all of them being improved by PLC treatment. Finally, the decrease of hepatic mitochondrial activity by high-fat diet was reversed by PLC.

CONCLUSIONS

Oral administration of PLC improves the insulin-resistant state developed by obese animals and decreases the cardiovascular risk associated to this metabolic alteration probably via correction of mitochondrial function.