Tomatidine, a tomato sapogenol, ameliorates hyperlipidemia and atherosclerosis in apoE-deficient mice by inhibiting acyl-CoA:cholesterol acyl-transferase (ACAT)

Antidepressant-like effects of tomatidine and tomatine, steroidal alkaloids from unripe tomatoes, via activation of mTORC1 in the medial prefrontal cortex in lipopolysaccharide-induced depression model mice

ABSTRACTKetamine, an N-methyl-D-aspartate receptor antagonist, produces rapid antidepressant effects in patients with treatment-resistant depression. However, owing to the undesirable adverse effects of ketamine, there is an urgent need for developing safer and more effective prophylactic and therapeutic interventions for depression. Preclinical studies have demonstrated that activation of the mechanistic target of rapamycin complex 1 (mTORC1) in the medial prefrontal cortex (mPFC) mediates the rapid antidepressant effects of ketamine. The steroidal alkaloid tomatidine and its glycoside α-tomatine (tomatine) can activate mTORC1 signaling in peripheral tissues/cells. We examined whether tomatidine and tomatine exerted prophylactic and therapeutic antidepressant-like actions via mPFC mTORC1 activation using a mouse model of lipopolysaccharide (LPS)-induced depression. Male mice were intraperitoneally (i.p.) administered tomatidine/tomatine before and after the LPS challenge to test their prophylactic and therapeutic effects, respectively. LPS-induced depression-like behaviors in the tail suspension test (TST) and forced swim test (FST) were significantly reversed by prophylactic and therapeutic tomatidine/tomatine administration. LPS-induced anhedonia in the female urine sniffing test was reversed by prophylactic, but not therapeutic, injection of tomatidine, and by prophylactic and therapeutic administration of tomatine. Intra-mPFC infusion of rapamycin, an mTORC1 inhibitor, blocked the prophylactic and therapeutic antidepressant-like effects of tomatidine/tomatine in TST and FST. Moreover, both tomatidine and tomatine produced antidepressant-like effects in ovariectomized female mice, a model of menopause-associated depression. These results indicate that tomatidine and tomatine exert prophylactic and therapeutic antidepressant-like effects via mTORC1 activation in the mPFC and suggest these compounds as promising candidates for novel prophylactic and therapeutic agents for depression.

Tomatidine activates autophagy to improve lung injury and inflammation in sepsis by inhibiting NF-κB and MAPK pathways

Sepsis-induced acute lung injury (ALI) is a life-threatening medical condition with high mortality and morbidity. Autophagy is involved in the pathophysiological process of sepsis-induced ALI, including inflammation, which indicates that regulating autophagy may be beneficial for this disease. Tomatidine, a natural compound abundant in unripe tomatoes, has been reported to have anti-inflammatory, anti-tumorigenic, and lipid-lowering effects. However, the biological functions and mechanisms of tomatidine in sepsis-induced ALI remain unknown. The principal objective of this study was to investigate the effect of tomatidine on sepsis-induced ALI. Cecal ligation and puncture (CLP) was used to induce septic lung injury in mice, and 10 mg/kg tomatidine was intraperitoneally injected into mice 2 h after the operation. The results of hematoxylin and eosin staining and assessment of lung edema and total protein levels in bronchoalveolar lavage fluid (BALF) demonstrated that tomatidine alleviated CLP-induced severe lung injuries such as hemorrhage, infiltration of inflammatory cells, and interstitial and alveolar edema in mice. Additionally, the levels of proinflammatory cytokines in BALF and lung tissues were measured by enzyme-linked immunosorbent assay (ELISA), and the results showed that tomatidine inhibited CLP-induced inflammatory damage to lungs. Moreover, the results of western blotting showed that tomatidine promoted autophagy during CLP-induced ALI. Mechanistically, immunofluorescence staining and western blotting were used to measure the protein levels of TLR4, phosphorylated NF-κB, phosphorylated IκBα, and phosphorylated MAPKs, showing that tomatidine inactivated NF-κB and MAPK signaling in lung tissues of CLP-induced ALI mice. In conclusion, tomatidine exerts protective effects against sepsis-induced severe damage to the lungs by inhibiting inflammation and activating autophagy in CLP-treated mice through inactivating the NF-κB and MAPK pathways, which may be an effective candidate for treating septic ALI.

Tomatidine ameliorates high-fat-diet/streptozocin (HFD/STZ)-induced type 2 diabetes mellitus in mice

OBJECTIVE

To investigate the effects of tomatidine (Td) on the progression of type 2 diabetes mellitus (T2DM) in mice and uncover the mechanism.

METHODS

T2DM mice model was induced by high-fat diet (HFD) and intrabitoneal injection of streptozotocin (STZ). The mice were grouped as follows: 1, control; 2, T2D; 3, T2D + tomatidine (5 mg/kg); 4, T2D + tomatidine (10 mg/kg); 5, T2D + tomatidine (20 mg/kg). Fasting blood glucose was detected by glucose metre and fasting insulin was detected by the kit to determine the effect of Td on T2DM mice. ELISA, qPCR, and Immunoblot assays were performed to detect the effects of Td on the hepatic glucose homeostasis and inflammation of mice. Immunoblot assays further confirmed the mechanism.

RESULTS

Td improved blood glucose and insulin resistance in T2DM mice. In addition, Td improved liver function and lipid metabolism disorder in T2DM mice. Td also affected the liver glucose homeostasis related genes in T2DM mice. Td alleviated serum inflammation in T2DM mice. We further found that Td activated AMPK pathway, therefore ameliorating T2DM.

CONCLUSION

Td ameliorated HFD/STZ-induced T2DM in mice, suggesting that it could serve as a drug of T2DM.

Esculeogenin A, a Glycan from Tomato, Alleviates Nonalcoholic Fatty Liver Disease in Rats through Hypolipidemic, Antioxidant, and Anti-Inflammatory Effects

This study examined the preventative effects of esculeogenin A (ESGA), a newly discovered glycan from tomato, on liver damage and hepatic steatosis in high-fat-diet (HFD)-fed male rats. The animals were divided into six groups (each of eight rats): a control group fed a normal diet, control + ESGA (200 mg/kg), HFD, and HFD + ESAG in 3 doses (50, 100, and 200 mg/kg). Feeding and treatments were conducted for 12 weeks. Treatment with ESGA did not affect gains in the body or fat weight nor increases in fasting glucose, insulin, and HOMA-IR or serum levels of free fatty acids (FFAs), tumor-necrosis factor-α, and interleukin-6 (IL-6). On the contrary, it significantly reduced the serum levels of gamma-glutamyl transpeptidase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), total triglycerides (TGs), cholesterol (CHOL), and low-density lipoprotein cholesterol (LDL-c) in the HFD-fed rats. In addition, it improved the liver structure, attenuating the increase in fat vacuoles; reduced levels of TGs and CHOL, and the mRNA levels of SREBP1 and acetyl CoA carboxylase (ACC); and upregulated the mRNA levels of proliferator-activated receptor α (PPARα) and carnitine palmitoyltransferase I (CPT I) in HFD-fed rats. These effects were concomitant with increases in the mRNA, cytoplasmic, and nuclear levels of nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and heme oxygenase-1 (HO); a reduction in the nuclear activity of nuclear factor-kappa beta (NF-κB); and inhibition of the activity of nuclear factor kappa B kinase subunit beta (IKKβ). All of these effects were dose-dependent effects in which a normal liver structure and normal levels of all measured parameters were seen in HFD + ESGA (200 mg/kg)-treated rats. In conclusion, ESGA prevents NAFLD in HFD-fed rats by attenuating hyperlipidemia, hepatic steatosis, oxidative stress, and inflammation by acting locally on Nrf2, NF-κB, SREBP1, and PPARα transcription factors.

Esculeoside A Decreases Diabetic Cardiomyopathy in Streptozotocin-Treated Rats by Attenuating Oxidative Stress, Inflammation, Fibrosis, and Apoptosis: Impressive Role of Nrf2

Background and Objectives: This experiment evaluated the preventative influence of the tomato-derived Esculeoside A (ESA) on diabetic cardiomyopathy in type 1 diabetes mellitus (T1DM) in rats induced by streptozotocin (STZ). It also examined whether the activation of Nrf2 signaling affords this protection. Materials and Methods: Adult male Wistar control nondiabetic rats and rats with T1DM (STZ-T1DM) were given either carboxymethylcellulose as a vehicle or ESA (100 mg/kg) (eight rats/group) orally daily for 12 weeks. A group of STZ-T1DM rats was also treated with 100 mg/kg ESA and co-treated i.p. with 2 mg/kg (twice/week), brusatol, and Nrf2 inhibitors for 12 weeks. Results and Conclusions: Treatment with ESA prevented the gain in heart weight and cardiomyocyte hypertrophy and improved the left ventricular (LV) systolic and diastolic function (LV) in the STZ-T1DM rat group. Likewise, it reduced their serum levels of triglycerides, cholesterol, and low-density lipoproteins (LDL-c), as well as their LV mRNA, cytoplasmic total, and nuclear total levels of NF-κB. ESA also reduced the total levels of malondialdehyde, tumor necrosis factor-α, interleukine-6 (IL-6), Bax, cytochrome-c, and caspase-3 in the LV of the STZ-T1DM rats. In parallel, ESA enhanced the nuclear and cytoplasmic levels of Nrf2 and the levels of superoxide dismutase, glutathione, and heme oxygenase-1, but decreased the mRNA and cytoplasmic levels of keap-1 in the LVs of the STZ-T1DM rats. Interestingly, ESA did not affect the fasting insulin and glucose levels of the diabetic rats. All of these beneficially protective effects of ESA were not seen in the ESA-treated rats that received brusatol. In conclusion, ESA represses diabetic cardiomyopathy in STZ-diabetic hearts by activating the Nrf2/antioxidant/NF-κB axis.

Physiological functions, pharmacological aspects and nutritional importance of green tomato- a future food

Green tomatoes contain significant levels of steroidal glycoalkoids (SGA) such as α-tomatine and green pigment chlorophyll. Tomatine is an admixture of two glycoalkoids; alpha tomatine and dehydrotomatine reported various health beneficial biological activities. Moreover, a hydrolyzed product of tomatine also contributes to age-related atrophy, and muscle weakness and helps the elderly recover from illness and injuries related to age. However, there is a lack of evidence regarding the absorption of tomatine in the human body concerning proposed biological activity, which should be an area of interest in the future. Once, the absorption study is established compounds concentrated in green tomatoes are potentially involved as protective compounds for several diseases and also used for functional food. To facilitate the use of green tomatoes in food processing, this comprehensive review provides data on the nutritional value of green tomatoes, with emphasis on the evolution of the physiological chemistry, analytical, medicinal, and pharmacological effects of the α-tomatine and chlorophyll in an experimental model. The broad aim of this review is to evaluate the health benefits of green tomatoes in addition to their nutritional value and to study the several features of the role of α-tomatine and chlorophyll in human health.

Isomers of the Tomato Glycoalkaloids α-Tomatine and Dehydrotomatine: Relationship to Health Benefits

High-performance liquid chromatography (HPLC) analysis of three commercial tomatine samples and another isolated from green tomatoes revealed the presence of two small peaks in addition to those associated with the glycoalkaloids dehydrotomatine and α-tomatine. The present study investigated the possible structures of the compounds associated with the two small peaks using HPLC-mass spectrophotometric (MS) methods. Although the two peaks elute much earlier on chromatographic columns than the elution times of the known tomato glycoalkaloids dehydrotomatine and α-tomatine, isolation of the two compounds by preparative chromatography and subsequent analysis by MS shows the two compounds have identical molecular weights, tetrasaccharide side chains, and MS and MS/MS fragmentation patterns to dehydrotomatine and α-tomatine. We suggest the two isolated compounds are isomeric forms of dehydrotomatine and α-tomatine. The analytical data indicate that widely used commercial tomatine preparations and those extracted from green tomatoes and tomato leaves consist of a mixture of α-tomatine, dehydrotomatine, an α-tomatine isomer, and a dehydrotomatine isomer in an approximate ratio of 81:15:4:1, respectively. The significance of the reported health benefits of tomatine and tomatidine is mentioned.

Targeting Sterol O-Acyltransferase/Acyl-CoA:Cholesterol Acyltransferase (ACAT): A Perspective on Small-Molecule Inhibitors and Their Therapeutic Potential

Sterol O-acyltransferase (SOAT) is a membrane-bound enzyme that aids the esterification of cholesterol and fatty acids to cholesterol esters. SOAT has been studied extensively as a potential drug target, since its inhibition can serve as an alternative to statin therapy. Two SOAT isozymes that have discrete functions in the human body, namely, SOAT1 and SOAT2, have been characterized. Over three decades of research has focused on candidate SOAT1 inhibitors with unsatisfactory results in clinical trials. Recent research has focused on targeting SOAT2 selectively. In this perspective, we summarize the literature covering various SOAT inhibitory agents and discuss the design, structural requirements, and mode of action of SOAT inhibitors.

Diosgenin and Its Analogs: Potential Protective Agents Against Atherosclerosis

Atherosclerosis is a chronic inflammatory disease of the artery wall associated with lipid metabolism imbalance and maladaptive immune response, which mediates most cardiovascular events. First-line drugs such as statins and antiplatelet drug aspirin have shown good effects against atherosclerosis but may lead to certain side effects. Thus, the development of new, safer, and less toxic agents for atherosclerosis is urgently needed. Diosgenin and its analogs have gained importance for their efficacy against life-threatening diseases, including cardiovascular, endocrine, nervous system diseases, and cancer. Diosgenin and its analogs are widely found in the rhizomes of Dioscore, Solanum, and other species and share similar chemical structures and pharmacological effects. Recent data suggested diosgenin plays an anti-atherosclerosis role through its anti-inflammatory, antioxidant, plasma cholesterol-lowering, anti-proliferation, and anti-thrombotic effects. However, a review of the effects of diosgenin and its natural structure analogs on AS is still lacking. This review summarizes the effects of diosgenin and its analogs on vascular endothelial dysfunction, vascular smooth muscle cell (VSMC) proliferation, migration and calcification, lipid metabolism, and inflammation, and provides a new overview of its anti-atherosclerosis mechanism. Besides, the structures, sources, safety, pharmacokinetic characteristics, and biological availability are introduced to reveal the limitations and challenges of current studies, hoping to provide a theoretical basis for the clinical application of diosgenin and its analogs and provide a new idea for developing new agents for atherosclerosis.

Mitophagy in aging and longevity

The clearance of damaged or unwanted mitochondria by autophagy (also known as mitophagy) is a mitochondrial quality control mechanism postulated to play an essential role in cellular homeostasis, metabolism, and development and confers protection against a wide range of diseases. Proper removal of damaged or unwanted mitochondria is essential for organismal health. Defects in mitophagy are associated with Parkinson's, Alzheimer's disease, cancer, and other degenerative disorders. Mitochondria regulate organismal fitness and longevity via multiple pathways, including cellular senescence, stem cell function, inflammation, mitochondrial unfolded protein response (mtUPR), and bioenergetics. Thus, mitophagy is postulated to be pivotal for maintaining organismal healthspan and lifespan and the protection against aged-related degeneration. In this review, we will summarize recent understanding of the mechanism of mitophagy and aspects of mitochondrial functions. We will focus on mitochondria-related cellular processes that are linked to aging and examine current genetic evidence that supports the hypothesis that mitophagy is a pro-longevity mechanism.

The steroidal alkaloids α-tomatine and tomatidine: Panorama of their mode of action and pharmacological properties

The steroidal glycoalkaloid α-tomatine (αTM) and its aglycone tomatidine (TD) are abundant in the skin of unripe green tomato and present in tomato leaves and flowers. They mainly serve as defensive agents to protect the plant against infections by insects, bacteria, parasites, viruses, and fungi. In addition, the two products display a range of pharmacological properties potentially useful to treat various human diseases. We have analyzed all known pharmacological activities of αTM and TD, and the corresponding molecular targets and pathways impacted by these two steroidal alkaloids. In experimental models, αTM displays anticancer effects, particularly strong against androgen-independent prostate cancer, as well as robust antifungal effects. αTM is a potent cholesterol binder, useful as a vaccine adjuvant to improve delivery of protein antigens or therapeutic oligonucleotides. TD is a much less cytotoxic compound, able to restrict the spread of certain viruses (such as dengue, chikungunya and porcine epidemic diarrhea viruses) and to provide cardio and neuro-protective effects toward human cells. Both αTM and TD exhibit marked anti-inflammatory activities. They proceed through multiple signaling pathways and protein targets, including the sterol C24 methyltransferase Erg6 and vitamin D receptor, both directly targeted by TD. αTM is a powerful regulator of the NFkB/ERK signaling pathway implicated in various diseases. Collectively, the analysis shed light on the multitargeted action of αTM/TD and their usefulness as chemo-preventive or chemotherapeutic agents. A novel medicinal application for αTM is proposed.

Tomatidine reduces Chikungunya virus progeny release by controlling viral protein expression

Tomatidine, a natural steroidal alkaloid from unripe green tomatoes has been shown to exhibit many health benefits. We recently provided in vitro evidence that tomatidine reduces the infectivity of Dengue virus (DENV) and Chikungunya virus (CHIKV), two medically important arthropod-borne human infections for which no treatment options are available. We observed a potent antiviral effect with EC50 values of 0.82 μM for DENV-2 and 1.3 μM for CHIKV-LR. In this study, we investigated how tomatidine controls CHIKV infectivity. Using mass spectrometry, we identified that tomatidine induces the expression of p62, CD98, metallothionein and thioredoxin-related transmembrane protein 2 in Huh7 cells. The hits p62 and CD98 were validated, yet subsequent analysis revealed that they are not responsible for the observed antiviral effect. In parallel, we sought to identify at which step of the virus replication cycle tomatidine controls virus infectivity. A strong antiviral effect was seen when in vitro transcribed CHIKV RNA was transfected into Huh7 cells treated with tomatidine, thereby excluding a role for tomatidine during CHIKV cell entry. Subsequent determination of the number of intracellular viral RNA copies and viral protein expression levels during natural infection revealed that tomatidine reduces the RNA copy number and viral protein expression levels in infected cells. Once cells are infected, tomatidine is not able to interfere with active RNA replication yet it can reduce viral protein expression. Collectively, the results delineate that tomatidine controls viral protein expression to exert its antiviral activity. Lastly, sequential passaging of CHIKV in presence of tomatidine did not lead to viral resistance. Collectively, these results further emphasize the potential of tomatidine as an antiviral treatment towards CHIKV infection.

Chikungunya fever is a debilitating disease caused by the mosquito-borne Chikungunya virus. Over the past two decades the geographical spread of the virus and its mosquito vector has drastically increased thereby causing millions of infections. To date there is no antiviral drug and no vaccine available to treat/prevent Chikungunya virus infection. We recently showed that the natural steroidal alkaloid tomatidine has potent antiviral activity towards Chikungunya virus at submicromolar concentrations. In this study we dissected how tomatidine reduces the production of Chikungunya virus particles. We show that tomatidine lowers viral protein expression and we hypothesize that the effect of tomatidine on viral protein translation hampers the production of progeny viral RNA copies / number of infected cells thereby leading to a reduced production of secreted virus particles. Also, we show that Chikungunya virus does not readily become resistant to tomatidine. Collectively, we deciphered the mechanism by which tomatidine exerts antiviral activity to Chikungunya virus and our results strengthen the potential of tomatidine as an antiviral treatment strategy towards Chikungunya virus.

Tomatidine Suppresses the Destructive Behaviors of Fibroblast-Like Synoviocytes and Ameliorates Type II Collagen-Induced Arthritis in Rats

Fibroblast-like synoviocytes (FLSs) are the prominent non-immune cells in synovium and play a pivotal role in rheumatoid arthritis (RA) pathogenesis. Searching for natural compounds that may suppress the pathological phenotypes of FLSs is important for the development of RA treatment. Tomatidine (Td), a steroidal alkaloid derived from the solanaceae family, has been reported to have anti-inflammatory, anti-tumor and immunomodulatory effects. However, its effect on RA remains unknown. Here, we examined the inhibitory effect of Td on TNFα-induced arthritic FLSs, and subsequently investigated its therapeutic effect on collagen-induced arthritis (CIA) rats. Our results revealed that Td significantly inhibited TNFα-induced proliferation and migration of arthritic FLSs. In addition, we found that Td treatment could efficaciously ameliorate synovial inflammation and joint destruction of rats with CIA. Both in vitro and in vivo studies showed that Td significantly suppressed the production of pro-inflammatory cytokines including IL-1β, IL-6 and TNFα, and downregulated the expression of MMP-9 and RANKL. Further molecular mechanism studies revealed that the inhibitory effect of Td on RA might attribute to the decreased activations of MAPKs (ERK and JNK) and NF-κB. These findings provide evidence that Td has the potential to be developed into a complementary or alternative agent for RA therapy.

Green Tomato Extract Prevents Bone Loss in Ovariectomized Rats, a Model of Osteoporosis

Although drug therapies are available for postmenopausal osteoporosis, these drugs are not free of side effects and long-term adherence to them are low. A safe and effective nutritional approach to counter postmenopausal osteoporosis is an important research goal. We fed ovariectomized (OVX) Sprague–Dawley rats a diet supplemented with 1% or 2% green tomato extract (GTE). After 12 weeks, micro-computed tomography scans revealed that GTE supplementation effectively prevented distal femur bone loss. This prevention was due to improved bone formation and suppressed bone resorption as observed by the regulation of osteoblast and osteoclast activities. GTE supplementation also improved bone formation through Bmp2-Smad 1/5/8-Runx2 signaling, while bone resorption was regulated by the receptor activator of nuclear factor kappa-B (RANKL)/osteoprogeterin (OPG) pathway. These results suggest that GTE supplementation prevents severe postmenopausal bone loss by maintaining the regulation of bone homeostasis in OVX rats. GTE as a diet supplement might be a potential novel alternative for the prevention of postmenopausal osteoporosis.

Chemical Characterisation and Antihypertensive Effects of Locular Gel and Serum of Lycopersicum esculentum L. var. "Camone" Tomato in Spontaneously Hypertensive Rats

Blood pressure control in hypertensive subjects calls for changes in lifestyle, especially diet. Tomato is widely consumed and rich in healthy components (i.e., carotenoids, vitamins and polyphenols). The aim of this study was to evaluate the chemical composition and antihypertensive effects of locular gel reconstituted in serum of green tomatoes of "Camone" variety. Tomato serum and locular gel were chemically characterised. The antihypertensive effects of the locular gel in serum, pure tomatine, and captopril, administered by oral gavage, were investigated for 4 weeks in male spontaneously hypertensive and normotensive rats. Systolic blood pressure and heart rate were monitored using the tail cuff method. Body and heart weight, serum glucose, triglycerides and inflammatory cytokines, aorta thickness and liver metabolising activity were also assessed. Locular gel and serum showed good tomatine and polyphenols content. Significant reductions in blood pressure and heart rate, as well as in inflammatory blood cytokines and aorta thickness, were observed in spontaneously hypertensive rats treated both with locular gel in serum and captopril. No significant effects were observed in normotensive rats. Green tomatoes locular gel and serum, usually discarded during tomato industrial processing, are rich in bioactive compounds (i.e., chlorogenic acid, caffeic acid and rutin, as well as the glycoalkaloids, α-tomatine and dehydrotomatine) that can lower in vivo blood pressure towards healthier values, as observed in spontaneously hypertensive rats.

Tomatidine suppresses inflammation in primary articular chondrocytes and attenuates cartilage degradation in osteoarthritic rats

In this study, we investigated whether the anti-inflammatory effects of tomatidine alleviate osteoarthritis (OA)-related pathology in primary articular chondrocytes and a rat OA model. STITCH database analysis identified 22 tomatidine-target genes that were enriched in 78 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Moreover,39 of the 105 OA-related KEGG pathways were related to tomatidine-target genes. The top two OA-related KEGG pathways with tomatidine-target genes were the MAPK and neutrophin signaling pathways. Pretreating primary chondrocytes with tomatidine suppressed interleukin-1β (IL-1β)-induced expression of iNOS, COX-2, MMP1, MMP3, MMP13, and ADAMTS-5. Tomatidine also suppressed IL-1β-induced degradation of collagen-II and aggrecan proteins by inhibiting NF-κB and MAPK signaling. In a rat OA model, histological and immunohistochemical analyses showed significantly less cartilage degeneration in thetibiofemoral joints of rats treated for 12 weeks with tomatidine after OA induction (experimental group) than in untreated OA group rats. However, micro-computed tomography (μ-CT) showed that tomatidine did not affect remodeling of the subchondral bone at the tibial plateau. These data shows that tomatidine suppresses IL-1β-induced inflammation in primary chondrocytes by inhibiting the NF-κB and MAPK signaling pathways, and protects against cartilage destruction in a rat OA model.

Tomatidine protects against ischemic neuronal injury by improving lysosomal function

Cerebral ischemia is a severe neurological disorder with limited therapy. Autophagy refers to the intracellular degradation process via an autophagosome-lysosome pathway. Emerging studies indicated the neuroprotective effects of autophagy against ischemic neuronal injury, suggesting the potential neuroprotection of autophagy-inducing compounds. Tomatidine is a gut microbiota-derived metabolite from unripe tomatoes. Tomatidine activates autophagy either in mammal cells or C elegans. However, potential neuroprotection of tomatidine against ischemic neuronal injury has not been determined. In the present investigation, N₂a cells and primary cultured mice cortical neurons were subjected to oxygen-glucose deprivation followed by reperfusion (OGD/R). Cell injury was determined by MTT and lactate dehydrogenase release. Autophagosomes and autolysosomes were visualized by transfecting mCherry-GFP-tandem fluorescent LC3. The protein levels of LC3, Cathepsin D, Cathepsin B, and transcription factor EB (TFEB) were detected by Western blot. Lysosomes were stained with LysoTracker Red and dequenched-bovine serum albumin (DQ-BSA red). Tomatidine alleviated OGD/R-induced injury in N₂a cells and neurons. Interestingly, tomatidine treatment attenuated, rather than reinforced, the OGD/R-elevated LC3-II, which can be reversed by lysosome inhibitor. These results indicated enhanced lysosomal activity rather than autophagosome generation with tomatidine treatment in our models. Indeed, tomatidine increased the lysosome number, proteolytic activities, as well as the expression of Cathepsin D and Cathepsin B. In addition, tomatidine increased the expression and nucleus translocation of (TFEB). Besides, lysosomal inhibitors chloroquine and bafilomycin, but not wortmannin, abolished the protection of tomatidine. In conclusion, the present study revealed the neuroprotection of tomatidine against ischemic injury by promoting lysosomal activity, possibly with the involvement of TFEB-related mechanisms.

Blocking ACAT-1 Activity for Tumor Therapy with Fluorescent Hyperstar Polymer-Encapsulated Avasimible

Targeting the distinct cholesterol metabolism of tumor cells is proposed as a novel way to treat tumors. Blocking acyl-CoA cholesterol acyltransferase-1 (ACAT-1) by the inhibitor avasimible (Ava), which elevates intracellular free cholesterol levels, is shown to effectively induce apoptosis. However, Ava faces disadvantages of poor water solubility, a short half-life, and no capability for fluorescence detection, which have greatly limited its application. Herein, a fluorescent hyperstar polymer (FHSP) is developed to encapsulate Ava to improve its ability to inhibit HeLa cells and K562 cells. The results of this study show that the obtained Ava-FHSP micelles possess a high drug loading capacity of 22.7% and bright green fluorescence. Ava and Ava-FHSP are cytotoxic to both HeLa and K562 cells and cause reductions in cell size, nuclear lysis, and chromatin condensation and hindered proliferation of both cell types by causing S phase cell cycle arrest. Further mechanistic analysis indicates that Ava-FHSP reduces the protein and messenger RNA expression of ACAT-1 and significantly increases intracellular free cholesterol levels, which can increase endoplasmic reticulum stress and finally cause cell apoptosis. All these results suggest that this fluorescent hyperstar polymer represents a potential therapeutic tumor strategy by changing the cholesterol metabolism of tumor cells.

Tomatidine, a natural steroidal alkaloid shows antiviral activity towards chikungunya virus in vitro

In recent decades, chikungunya virus (CHIKV) has re-emerged, leading to outbreaks of chikungunya fever in Africa, Asia and Central and South America. The disease is characterized by a rapid onset febrile illness with (poly)arthralgia, myalgia, rashes, headaches and nausea. In 30 to 40% of the cases, CHIKV infection causes persistent (poly)arthralgia, lasting for months or even years after initial infection. Despite the drastic re-emergence and clinical impact there is no vaccine nor antiviral compound available to prevent or control CHIKV infection. Here, we evaluated the antiviral potential of tomatidine towards CHIKV infection. We demonstrate that tomatidine potently inhibits virus particle production of multiple CHIKV strains. Time-of -addition experiments in Huh7 cells revealed that tomatidine acts at a post-entry step of the virus replication cycle. Furthermore, a marked decrease in the number of CHIKV-infected cells was seen, suggesting that tomatidine predominantly acts early in infection yet after virus attachment and cell entry. Antiviral activity was still detected at 24 hours post-infection, indicating that tomatidine controls multiple rounds of CHIKV replication. Solasodine and sarsasapogenin, two structural derivatives of tomatidine, also showed strong albeit less potent antiviral activity towards CHIKV. In conclusion, this study identifies tomatidine as a novel compound to combat CHIKV infection in vitro.

Tomato as Potential Source of Natural Additives for Meat Industry. A Review

Tomato industry produces huge amounts of by-products that represent an environmental and economic problem. However, these by-products contain multiple bioactive compounds, which would make them a renewable source for obtaining natural antioxidants and colourants (carotenoids). This is in line with the preferences of the current consumer who demands more natural and healthy products. However, the lipophilic character of carotenoids means that their extraction must be carried out using toxic organic solvents. To overcome environmental and health problems of organic solvents, the application of supercritical fluid extraction (SFE) for the extraction of lipophilic compounds such as lycopene was used successfully, achieving yields similar to those obtained with conventional techniques. Nonetheless, the extraction conditions must be carefully selected, to obtain high yields and at the same time maintain a high antioxidant capacity. On the other hand, the use of tomato and tomato extracts as natural additives in meat products are reduced in comparison with other natural antioxidant/colourant extracts. However, different researches conclude that the use of tomato improved nutritional quality, reduced lipid oxidation and increased stability during the shelf-life period of meat products, while retaining or increasing sensory properties and overall acceptability, which converts tomato by-products into a promising source of natural additives.

Tomatidine Represses Invasion and Migration of Human Osteosarcoma U2OS and HOS Cells by Suppression of Presenilin 1 and c-Raf-MEK-ERK Pathway

Osteosarcoma, which is the most prevalent malignant bone tumor, is responsible for the great majority of bone cancer-associated deaths because of its highly metastatic potential. Although tomatidine is suggested to serve as a chemosensitizer in multidrug-resistant tumors, the anti-metastatic effect of tomatidine in osteosarcoma is still unknown. Here, we tested the hypothesis that tomatidine suppresses migration and invasion, features that are associated with metastatic process in human osteosarcoma cells and also investigate its underlying pathway. Tomatidine, up to 100 μM, without cytotoxicity, inhibited the invasion and migration capabilities of human osteosarcoma U2OS and HOS cells and repressed presenilin 1 (PS-1) expression of U2OS cells. After the knockdown of PS-1, U2OS and HOS cells’ biological behaviors of cellular invasion and migratory potential were significantly reduced. While tomatidine significantly decreased the phosphorylation of c-Raf, mitogen/extracellular signal-regulated kinase (MEK), and extracellular signal-regulated protein kinase (ERK)1/2 in U2OS cells, no obvious influences on p-Jun N-terminal kinase, p38, and Akt, including their phosphorylation, were observed. In ERK 1 silencing U2 OS cells, tomatidine further enhanced the decrease of their migratory potential and invasive activities. We conclude that both PS-1 derived from U2OS and HOS cells and the c-Raf–MEK–ERK pathway contribute to cellular invasion and migration and tomatidine could inhibit the phenomenons. These findings indicate that tomatidine might be a potential candidate for anti-metastasis treatment of human osteosarcoma.

Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products

Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.

Xuezhitong capsule, an extract of Allium macrostemon Bunge, exhibits reverse cholesterol transport and accompanies high-density lipoprotein levels to protect against hyperlipidemia in ApoE-/- mice

Background

Xuezhitong capsules (XZT) are derived from Xie Bai and used for abnormal lipid homeostasis treatment through maintained metabolic balance. However, their mechanisms are largely unknown. Here, we mainly assessed the contribution of reverse cholesterol transport (RCT) and the accompanying increase in the high-density lipoprotein (HDL) effects of XZT to cholesterol dysfunction amelioration in mice.

Methods

We assessed serum lipids by using enzymatic kits. We observed atherosclerotic plaque formation by hematoxylin-eosin (HE) and Oil Red O staining. We studied the lipid metabolism, fatty acid synthase (FAS), HDL, low-density lipoprotein receptor (LDLR), triglyceride (TG) metabolic enzyme expression levels, and RCT function in various tissues upon stimulation with high-fat diet, XZT, and some positive drugs by ELISA.

Results

After 34 weeks of high-fat diet administration, blood lipids levels increased because attenuated by XZT treatment (800 and 1,600 mg/kg, i.g.). XZT improved the lipid metabolism instability, induced RCT activation, and subsequently increased the HDL levels in hyperlipidemic mice (P<0.05). FAS (P<0.05) and LDLR (P<0.01) levels also remarkably improved. The effects of XZT were closely associated with RCT activation and the accompanying increase in the HDL levels, as characterized by XZT-induced preservation in ATP-binding cassette transporter member 1 (ABCA1), scavenger receptor class B type 1 (SRB1), acyl coenzyme A: cholesterol acyltransferase (ACAT), lecithin cholesterol acyltransferase (LCAT), apolipoprotein A I (ApoA1) and apolipoprotein B (ApoB). However, XZT showed no effect on high fat diet-activated TG metabolic enzyme expression levels (P>0.05).

Conclusions

XZT are promising drugs in balancing the cholesterol dysfunction from hyperlipidemia through RCT activation and accompanying increase in HDL levels.

Identification of potential human urinary biomarkers for tomato juice intake by mass spectrometry-based metabolomics

PURPOSE

Dietary biomarkers allow the accurate and objective determination of the dietary intake of humans and can thus be valuable for investigating the relation between consumption of foods and biochemical as well as physiological responses. The objective of this study was the identification of potential urinary biomarkers for consumption of tomato juice.

METHODS

In the course of a dietary intervention study, the human urine metabolome of a study cohort was compared between a tomato-free diet and after intake of tomato juice by application of an LC-HRMS-based metabolomics approach. The data acquisition was achieved using an orbitrap mass spectrometer, followed by multistage data processing and univariate as well as multivariate statistical analysis to identify discriminating features.

RESULTS

Statistical analysis revealed several unique features detectable after tomato juice intake. The most discriminating markers were putatively identified as hydroxylated and sulfonated metabolites of esculeogenin B, aglycone of the steroidal glycoalkaloid esculeoside B recently found in tomato juice. Furthermore, the β-carboline alkaloids tangutorid E and F and glucuronidated derivatives thereof were identified in urine.

CONCLUSIONS

Steroidal glycoalkaloids in tomato juice are cleaved after ingestion, and hydroxylated and sulfonated metabolites of their aglycones might serve as urinary biomarkers for tomato juice intake. Similarly, β-carboline alkaloids and glucuronidated derivatives were identified as potential urinary biomarkers. Both the aglycones of the steroidal alkaloids and the β-carboline alkaloids might exhibit biological activities worth investigating.

Tomatidine, a novel antiviral compound towards dengue virus

Dengue is the most common arboviral disease worldwide with 96 million symptomatic cases annually. Despite its major impact on global human health and huge economic burden there is no antiviral drug available to treat the disease. The first tetravalent dengue virus vaccine was licensed in 2015 for individuals aged 9 to 45, however, most cases are reported in infants and young children. This, together with the limited efficacy of the vaccine to dengue virus (DENV) serotype 2, stresses the need to continue the search for compounds with antiviral activity to DENV. In this report, we describe tomatidine as a novel compound with potent antiviral properties towards all DENV serotypes and the related Zika virus. The strongest effect was observed for DENV-2 with an EC50 and EC90 value of 0.82 and 1.61 μM, respectively, following infection of Huh7 cells at multiplicity of infection of 1. The selectivity index is 97.7. Time-of-drug-addition experiments revealed that tomatidine inhibits virus particle production when added pre, during and up to 12 h post-infection. Subsequent experiments show that tomatidine predominantly acts at a step after virus-cell binding and membrane fusion but prior to the secretion of progeny virions. Tomatidine was found to control the expression of the cellular protein activating transcription factor 4 (ATF4), yet, this protein is not solely responsible for the observed antiviral effect. Here, we propose tomatidine as a candidate for the treatment of dengue given its potent antiviral activity.

Isoquinoline Alkaloids and Indole Alkaloids Attenuate Aortic Atherosclerosis in Apolipoprotein E Deficient Mice: A Systematic Review and Meta-Analysis

Background: Several studies have attempted to relate the bioactive alkaloid with atherosclerotic cardiovascular diseases prevention in animal models, providing inconsistent results. Moreover, the direct anti-atherosclerotic effects of alkaloid have hardly been studied in patients. Therefore, the aim of this systematic review was to assess the reported effects of alkaloids on aortic atherosclerosis in ApoE^−/− mouse models.

Methods: Pubmed and Embase were searched to identify studies which estimated the effect of isolated alkaloids on atherosclerosis in apolipoprotein E deficient mice. Study quality was assessed using SYRCLE's risk of bias tool. We conducted a meta-analysis across 14 studies using a random-effect model to determine the overall effect of the alkaloids, and performed subgroup analyses to compare the effects of the isoquinolone alkaloids and indole alkaloids.

Results: The quality of the included studies was low in the majority of included studies. We clarified that alkaloid administration was significantly associated with reduced aortic atherosclerotic lesion area (SMD −3.19, 95% CI −3.88, −2.51). It is important to remark that the experimental characteristics of studies were quite diverse, and the methodological variability could also contribute to heterogeneity. Subgroup analyses suggested that the isoquinoline alkaloids (SMD −4.19, 95% CI −5.18, −3.20), and the indole alkaloids (SMD −2.73, 95% CI −3.56, −1.90) obviously decreased atherosclerotic burden.

Conclusion: Isoquinoline alkaloids and indole alkaloids appear to have a direct anti-atherosclerotic effect in ApoE^−/− mice. Besides the limitations of animal modal studies, this systematic review could provide an important reference for future preclinical animal trials of good quality and clinical development.

Effects of Vegetables on Cardiovascular Diseases and Related Mechanisms

Epidemiological studies have shown that vegetable consumption is inversely related to the risk of cardiovascular diseases. Moreover, research has indicated that many vegetables like potatoes, soybeans, sesame, tomatoes, dioscorea, onions, celery, broccoli, lettuce and asparagus showed great potential in preventing and treating cardiovascular diseases, and vitamins, essential elements, dietary fibers, botanic proteins and phytochemicals were bioactive components. The cardioprotective effects of vegetables might involve antioxidation; anti-inflammation; anti-platelet; regulating blood pressure, blood glucose, and lipid profile; attenuating myocardial damage; and modulating relevant enzyme activities, gene expression, and signaling pathways as well as some other biomarkers associated to cardiovascular diseases. In addition, several vegetables and their bioactive components have been proven to protect against cardiovascular diseases in clinical trials. In this review, we analyze and summarize the effects of vegetables on cardiovascular diseases based on epidemiological studies, experimental research, and clinical trials, which are significant to the application of vegetables in prevention and treatment of cardiovascular diseases.

Tomatidine enhances lifespan and healthspan in C. elegans through mitophagy induction via the SKN-1/Nrf2 pathway

Aging is a major international concern that brings formidable socioeconomic and healthcare challenges. Small molecules capable of improving the health of older individuals are being explored. Small molecules that enhance cellular stress resistance are a promising avenue to alleviate declines seen in human aging. Tomatidine, a natural compound abundant in unripe tomatoes, inhibits age-related skeletal muscle atrophy in mice. Here we show that tomatidine extends lifespan and healthspan in C. elegans, an animal model of aging which shares many major longevity pathways with mammals. Tomatidine improves many C. elegans behaviors related to healthspan and muscle health, including increased pharyngeal pumping, swimming movement, and reduced percentage of severely damaged muscle cells. Microarray, imaging, and behavioral analyses reveal that tomatidine maintains mitochondrial homeostasis by modulating mitochondrial biogenesis and PINK-1/DCT-1-dependent mitophagy. Mechanistically, tomatidine induces mitochondrial hormesis by mildly inducing ROS production, which in turn activates the SKN-1/Nrf2 pathway and possibly other cellular antioxidant response pathways, followed by increased mitophagy. This mechanism occurs in C. elegans, primary rat neurons, and human cells. Our data suggest that tomatidine may delay some physiological aspects of aging, and points to new approaches for pharmacological interventions for diseases of aging.

Hypolipidemic Effect of Tomato Juice in Hamsters in High Cholesterol Diet-Induced Hyperlipidemia

Tomato is a globally famous food and contains several phytonutrients including lycopene, β-carotene, anthocyanin, and flavonoids. The increased temperature used to produce tomato juice, ketchup, tomato paste and canned tomato enhances the bioactive composition. We aimed to verify the beneficial effects of processed tomato juice from Kagome Ltd. (KOT) on hypolipidemic action in hamsters with hyperlipidemia induced by a 0.2% cholesterol and 10% lard diet (i.e., high-cholesterol diet (HCD)). Male Golden Syrian hamsters were randomly divided into two groups for treatment: normal (n = 8), standard diet (control); and experimental (n = 32), HCD. The 32 hamsters were further divided into four groups (n = 8 per group) to receive vehicle or KOT by oral gavage at 2787, 5573, or 13,934 mg/kg/day for six weeks, designated the HCD-1X, -2X and -5X groups, respectively. The efficacy and safety of KOT supplementation was evaluated by lipid profiles of serum, liver and feces and by clinical biochemistry and histopathology. HCD significantly increased serum levels of total cholesterol (TC), triacylglycerol (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), LDL-C/HDL-C ratio, hepatic and fetal TC and TG levels, and degree of fatty liver as compared with controls. KOT supplementation dose-dependently decreased serum TC, TG, LDL-C levels, LDL-C/HDL-C ratio, hepatic TC and TG levels, and fecal TG level. Our study provides experiment-based evidence to support that KOT may be useful in treating or preventing the onset of hyperlipidemia.

Inhibitors for cholesterol ester accumulation in macrophages from Chinese cabbage

The cholesterol ester accumulates in macrophages in the early stage of atherosclerotic lesions, leading to the formation of foam cells. We examined the inhibitory effects of the crude extracts of 22 edible plants on foam cell formation and isolated nine chlorophyll derivatives as potent inhibitors from Chinese cabbage. The results of the present study suggest that the chlorophyll derivatives contained in edible plants may be useful for the prevention and treatment of atherosclerosis.

Use of mRNA expression signatures to discover small molecule inhibitors of skeletal muscle atrophy

PURPOSE OF REVIEW

Here, we discuss a recently developed experimental strategy for discovering small molecules with potential to prevent and treat skeletal muscle atrophy.

RECENT FINDINGS

Muscle atrophy involves and requires widespread changes in skeletal muscle gene expression, which generate complex but measurable patterns of positive and negative changes in skeletal muscle mRNA levels (a.k.a. mRNA expression signatures of muscle atrophy). Many bioactive small molecules generate their own characteristic mRNA expression signatures, and by identifying small molecules whose signatures approximate mirror images of muscle atrophy signatures, one may identify small molecules with potential to prevent and/or reverse muscle atrophy. Unlike a conventional drug discovery approach, this strategy does not rely on a predefined molecular target but rather exploits the complexity of muscle atrophy to identify small molecules that counter the entire spectrum of pathological changes in atrophic muscle. We discuss how this strategy has been used to identify two natural compounds, ursolic acid and tomatidine, that reduce muscle atrophy and improve skeletal muscle function.

SUMMARY

Discovery strategies based on mRNA expression signatures can elucidate new approaches for preserving and restoring muscle mass and function.

Unraveling the structure-activity relationship of tomatidine, a steroid alkaloid with unique antibiotic properties against persistent forms of Staphylococcus aureus

Staphylococcus aureus (S. aureus) is responsible for difficult-to-treat and relapsing infections and constitutes one of the most problematic pathogens due to its multiple resistances to clinically available antibiotics. Additionally, the ability of S. aureus to develop small-colony variants is associated with a reduced susceptibility to aminoglycoside antibiotics and in vivo persistence. We have recently demonstrated that tomatidine, a steroid alkaloid isolated from tomato plants, possesses anti-virulence activity against normal strains of S. aureus as well as the ability to potentiate the effect of aminoglycoside antibiotics. In addition, tomatidine has shown antibiotic activity against small-colony variants of S. aureus. We herein report the first study of the structure-activity relationship of tomatidine against S. aureus.

On the regulation and function of secondary metabolism during fruit development and ripening

The maturation and development of tomato fruit has received much attention due both to the complexity and intricacy of the changes which occur during this process and to the importance of these fruits as a component of the human diet. Whilst great advances have been made in understanding molecular genetic aspects of fruit development, our knowledge concerning the metabolic shifts underpinning this process remains largely confined to primary metabolism. Conversely, the majority of the metabolites considered to have health benefits are secondary or specialized metabolites. Prior to assessing the role (if any) of these metabolites in tomato fruit development, considerable effort will be required in order to better describe the complement of secondary metabolites in the tomato and to elucidate the metabolic pathways involved in their synthesis and degradation. Advances in tomato secondary metabolism will be reviewed here focusing on the use of metabolomics strategies and, where applicable, the enabling of these strategies by their coupling to information resident in the tomato genome sequence.

Patent Highlights

A snapshot of recent key developments in the patent literature of relevance to the advancement of pharmaceutical and medical R&D.

Systems-based discovery of tomatidine as a natural small molecule inhibitor of skeletal muscle atrophy

Skeletal muscle atrophy is a common and debilitating condition that lacks an effective therapy. To address this problem, we used a systems-based discovery strategy to search for a small molecule whose mRNA expression signature negatively correlates to mRNA expression signatures of human skeletal muscle atrophy. This strategy identified a natural small molecule from tomato plants, tomatidine. Using cultured skeletal myotubes from both humans and mice, we found that tomatidine stimulated mTORC1 signaling and anabolism, leading to accumulation of protein and mitochondria, and ultimately, cell growth. Furthermore, in mice, tomatidine increased skeletal muscle mTORC1 signaling, reduced skeletal muscle atrophy, enhanced recovery from skeletal muscle atrophy, stimulated skeletal muscle hypertrophy, and increased strength and exercise capacity. Collectively, these results identify tomatidine as a novel small molecule inhibitor of muscle atrophy. Tomatidine may have utility as a therapeutic agent or lead compound for skeletal muscle atrophy.

Anticarcinogenic, cardioprotective, and other health benefits of tomato compounds lycopene, α-tomatine, and tomatidine in pure form and in fresh and processed tomatoes

Tomatoes produce the bioactive compounds lycopene and α-tomatine that are reported to have potential health-promoting effects in animals and humans, but our understanding of the roles of these compounds in the diet is incomplete. Our current knowledge gained from the chemistry and analysis of these compounds in fresh and processed tomatoes and from studies on their bioavailability, bioactivity, and mechanisms of action against cancer cells and other beneficial bioactivities including antibiotic, anti-inflammatory, antioxidative, cardiovascular, and immunostimulating effects in cells, animals, and humans is discussed and interpreted here. Areas for future research are also suggested. The collated information and suggested research might contribute to a better understanding of the agronomical, biochemical, chemical, physiological, molecular, and cellular bases of the health-promoting effects and facilitate and guide further studies needed to optimize the use of lycopene and α-tomatine in pure form and in fresh tomatoes and processed tomato products to help prevent or treat human disease.

Tomatidine inhibits invasion of human lung adenocarcinoma cell A549 by reducing matrix metalloproteinases expression

Tomatidine is an aglycone of glycoalkaloid tomatine in tomato. Tomatidine is found to possess anti-inflammatory properties and may serve as a chemosensitizer in multidrug-resistant tumor cells. However, the effect of tomatidine on cancer cell metastasis remains unclear. This study examines the effect of tomatidine on the migration and invasion of human lung adenocarcinoma A549 cell in vitro. The data demonstrates that tomatidine does not effectively inhibit the viability of A549 cells. When treated with non-toxic doses of tomatidine, cell invasion is markedly suppressed by Boyden chamber invasion assay, while cell migration is not affected. Tomatidine reduces the mRNA level of matrix metalloproteinase-2 (MMP-2), MMP-9 and increases the expression of reversion-inducing cysteine-rich protein with kazal motifs (RECK), as well as tissue inhibitor of metalloproteinase-1 (TIMP-1). The immunoblotting assays indicate that tomatidine is very effective in suppressing the phosphorylation of Akt and extracellular signal regulating kinase (ERK). In addition, tomatidine significantly decreases the nuclear level of nuclear factor kappa B (NF-κB), which suggests that tomatidine inhibits NF-κB activity. Furthermore, the treatment of inhibitors specific for PI3K/Akt (LY294002), ERK (U0126), or NF-κB (pyrrolidine dithiocarbamate) to A549 cells reduced cell invasion and MMP-2/9 expression. The results suggest that tomatidine inhibits the invasion of A549 cells by reducing the expression of MMPs. It also inhibits ERK and Akt signaling pathways and NF-κB activity. These findings demonstrate a new therapeutic potential for tomatidine in anti-metastatic therapy.