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

Review on toxicology and activity of tomato glycoalkaloids in immature tomatoes

Owing to the lack of selection and limited intelligence in mechanical picking, some immature tomatoes that contain alkaloids are thrown away. Tomatine alkaloids are steroidal alkaloids naturally present in Solanaceae plants, which are distributed in small amounts in immature tomato fruits and decrease as the fruits ripen. Tomato glycoalkaloids are harmful to human health. However, in small quantities, there is some evidence that these compounds might be beneficial, as other non-antioxidant bioactivities. This article considers recent research on the biological effects of tomato glycoalkaloids in immature tomatoes, providing reference value for the potential development of these compounds.

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.

Agri-Food Waste Recycling for Healthy Remedies: Biomedical Potential of Nutraceuticals from Unripe Tomatoes (Solanum lycopersicum L.)

Unripe tomatoes represent an agri-food waste resulting from industrial by-processing products of tomatoes, yielding products with a high content of bioactive compounds with potential nutraceutical properties. The food-matrix biological properties are attributed to the high steroidal glycoalkaloid (SGA) content. Among them, α-tomatine is the main SGA reported in unripe green tomatoes. This review provides an overview of the main chemical and pharmacological features of α-tomatine and green tomato extracts. The extraction processes and methods employed in SGA identification and the quantification are discussed. Special attention was given to the methods used in α-tomatine qualitative and quantitative analyses, including the extraction procedures and the clean-up methods applied in the analysis of Solanum lycopersicum L. extracts. Finally, the health-beneficial properties and the pharmacokinetics and toxicological aspects of SGAs and α-tomatine-containing extracts are considered in depth. In particular, the relevant results of the main in vivo and in vitro studies reporting the therapeutic properties and the mechanisms of action were described in detail.

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.

The Therapeutic Value of Solanum Steroidal (Glyco)Alkaloids: A 10-Year Comprehensive Review

Steroidal (glycol)alkaloids S(G)As are secondary metabolites made of a nitrogen-containing steroidal skeleton linked to a (poly)saccharide, naturally occurring in the members of the Solanaceae and Liliaceae plant families. The genus Solanum is familiar to all of us as a food source (tomato, potato, eggplant), but a few populations have also made it part of their ethnobotany for their medicinal properties. The recent development of the isolation, purification and analysis techniques have shed light on the structural diversity among the SGAs family, thus attracting scientists to investigate their various pharmacological properties. This review aims to overview the recent literature (2012-2022) on the pharmacological benefits displayed by the SGAs family. Over 17 different potential therapeutic applications (antibiotic, antiviral, anti-inflammatory, etc.) were reported over the past ten years, and this unique review analyzes each pharmacological effect independently without discrimination of either the SGA's chemical identity or their sources. A strong emphasis is placed on the discovery of their biological targets and the subsequent cellular mechanisms, discussing in vitro to in vivo biological data. The therapeutic value and the challenges of the solanum steroidal glycoalkaloid family is debated to provide new insights for future research towards clinical development.

Potential role of nutraceuticals via targeting a Wnt/β-catenin and NF-κB pathway in treatment of osteoarthritis

Osteoarthritis (OA) is a disease due to the aging of the articular cartilage, a post-mitotic tissue that stays functioning until primary homeostatic processes fail. Because of pain and disability, OA significantly influences national healthcare expenses and patient quality of life. It is a whole-joint illness characterized by inflammatory and oxidative signaling pathways and significant epigenetic alterations that cause cartilage extracellular matrix degradation. The canonical Wnt pathway (Wnt/β-catenin pathway) and nuclear factor kappa B (NF-κB) signaling pathways may function in joint tissues by modulating the activity of synovial cells, osteoblasts, and chondrocytes. However, finding innovative ways to treat osteoarthritis and get the joint back to average balance is still a struggle. Nutraceuticals are dietary supplements that promote joint health by balancing anabolic and catabolic signals. New therapeutic methods for OA treatment have been developed based on many research findings that show nutraceuticals have strong anti-inflammation, antioxidant, anti-bone resorption, and anabolic properties. For the treatment of osteoarthritis, we explore the possible involvement of nutraceuticals that target the Wnt/β-catenin and NF-κB pathways. PRACTICAL APPLICATIONS: In keeping with the aging population, osteoarthritis is becoming more widespread. In this extensive research, we studied the role of the Wnt/β-catenin and NF-κB pathway in OA formation and progression. Nutraceuticals that target these OA-related signaling pathways are a viable therapy option. Wnt/β-catenin and NF-κB signaling pathway are inhibited by polyphenols, flavonoids, alkaloids, and vitamins from the nutraceutical category, making them possible therapeutic drugs for OA therapy.

ALPK1 Accelerates the Pathogenesis of Osteoarthritis by Activating NLRP3 Signaling

Alpha-kinase 1 (ALPK1), a member of the alpha-kinase family, has been shown to be involved in mediating inflammatory responses and is strongly associated with gout; however, its modulatory role in osteoarthritis (OA) remains unclear. Here, we uncovered elevation of ALPK1 in degraded cartilage of destabilized medial meniscus (DMM) and collagenase-induced osteoarthritis (CIOA), two different mouse OA models induced by mechanical stress or synovitis. Intraarticular administration of recombinant human ALPK1 (rhALPK1) in vivo exacerbated OA pathogenesis in both DMM and CIOA mice, whereas ALPK1 knockout reversed this process. In vitro study demonstrated that ALPK1 aggravates metabolic disturbances in chondrocytes by enhancing the production of NOD-like receptor protein 3 (NLRP3), an inflammasome sensors driving interlukin-1β (IL-1β)-mediated inflammatory conditions. Furthermore, the selective inhibition of nuclear factor-κB (NF-κB) or NLRP3 indicates that NLRP3 is a downstream signaling governed by NF-κB in ALPK1-activated chondrocytes. Collectively, these results establish ALPK1 as a novel catabolic regulator of OA pathogenesis, and targeting this signaling may be a promising treatment strategy for OA. © 2022 American Society for Bone and Mineral Research (ASBMR).

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 Improves Pulmonary Inflammation in Mice with Acute Lung Injury

Tomatidine, which is isolated from green tomato, can ameliorate inflammation and oxidative stress in cells and animal experiments and has been shown to improve airway inflammation in a murine model of asthma. Here, we investigated whether tomatidine can ameliorate acute lung injury in mice. Mice were given tomatidine by intraperitoneal injection for 7 consecutive days, and then, lung injury was induced via intratracheal instillation of lipopolysaccharide (LPS). Tomatidine reduced inflammatory cytokine expressions in bronchoalveolar lavage fluid (BALF), attenuated neutrophil infiltration in the BALF and lung tissue, increased superoxide dismutase activity and glutathione levels, and alleviated myeloperoxidase expression in the lung tissue of mice with lung injury. Tomatidine also decreased inflammatory cytokine and chemokine gene expression in inflammatory lungs and attenuated the phosphorylation of mitogen-activated protein kinase and nuclear factor kappa B. Furthermore, tomatidine enhanced the production of heme oxygenase-1, decreased the secretion of inflammatory cytokines and chemokines in LPS-stimulated lung epithelial cells, and attenuated THP-1 monocyte adhesion. Our findings suggest that tomatidine attenuates oxidative stress and inflammation, improving acute lung injury in mice.

Interleukin-35 Regulates Angiogenesis Through P38 Mitogen-Activated Protein Kinase Signaling Pathway in Interleukin-1β-Stimulated SW1353 Cells and Cartilage Bioinformatics Analysis

We aimed to investigate the effects of interleukin (IL)-35 on proangiogenic factors in IL-1β-pretreated chondrocyte-like SW1353 cells and screen-related genes that participated in osteoarthritis (OA) cartilage with IL-35, proangiogenic factors, and P38 mitogen-activated protein kinase (MAPK) signaling pathway. Different concentrations of IL-35 incubated with IL-1β stimulated SW1353 cells with or without SB203580 (inhibitor of P38 MAPK). Proangiogenic molecule expression was assessed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Microarray datasets were downloaded from the Gene Expression Omnibus database of OA cartilage. Protein-protein interaction of genes was visualized by Search Tool for the Retrieval Interacting Genes and Cytoscape. Database for Annotation, Visualization, and Integrated Discovery was used to screen biological processes and pathways. IL-35 inhibited mRNA expression of proangiogenic factors in IL-1β-stimulated SW1353 cells through the P38 MAPK signaling pathway. IL-35 inhibited angiopoietin-2 secretion. We found that 8 related genes, 18 biological processes, and 6 pathways may associate with IL-35, P38 MAPK signaling pathway, and cartilage angiogenesis. IL-35 regulated the expression of proangiogenic factors through P38 MAPK signaling pathway in IL-1β-stimulated SW1353 cells. IL-35 and P38 MAPK pathway may participate in neovascularization of cartilage. Our findings may provide molecular mechanisms and possible genes target treatment for OA.

Anti-Parasitic Activity of Cherry Tomato Peel Powders

Trichomoniasis in humans, caused by the protozoal parasite Trichomonas vaginalis, is the most common non-viral sexually transmitted disease, while Tritrichomonas foetus causes trichomonosis, an infection of the gastrointestinal tract and diarrhea in farm animals and domesticated cats. As part of an effort to determine the inhibitory effects of plant-based extracts and pure compounds, seven commercially available cherry tomato varieties were hand-peeled, freeze-dried, and pounded into powders. The anti-trichomonad inhibitory activities of these peel powders at 0.02% concentration determined using an in vitro cell assay varied widely from 0.0% to 66.7% against T. vaginalis G3 (human); from 0.9% to 66.8% for T. foetus C1 (feline); and from 0.0% to 81.3% for T. foetus D1 (bovine). The organic Solanum lycopersicum var. cerasiforme (D) peels were the most active against all three trichomonads, inhibiting 52.2% (G3), 66.8% (C1), and 81.3% (D1). Additional assays showed that none of the powders inhibited the growth of foodborne pathogenic bacteria, pathogenic fungi, or non-pathogenic lactobacilli. Tomato peel and pomace powders with high content of described biologically active compounds could serve as functional food and feed additives that might help overcome adverse effects of wide-ranging diseases and complement the treatment of parasites with the anti-trichomonad drug metronidazole.