Antiproliferative activity of Solanum lycocarpum alkaloidic extract and their constituents, solamargine and solasonine, in tumor cell lines

Convergent synthesis of glycoalkaloids solasonine and its saponin derivative

We present a practical and convergent synthesis of glycoalkaloids solasonine 1 and its saponin derivative 2, incorporating a {3-O-α-L-rhamnopyranosyl-(1→2)-O-[β-D-glucopyranosyl-(1→3)]-β-D-galactopyranoside} moiety. The key features of this strategy include the following: (1) AuCl3-tBuCN cooperative catalysis enabling 1,2-trans stereoselective glycosidation of 2-branched trisaccharide trichloroacetimidate donors with steroidal aglycons, in the absence of neighboring group participation; (2) "cyanide effect" mediated regioselective benzoylation of the 4- and 6-hydroxyl groups of galactopyranosyl disaccharide; and (3) an effective approach to prevent orthoester byproduct formation.

Main chemical constituents and mechanism of anti-tumor action of Solanum nigrum L

OBJECTIVE

Solanum nigrum L. (SNL) is a natural drugwith diverse bioactive components and multi-targeted anti-tumor effects, gaining increasing attention in clinical application.

METHOD AND RESULTS

This paper reviews the studies on SNL by searching academic databases (Google Scholar, PubMed, Science Direct,and Web of Science, among others), analyzing its chemical compositions (alkaloids, saponins, polysaccharides, and polyphenols, among others), andbriefly describes the anti-tumor mechanisms of the main components.

DISCUSSION

This paper discusses the shortcomings of the current research on SNL and proposes corresponding solutions, providing theoretical support for further research on its biological functions and clinical efficacy.

Therapeutic Potential of Solanum Alkaloids with Special Emphasis on Cancer: A Comprehensive Review

Cancer has emerged as a formidable global health challenge, with treatment methods like chemotherapy and radiation often exacerbating the situation due to their associated side effects. Opting for natural sources like plants as a safer and environmentally friendly alternative seems promising. Historically, plants have served as valuable sources for treating diverse health conditions, attributable to their rich composition of therapeutic phytochemicals. Within this array of phytochemicals, alkaloids, especially those found in the Solanaceae plant family, are notably prominent. Alkaloids from Solanaceae plant family called Solanum alkaloids demonstrate noteworthy anti-tumour characteristics and exert a potent inhibitory influence on cancer cell proliferation. They trigger programmed cell death in cancerous cells through various molecular pathways, whether administered alone or combined with other medications. Solanum alkaloids act upon cancer cells via multiple mechanisms, including apoptosis induction, suppression of cell growth and migration, as well as inhibition of angiogenesis. This review provides insights into the anti-cancer attributes of Solanum alkaloids found in various Solanum plant species, along with a brief overview of their other medicinal properties.

Solamargine improves the therapeutic efficacy of anti-PD-L1 in lung adenocarcinoma by inhibiting STAT1 activation

OBJECTIVE

The effect of solamargine on lung adenocarcinoma and its effect on STAT1 signaling pathway mediated immune escape were studied through network pharmacology and in vitro and in vivo experiments.

METHODS

The solamargine targets were screened using the TCMSP and the LUAD targets were screened using the GeneCard, OMIM, PharmGkb, TTD and DrugBank databases. PPI network analysis and target prediction were performed using GO and KEGG. Colony formation assay, EDU staining, wound healing, transwell assay, Hoechst and flow cytometry were used to detect the effects of solamargine on the proliferation, migration and apoptosis of LUAD. Western blotting (WB) and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to detect P-STAT1 and PD-L1 expression. And immunofluorescence was used to detect P-STAT1 expression. In vivo experiments, C57BL/6 mice were divided into control group, low concentration group, high concentration group, positive control group and combination group. Every other day, following seven consecutive doses, the size of the tumor was assessed. Finally, the expressions of P-STAT1, STAT1, PD-L1 and apoptosis index proteins were detected by WB.

RESULTS

The anti-LUAD effect of solamargine was found by wound healing, colony formation assay, transwell assay, hoechst and EdU staining. The results of network pharmacological analysis showed that solamargine could suppress STAT1 expression level. Further enrichment assay of STAT1 showed that STAT1 was associated with immune-related pathways. In addition, molecular signal analysis by WB and RT-qPCR indicated that solamargine could reduce the expression levels of P-STAT1 and PD-L1 in a concentration-dependent manner. According to the results of in vivo assays, combination of solamargine and immune checkpoint inhibitors (ICIs) durvalumab could significantly inhibit the growth of Lewis transplanted tumors in C57BL/6 mice, and no toxic side effect was recoded.

CONCLUSION

These results indicated that solamargine could inhibit the proliferation and promote the apoptosis of LUAD. It also could reduce the expression level of P-STAT1 protein and inhibit the expression level of PD-L1. At the same time, the combination with the ICIs can better block the expression of PD-L1 in cells, thereby inhibiting the immune escape pathway of tumor cells and achieving anti-tumor effects. This study proposed a novel combined therapeutic approach, involving the inhibition of STAT1 by solamargine in conjunction with ICIs.

Health Benefits of the Alkaloids from Lobeira (Solanum lycocarpum St. Hill): A Comprehensive Review

Solanum is the largest genus within the Solanaceae family and has garnered considerable attention in chemical and biological investigations over the past 30 years. In this context, lobeira or "fruta-do-lobo" (Solanum lycocarpum St. Hill), a species predominantly found in the Brazilian Cerrado, stands out. Beyond the interesting nutritional composition of the fruits, various parts of the lobeira plant have been used in folk medicine as hypoglycemic, sedative, diuretic, antiepileptic, and antispasmodic agents. These health-beneficial effects have been correlated with various bioactive compounds found in the plant, particularly alkaloids. In this review, we summarize the alkaloid composition of the lobeira plant and its biological activities that have been reported in the scientific literature in the last decades. The compiled data showed that lobeira plants and fruits contain a wide range of alkaloids, with steroidal glycoalkaloid solamargine and solasonine being the major ones. These alkaloids, but not limited to them, contribute to different biological activities verified in alkaloid-rich extracts/fractions from the lobeira, including antioxidant, anti-inflammatory, anticancer, antigenotoxic, antidiabetic, antinociceptive, and antiparasitic effects. Despite the encouraging results, additional research, especially toxicological, pre-clinical, and clinical trials, is essential to validate these human health benefits and ensure consumers' safety and well-being.

Unleashed Treasures of Solanaceae: Mechanistic Insights into Phytochemicals with Therapeutic Potential for Combatting Human Diseases

Plants that possess a diverse range of bioactive compounds are essential for maintaining human health and survival. The diversity of bioactive compounds with distinct therapeutic potential contributes to their role in health systems, in addition to their function as a source of nutrients. Studies on the genetic makeup and composition of bioactive compounds have revealed them to be rich in steroidal alkaloids, saponins, terpenes, flavonoids, and phenolics. The Solanaceae family, having a rich abundance of bioactive compounds with varying degrees of pharmacological activities, holds significant promise in the management of different diseases. Investigation into Solanum species has revealed them to exhibit a wide range of pharmacological properties, including antioxidant, hepatoprotective, cardioprotective, nephroprotective, anti-inflammatory, and anti-ulcerogenic effects. Phytochemical analysis of isolated compounds such as diosgenin, solamargine, solanine, apigenin, and lupeol has shown them to be cytotoxic in different cancer cell lines, including liver cancer (HepG2, Hep3B, SMMC-772), lung cancer (A549, H441, H520), human breast cancer (HBL-100), and prostate cancer (PC3). Since analysis of their phytochemical constituents has shown them to have a notable effect on several signaling pathways, a great deal of attention has been paid to identifying the biological targets and cellular mechanisms involved therein. Considering the promising aspects of bioactive constituents of different Solanum members, the main emphasis was on finding and reporting notable cultivars, their phytochemical contents, and their pharmacological properties. This review offers mechanistic insights into the bioactive ingredients intended to treat different ailments with the least harmful effects for potential applications in the advancement of medical research.

Extract of Astragali Radix and Solanum nigrum Linne regulates microglia and macrophage polarization and inhibits the growth and infiltration of C6 glioblastoma

ETHNOPHARMACOLOGICAL RELEVANCE

The polarization of glioma-associated microglia/macrophages (GAMs) affects the growth and infiltration of glioma. Astragali Radix (AR) and Solanum nigrum L. (SN) are traditional antitumor combinations in Chinese herbal medicine, but their roles and mechanisms against glioma are not yet clear.

AIM OF THE STUDY

The effects of AR and SN compound (ARSN) on the polarization of GAMs and glioma cells in vitro and in vivo were studied, providing new ideas for the treatment of glioma.

MATERIALS AND METHODS

The UPLC-QTOF-MS method was used to examine the quality of ARSN extracts. The effects of ARSN on proliferation, migration and apoptosis of C6 cells were investigated using CCK-8 assay, colony-forming assay, wound healing assay and flow cytometry. The impact of ARSN on the polarization of GAMs was verified by PCR, ELISA, and flow cytometry. In addition, a rat glioma model was established to assess the effects of ARSN on glioma growth, infiltration, and polarization of GAMs.

RESULTS

In vitro experiments, ARSN can effectively inhibit the proliferation and migration of C6 cells and promote apoptosis. In the rat orthotopic tumor model, ARSN also effectively inhibited tumor growth and infiltration. The SN part of ARSN has strong cytotoxicity. Meanwhile the AR part can effectively inhibit the M2 polarization of GAMs and chemokine production induced by tumor, promote the M1 phenotype of GAMs, and regulate the tumor immune microenvironment to indirectly kill glioma.

CONCLUSIONS

ARSN inhibited glioma growth both in vitro and in vivo. SN takes effect through direct cytotoxicity, while AR works by regulating GAMs polarization. ARSN extracts can be used as a potential agent for glioma treatment.

Active components of Solanum nigrum and their antitumor effects: a literature review

Cancer poses a serious threat to human health and overall well-being. Conventional cancer treatments predominantly encompass surgical procedures and radiotherapy. Nevertheless, the substantial side effects and the emergence of drug resistance in patients significantly diminish their quality of life and overall prognosis. There is an acute need for innovative, efficient therapeutic agents to address these challenges. Plant-based herbal medicines and their derived compounds offer promising potential for cancer research and treatment due to their numerous advantages. Solanum nigrum (S. nigrum), a traditional Chinese medicine, finds extensive use in clinical settings. The steroidal compounds within S. nigrum, particularly steroidal alkaloids, exhibit robust antitumor properties either independently or when combined with other drugs. Many researchers have delved into unraveling the antitumor mechanisms of the active components present in S. nigrum, yielding notable progress. This literature review provides a comprehensive analysis of the research advancements concerning the active constituents of S. nigrum. Furthermore, it outlines the action mechanisms of select monomeric anticancer ingredients. Overall, the insights derived from this review offer a new perspective on the development of clinical anticancer drugs.

Solanum nigrum Linn.: Advances in anti-cancer activity and mechanism in digestive system tumors

Cancer has currently become a serious public health issue in many countries worldwide, and tumors of the digestive system have attracted an increasing number of researchers' due to their numerous types, high proportion and wide area of occurrence. While tumors of the digestive system suffer from high mortality rates, leading to untimely diagnosis and a poor prognosis, making it necessary to update current treatment approaches such as surgery, radiation therapy, and chemotherapy. This highlights the importance of exploring novel therapeutic ideas and targets. Traditional Chinese medicine has a long history of clinical use due to its low toxicity and multi-factor targeting of multiple pathways. As a kind of traditional Chinese herb, S. nigrum Linn. is highly regarded for its proven antitumor activity. The aim of this study was to comprehensively recapitulate and analyze the anti-cancer effects and molecular mechanisms of treatment of gastrointestinal tumors with S. nigrum Linn. extracts and related compounds, including classical signaling pathways mediated by them as well as noncoding RNA pathways associated with tumor suppression. Components that have been found to be responsible for the anti-cancer activity of S. nigrum Linn. include solanine, solasonine, solamargine, a-L-rhhamnopyranose, uttroside B, degalactotigonin, glycoprotein, and other compounds. The underlying mechanisms of anti-cancer activity reflected in this study include apoptosis, cell cycle arrest, autophagy, anti-angiogenesis, suppression of metastasis and invasion, immune escape, and increased sensitivity to radiotherapy. S. nigrum Linn. has great potential in the treatment of tumors of the digestive system, and through further clinical trials and pharmacological mechanisms it has the potential to become a uniform and standardized anti-tumor drug.

Cytotoxic activity of essential oil from Leaves of Myrcia splendens against A549 Lung Cancer cells

BACKGROUND

Plants of the Myrcia genus have been widely used in folk medicine to treat various diseases, including cancer. Myrcia splendens species has a diverse chemical constitution, but the biological activities of its essential oil have not been well investigated. In this study to out the chemistry characterization of essential oil (EO) from the leaves of the species M. splendens from Brazil and evaluate cytotoxic effect in A549 lung cancer cells.

METHODS

M. splendens EO was obtained by hydrodistillation and analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). EO was isolated and evaluated for cellular viability in tumor cell lines by MTT assay. The evaluation of the formation of clones and the migratory capacity of the A549 cells treated with EO was done by the clonogenic assay and the wound healing assay. Morphological changes were observed in A549 cells by fluorescence using Phalloidin/FITC and DAPI.

RESULTS

22 compounds were identified in the chemical analysis of EO, corresponding to 88% of the sample. Major compounds were the sesquiterpenic hydrocarbons bicyclogermacrene (15.4%), germacrene D (8.9%) and E-caryophyllene (10.1%). The biological analysis of the EO showed high cytotoxic activity with an IC₅₀ below 20 µg/ml in the THP-1, A549 and B16-F10 tumor cells. The treatment with EO reduced colony formation and inhibited the migratory capacity of A549 cells. Furthermore, apoptotic morphological changes in the nucleus and cytoplasm of A549 cells was observed after of treatment with EO.

CONCLUSION

The findings of this study suggest that the M. splendens EO has cytotoxic compounds for the A549 lung cancer cells. Treatment with the EO decreased the colony formation and reduced the ability of lung cancer cells to migrate. Future studies may be used to isolate compounds from the EO for the study of lung cancer.

Diallyl Disulfide: A Bioactive Garlic Compound with Anticancer Potential

Cancer is a life-threatening disease caused by the uncontrolled division of cells, which culminates in a solid mass of cells known as a tumor or liquid cancer. It is the leading cause of mortality worldwide, and the number of cancer patients has been increasing at an alarming rate, with an estimated 20 million cases expected by 2030. Thus, the use of complementary or alternative therapeutic techniques that can help prevent cancer has been the subject of increased attention. Garlic, the most widely used plant medicinal product, exhibits a wide spectrum of biological activities, including antibacterial, hypo-lipidemic, antithrombotic, and anticancer effects. Diallyl disulfide (DADS) is a major organosulfur compound contained within garlic. Recently, several experimental studies have demonstrated that DADS exhibits anti-tumor activity against many types of tumor cells, including gynecological cancers (cervical cancer, ovarian cancer), hematological cancers (leukemia, lymphoma), lung cancer, neural cancer, skin cancer, prostate cancer, gastrointestinal tract and associated cancers (esophageal cancer, gastric cancer, colorectal cancer), hepatocellular cancer cell line, etc. The mechanisms behind the anticancer action of DADS include epithelial-mesenchymal transition (EMT), invasion, and migration. This article aims to review the available information regarding the anti-cancer potential of DADS, as well as summarize its mechanisms of action, bioavailability, and pharmacokinetics from published clinical and toxicity studies.

Solasonine Inhibits Pancreatic Cancer Progression With Involvement of Ferroptosis Induction

Pancreatic cancer is a highly fatal malignant tumor of the digestive system. It is characterized by early metastasis and high mortality rates. Solasonine, a steroidal alkaloid, is derived from Solanum nigrum L., a natural herb. Solasonine is associated with excellent anti-tumor effects, however, its effects on pancreatic cancer have not been fully established. Pancreatic cancer cells (PANC-1 and CFPAC-1) were used to verify the in vitro and in vivo effects of solasonine. Metabolomics were used to evaluate its underlying mechanisms. Solasonine promoted PANC-1 and CFPAC-1 cell apoptosis while inhibiting their proliferation, migration and invasion. Mouse xenograft models and metastasis models of ANC-1 and CFPAC-1 confirmed that solasonine blocked tumor formation and metastasis. Metabolomics confirmed the effects of solasonine on glutathione metabolism and SLC7A11-mediated ferroptosis. Furthermore, Co-Immunoprecipitation and Duolink^®in situ PLA confirmed that OTUB1, a deubiquitylating enzyme, interacted with SLC7A11 and solasonine to enhance ubiquitinated degradation of SLC7A11 in PANC-1 and CFPAC-1 cells. Besides, molecular docking confirmed that solasonine directly bound TFAP2A and suppressed its protein levels. Bioinformatics and luciferase assays revealed that TFAP2A binds the OTUB1 promoter region, thereby promoting its transcription. In summary, solasonine inhibits the TFAP2A/OTUB1 SLC7A11 axis to activate ferroptosis and suppress pancreatic cancer cell progression.

Solasonine Induces Apoptosis and Inhibits Proliferation of Bladder Cancer Cells by Suppressing NRP1 Expression

Solasonine, a steroidal alkaloid extracted from Solanum nigrum L., has been found to exert inhibitory effect on cancers. However, the underlying anticancer mechanisms of solasonine, particularly in urinary bladder cancer (BC), remain unclear. In this study, we identified the potential targets and biological functions associated with solasonine activity using a bioinformatics approach. Ingenuity pathway analysis revealed that neuropilin-1 (NRP1) and other signaling pathways, such as PI3K/AKT and ERK/MAPK pathways, were potentially involved in the therapeutic effects of solasonine. The ability of solasonine in inducing apoptosis and inhibiting proliferation in BC cells was confirmed experimentally, and the inhibition of ERK/MAPK, P38/MAPK, and PI3K/AKT pathways was validated by Western blot. Mechanistically, solasonine suppressed the expression of NRP1 protein, but not that of mRNA. Further results of molecular docking and molecular dynamics simulation analysis indicated that solasonine could directly bind to the b1 domain of NRP1 protein with a reasonable and stable docking conformation. We previously found that targeting NRP1 is a potential antitumor strategy. Combined with these findings, it can be speculated that the binding of solasonine with NRP1 on the cell membrane could prevent the formation of NRP1/VEGFA/VEGFR2 and NRP1/EGFR complexes, resulting in the inhibition of downstream signaling, including ERK/MAPK, P38/MAPK, and PI3K/AKT pathways. Additionally, intracellular solasonine could inhibit the membrane localization of NRP1 and provoke its cytoplasmic retention, facilitating the degradation of NRP1 protein in the cytoplasm. The dual effects induced by the binding of solasonine to NRP1 extracellularly and intracellularly could account for the antiproliferative and proapoptotic effects of solasonine on BC.

Antitumor activity of solamargine in mouse melanoma model: relevance to clinical safety

Melanoma is the most aggressive type of skin cancer, and thus it is important to develop new drugs for its treatment. The present study aimed to examine the antitumor effects of solamargine a major alkaloid heteroside present in Solanum lycocarpum fruit. In addition solamargine was incorporated into nanoparticles (NP) of yttrium vanadate functionalized with 3-chloropropyltrimethoxysilane (YVO₄:Eu³⁺:CPTES:SM) to determine antitumor activity. The anti-melanoma assessment was performed using a syngeneic mouse melanoma model B16F10 cell line. In addition, systemic toxicity, nephrotoxic, and genotoxic parameters were assessed. Solamargine, at doses of 5 or 10 mg/kg/day administered subcutaneously to male C57BL/6 mice for 5 days, decreased tumor size and frequency of mitoses in tumor tissue, indicative of a decrease in cell proliferation. Treatments with YVO₄:Eu³⁺:CPTES:SM significantly reduced the number of mitoses in tumor tissue, associated with no change in tumor size. There were no apparent signs of systemic toxicity, nephrotoxicity, and genotoxicity initiated by treatments either with solamargine alone or plant alkaloid incorporated into NP. The animals treated with YVO₄:Eu³⁺:CPTES:SM exhibited significant increase in spleen weight accompanied by no apparent histological changes in all tissues examined. In addition, animals treated with solamargine (10 mg/kg/day) and YVO₄:Eu³⁺:CPTES:SM demonstrated significant reduction in hepatic DNA damage which was induced by tumor growth. Therefore, data suggest that solamargine may be considered a promising candidate in cancer therapy with no apparent toxic effects.

Determination of Cytotoxic Activity of Sanguinaria canadensis Extracts against Human Melanoma Cells and Comparison of Their Cytotoxicity with Cytotoxicity of Some Anticancer Drugs

Melanoma is an enormous global health burden, and should be effectively addressed with better therapeutic strategies. Therefore, new therapeutic agents are needed for the management of this disease. The aim of this study was the investigation of cytotoxic activity of some isoquinoline alkaloid standards and extracts obtained from Sanguinaria canadensis—collected before, during, and after flowering—against three different human melanoma cells (A375, G361, SK-MEL-3). The cytotoxicity of these extracts was not previously tested on these melanoma cell lines. Determination of alkaloid contents was performed by HPLC-DAD using Polar RP column and mobile phase containing acetonitrile, water, and 1-butyl-3-methylimidazolium tetrafluoroborate. The cytotoxicity of alkaloid standards was investigated by determination of cell viability and calculation of IC₅₀ values. Significant differences were observed in the alkaloids content and cytotoxic activity of the extracts, depending on the season of collection of the plant material. In the Sanguinaria canadensis extracts high contents of sanguinarine (from 4.8543 to 9.5899 mg/g of dry plant material) and chelerythrine (from 42.7224 to 6.8722 mg/g of dry plant material) were found. For both of these alkaloids, very high cytotoxic activity against the tested cell lines were observed. The IC₅₀ values were in the range of 0.11–0.54 µg/mL for sanguinarine and 0.14 to 0.46 µg/mL for chelerythrine. IC₅₀ values obtained for Sanguinaria canadensis extracts against all tested cell lines were also very low (from 0.88 to 10.96 µg/mL). Cytotoxic activity of alkaloid standards and Sanguinaria canadensis extracts were compared with the cytotoxicity of anticancer drugs—etoposide, cisplatin, and hydroxyurea. In all cases except the one obtained for cisplatin against A375, which was similar to that obtained for Sanguinaria canadensis after flowering against the same cell line, IC₅₀ values obtained for anticancer drugs were higher than the IC₅₀ values obtained for sanguinarine, chelerythrine, and Sanguinaria canadensis extracts. Our results showed that Sanguinaria canadensis extracts and isoquinoline alkaloids, especially sanguinarine and chelerythrine, could be recommended for further in vivo experiments in order to confirm the possibility of their application in the treatment of human melanomas.

Determination of Cytotoxic Activity of Selected Isoquinoline Alkaloids and Plant Extracts Obtained from Various Parts of Mahonia aquifolium Collected in Various Vegetation Seasons

Melanoma is a serious form of skin cancer that begins in cells known as melanocytes. While it is less common than the other forms of skin cancer, melanoma is more dangerous because of its ability to spread to other organs more rapidly if it is not treated at an early stage. The number of people diagnosed with melanoma has increased over the last few decades. The most widely used treatments include surgery, chemotherapy, and radiation therapy. The search for new drugs to treat various cancers is one of the most important challenges of modern scientific research. Some isoquinoline alkaloids found in different plant species have strong cytotoxic effects on various cancer cells. We tested the effect of isoquinoline alkaloids and extracts obtained from various parts of Mahonia aquifolium collected in various vegetation seasons on human melanoma cancer cells and our data indicated that investigated extract induced significant reduction in cell viability of Human malignant melanoma cells (A375), human Caucasian malignant melanoma cell line (G361), and human malignant melanoma cell line (SKMEL3 cancer cell lines in a dose- and time-dependent manner. Differences in cytotoxic activity were observed for extracts obtained from various parts of Mahonia aquifolium. Significant differences were also obtained in the alkaloids content and cytotoxic activity of the extracts depending on the season of collection of plant material. Our investigations exhibit that these plant extracts can be recommended for further in vivo experiments in order to confirm the possibility of their use in the treatment of human melanomas.

Cytotoxic and chemosensitizing effects of glycoalkaloidic extract on 2D and 3D models using RT4 and patient derived xenografts bladder cancer cells

Glycoalkaloids have been widely demonstrated as potential anticancer agents. However, the chemosensitizing effect of these compounds with traditional chemotherapeutic agents has not been explored yet. In a quest for novel effective therapies to treat bladder cancer (BC), we evaluated the chemosensitizing potential of glycoalkaloidic extract (GE) with cisplatin (cDDP) in RT4 and PDX cells using 2D and 3D cell culture models. Additionally, we also investigated the underlying molecular mechanism behind this effect in RT4 cells. Herein, we observed that PDX cells were highly resistant to cisplatin when compared to RT4 cells. IC50 values showed at least 2.16-folds and 1.4-folds higher in 3D cultures when compared to 2D monolayers in RT4 cells and PDX cells, respectively. GE + cDDP inhibited colony formation (40%) and migration (28.38%) and induced apoptosis (57%) in RT4 cells. Combination therapy induced apoptosis by down-regulating the expression of Bcl-2 (p < 0.001), Bcl-xL (p < 0.001) and survivin (p < 0.01), and activating the caspase cascade in RT4 cells. Moreover, decreased expression of MMP-2 and 9 (p < 0.01) were observed with combination therapy, implying its effect on cell invasion/migration. Furthermore, we used 3D bioprinting to grow RT4 spheroids using sodium alginate-gelatin as a bioink and evaluated the effect of GE + cDDP on this system. Cell viability assay showed the chemosensitizing effect of GE with cDDP on bio-printed spheroids. In summary, we showed the cytotoxicity effect of GE on BC cells and also demonstrated that GE could sensitize BC cells to chemotherapy.

Solasonine Suppresses the Proliferation of Acute Monocytic Leukemia Through the Activation of the AMPK/FOXO3A Axis

Solasonine, the main active ingredient of Solanum nigrum L., has been reported to exert extensive antitumor activity. However, the antitumor effects in acute monocytic leukemia and the exact mechanisms involved are unknown. In this study, we investigated the role of solasonine on inhibiting the progression of acute monocytic leukemia. Our findings showed that solasonine inhibited the proliferation of acute monocytic leukemic cell lines (THP-1 and MV4-11) in vitro. Solasonine promoted apoptosis and induced cell cycle arrest in the G2/M phase. Analysis of RNA-seq data suggested that solasonine correlated with increased expression of genes in the AMPK/FOXO3A pathway. Inhibition of AMPK with compound C followed by treatment with solasonine showed that solasonine reduced apoptosis, caused less cell cycle arrest, and inactivated the AMPK/FOXO3A axis in THP-1 and MV4-11 cells. Solasonine also inhibited tumor growth by the activation of the AMPK/FOXO3A axis. In conclusion, solasonine inhibited the progress of acute monocytic leukemia in vitro and in vivo and triggered the apoptosis and cell cycle arrest in the G2/M phase by upregulating the AMPK/FOXO3A pathway.

Hydroalcoholic Extract of Solanum lycocarpum A. St. Hil. (Solanaceae) Leaves Improves Alloxan-Induced Diabetes Complications in Mice

BACKGROUND

Solanum lycocarpum is a medicinal plant widely-used in Brazil because its fruits have hypoglycemic activity. However, the fruits are restricted in some periods of the year.

OBJECTIVE

To evaluate the effects of hydroalcoholic extracts of S. lycocarpum leaves in alloxan-induced diabetic mice.

METHODS

Hydroalcoholic extract of S. lycocarpum was characterized by phytochemical and GC-MS analysis. The Antidiabetic activity was assessed following treatment for 22 days with S. lycocarpum extract at 125, 250, and 500 mg/kg. Bodyweight, water, and food intake, glycemia, biochemical parameters, anatomy-histopathology of the pancreas, liver and kidney, and expression of target genes were analyzed. In addition, oral acute toxicity was evaluated.

RESULTS

Animals treated showed a significant reduction (p < 0.05) in glycemia following a dose of 125 mg/kg. Food intake remained similar for all groups. Decreased polydipsia symptoms were observed after treatment with 250 (p < 0.001) and 500 mg/kg (p < 0.01) compared with diabetic control, although normal rates were observed when 125 mg/kg was administered. A protective effect was also observed in the pancreas, liver, and kidneys, through the regeneration of the islets. Hypoglycemic activity can be attributed to myo-inositol, which stimulates insulin secretion, associated with α-tocopherol, which prevents damage from oxidative stress and apoptosis of β-pancreatic cells by an increased Catalase (CAT) and Glutathione peroxidase 4 (GPX4) mRNA expression. The toxicological test demonstrated safe oral use of the extract under the present conditions.

CONCLUSION

Hydroalcoholic extract of S. lycocarpum promotes the regulation of diabetes in the case of moderate glycemic levels, by decreasing glycemia and exerting protective effects on the islets.

Targeted uptake of folic acid-functionalized polymeric nanoparticles loading glycoalkaloidic extract in vitro and in vivo assays

Solanum lycocarpum fruits contain two major glycoalkaloids (GAs), solamargine (SM) and solasonine (SS). These compounds are reported as cytotoxic. However, they have poor water solubility and low bioavailability. To overcome these disadvantages and getting an efficient formulation the current study aimed to develop, characterize, and test the effectiveness of a nanotechnology-based strategy using poly(D,L-lactide) (PLA) nanoparticles functionalized with folate as delivery system of glycoalkaloidic extract (AE) for bladder cancer therapy. The strategic of adding folic acid into nanoformulations can increase the selectivity of the compounds to the cancer cells reducing the side effects. Our results revealed the successful preparation of AE-loaded folate-targeted nanoparticles (NP-F-AE) with particle size around 177 nm, negative zeta potential, polydispersity index <0.20, and higher efficiency of encapsulation for both GAs present in the extract (>85 %). To investigate the cellular uptake, the fluorescent dye coumarin-6 was encapsulated into the nanoparticle (NP-F-C6). The cell studies showed high uptake of nanoparticles by breast (MDA-MB-231) and bladder (RT4) cancer cells, but not for normal keratinocytes cells (HaCaT) indicating the target uptake to cancer cells. The cytotoxicity of nanoparticles was evaluated on RT4 2D culture model showing 2.16-fold lower IC50 than the free AE. Furthermore, the IC50 increased on the RT4 spheroids compared to 2D model. The nanoparticles penetrated homogeneously into the urotheliumof porcine bladder. These results showed that folate-conjugated polymeric nanoparticles are potential carriers for targeted glycoalkaloidic extract delivery to bladder cancer cells.

The regulation and interaction of colon cancer-associated transcript-1 and miR7-5p contribute to the inhibition of SP1 expression by solamargine in human nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is a common head and neck malignancy with higher incidence in Southern China and Southeast Asia. Solamargine (SM), a steroidal alkaloid glycoside, has been shown to have anticancer properties. However, the underlying mechanism involved remains undetermined. In this study, we showed that SM inhibited the growth of NPC cells. Mechanistically, we found that solamargine decreased lncRNA colon cancer-associated transcript-1 (CCAT1) and increased miR7-5p expression. There was a reciprocal interaction of CCAT1 and miR7-5p. In addition, SM inhibited the expression of SP1 protein and promoter activity, which was strengthened by miR7-5p mimics and inhibited by overexpressed CCAT1. MiR7-5p could bind to 3'-UTR of SP1 and attenuated SP1 gene expression. Exogenously expressed SP1 feedback resisted SM-increased miR7-5p expression and more importantly reversed SM-inhibited growth of NPC cells. Finally, SM inhibited NPC tumor growth in vivo. Collectively, our results show that SM inhibits the growth of NPC cells through reciprocal regulation of CCAT1 and miR7-5p, followed by inhibition of SP1 gene expression in vitro and in vivo. The interregulation and correlation among CCAT1, miR7-5p and SP1, and the feedback regulatory loop unveil the novel molecular mechanism underlying the overall responses of SM in anti-NPC.

Alkaloids from Traditional Chinese Medicine against hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has become one of the major diseases that are threatening human health in the 21st century. Currently there are many approaches to treat liver cancer, but each has its own advantages and disadvantages. Among various methods of treating liver cancer, natural medicine treatment has achieved promising results because of their superiorities of high efficiency and availability, as well as low side effects. Alkaloids, as a class of natural ingredients derived from traditional Chinese medicines, have previously been shown to exert prominent anti-hepatocarcinogenic effects, through various mechanisms including inhibition of proliferation, metastasis and angiogenesis, changing cell morphology, promoting apoptosis and autophagy, triggering cell cycle arrest, regulating various cancer-related genes as well as pathways and so on. As a consequence, alkaloids suppress the development and progression of liver cancer. In this study, the mechanisms of representative alkaloids against hepatocarcinoma in each class are described systematically according to the structure classification, which mainly divides alkaloids into piperidine alkaloids, isoquinoline alkaloids, indole alkaloids, terpenoids alkaloids, steroidal alkaloids and other alkaloids. Besides using them alone, synergistic effects created together with other chemotherapy drugs and some special preparation methods also have been demonstrated. In this review, we have summarized the potential roles of several common alkaloids in the prevention and treatment of HCC, by revising the preclinical studies, highlighting the potential applications of alkaloids when they function as a therapeutic choice for HCC treatment, and integrating them into clinical practices.

The Reciprocal Interaction Between LncRNA CCAT1 and miR-375-3p Contribute to the Downregulation of IRF5 Gene Expression by Solasonine in HepG2 Human Hepatocellular Carcinoma Cells

Solasonine (SS), a natural glycoalkaloid component, has been shown to have potent inhibitory activity and cytotoxicity against many cancer types. However, the precise mechanisms underlying this, particularly in hepatocellular carcinoma (HCC) are poorly understood. In this study, we showed that SS inhibited growth of HCC cells. Mechanistically, we observed that SS increased the expression of miR-375-3p, whereas reducing levels of long non-coding RNAs (lncRNAs) CCAT1 was noticed in HepG2 HCC and other cells. In addition, we found that SS repressed transcription factors, SP1 and interferon regulatory factor 5 (IRF5), protein expressions. There was a reciprocal interaction among miR-375-3p, CCAT1, and SP1. Moreover, SS inhibited IRF5 promoter activity, which was not observed in cells transfected with excessive expressed SP1 vectors. Interestingly, exogenously expressed IRF5 was shown to reverse expressions of SS-inhibited CCAT1 and induced-miR-375-3p; and neutralized SS-inhibited growth of HCC cells. Similar results were also found in vivo mouse model. Collectively, our results show that SS inhibits HepG2 HCC growth through the reciprocal regulation between the miR-375-3p and lncRNA CCAT1, and this results in transcription factor SP1-mediated reduction of IRF5 expression. The regulations and interactions among miR-375-3p, CCAT1, SP1, and IRF5 axis unveil a novel molecular mechanism underlying the anti-HCC growth by SS. IRF5 may be a potential target for treatment of HCC.

Therapeutic value of steroidal alkaloids in cancer: Current trends and future perspectives

Discovery and development of new potentially selective anticancer agents are necessary to prevent a global cancer health crisis. Currently, alternative medicinal agents derived from plants have been extensively investigated to develop anticancer drugs with fewer adverse effects. Among them, steroidal alkaloids are conventional secondary metabolites that comprise an important class of natural products found in plants, marine organisms and invertebrates, and constitute a judicious choice as potential anti-cancer leads. Traditional medicine and modern science have shown that representatives from this compound group possess potential antimicrobial, analgesic, anticancer and anti-inflammatory effects. Therefore, systematic and recapitulated information about the bioactivity of these compounds, with special emphasis on the molecular or cellular mechanisms, is of high interest. In this review, we methodically discuss the in vitro and in vivo potential of the anticancer activity of natural steroidal alkaloids and their synthetic and semi-synthetic derivatives. This review focuses on cumulative and comprehensive molecular mechanisms, which will help researchers understand the molecular pathways involving steroid alkaloids to generate a selective and safe new lead compound with improved therapeutic applications for cancer prevention and therapy. In vitro and in vivo studies provide evidence about the promising therapeutic potential of steroidal alkaloids in various cancer cell lines, but advanced pharmacokinetic and clinical experiments are required to develop more selective and safe drugs for cancer treatment.

Assessing the cytotoxic potential of glycoalkaloidic extract in nanoparticles against bladder cancer cells

OBJECTIVE

This study proposed to use the nanotechnology to deliver glycoalkaloidic extract (AE) to bladder cancer cells, evaluating their activity in 2D and 3D models and the biological mechanism of cell death.

METHODS

NPs were prepared by nanoprecipitation method using polylactic acid (PLA) and characterized considering their size, charge, particle concentration and stability. The cytotoxicity was evaluated in 2D and 3D model, and the apoptosis and cell cycle were investigated using flow cytometry.

KEY FINDINGS

NPs loading AE (NP-AE) had diameter around 125 ± 6 nm (PdI <0.1) and negative charge. The encapsulation efficiency of SM and SS was higher than 85% for both compounds. The obtained formulation showed a significant in-vitro cytotoxic effect against RT4 cells in a dose-dependent manner with IC₅₀ two fold lower than the free AE. The cytotoxic effect of NP-AE was mediated by apoptosis and cell cycle arrested in the S phase. RT4 cells cultured under 3D conditions exhibited a higher resistance to the treatments (IC₅₀ ~ three fold higher than in 2D cell culture).

CONCLUSION

The NP-AE might be a promising nanocarrier to load and deliver glycoalkaloids against bladder cancer.

The Genus Solanum: An Ethnopharmacological, Phytochemical and Biological Properties Review

Over the past 30 years, the genus Solanum has received considerable attention in chemical and biological studies. Solanum is the largest genus in the family Solanaceae, comprising of about 2000 species distributed in the subtropical and tropical regions of Africa, Australia, and parts of Asia, e.g., China, India and Japan. Many of them are economically significant species. Previous phytochemical investigations on Solanum species led to the identification of steroidal saponins, steroidal alkaloids, terpenes, flavonoids, lignans, sterols, phenolic comopunds, coumarins, amongst other compounds. Many species belonging to this genus present huge range of pharmacological activities such as cytotoxicity to different tumors as breast cancer (4T1 and EMT), colorectal cancer (HCT116, HT29, and SW480), and prostate cancer (DU145) cell lines. The biological activities have been attributed to a number of steroidal saponins, steroidal alkaloids and phenols. This review features 65 phytochemically studied species of Solanum between 1990 and 2018, fetched from SciFinder, Pubmed, ScienceDirect, Wikipedia and Baidu, using "Solanum" and the species' names as search terms ("all fields").

Solamargine inhibits proliferation and promotes apoptosis of CM-319 human chordoma cells through suppression of notch pathway

Background

Solamargine (SM), which represents a natural steroid alkaloid glycoside compound and a cytotoxic agent, has been proved to enhance the sensitivity of lung cancer cells to tumor necrosis factors (TNFs). In this study, we aimed to investigate the roles and mechanisms of SM in chordoma.

Methods

Cell viability, proliferation, apoptosis and cell cycle were measured by cell counting Kit-8 (CCK-8) assay, 5(6)-carboxyfluorescein diacetate succinimidyl ester (CFSE) labeling and flow cytometry (FCM), respectively. Western blot and quantitative real-time reverse transcription PCR (qRT-PCR) assays were performed to detect the expressions of related mRNAs and proteins.

Results

The results revealed that SM distinctly suppressed the proliferation of CM-319 cells. SM significantly induced the CM-319 cells apoptosis through up-regulating the expression levels of Caspase-3/8/9. The cell cycle of CM-319 cells was blocked by SM in G1 phase. Moreover, SM could significantly suppress the Notch pathway in CM-319 cells.

Conclusions

In conclusion, SM suppressed the proliferation and enhanced the apoptosis ability of CM-319 cells via suppressing the Notch pathway. The results suggested that SM might be a novel therapeutic agent and supported the utilization of SM in chordoma.

In Vivo Toxicity of Solasonine and Its Effects on cyp450 Family Gene Expression in the Livers of Male Mice from Four Strains

Solasonine was reported to inhibit tumour cell growth in several different models. The in vivo toxicity of solasonine, the effects of genetic background on its toxicity, and its possible roles in regulating the expression of cyp450 family genes were still unclear and required characterisation. Here, Horn’s assays were performed on male mice from four different strains, and the expression of cyp450 family genes in their livers was examined by RT-PCR and ELISA. Mice treated by intraperitoneal injection with high levels of solasonine showed immediate post-excitatory depression, intraperitoneal tissue adhesion, and dissolving of cells in the liver. Furthermore, these four mouse strains showed different toxicological sensitivity to solasonine. The strains, in decreasing order of LD50 value, rescuing speed of body weight, and more severe pathological symptoms, were KM, ICR, C57BL/6, and BALB/c. Interestingly, more cyp450 genes were downregulated at the mRNA and/or protein level in the livers of male mice from C57BL/6 or BALB/c strains than those from KM or ICR strains. These results suggest that (1) Solasonine has hepatic toxicity and downregulates cyp450 genes expression at transcriptional and/or post-transcriptional levels; (2) Genetic background is an important factor which can affect the in vivo toxicity; (3) Downregulation of cyp450 gene expression in the liver may be a clue to help understand whether or not a given strain is sensitive to solasonine; (4) Influences on the expression of cyp450 genes should be considered when using solasonine alone, or in combination with other drugs.

Kaurenoic acid and its sodium salt derivative: antibacterial activity against Porphyromonas gingivalis and their mechanism of action

Aim: To evaluate the antibacterial activity of 12 kaurane-type diterpenes against a panel of bacteria that cause endodontic infection. Methods & materials: We conducted tests against bacteria in the planktonic or in the sessile mode, cytotoxic assays for the most promising compounds against human normal lung fibroblast cells, and Porphyromonas gingivalis (ATCC 33277) proteomic analysis. Results & conclusion: Kaurenoic acid and its salt exhibited satisfactory antibacterial action against the evaluated bacteria. Proteomic analysis suggested that these compounds might interfere in bacterial metabolism and virulence factor expression. Kaurane-type diterpenes are an important class of natural products and should be considered in the search for new irrigating solutions to treat endodontic infections.

An-te-xiao capsule inhibits tumor growth in non-small cell lung cancer by targeting angiogenesis

An-te-xiao capsule consists of total alkaloids from the dried whole plantof Solanum lyratum, and showed antitumor effects in our previous study. However, its inhibitory effect on multiple non-small cell lung cancer (NSCLC) cell lines and the underlying mechanisms have not been elucidated clearly. This study sought to investigate the inhibitory effects of An-te-xiao capsule on three main types of NSCLC cell lines (A549, NCI-H460, and NCI-H520) in vitro and in vivo and the underlying mechanisms of action including its potential anti-angiogenesis effects. An-te-xiao capsule showed no acute oral toxicity in mice, and significantly prolonged survival time in a mouse model of Lewis tumor xenograft. The inhibition of A549, NCI-H460, and NCI-H520 cells by An-te-xiao capsule was reflected in its effects on tumor growth, histopathological changes, tumor microvessel density (MVD), cell cycle regulatory proteins, and cell apoptosis. In vitro, An-te-xiao capsule repressed migration, invasion, and tube formation of tumor-derived vascular endothelial cells (Td-ECs), which were obtained using a co-culture system, in the presence or absence of vascular endothelial growth factor (VEGF) at safe concentrations selected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Moreover, An-te-xiao capsule inhibited the secretion of VEGF by A549 cells in the co-culture system and suppressed the phosphorylation of VEGF receptor 2 (VEGFR2). Taken together, An-te-xiao capsule has potential for treating NSCLC.

Solamargine, a bioactive steroidal alkaloid isolated from Solanum aculeastrum induces non-selective cytotoxicity and P-glycoprotein inhibition

Background

Solanum aculeastrum fruits are used by some cancer sufferers as a form of alternative treatment. Scientific literature is scarce concerning its anticancer activity, and thus the aim of the study was to assess the in vitro anticancer and P-glycoprotein inhibitory potential of extracts of S. aculeastrum fruits. Furthermore, assessment of the combinational effect with doxorubicin was also done.

Methods

The crude extract was prepared by ultrasonic maceration. Liquid-liquid extraction yielded one aqueous and two organic fractions. Bioactive constituents were isolated from the aqueous fraction by means of column chromatography, solid phase extraction and preparative thin-layer chromatography. Confirmation of bioactive constituent identity was done by nuclear magnetic resonance and ultra-performance liquid chromatography mass spectrometry. The crude extract and fractions were assessed for cytotoxicity and P-glycoprotein inhibition in both cancerous and non-cancerous cell lines using the sulforhodamine B and rhodamine-123 assays, respectively.

Results

Both the crude extract and aqueous fraction was cytotoxic to all cell lines, with the SH-SY5Y neuroblastoma cell line being most susceptible to exposure (IC₅₀ = 10.72 μg/mL [crude], 17.21 μg/mL [aqueous]). Dose-dependent P-glycoprotein inhibition was observed for the crude extract (5.9 to 18.9-fold at 100 μg/mL) and aqueous fraction (2.9 to 21.2 at 100 μg/mL). The steroidal alkaloids solamargine and solanine were identified. While solanine was not bioactive, solamargine displayed an IC₅₀ of 15.62 μg/mL, and 9.1-fold P-glycoprotein inhibition at 100 μg/mL against the SH-SY5Y cell line. Additive effects were noted for combinations of doxorubicin against the SH-SY5Y cell line.

Conclusions

The crude extract and aqueous fraction displayed potent non-selective cytotoxicity and noteworthy P-glycoprotein inhibition. These effects were attributed to solamargine. P-glycoprotein inhibitory activity was only present at concentrations higher than those inducing cytotoxicity, and thus does not appear to be the likely mechanism for the enhancement of doxorubicin’s cytotoxicity. Preliminary results suggest that non-selective cytotoxicity may hinder drug development, however, further assessment of the mode of cell death is necessary to determine the route forward.

Solamargine derived from Solanum nigrum induces apoptosis of human cholangiocarcinoma QBC939 cells

Solamargine, an active ingredient of Solanum nigrum, has been previously revealed to inhibit the proliferation of cancer cells. However, the effect of solamargine on human cholangiocarcinoma cells and the underlying molecular mechanism remain unknown. In the present study, the molecular mechanism underlying the anti-cancer effect of solamargine was assessed in human cholangiocarcinoma QBC939 cells. The results of the present study revealed that solamargine inhibited the viability of QBC939 cells in a dose-dependent manner. Furthermore, solamargine significantly induced the apoptosis of QBC939 cells and altered the mitochondrial membrane potential of cells. Quantitative polymerase chain reaction analysis revealed that solamargine decreased the mRNA level of B-cell lymphoma-2 (Bcl-2), Bcl-extra-large and X-linked inhibitor of apoptosis protein but increased the mRNA level of Bcl-2-associated X protein (Bax). In addition, western blot analysis demonstrated that solamargine inhibited the protein expression of Bcl-2 and poly ADP ribose polymerase (PARP), and promoted the protein expression of Bax, cleaved PARP, caspase 3, cleaved caspase 3 and caspase 7. Therefore, the results of the present study revealed that solamargine may induce apoptosis via the mitochondrial pathway and alter the level of apoptosis-associated proteins in human cholangiocarcinoma QBC939 cells. This in vitro study demonstrated that solamargine may be an effective chemotherapeutic agent against cholangiocarcinoma in clinical practice.

Metformin: A Bridge between Diabetes and Prostate Cancer

Prostate cancer (PCa) has become the most frequent type of cancer in men. Recent data suggest that diabetic patients taking metformin have a lower incidence of certain cancer, including PCa. Metformin is the most common drug used in type II diabetes mellitus; its use has been shown to lower the incidence of several cancers, although there are ambiguous data about the anticancer activity of metformin. A large number of studies examined the potential antineoplastic mechanism of metformin although it is not still completely understood. This review summarizes the literature concerning the effects of metformin on PCa cells, highlighting its numerous mechanisms of action through which it can act. We analyze the possible causes of the discordances regarding the impact of metformin on risk of PCa; we discuss the latest findings in this field, suggesting that metformin may have a future role in the management of PCa both as monotherapy and in combination with other drugs.

Aglycone solanidine and solasodine derivatives: A natural approach towards cancer

Over the past few years, it was suggested that a rational approach to treat cancer in clinical settings requires a multipronged approach that augments improvement in systemic efficiency along with modification in cellular phenotype leads to more efficient cell death response. Recently, the combinatory delivery of traditional chemotherapeutic drugs with natural compounds proved to be astonishing to deal with a variety of cancers, especially that are resistant to chemotherapeutic drugs. The natural compounds not only synergize the effects of chemotherapeutics but also minimize drug associated systemic toxicity. In this review, our primary focus was on antitumor effects of natural compounds. Previously, the drugs from natural sources are highly precise and safer than drugs of synthetic origins. Many natural compounds exhibit anti-cancer potentials by inducing apoptosis in different tumor models, in-vitro and in-vivo. Furthermore, natural compounds are also found equally useful in chemotherapeutic drug resistant tumors. Moreover, these Phyto-compounds also possess numerous other pharmacological properties such as antifungal, antimicrobial, antiprotozoal, and hepatoprotection. Aglycone solasodine and solanidine derivatives are the utmost important steroidal glycoalkaloids that are present in various Solanum species, are discussed here. These natural compounds are highly cytotoxic against different tumor cell lines. As the molecular weight is concerned; these are smaller molecular weight chemotherapeutic agents that induce cell death response by initiating apoptosis through both extrinsic and intrinsic pathways.

Activation of AMPKα mediates additive effects of solamargine and metformin on suppressing MUC1 expression in castration-resistant prostate cancer cells

Prostate cancer is the second most common cause of cancer-related deaths worldwide. The mucin 1 (MUC1) oncoprotein is highly expressed in human prostate cancers with aggressive features. However, the role for MUC1 in occurrence and progression of castration-resistant prostate cancer (CRPC) remained elusive. In this study, we showed that solamargine, a major steroidal alkaloid glycoside, inhibited the growth of CRPC cells, which was enhanced in the presence of metformin. Furthermore, we found that solamargine increased phosphorylation of AMPKα, whereas reducing the protein expression and promoter activity of MUC1. A greater effect was observed in the presence of metformin. In addition, solamargine reduced NF-κB subunit p65 protein expression. Exogenously expressed p65 resisted solamargine-reduced MUC1 protein and promoter activity. Interestingly, exogenously expressed MUC1 attenuated solamargine-stimulated phosphorylation of AMPKα and, more importantly reversed solamargine-inhibited cell growth. Finally, solamargine increased phosphorylation of AMPKα, while inhibiting MUC1, p65 and tumor growth were observed in vivo. Overall, our results show that solamargine inhibits the growth of CRPC cells through AMPKα-mediated inhibition of p65, followed by reduction of MUC1 expression in vitro and in vivo. More importantly, metformin facilitates the antitumor effect of solamargine on CRPC cells.

Solasonine, A Natural Glycoalkaloid Compound, Inhibits Gli-Mediated Transcriptional Activity

The major obstacle limiting the efficacy of current Smoothened (Smo) inhibitors is the primary and acquired resistance mainly caused by Smo mutations and Gli amplification. In this context, developing Hh inhibitors targeting Gli, the final effector of this signaling pathway, may combat the resistance. In this study we found that solasonine, a natural glycoalkaloid compound, significantly inhibited the hedgehog (Hh) pathway activity. Meanwhile, solasonine may obviously inhibit the alkaline phosphatase (ALP) activity in C3H10T1/2 cells, concomitantly with reductions of the mRNA expression of Gli1 and Ptch1. However, we found that solasonine exhibited no effect on the transcriptional factors activities provoked by TNF-α and PGE2, thus suggesting its selectivity against Hh pathway activity. Furthermore, we identified that solasonine inhibited the Hh pathway activity by acting on its transcriptional factor Gli using a series of complementary data. We also observed that solasonine obviously inhibited the Gli-luciferase activity provoked by ectopic expression of Smo mutants which may cause the resistance to the current Smo inhibitors. Our study suggests that solasonine may significantly inhibit the Hh pathway activity by acting on Gli, therefore indicating the possibility to use solasonine as a lead compound to develop anticancer drugs for combating the resistance of current Smo inhibitors.

Targeting EP4 downstream c-Jun through ERK1/2-mediated reduction of DNMT1 reveals novel mechanism of solamargine-inhibited growth of lung cancer cells

Lung cancer is the most common cancer and the leading cause of cancer deaths worldwide. We previously showed that solamargine, one natural phytochemicals from traditional plants, inhibited the growth of lung cancer cells through inhibition of prostaglandin E2 (PGE₂ ) receptor EP4. However, the potential downstream effectors of EP4 involving in the anti-lung cancer effects of solamargine still remained to be determined. In this study, we further verified that solamargine inhibited growth of non-small-cell lung cancer (NSCLC) cells in multiple cell lines. Mechanistically, solamargine increased phosphorylation of ERK1/2. Moreover, solamargine inhibited the protein expression of DNA methyltransferase 1 (DNMT1) and c-Jun, which were abrogated in cells treated with MEK/ERK1/2 inhibitor (PD98059) and transfected with exogenously expressed DNMT1 gene, respectively. Interestingly, overexpressed DNMT1 gene antagonized the effect of solamargine on c-Jun protein expression. Intriguingly, overexpressed c-Jun blocked solamargine-inhibited lung cancer cell growth, and feedback resisted the solamargine-induced phosphorylation of ERK1/2. A nude mouse xenograft model implanted with lung cancer cells in vivo confirmed the results in vitro. Collectively, our results show that solamargine inhibits the growth of human lung cancer cells through reduction of EP4 protein expression, followed by increasing ERK1/2 phosphorylation. This results in decrease in DNMT1 and c-Jun protein expressions. The inter-correlations between EP4, DNMT1 and c-Jun and feedback regulation of ERK1/2 by c-Jun contribute to the overall responses of solamargine in this process. This study uncovers an additional novel mechanism by which solamargine inhibits growth of human lung cancer cells.

Antiproliferative and toxicological properties of methanolic extract obtained from Solanum capsicoides All. seeds and carpesterol

Natural products are considered important sources of potential chemotherapeutic agents. Here, we evaluated the antiproliferative activity and the toxicological effects of the methanolic extract and a pure compound obtained from Solanum capsicoides seeds. The phytochemical profile was analyzed by chromatographic and spectroscopy methods. The acute toxicity was assessed in mice orally treated with the extract (2000 mg/kg), in vitro hemolytic activity and micronucleus test. The mutagenicity, developmental toxicity, and lethal dose (LD50) of carpesterol were estimated by the Toxicity Estimation Software Tool (TEST) software. A sulforhodamine B assay was employed to evaluate the antiproliferative activity. The toxicological assays did not observe signs of toxicity, either during the behavioral observations or in the autopsies, as well as no mutagenicity and hemolytic activity. The carpesterol did not present mutagenic effect and hemolytic activity but presents developmental toxicology and LD50 of 410 mg/kg in toxicity estimations by the TEST software. The S. capsicoides extract exhibited antiproliferative activity mainly in leukemia (K562) cell lineage. However, carpesterol presented antiproliferative activity in glioma (U251), breast (MCF-7), kidney (786-0), ovary (OVCAR-03), and K562 cell lineages. The data obtained show that S. capsicoides extract presents antiproliferative and does not present toxicological effects. In addition, it was shown for the first time the antiproliferative and toxicological parameters of carpesterol.

Inactivation of PI3-K/Akt and reduction of SP1 and p65 expression increase the effect of solamargine on suppressing EP4 expression in human lung cancer cells

BACKGROUND

Lung cancer is the most common cause of cancer-related deaths worldwide. Natural phytochemicals from traditional medicinal plants such as solamargine have been shown to have anticancer properties. The prostaglandin E2 receptor EP4 is highly expressed in human cancer, however, the functional role of EP4 in the occurrence and progression of non small cell lung cancer (NSCLC) remained to be elucidated.

METHODS

Cell viability was measured by MTT assays. Western blot was performed to measure the phosphorylation and protein expression of PI3-K downstream effector Akt, transcription factors SP1, p65, and EP4. Quantitative real-time PCR (qRT-PCR) was used to examine the mRNA levels of EP4 gene. Exogenous expression of SP1, p65, and EP4 genes was carried out by transient transfection assays. EP4 promoter activity was measured by Dual Luciferase Reporter Kit.

RESULTS

We showed that solamargine inhibited the growth of lung cancer cells. Mechanistically, we found that solamargine decreased the phosphorylation of Akt, the protein, mRNA expression, and promoter activity of EP4. Moreover, solamargine inhibited protein expression of SP1 and NF-κB subunit p65, all of which were abrogated in cells transfected with exogenous expressed Akt. Intriguingly, exogenous expressed SP1 overcame the effect of solamargine on inhibition of p65 protein expression, and EP4 protein expression and promoter activity. Finally, exogenous expressed EP4 feedback reversed the effect of solamargine on phosphorylation of Akt and cell growth inhibition.

CONCLUSION

Our results show that solamargine inhibits the growth of human lung cancer cells through inactivation of Akt signaling, followed by reduction of SP1 and p65 protein expression. This results in the inhibition of EP4 gene expression. The cross-talk between SP1 and p65, and the positive feedback regulatory loop of PI3-K/Akt signaling by EP4 contribute to the overall responses of solamargine in this process. This study unveils a novel mechanism by which solamargine inhibits growth of human lung cancer cells.

Manool, a Salvia officinalis diterpene, induces selective cytotoxicity in cancer cells

Manool, a diterpene isolated from Salvia officinalis, was evaluated by the XTT colorimetric assay for cytotoxicity and selectivity against different cancer cell lines: B16F10 (murine melanoma), MCF-7 (human breast adenocarcinoma), HeLa (human cervical adenocarcinoma), HepG2 (human hepatocellular carcinoma), and MO59J, U343 and U251 (human glioblastoma). A normal cell line (V79, Chinese hamster lung fibroblasts) was used to compare the selectivity of the test substance. Manool exhibited higher cytotoxic activity against HeLa (IC50 = 6.7 ± 1.1 µg/mL) and U343 (IC50 = 6.7 ± 1.2 µg/mL) cells. In addition, in the used experimental protocols, the treatment with manool was significantly more cytotoxic for different tumor cell lines than for the normal cell line V79 (IC50 = 49.3 ± 3.3 µg/mL), and showed high selectivity. These results suggest that manool may be used to treat cancer without affecting normal cells.

Bioactive Compounds Found in Brazilian Cerrado Fruits

Functional foods include any natural product that presents health-promoting effects, thereby reducing the risk of chronic diseases. Cerrado fruits are considered a source of bioactive substances, mainly phenolic compounds, making them important functional foods. Despite this, the losses of natural vegetation in the Cerrado are progressive. Hence, the knowledge propagation about the importance of the species found in Cerrado could contribute to the preservation of this biome. This review provides information about Cerrado fruits and highlights the structures and pharmacologic potential of functional compounds found in these fruits. Compounds detected in Caryocar brasiliense Camb. (pequi), Dipteryx alata Vog. (baru), Eugenia dysenterica DC. (cagaita), Eugenia uniflora L. (pitanga), Genipa americana L. (jenipapo), Hancornia speciosa Gomes (mangaba), Mauritia flexuosa L.f. (buriti), Myrciaria cauliflora (DC) Berg (jabuticaba), Psidiumguajava L. (goiaba), Psidium spp. (araçá), Solanum lycocarpum St. Hill (lobeira), Spondias mombin L. (cajá), Annona crassiflora Mart. (araticum), among others are reported here.

Molecular docking study of natural alkaloids as multi-targeted hedgehog pathway inhibitors in cancer stem cell therapy

Cancer is responsible for millions of deaths throughout the world every year. Increased understanding as well as advancements in the therapeutic aspect seems suboptimal to restrict the huge deaths associated with cancer. The major cause responsible for this is high resistance as well as relapse rate associated with cancers. Several evidences indicated that cancer stem cells (CSC) are mainly responsible for the resistance and relapses associated with cancer. Furthermore, agents targeting a single protein seem to have higher chances of resistance than multitargeting drugs. According to the concept of network model, partial inhibition of multiple targets is more productive than single hit agents. Thus, by fusing both the premises that CSC and single hit anticancer drugs, both are responsible for cancer related resistances and screened alkaloids for the search of leads having CSC targeting ability as well as the capability to modulating multiple target proteins. The in silico experimental data indicated that emetine and cortistatin have the ability to modulate hedgehog (Hh) pathway by binding to sonic hedgehog (Hh), smoothened (Smo) and Gli protein, involved in maintenance CSCs. Furthermore, solamargine, solasonine and tylophorine are also seems to be good lead molecules targeting towards CSCs by modulating Hh pathway. Except solamargine and solasonine, other best lead molecules also showed acceptable in silico ADME profile. The predicted lead molecules can be suitably modified to get multitargeting CSC targeting agent to get rid of associate resistances.

Chemistry and anticarcinogenic mechanisms of glycoalkaloids produced by eggplants, potatoes, and tomatoes

Inhibition of cancer can occur via apoptosis, a genetically directed process of cell self-destruction that involves numerous biomarkers and signaling pathways. Glycoalkaloids are nitrogen-containing secondary plant metabolites found in numerous Solanaceous plants including eggplants, potatoes, and tomatoes. Exposure of cancer cells to glycoalkaloids produced by eggplants (α-solamargine and α-solasonine), potatoes (α-chaconine and α-solanine), and tomatoes (α-tomatine) or their hydrolysis products (mono-, di-, and trisaccharide derivatives and the aglycones solasodine, solanidine, and tomatidine) inhibits the growth of the cells in culture (in vitro) as well as tumor growth in vivo. This overview comprehensively surveys and consolidates worldwide efforts to define the following aspects of these natural compounds: (a) their prevalence in the three foods; (b) their chemistry and structure-activity relationships; (c) the reported factors (biomarkers, signaling pathways) associated with apoptosis of bone, breast, cervical, colon, gastric, glioblastoma, leukemia, liver, lung, lymphoma, melanoma, pancreas, prostate, and squamous cell carcinoma cell lines in vitro and the in vivo inhibition of tumor formation and growth in fish and mice and in human skin cancers; and (d) future research needs. The described results may make it possible to better relate the structures of the active compounds to their health-promoting function, individually, in combination, and in food, and allow the consumer to select glycoalkaloid-containing food with the optimal content of nontoxic beneficial compounds. The described findings are expected to be a valuable record and resource for further investigation of the health benefits of food-related natural compounds.