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.

Solamargine induces apoptosis of human renal carcinoma cells via downregulating phosphorylated STAT3 expression

Solamargine (SM), an active compound derived from Solanum nigrum, triggers apoptosis and inhibits the metastatic and oxidative activities of various types of tumor cells. However, the effect of SM on human renal carcinoma cells remains unknown. In the present study, the molecular mechanisms underlying the antitumor effects of SM on ACHN and 786-O cells were elucidated. Specifically, MTT and colony formation assays were conducted to evaluate the impact of SM treatment on the proliferation of ACHN and 786-O cells, and flow cytometry was conducted to determine the influence of SM on the apoptosis rates of these cells. In addition, the expression of target proteins was determined by western blotting. The results revealed that SM not only inhibited cell viability but also promoted the apoptosis of ACHN and 786-O cells in a time- and dose-dependent manner. Moreover, treatment of ACHN and 786-O cells with SM significantly enhanced the caspase-3, caspase-8 and caspase-9 activities. Furthermore, SM downregulated the expression of phosphorylated signal transducer and activator of transcription-3 (p-STAT3) and Bcl-2 but increased the expression of cleaved caspase-3, -8, -9 and Bax. BAY2353, a p-STAT3 inhibitor, inhibited the viability of ACHN and 786-O cells, increased the expression of cleaved caspase-9 and Bax and decreased the expression of p-STAT3 and Bcl-2. Further experiments demonstrated that SM inhibited tumor growth in xenograft nude mice without causing specific toxicity to the major organs. Collectively, these findings indicated that SM not only inhibited the viability but also promoted the apoptosis of ACHN and 786-O cells, through a mechanism involving downregulation of p-STAT3 expression.

Glycoalkaloid Composition and Flavonoid Content as Driving Forces of Phytotoxicity in Diploid Potato

Despite their advantages, biotechnological and omic techniques have not been applied often to characterize phytotoxicity in depth. Here, we show the distribution of phytotoxicity and glycoalkaloid content in a diploid potato population and try to clarify the source of variability of phytotoxicity among plants whose leaf extracts have a high glycoalkaloid content against the test plant species, mustard. Six glycoalkaloids were recognized in the potato leaf extracts: solasonine, solamargine, α-solanine, α-chaconine, leptinine I, and leptine II. The glycoalkaloid profiles of the progeny of the group with high phytotoxicity differed from those of the progeny of the group with low phytotoxicity, which stimulated mustard growth. RNA sequencing analysis revealed that the upregulated flavonol synthase/flavonone 3-hydroxylase-like gene was expressed in the progeny of the low phytotoxicity group, stimulating plant growth. We concluded that the metabolic shift among potato progeny may be a source of different physiological responses in mustard. The composition of glycoalkaloids, rather than the total glycoalkaloid content itself, in potato leaf extracts, may be a driving force of phytotoxicity. We suggest that, in addition to glycoalkaloids, other metabolites may shape phytotoxicity, and we assume that these metabolites may be flavonoids.

Solamargine induces autophagy-mediated apoptosis and enhances bortezomib activity in multiple myeloma

Multiple myeloma (MM) is an incurable plasma cell malignancy with a poor survival rate. Conventional chemotherapeutic agent‐induced adverse events, including toxicity, neuropathy or drug resistance, significantly decrease the patients' quality of life and can even lead to interruption of treatment. Therefore, novel therapeutic drugs and strategies are urgently needed to improve MM therapy and patient outcomes. Here, we show that solamargine (SM), a steroidal alkaloid glycoside isolated from a Chinese herb Solanum nigrum L., exhibits promising anti‐MM activity. In particular, SM suppressed the viability of MM cell lines (ARP‐1 and NCI‐H929) in a concentration‐ and time‐dependent manner, inducing apoptosis in these cells. RNA‐seq analysis showed that treatment with SM led to the upregulation of genes associated with cell death and autophagy in H929 cells. Further, we found that treatment with SM activated autophagy in the MM cells, as incubation with 3‐Methyladenine, an inhibitor of autophagy, significantly alleviated SM‐triggered apoptosis and inhibition of viability in MM cells. Interestingly, we also observed a synergistic effect between SM and bortezomib (BTZ), a common chemotherapeutic agent for MM, in both MM cells and human bone marrow CD138+ primary myeloma cells. We also confirmed the single‐agent efficacy of SM and the synergistic effects between SM and BTZ in an MM xenograft mouse model. Collectively, these findings indicate that SM exerts an anti‐MM effect, at least in part, by activating cell autophagy and reveal that SM alone or in combination with BTZ is a potential therapeutic strategy for treating MM.

Solamargine inhibits the growth of hepatocellular carcinoma and enhances the anticancer effect of sorafenib by regulating HOTTIP-TUG1/miR-4726-5p/MUC1 pathway

Hepatocellular carcinoma (HCC) is one of the most common primary malignancies. Drug resistance has significantly prevented the clinical application of sorafenib (SF), a first‐line targeted medicine for the treatment of HCC. Solamargine (SM), a natural alkaloid, has shown potential antitumor activity, but studies about antitumor effect of SM are obviously insufficient in HCC. In the present study, we found that SM significantly inhibited the growth of HCC and enhanced the anticancer effect of SF. In brief, SM significantly inhibited the growth of HepG2 and Huh‐7 cells. The combination of SM and SF showed a synergistic antitumor effect. Mechanistically, SM downregulated the expression of long noncoding RNA HOTTIP and TUG1, followed by increasing the expression of miR‐4726‐5p. Moreover, miR‐4726‐5p directly bound to the 3′‐UTR region of MUC1 and decreased the expression of MUC1 protein. Overexpression of MUC1 partially reversed the inhibitory effect of SM on HepG2 and Huh‐7 cells viability, which suggested that MUC1 may be the key target in SM‐induced growth inhibition of HCC. More importantly, the combination of SM and SF synergistically restrained the expression of MUC1 protein. Taken together, our study revealed that SM inhibited the growth of HCC and enhanced the anticancer effect of SF through HOTTIP‐TUG1/miR‐4726‐5p/MUC1 signaling pathway. These findings will provide potential therapeutic targets and strategies for the treatment of HCC.

A Programmed Cell-Mimicking Nanoparticle Driven by Potato Alkaloid for Targeted Cancer Chemoimmunotherapy

Membrane camouflaged-nanoparticles (CM-NPs) have been exploited to inherit desired functionalities from source cells. Despite those advantages, membrane cloak may play a "double-edged sword" role in tumor-targeting therapy, as the intact membrane coating may hinder function-exertion of loaded drugs after reaching predetermined site. Therefore, further optimization of CM-NPs is still needed to enhance their delivery efficiency. Herein, natural product, Solamargine (SM), a cholesterol-affiliative amphiphilic potato alkaloid is first applied as core component of "inner core," to design a cell-mimicking "core-shell" nanoparticle (RBC-SLip) with acid-responsive off-coating properties for tumor-targeted therapy. Owing to red blood cell membrane (RBCm)-derived outer coating, it circulates stably in physiological conditions. While it would undergo an off-coating morphological change in response to acid stimuli in tumor microenvironment (TME), afterwards, the resulting off-coating liposome (SLip) shows active tumor-targeting and endosomal escape abilities, thus contributing to superior antitumor efficacy. In addition, SM also possesses natural TME-modulating ability; therefore, RBC-SLip can synergize with the PD1/PD-L1 blockade immunotherapy when encapsulated with PTX to achieve enhanced chemoimmunotherapy. The off-coating strategy developed by natural products SM, provide a brand-new perspective to optimize CM-NPs, and it also embodies application value of "unification of medicines and excipients" of natural products.

Effects of Solanum undatum extract (SR-T100) on photocarcinogenesis and photoaging of actinic keratosis

SR-T100 gel, containing solamargine extracted from Solanum undatum (synonym: Solanum incanum), had good therapeutic effects on actinic keratosis (AK) in human and ultraviolet B-induced papilloma in mice. This study aimed to investigate the immunohistochemical changes in the human skin after SR-T100 treatment. An immunohistochemical study was performed and the changes in photocarcinogenesis and photoaging markers after 16-week SR-T100 gel treatment were documented. SR-T100 gel treatment for 16 weeks resulted in complete remission in nine AK lesions and partial remission in four AK lesions. SR-T100 gel abolished the expression of mutant p53 and SOX2 and restored the expression of NOTCH1. Additionally, SR-T100 gel improved wrinkling in human skin, while restoring the expression of lamin B1 and increasing synthesis of new elastic fibers. SR-T100 gel had therapeutic effects on photocarcinogenesis and photoaging of photodamaged skin with AK.

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.

Novel reciprocal interaction of lncRNA HOTAIR and miR-214-3p contribute to the solamargine-inhibited PDPK1 gene expression in human lung cancer

Solamargine (SM) has been shown to have anti‐cancer properties. However, the underlying mechanism involved remains undetermined. We showed that SM inhibited the growth of non‐small cell lung cancer (NSCLC) cells, which was enhanced in cells with silencing of long non‐coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR), while it overcame by overexpression of HOTAIR. In addition, SM increased the expression of miR‐214‐3p and inhibited 3‐phosphoinositide‐dependent protein kinase‐1 (PDPK1) gene expression, which was strengthened by miR‐214‐3p mimics. Intriguingly, HOTAIR could directly bind to miR‐214‐3p and sequestered miR‐214‐3p from the target gene PDPK1. Intriguingly, overexpression of PDPK1 overcame the effects of SM on miR‐214‐3p expressions and neutralized the SM‐inhibited cell growth. Similar results were observed in vivo. In summary, our results showed that SM‐inhibited NSCLC cell growth through the reciprocal interaction between HOTAIR and miR‐214‐3p, which ultimately suppressed PDPK1 gene expression. HOTAIR effectively acted as a competing endogenous RNA (ceRNA) to stimulate the expression of target gene PDPK1. These complex interactions and feedback mechanisms contribute to the overall effect of SM. This unveils a novel molecular mechanism underlying the anti‐cancer effect of SM in human lung cancer.

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.

A Complete Survey of Glycoalkaloids Using LC-FTICR-MS and IRMPD in a Commercial Variety and a Local Landrace of Eggplant (Solanum melongena L.) and their Anticholinesterase and Antioxidant Activities

Eggplant contains glycoalkaloids (GAs), a class of nitrogen-containing secondary metabolites of great structural variety that may have both adverse and beneficial biological effects. In this study, we performed a complete survey of GAs and their malonylated form, in two genotypes of eggplants: A commercial cultivated type, Mirabella (Mir), with purple peel and bitter taste and a local landrace, named Melanzana Bianca di Senise (Sen), characterized by white peel with purple strip and a typical sweet aroma. Besides the analysis of their morphological traits, nineteen glycoalkaloids were tentatively identified in eggplant berry extracts based upon LC-ESI-FTICR-MS analysis using retention times, elution orders, high-resolution mass spectra, as well as high-resolution fragmentation by IRMPD. The relative signal intensities (i.e., ion counts) of the GAs identified in Mir and Sen pulp extracts showed as solamargine, and its isomers are the most abundant. In addition, anticholinesterase and antioxidant activities of the extracts were evaluated. Pulp tissue was found to be more active in inhibiting acetylcholinesterase enzyme than peel showing an inhibitory effect higher than 20% for Mir pulp. The identification of new malonylated GAs in eggplant is proposed.

Comparative Molluscicidal and Schistosomicidal Potentiality of Two Solanum Species and Its Isolated Glycoalkaloids

Schistosomiasis is the most noteworthy parasitic disease after malaria. Furthermore, the significant activity of the genus Solanum against Schistosoma worms and its intermediate host snails reinforced the study of Solanum seaforthianum Andr. (SS) and Solanum macrocarpon L. (SM) for their molluscicidal and schistosomicidal potentiality. In this study, different extracts, fractions and isolated compounds of both Solanum species are evaluated for the molluscicidal and schistosomicidal potentialities. The niclosamide was used as positive molluscicide control against Biomphalaria alexandrina snails. Different extracts, fractions, or isolated compounds were used at a concentration of 100 μg/ml and dead snails were counted in each case. On the other hand, washed and sterilized Schistosoma mansoni adult worms were used in three replicates, and three worm pairs were placed in each well with 2 ml test solution of 100 μg/ml concentration. Positive (praziquantel [PZQ] 0.2 ug/ml) and negative controls were concurrently used and examined daily for 3 days for viability. The mortality rate was calculated and then both LC₅₀ and LC₉₀ were determined in triplicates. Highest potency was indicated to total glycoalkaloid (TGA) fraction of SM followed by TGA of SS. On the other hand, TGA fractions of both species showed higher potency than other extracts and isolated compounds. Meanwhile, solasodine-free aglycone showed declined activity compared to its glycosides. Promising molluscicidal and schistosomicidal activities were displayed which are attributed to the glycoalkaloid content. Therefore, this study can efficiently contribute toward validation of the traditional use of SS and SM in schistosomiasis control.

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.

Solanum incanum extract (SR-T100) induces melanoma cell apoptosis and inhibits established lung metastasis

Melanoma, a cancer derived from melanocytes, is one of the most chemoresistant cancers and tends to metastasize. Once it metastasizes, the prognosis is poor. Even with the recent advancement of targeted therapy and immunotherapy, the prognosis remains discouraging. SR-T100, a Solanum incanum extract, shows anticancer effects against several cancers; however, its therapeutic efficacy against melanoma and established metastasis remains unknown. In this study, we showed that SR-T100 induces apoptosis, DNA damage, and G0/G1 cell cycle arrest in murine B16 melanoma cells in vitro. In vivo, intralesional injection of SR-T100 decreased the tumor size of the regional melanoma in the foot pad. Moreover, intraperitoneal injection of SR-T100 inhibited the growth and the number of established melanoma metastases in the lungs. Our study highlights SR-T100 as a potential novel treatment for established tumors from regional and metastatic melanoma.

Solamargine inhibits the migration and invasion of HepG2 cells by blocking epithelial-to-mesenchymal transition

Solamargine (SM), a steroidal alkaloid glycoside purified from the Chinese traditional herb Solanum incanum, is known to possess various biological activities. However, only a few previous studies have reported the anti-metastatic activity of SM. In the present study, the inhibitory effects of SM on metastatic action were investigated in human HepG2 cells. The proliferation effects of SM on the HepG2 cells was evaluated by MTT and colony formation assays. Wound-healing and Transwell assays were performed to examine the migration and invasion effects on SM-treated HepG2 cells. The epithelial-to-mesenchymal transition (EMT)-associated markers (E-cadherin, Vimentin and N-cadherin) were detected by western blotting analysis. In the present study, MTT and colony formation assays indicated that SM suppressed HepG2 cell viability in a dose-dependent manner. The wound-healing and Transwell assays revealed that the migration and invasion activities were significantly inhibited following exposure to SM. EMT has been demonstrated to be essential for promoting migration and invasion in tumor cells and has often been characterized with a loss of epithelial markers (E-cadherin) and an increase of mesenchymal markers (Vimentin and N-cadherin). In the western blotting analysis, the expression level of E-cadherin was significantly upregulated compared with that in the control group, whereas the expression levels of N-cadherin and Vimentin were downregulated. Thus, it was suggested that the underlying mechanism of SM inhibits migration and invasion in HepG2 cells and is associated with suppression of EMT.

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.

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.

Effects of the extract and glycoalkaloids of Solanum lycocarpum St. Hill on Giardia lamblia trophozoites

Background:

Solanum lycocarpum has great importance for food and medicinal traditional use. Recently, it was also evidenced that extracts of S. lycocarpum St. Hill (Solanaceae) and its glycoalkaloids, solamargine (Sg) and solasonine (Sn), are active against flagellated protozoa.

Objective:

The aim was to assess the effects of the extract of S. lycocarpum and its glycoalkaloids, Sn, and Sg, on Giardia lamblia trophozoites.

Materials and Methods:

A crude extract (96%ethanol) (EB) of fruits of S. lycocarpum was prepared and fractionated by partition with 40%ethanol and n-hexane: Ethyl acetate. Glycoalkaloids, Sn, and Sg were recognized in the ethanol fraction (EF) and further isolated by column chromatography. EB, EF, the isolated Sn and Sg and a mixture (1:1) of both glycoalkaloids were tested on cultures of G. lamblia trophozoites and macrophages.

Results:

EB, EF and glycoalkaloids of S. lycocarpum showed activity against Giardia (95.0 < Inhibitory concentration 50 [IC₅₀] ≤120.3 μg/mL). The mixture of glycoalkaloids (1:1) was more active (IC₅₀ = 13.23 μg/mL) than each one individually, suggesting a synergic effect. Moreover, the mixture is nontoxic to macrophage cells.

Conclusion:

Results are optimistic concerning the anti-Giardia potential of the mixture Sn + Sg. Further studies, in vitro and in vivo, will be required to consolidate the usefulness of the mixture of Sn + Sg in view of a new therapeutic strategy for giardiasis.

Solamargine triggers hepatoma cell death through apoptosis

Solamargine (SM), a steroidal alkaloid glycoside extracted from the traditional Chinese herb Solanum incanum, has been evidenced to inhibit the growth and induce apoptosis in a number of human cancer cell lines. In the present study, the anticancer effect of SM and underlying molecular mechanism of SM-induced apoptosis were investigated on the human hepatocellular carcinoma cells, SMMC7721 and HepG2. The proliferation effects of SM on the SMMC7721 and HepG2 cell lines were evaluated using MTT and colony formation assays. In addition, the percentage of apoptosis was measured using an Annexin V/propidium iodide staining method and the cell cycle distribution mediated by SM was analyzed using flow cytometry. The expression levels of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase-3, caspase-9, proliferating cell nuclear antigen (pcna) and Ki67 proteins were examined to further demonstrate the proliferate and apoptosis effects of SM on the hepatoma cells. The results indicated that SM effectively inhibited hepatoma cell proliferation and promoted apoptosis. SM resulted in cell cycle arrest at the G₂/M phase in the two cell lines. In addition, SM downregulated the levels of proliferation-associated (Ki67 and pcna) and anti-apoptotic (Bcl-2) proteins, and promoted the activity of apoptosis-associated proteins (Bax, caspase-3 and caspase-9). Therefore, the activation of the Bcl-2/Bax and caspase signaling pathways may be involved in the SM-induced apoptosis of hepatoma cells.