Therapeutic Role of Alkaloids and Alkaloid Derivatives in Cancer Management

Caulerpin alleviates cyclophosphamide-induced ovarian toxicity by modulating macrophage-associated granulosa cell senescence during breast cancer chemotherapy

For fertility preservation, preventing chemotherapy-induced premature ovarian insufficiency (POI) in patients with breast cancer is challenging. Our previous study suggested that caulerpin, a marine indole alkaloid, exerts antitumor effects on breast cancer cells. However, the potential effects of caulerpin on ovarian tissues remain unknown. In the present study, xenograft tumors derived from the MDA-MB-231 breast cancer cell line were established in a female BALB/c nude mouse model. Cyclophosphamide (CTX) alone caused remarkable ovarian damage, including irregular estrous cycles, follicle loss, and reduced expression of anti-Mullerian hormone (AMH) and follicle-stimulating hormone receptor (FSHR), whereas ovarian toxicity was largely reduced after caulerpin treatment in mice and in vitro. The gene signature of the ovaries of CTX-treated tumor-bearing mice revealed differentially expressed genes (DEGs) that regulate two important processes, namely, macrophage polarization and cellular senescence, as well as the activation of the p53/NF-κB signaling pathway. In vitro, CTX induced M1 macrophage polarization in THP-1 cells, which was accompanied by activation of the p53/NF-κB signaling pathway. Additionally, senescence was upregulated in the ovaries of CTX-treated tumor-bearing mice and in granulosa cells (GCs) cocultured with THP-1 cells exposed to LPS/IFN-γ, characterized by increased activity of senescence-associated β-galactosidase (SAβG), increased ROS levels and elevated levels of senescence-related markers (p53, p21 and p38MAPK). Furthermore, caulerpin or a p53 inhibitor (pifithrin-α) modulated CTX-induced M1 polarization in macrophages, thereby delaying GC senescence. These findings demonstrated that caulerpin contributes to alleviating CTX-induced ovarian toxicity by modulating M1 macrophage polarization through the p53/NF-κB signaling pathway, which promotes the senescence of GCs by inducing ROS production.Thus, caulerpin may be a potential therapeutic strategy for breast cancer patients.

Research Progress of Chinese Medicine Monomers in Treatment of Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a malignant tumor originating from cholangiocytes. However, it remains unclear about the pathogenesis of this carcinoma, which may be related to multiple factors. Currently, CCA is mainly treated by surgery, chemotherapy, and radiotherapy. Among them, surgery is the only potentially curative option for CCA. Nevertheless, the high malignancy and asymptomatic nature of CCA may lead to poor treatment outcomes. It has been demonstrated that Chinese medicine (CM) plays a significant role in various antitumor applications. Meanwhile, CM exhibits fewer side effects and high availability. Moreover, the in vitro application of CM monomers has been explored in many domestic and foreign studies. This article mainly reviews the signaling pathways and molecular mechanisms of CM monomers in the treatment of CCA in recent years. These findings are expected to provide new insights into the treatment of CCA.

Yes-associated protein indispensably mediates hirsutine-induced inhibition on cell growth and Wnt/β-catenin signaling in colorectal cancer

BACKGROUND AND PURPOSE

Targeting Wnt/β-catenin signaling emerges as one of the promising strategies for colorectal cancer (CRC) treatment, as this signaling is highly activated in CRC progression. Despite reports on the cytotoxic effects of hirsutine (HT), an indole alkaloid found in herbal medicines from the genus Uncaria, its therapeutic potential for CRC and the involved mechanisms are poorly understood. This study investigates the anticancer efficacy and the probable mechanisms of HT against CRC.

METHODS

To evaluate in vitro anticancer activity of HT, cell growth examined by MTT and colony formation assay, and apoptosis examined by flow cytometry were analyzed. To explore the mechanisms, RNA-sequencing, western blotting, dual-luciferase reporter assays, immunofluorescence, and co-immunoprecipitation were performed. Mouse model of azoxymethane/dextran sodium sulfate (AOM/DSS)-induced colon cancer was utilized to assess HT's in vivo anticancer efficacy.

RESULTS

HT significantly inhibited CRC cell proliferation with IC50 values of 22.25 ± 3.27 μM for SW620 cells and 22.24 ± 2.36 μM for HCT116 cells, and induced apoptosis. HT decreased protein levels of Wnt3a and β-catenin dose- and time-dependently, and inhibited TOP/FOP FLASH reporter activity, nuclear travel of β-catenin, and downstream targets like c-Myc, Cyclin D1, VEGF. HT reduced β-catenin protein half-life, and the reversal of this effect by MG132 indicated that HT facilitated proteasome-dependent degradation of β-catenin in these two cell lines. HT also increased β-catenin ubiquitination without affecting Axin and β-TrCP levels. HT treatment for 24 h induced YAP cytoplasmic retention, enhanced YAP interacting with β-catenin and β-TrCP, triggering destruction complex formation and β-catenin ubiquitination and degradation, while YAP siRNA impaired these effects. Additionally, β-catenin overexpression and LiCl treatment counteracted HT-induced inhibition on cell growth and Wnt/β-catenin cascade. In model of AOM/DSS-induced mouse colon cancer, compared with AOM/DSS treatment group, HT recovered colon length, reduced tumor numbers and radius, and downregulated β-catenin and Ki-67, while upregulated cleaved PARP in the colorectal tissue with tumors.

CONCLUSION

HT exhibits anticancer activity against CRC probably by inhibiting Wnt/β-catenin signaling, with YAP playing an indispensible role during the process, highlighting HT as a potential novel candidate drug for CRC therapy.

Stephania tetrandra and Its Active Compound Coclaurine Sensitize NSCLC Cells to Cisplatin through EFHD2 Inhibition

BACKGROUND

Adjuvant chemotherapy, particularly cisplatin, is recommended for non-small cell lung carcinoma (NSCLC) patients at high risk of recurrence. EF-hand domain-containing protein D2 (EFHD2) has been recently shown to increase cisplatin resistance and is significantly associated with recurrence in early-stage NSCLC patients. Natural products, commonly used as phytonutrients, are also recognized for their potential as pharmaceutical anticancer agents.

RESULT

In this study, a range of Chinese herbs known for their antitumor or chemotherapy-enhancing properties were evaluated for their ability to inhibit EFHD2 expression in NSCLC cells. Among the herbs tested, Stephania tetrandra (S. tetrandra) exhibited the highest efficacy in inhibiting EFHD2 and sensitizing cells to cisplatin. Through LC-MS identification and functional assays, coclaurine was identified as a key molecule in S. tetrandra responsible for EFHD2 inhibition. Coclaurine not only downregulated EFHD2-related NOX4-ABCC1 signaling and enhanced cisplatin sensitivity, but also suppressed the stemness and metastatic properties of NSCLC cells. Mechanistically, coclaurine disrupted the interaction between the transcription factor FOXG1 and the EFHD2 promoter, leading to a reduction in EFHD2 transcription. Silencing FOXG1 further inhibited EFHD2 expression and sensitized NSCLC cells to cisplatin.

CONCLUSIONS

S. tetrandra and its active compound coclaurine may serve as effective adjuvant therapies to improve cisplatin efficacy in the treatment of NSCLC.

High-throughput screening of the natural STK11 agonist dauricine: A biphenylisoquinoline alkaloid exerting anti-NSCLC effects and reversing gefitinib resistance

BACKGROUND

Serine/threonine kinase 11 (STK11) deletion and downregulation caused cancer progression, and were widely associated with drug resistance. Accurate screening of natural small molecules about anti-cancer and anti-drug resistance is the key to the development and utilization of natural product application, which could promote traditional Chinese medicine in the treatment of cancer. Dauricine, which is derived from the rhizome of Menispermum dauricum DC., has certain potential but unexplored mechanism for the treatment of cancer.

PURPOSE

The aim of this study was to screen and validate the role and mechanism of natural STK11 agonists with anti-drug resistance from plants in the treatment of NSCLC.

METHODS

A lentiviral STK11 overexpression cell model was employed for the screening of natural STK11 agonists. The efficacy of dauricine in the treatment of NSCLC was validated on PC-9 and HCC827 cells. In vivo validation of dauricine activity was performed using nude mouse models equipped with PC9 xenografts. To investigate the anti-resistant effects of dauricine, gefitinib-resistant PC9 cell models were constructed.

RESULTS

As a natural agonist of STK11, it causes the activation of the STK11/AMPK pathway and inhibits the growth of PC-9 cells. Dauricine synergises the inhibitory effect with gefitinib on PC9. The up-regulation of STK11 protein expression by dauricine was demonstrated in vitro and in vivo, while restoring the sensitivity of PC9/GR to gefitinib by down-regulating the protein expression of Nrf2 and Pgp.

CONCLUSION

Dauricine, a natural agonist of STK11, effectively inhibited NSCLC, and its combination treatment with gefitinib reversed drug-resistant NSCLC.

Review on effects and mechanisms of plant-derived natural products against breast cancer bone metastasis

Bone metastasis is the prevalent form of metastasis in breast cancer, resulting in severe pain, pathological fractures, nerve compression, hypercalcemia, and other complications that significantly impair patients' quality of life. The infiltration and colonization of breast cancer (BC) cells in bone tissue disrupt the delicate balance between osteoblasts and osteoclasts within the bone microenvironment, initiating a vicious cycle of bone metastasis. Once bone metastasis occurs, conventional medical therapy with bone-modifying agents is commonly used to alleviate bone-related complications and improve patients' quality of life. However, the utilization of bone-modifying agents may cause severe drug-related adverse effects. Plant-derived natural products such as terpenoids, alkaloids, coumarins, and phenols have anti-tumor, anti-inflammatory, and anti-angiogenic pharmacological properties with minimal side effects. Certain natural products that exhibit both anti-breast cancer and anti-bone metastasis effects are potential therapeutic agents for breast cancer bone metastasis (BCBM). This article reviewed the effects of plant-derived natural products against BCBM and their mechanisms to provide a reference for the research and development of drugs related to BCBM.

Alkaloids in Cancer therapy: Targeting the tumor microenvironment and metastasis signaling pathways

The use of phytomedicine in cancer therapy is a growing field of research that takes use of the medicinal properties of plant-derived compounds. Under the domain of cancer therapy and management, alkaloids, a prominent group of natural compounds, have showed significant potential. Alkaloids often affect a wide range of essential cellular mechanisms involved in cancer progression. These multi-targeting capabilities, can give significant advantages to alkaloids in overcoming resistance mechanisms. For example, berberine, an alkaloid found in Berberis species, is widely reported to induce apoptosis by activating caspases and regulating apoptotic pathways. Notably, alkaloids like as quinine have showed promise in inhibiting the formation of new blood vessels required for tumor growth. In addition, alkaloids have shown anti-proliferative and anticancer properties mostly via modulating key signaling pathways involved in metastasis, including those regulating epithelial-mesenchymal transition. This work provides a comprehensive overview of naturally occurring alkaloids that exhibit anticancer properties, with a specific emphasis on their underlying molecular mechanisms of action. Furthermore, many methods to modify previously reported difficult physicochemical properties using nanocarriers in order to enhance its systemic bioavailability have been discussed as well. This study also includes information on newly discovered alkaloids that are now being studied in clinical trials for their potential use in cancer treatment. Further, we have also briefly mentioned on the application of high-throughput screening and molecular dynamics simulation for acceleration on the identification of potent alkaloids based compounds to target and treat cancer.

[Sanguinarine induces ferroptosis of colorectal cancer cells by upregulating STUB1 and downregulating GPX4]

OBJECTIVE

To investigate the effect of sanguinarine (SAN) on proliferation and ferroptosis of colorectal cancer cells.

METHODS

SW620 and HCT-116 cells treated with different concentrations of SAN were examined for cell viability changes using CCK8 assay to determine the IC50 of SAN in the two cells. The inhibitory effects of SAN on proliferation, invasion and migration of the cells were evaluated using colony-forming assay and Transwell assays. ROS production in the treated cells was analyzed with flow cytometry, and lipid peroxide production was assessed by detecting malondialdehyde (MDA) level. Glutathione (GSH) levels in the cells were detected, and Western blotting was used to detect the expressions of ferroptosis-related proteins STUB1 and GPX4.

RESULTS

SAN significantly inhibited the proliferation, invasion and migration of SW620 and HCT-116 cells. SAN treatment significantly promoted ROS production, increased intracellular MDA level, and lowered GSH level in the two cells (P<0.05). Western blotting showed that SAN significantly upregulated the expression of STUB1 and down-regulated the expression of its downstream protein GPX4 (P<0.05).

CONCLUSION

SAN induces ferroptosis in colorectal cancer cells by regulating STUB1/GPX4, which may serve as a new therapeutic target for colorectal cancer.

Colchicine-mediated selective autophagic degradation of HBV core proteins inhibits HBV replication and HBV-related hepatocellular carcinoma progression

The HBV core protein (HBc) is an important viral protein of HBV that plays an indispensable role in the lifecycle of HBV, including capsid assembly and transport, reverse transcription and virus release. In recent years, evidence has shown that HBc may be involved in the malignant progression of HCC. Thus, HBc is an attractive target for antiviral agents and provides a new strategy for the treatment of HBV-related HCC. Here, we identified a novel anti-HBc compound-colchicine, an alkaloid compound-that promoted selective autophagic degradation of HBc through the AMPK/mTOR/ULK1 signalling pathway. We further confirmed that colchicine promoted the selective autophagy of HBc by enhancing the binding of HBc to the autophagy receptor p62. Finally, we evaluated the effects of colchicine on HBV replication and HBc-mediated HCC metastasis in vitro and in vivo. Our research indicated that the inhibitory effects of colchicine on HBV and HBV-related HCC depend on the selective autophagic degradation of HBc. Thus, colchicine is not only a promising therapeutic strategy for chronic hepatitis B but also a new treatment for HBV-related HCC.

The Emerging Role of Natural Products in Cancer Treatment

The exploration of natural products as potential agents for cancer treatment has garnered significant attention in recent years. In this comprehensive review, we delve into the diverse array of natural compounds, including alkaloids, carbohydrates, flavonoids, lignans, polyketides, saponins, tannins, and terpenoids, highlighting their emerging roles in cancer therapy. These compounds, derived from various botanical sources, exhibit a wide range of mechanisms of action, targeting critical pathways involved in cancer progression such as cell proliferation, apoptosis, angiogenesis, and metastasis. Through a meticulous examination of preclinical and clinical studies, we provide insights into the therapeutic potential of these natural products across different cancer types. Furthermore, we discuss the advantages and challenges associated with their use in cancer treatment, emphasizing the need for further research to optimize their efficacy, pharmacokinetics, and delivery methods. Overall, this review underscores the importance of natural products in advancing cancer therapeutics and paves the way for future investigations into their clinical applications.

Prospects of compounds of herbal plants as anticancer agents: a comprehensive review from molecular pathways

Cancer refers to the proliferation and multiplication of aberrant cells inside the human body, characterized by their capacity to proliferate and infiltrate various anatomical regions. Numerous biochemical pathways and signaling molecules have an impact on the cancer auto biogenesis process. The regulation of crucial cellular processes necessary for cell survival and proliferation, which are triggered by phytochemicals, is significantly influenced by signaling pathways. These pathways or components are regulated by phytochemicals. Medicinal plants are a significant reservoir of diverse anticancer medications employed in chemotherapy. The anticancer effects of phytochemicals are mediated by several methods, including induction of apoptosis, cessation of the cell cycle, inhibition of kinases, and prevention of carcinogenic substances. This paper analyzes the phytochemistry of seven prominent plant constituents, namely, alkaloids, tannins, flavonoids, phenols, steroids, terpenoids, and saponins, focusing on the involvement of the MAPK/ERK pathway, TNF signaling, death receptors, p53, p38, and actin dynamics. Hence, this review has examined a range of phytochemicals, encompassing their structural characteristics and potential anticancer mechanisms. It has underscored the significance of plant-derived bioactive compounds in the prevention of cancer, utilizing diverse molecular pathways. In addition, this endeavor also seeks to incentivize scientists to carry out clinical trials on anticancer medications derived from plants.

Natural 3,4-Dihydro-2(1H)-quinolinones - part III: biological activities

Natural products have played a crucial role in drug discovery, but their development is hindered by challenges such as inadequate availability and complex synthesis methods. However, both natural and synthetic compounds that have the core structure of 3,4-dihydro-2(1H)-quinolinone, also known as 2-oxo-1,2,3,4-tetrahydroquinoline (2O-THQ), display a diverse array of effects in both central and peripheral tissues, with some showing therapeutic potential in treating various disorders. Despite the significance of this family of compounds, the current literature lacks comprehensive coverage of their biological functions. This article aims to address this gap by extensively reviewing the biological activities of 2O-THQ alkaloids from diverse organisms and exploring their potential to serve as a source of innovative bioactive natural products.

Promising Role of Alkaloids in the Prevention and Treatment of Thyroid Cancer and Autoimmune Thyroid Disease: A Comprehensive Review of the Current Evidence

Thyroid cancer (TC) and thyroid autoimmune disorders (AITD) are among the most common diseases in the general population, with higher incidence in women. Chronic inflammation and autoimmunity play a pivotal role in carcinogenesis. Some studies, indeed, have pointed out the presence of AITD as a risk factor for TC, although this issue remains controversial. Prevention of autoimmune disease and cancer is the ultimate goal for clinicians and scientists, but it is not always feasible. Thus, new treatments, that overcome the current barriers to prevention and treatment of TC and AITD are needed. Alkaloids are secondary plant metabolites endowed with several biological activities including anticancer and immunomodulatory properties. In this perspective, alkaloids may represent a promising source of prophylactic and therapeutic agents for TC and AITD. This review encompasses the current published literature on alkaloids effects on TC and AITD, with a specific focus on the pathways involved in TC and AITD development and progression.

Novel C3-Methylene-Bridged Indole Derivatives with and without Substituents at N1: The Influence of Substituents on Their Hemolytic, Cytoprotective, and Antimicrobial Activity

Alkaloids are natural compounds useful as scaffolds for discovering new bioactive molecules. This study utilized alkaloid gramine to synthesize two groups of C3-substituted indole derivatives, which were either functionalized at N1 or not. The compounds were characterized by spectroscopic methods. The protective effects of the new compounds against in vitro oxidative hemolysis induced by standard oxidant 2,2'-azobis(2-amidinopropane dihydro chloride (AAPH) on human erythrocytes as a cell model were investigated. Additionally, the compounds were screened for antimicrobial activity. The results indicated that most of the indole derivatives devoid of the N1 substitution exhibited strong cytoprotective properties. The docking studies supported the affinities of selected indole-based ligands as potential antioxidants. Furthermore, the derivatives obtained exhibited potent fungicidal properties. The structures of the eight derivatives possessing indole moiety bridged to the imidazole-, benzimidazole-, thiazole-, benzothiazole-, and 5-methylbenzothiazoline-2-thiones were determined by X-ray diffraction. The C=S bond lengths in the thioamide fragment pointed to the involvement of zwitterionic structures of varying contribution. The predominance of zwitterionic mesomers may explain the lack of cytoprotective properties, while steric effects, which limit multiple the hydrogen-bond acceptor properties of a thione sulfur, seem to be responsible for the high hemolytic activity.

Aptamers for the Delivery of Plant-Based Compounds: A Review

Natural compounds have a high potential for the treatment of various conditions, including infections, inflammatory diseases, and cancer. However, they usually present poor pharmacokinetics, low specificity, and even toxicity, which limits their use. Therefore, targeted drug delivery systems, typically composed of a carrier and a targeting ligand, can enhance natural product selectivity and effectiveness. Notably, aptamers-short RNA or single-stranded DNA molecules-have gained attention as promising ligands in targeted drug delivery since they are simple to synthesize and modify, and they present high tissue permeability, stability, and a wide array of available targets. The combination of natural products, namely plant-based compounds, with a drug delivery system utilizing aptamers as targeting agents represents an emerging strategy that has the potential to broaden its applications. This review discusses the potential of aptamers as targeting agents in the delivery of natural compounds, as well as new trends and developments in their utilization in the field of medicine.

A toxicological review of alkaloids

Alkaloids are naturally occurring compounds with complex structures found in natural plants. To further improve the understanding of plant alkaloids, this review focuses on the classification, toxicity and mechanisms of action, providing insight into the occurrence of alkaloid-poisoning events and guiding the safe use of alkaloids in food, supplements and clinical applications. Based on their chemical structure, alkaloids can be divided into organic amines, diterpenoids, pyridines, isoquinolines, indoles, pyrrolidines, steroids, imidazoles and purines. The mechanisms of toxicity of alkaloids, including neurotoxicity, hepatoxicity, nephrotoxicity, cardiotoxicity and cytotoxicity, have also been reviewed. Some cases of alkaloid poisoning have been introduced when used as food or clinically, including accidental food poisoning, excessive consumption, and poisoning caused by the improper use of alkaloids in a clinical setting, and the importance of safety evaluation was illustrated. This review summarizes the toxicity and mechanism of action of alkaloids and provides evidence for the need for the safe use of alkaloids in food, supplements and clinical applications.

Molecular mechanism of miRNA mediated biosynthesis of secondary metabolites in medicinal plants

Plant secondary metabolites are important raw materials for the pharmaceutical industry, and their biosynthetic processes are subject to diverse and precise regulation by miRNA. The identification of miRNA molecules in medicinal plants and exploration of their mechanisms not only contribute to a deeper understanding of the molecular genetic mechanisms of plant growth, development and resistance to stress, but also provide a theoretical basis for elucidating the pharmacological effects of authentic medicinal materials and constructing bioreactors for the synthesis of medicinal secondary metabolite components. This paper summarizes the research reports on the discovery of miRNA in medicinal plants and their regulatory mechanisms on the synthesis of secondary metabolites by searching the relevant literature in public databases. It summarizes the currently discovered miRNA and their functions in medicinal plants, and summarizes the molecular mechanisms regulating the synthesis and degradation of secondary metabolites. Furthermore, it provides a prospect for the research and development of medicinal plant miRNA. The compiled information contributes to a comprehensive understanding of the research progress on miRNA in medicinal plants and provides a reference for the industrial development of related secondary metabolite biosynthesis.

Investigation of steric hindrance effect on the interactions between four alkaloids and HSA by isothermal titration calorimetry and molecular docking

The binding of four alkaloids with human serum albumin (HSA) was investigated by isothermal titration calorimetry (ITC), spectroscopy and molecular docking techniques. The findings demonstrated that theophylline or caffeine can bind to HAS, respectively. The number of binding sites and binding constants are obtained. The binding mode is a static quenching process. The effects of steric hindrance, temperature, salt concentration and buffer solution on the binding indicated that theophylline and HSA have higher binding affinity than caffeine. The fluorescence and ITC results showed that the interaction between HSA and theophylline or caffeine is an entropy-driven spontaneous exothermic process. The hydrophobic force was the primary driving factor. The experimental results were consistent with the molecular docking data. Based on the molecular structures of the four alkaloids, steric hindrance might be a major factor in the binding between HSA and these four alkaloids. This study elucidates the mechanism of interactions between four alkaloids and HSA.

Natural Products Derived from Marine Sponges with Antitumor Potential against Lung Cancer: A Systematic Review

Non-small-cell lung cancer (NSCLC), the most commonly diagnosed cancer and the leading cause of cancer-related death worldwide, has been extensively investigated in the last decade in terms of developing new therapeutic options that increase patient survival. In this context, marine animals are a source of new, interesting bioactive molecules that have been applied to the treatment of different types of cancer. Many efforts have been made to search for new therapeutic strategies to improve the prognosis of lung cancer patients, including new bioactive compounds and cytotoxic drugs from marine sponges. Their antitumoral effect can be explained by several cellular and molecular mechanisms, such as modulation of the cell cycle or induction of apoptosis. Thus, this systematic review aims to summarize the bioactive compounds derived from marine sponges and the mechanisms by which they show antitumor effects against lung cancer, exploring their limitations and the challenges associated with their discovery. The search process was performed in three databases (PubMed, SCOPUS, and Web of Science), yielding a total of 105 articles identified in the last 10 years, and after a screening process, 33 articles were included in this systematic review. The results showed that these natural sponge-derived compounds are a valuable source of inspiration for the development of new drugs. However, more research in this field is needed for the translation of these novel compounds to the clinic.

Melinjo Seeds (Gnetum gnemon L.) Antioxidant Activity and Cytotoxic Effects on MCF-7 Breast Cancer Cells: A Study Based on Tracing of Resveratrol Compound

Introduction

Breast cancer is one of the deadliest cancers worldwide. One of the polyphenols, namely, resveratrol, has been proven to have anticancer activity. Melinjo seeds which contain resveratrol need to be tested for their potential as an anti-breast cancer agent. This study aims to determine the antioxidant activity and cytotoxic effect of melinjo seeds based on solvent variations and resveratrol tracing.

Methods

Extraction of melinjo seeds was performed using the soxhletation method. Antioxidant test was performed using the 2,2-diphenyl-1-picrylhydrazil method. The in vitro cytotoxic test was carried out using the microtetrazolium method. Cytotoxic test was carried out on MCF-7 breast cancer cells using a concentration range of melinjo seeds between 31,25 and 1000 μg/mL. Antioxidant and anticancer potentials are expressed in inhibitory concentration (IC)50 values. Resveratrol was traced using preparative high-performance liquid chromatography (Prep-HPLC).

Results

Melinjo seed ethanol extract provided the largest total phenolics (126,154 ± 0,865 mg GAE/g sample) and total flavonoids (44,576 ± 0,611 mg QE/g sample) among all solvent fractions. The antioxidant activity of melinjo seeds from ethanol extract, n-hexane fraction, ethyl acetate fraction, and ethanol fraction was 263,307 ppm, 317,595 ppm, 160,878 ppm, and 181,159 ppm, respectively. The ethyl acetate fraction of melinjo seeds showed the strongest cytotoxic effect (94.6 μg/mL) among all extracts and solvent fractions. Prep-HPLC showed that the ethanol extract of melinjo seeds contained resveratrol, while the ethanol and ethyl acetate fractions of melinjo seeds were thought to contain resveratrol derivatives.

Conclusion

The antioxidant activity of melinjo seeds showed a cytotoxic effect on MCF-7 cells, which varied based on solvent polarity and total phenolic and total flavonoid. The ethyl acetate fraction which is thought to contain resveratrol derivatives provides the most potent antioxidant activity and cytotoxic effect. These results indicate that melinjo seeds containing resveratrol and its derivatives have the potential for anticancer of the breast. Further studies are still needed in determining the structure of resveratrol compounds and their derivatives to ensure their biological activity and mechanism of action.

Piperlongumine induces apoptosis via the MAPK pathway and ERK‑mediated autophagy in human melanoma cells

Piperlongumine (PL) is an amide alkaloid with diverse pharmacological effects against cancer, bronchitis and asthma; however, research on its efficacy against melanoma is lacking. The present study investigated the anticancer effects of PL on A375SM and A375P human melanoma cells. PL decreased the survival rate of A375SM and A375P cells, as shown by MTT assay, increase of apoptotic cells by DAPI staining. And PL induced apoptosis by decreasing the expression of the anti‑apoptotic protein Bcl‑2 and increasing that of the pro‑apoptotic proteins cleaved‑PARP and Bax. PL also induced apoptosis in A375SM and A375P cells via the MAPK pathway, increasing expression of the MAPK pathway proteins, phosphorylated‑(p‑ERK), p‑JNK p‑p38. These proteins were confirmed by western blot. In addition, A375SM and A375P cells treated with PL showed an increased number of acidic vesicular organelles by acridine orange staining. Also, autophagy induced by the expression of 1A/1B‑light chain 3, Beclin 1and mTOR was investigated through western blot. When PL was applied following treatment with autophagy inhibitors 3‑methyladenine and hydroxychloroquine, autophagy exhibited a cytoprotective effect against apoptosis in MTT assay. Pretreatment of A375P cells with the ERK inhibitor PD98059 and the JNK inhibitor SP600125 followed by treatment with PL confirmed that apoptosis and autophagy were mediated via the MAPK/ERK pathway by western blot. In summary, the present study provided empirical evidence supporting the anticancer effects of PL on human melanoma cells and indicated the potential of PL as a treatment for melanoma.

Pyrrolizidine Alkaloids-Pros and Cons for Pharmaceutical and Medical Applications

Heterocyclic organic compounds named pyrrolizidine alkaloids (PAs) belong to a group of alkaloids and are synthesized by either plants or microorganisms. Therefore, they are naturally occurring secondary metabolites. They are found in species applied in the pharmaceutical and food industries, thus a thorough knowledge of their pharmacological properties and toxicology to humans is of great importance for their further safe employment. This review is original because it synthesizes knowledge of plant and microbial PAs, which is unusual in the scientific literature. We have focused on the Boraginaceae family, which is unique due to the exceptional richness and diversity of its PAs in plant species. We have also presented the microbial sources of PAs, both from fungi and bacteria. The structure and metabolism of PAs have been discussed. Our main aim was to summarize the effects of PAs on humans, including both negative, toxic ones, mainly concerning hepatotoxicity and carcinogenicity, as well as potentially positive ones for pharmacological and medical applications. We have collected the results of studies on the anticancer activity of PAs from plant and microbial sources (mainly Streptomyces strains) and on the antimicrobial activity of PAs on different strains of microorganisms (bacteria and fungi). Finally, we have suggested potential applications and future perspectives.

Molecular Hybridization of Alkaloids Using 1,2,3-Triazole-Based Click Chemistry

Alkaloids found in multiple species, known as 'driver species', are more likely to be included in early-stage drug development due to their high biodiversity compared to rare alkaloids. Many synthetic approaches have been employed to hybridize the natural alkaloids in drug development. Click chemistry is a highly efficient and versatile reaction targeting specific areas, making it a valuable tool for creating complex natural products and diverse molecular structures. It has been used to create hybrid alkaloids that address their limitations and serve as potential drugs that mimic natural products. In this review, we highlight the recent advancements made in modifying alkaloids using click chemistry and their potential medicinal applications. We discuss the significance, current trends, and prospects of click chemistry in natural product-based medicine. Furthermore, we have employed computational methods to evaluate the ADMET properties and drug-like qualities of hybrid molecules.