Damnacanthal from the Congolese medicinal plant Garcinia huillensis has a potent preferential cytotoxicity against human pancreatic cancer PANC-1 cells

Potent anticancer activity of (Z)-3-hexenyl-β-D-glucopyranoside in pancreatic cancer cells

This current study reports, for the first time, on the potent cytotoxicity of (Z)-3-hexenyl-β-D-glucopyranoside, as well as its cellular and molecular apoptotic mechanisms against Panc1 cancer cells. The cytotoxicity of three compounds, namely (Z)-3-hexenyl-β-D-glucopyranoside (1), gallic acid (2), and pyrogallol (3), which were isolated from C. rotang leaf, was investigated against certain cancer and normal cells using the MTT assay. The cellular apoptotic activity and Panc1 cell cycle impact of compound (1) were examined through flow cytometry analysis and Annexin V-FITC cellular apoptotic assays. Additionally, RT-PCR was employed to evaluate the effect of compound (1) on the Panc1 apoptotic genes Casp3 and Bax, as well as the antiapoptotic gene Bcl-2. (Z)-3-hexenyl-β-D-glucopyranoside demonstrated the highest cytotoxic activity against Panc1 cancer cells, with an IC50 value of 7.6 µM. In comparison, gallic acid exhibited an IC50 value of 21.8 µM, and pyrogallol showed an IC50 value of 198.2 µM. However, (Z)-3-hexenyl-β-D-glucopyranoside displayed minimal or no significant cytotoxic activity against HepG2 and MCF7 cancer cells as well as WI-38 normal cells, with IC50 values of 45.8 µM, 108.7 µM, and 194. µM, respectively. (Z)-3-hexenyl-β-D-glucopyranoside (10 µM) was demonstrated to induce cellular apoptosis and cell growth arrest at the S phase of the cell cycle in Panc1 cells. These findings were supported by RT-PCR analysis, which revealed the upregulation of apoptotic genes (Casp3 and Bax) and the downregulation of the antiapoptotic gene Bcl-2. This study emphasizes the significant cellular potency of (Z)-3-hexenyl-β-D-glucopyranoside in specifically inducing cytotoxicity in Panc1 cells.

Damnacanthal isolated from morinda species inhibited ovarian cancer cell proliferation and migration through activating autophagy

BACKGROUND

Ovarian cancer is a very common gynecological malignant tumor. Natural products are important sources of chemotherapy drugs for ovarian cancer. Damnacanthal is an anthraquinone derivative with anti-cancer pharmacological properties.

OBJECTIVE

This study aimed to investigate the mechanisms underlying damnacanthal's effects against ovarian cancer.

METHODS

In vitro experiments, CCK8, colony formation and flow cytometry assays were used to evaluate the anti-ovarian cancer effect of damnacanthal on SKVO3 and A2780 cells. The wound healing tests and the transwell invasion assays were used to detect the migration and infiltration of ovarian cancer cells. Western Blot assays and immunofluorescence staining were used to measure autophagy levels. In vivo experiments, the anti-ovarian cancer effect of damnacanthal was further evaluated in a xenograft nude mouse model of SKVO3 cells.

RESULTS

Damnacanthal induced significant cell death and apoptosis, as well as significant inhibition in migration and invasion, in SKVO3 and A2780 cells, Furthermore, damnacanthal induced cell cycle arrest by increasing the protein levels of p27Kip1 and decreasing cyclin D1 levels. In addition, damnacanthal induced a significant accumulation of autophagosomes, accompanied with an increase in LC3II protein levels, and a decrease in p62 protein levels. 3-methyladenine, an autophagy formation inhibitor, significantly mitigated the damnacanthal-induced apoptosis and migration hindrance, as well as the decline in cell viability. Furthermore, the inactivation of ERK and its downstream effector mTOR signaling pathways, rather than Akt or P38 pathway, were involved in damnacanthal's activation in autophagy. In addition, TBHQ, an ERK activator, significantly inhibited damnacanthal-boosted LC3 II levels and autophagosome accumulation, and reversed damnacanthal-induced cell death, apoptosis, cell cycle arrest and migration hindrance. Finally, the anti-ovarian cancer effect of damnacanthal was confirmed in the orthotopic xenograft model of SKVO3 cells in nude mice, with tumor growth being significantly inhibited comparably to the efficacy of cisplatin. Damnacanthal was also synergistic with cisplatin and showed inhibition in cisplatin-resistant ovarian cancer cells.

CONCLUSION

Damnacanthal inhibited the growth of ovarian cancer via the ERK/mTOR/autophagy signaling cascade, indicating that it may be a potential anti-ovarian cancer drug candidate.

Anticancer Potential of Damnacanthal and Nordamnacanthal from Morinda elliptica Roots on T-lymphoblastic Leukemia Cells

Background: This study reports on the cytotoxic properties of nordamnacanthal and damnacanthal, isolated from roots of Morinda elliptica on T-lymphoblastic leukaemia (CEM-SS) cell lines. Methods: MTT assay, DNA fragmentation, ELISA and cell cycle analysis were carried out. Results: Nordamnacanthal and damnacanthal at IC₅₀ values of 1.7 μg/mL and10 μg/mL, respectively. At the molecular level, these compounds caused internucleosomal DNA cleavage producing multiple 180–200 bp fragments that are visible as a “ladder” on the agarose gel. This was due to the activation of the Mg²⁺/Ca²⁺-dependent endonuclease. The induction of apoptosis by nordamnacanthal was different from the one induced by damnacanthal, in a way that it occurs independently of ongoing transcription process. Nevertheless, in both cases, the process of dephosphorylation of protein phosphates 1 and 2A, the ongoing protein synthesis and the elevations of the cytosolic Ca²⁺ concentration were not needed for apoptosis to take place. Nordamnacanthal was found to have a cytotoxic effect by inducing apoptosis, while damnacanthal caused arrest at the G0/G1 phase of the cell cycle. Conclusion: Damnacanthal and nordamnacanthal have anticancer properties, and could act as potential treatment for T-lymphoblastic leukemia.

[Acute and subacute toxicity of Garcinia huillensis Baker, a plant used against urogenital schistosomiasis in Haut-Katanga, DR Congo]

This research evaluated acute and subacute toxicity of aqueous and methanolic extract from stem bark of Garcinia huillensis Baker, a plant used in Congolese traditional medicine against urogenital schistosomiasis. The acute toxicity is evaluated on guinea pigs by single oral administration of 1500, 2000, 2500, 3000 and 3500mg/kg of body weight of extracts based on the method described by protocol 423 of the Organization for Cooperation and Economic Development. Subacute toxicity is assessed after 28 days after daily administration of 4.5, 45, 450 and 1500mg/kg of body weight of extracts. Weight evolution, hematological and biochemical parameters of the guinea pigs that survived were analyzed and compared with those of the controls. Acute oral toxicity data were used to calculate the LD₅₀ of 2717.39 and 2625.00mg/kg bw for the aqueous and methanolic extract, respectively. Some signs of intoxication were noted, and certain haematological and biochemical parameters analyzed in the treated guinea pigs sometimes presented statistically significant differences compared to those of the controls. The minimum tolerated dose (1652.17mg/kg bw) found for the aqueous extract is far greater than the therapeutic dose administered by traditional therapists (4.5mg). Thus, the study shows that the stem bark of G. huillensis would be moderately toxic and would present a good margin of safety under the conditions of our experimentation, which would justify the non-toxic use of the plant under the traditional conditions of preparation and oral administration.

Medicinal plants used by 'root doctors', local traditional healers in Bié province, Angola

ETHNOPHARMACOLOGICAL RELEVANCE

This study is one of the first post-civil war efforts to document traditional botanical knowledge in Bié province, central Angola, in a first step to bring more studies on the use of medicinal plant resources in this area so as to bring new insights into Angolan bio-cultural diversity.

AIM OF THE STUDY

Examine the variety of plant species used for medical purposes, as well as characterize their social and cultural values. Also, it is aimed to compare their uses in the studied region with those in Sub-Saharan Africa and report new ethnomedicinal uses.

MATERIALS AND METHODS

We documented traditional medicinal plant knowledge among professional herbalists in two areas in Bié province through participatory observation, semi-structured interviews and transect walks. Ethnobotanical information was quantified based on Use Reports to (1) rate traditional knowledge; and (2) determine most useful taxa.

RESULTS

In total, 10 traditional healers shared information on their knowledge. A total of 87 plant species distributed among 57 genera and 36 botanical families were documented with Fabaceae being the best-represented family with 18 species, followed by Phyllanthaceae (6), Apocynaceae (5), Asteraceae (5), Rubiaceae (5), Lamiaceae (4), and Ochnaceae (3). Most medicinal plants are usually gathered at a distance from human settlements because of the belief in the higher efficacy of 'wild' plants shared by all herbalists. Roots are the most common plant part used (79%), explaining why the consulted herbalists call themselves 'root doctors'.

CONCLUSIONS

The culturally most important medicinal species identified in this study, i.e. Securidaca longepedunculata, Garcinia huillensis, Annona stenophylla, Afzelia quanzensis and Strychnos cocculoides, were previously reported for the same use in neighbouring countries and elsewhere in Africa. Our study also indicates that there are several locally valuable species that have not yet been studied for their medical potential, to name a few: Alvesia rosmarinifolia, Diplorhynchus condylocarpon, Eriosema affine, Paropsia brazzaeana, Rhus squalida, Sclerocroton cornutus or Xylopia tomentosa. Moreover, the ethnomedicinal use of 26 species was reported for the first time to sub-Saharan Africa.

CLASSIFICATION

Ethnopharmacological field studies.

Residual Larvicidal Activity of Quinones against Aedes aegypti

The number of documented dengue cases has increased dramatically in recent years due to transmission through the Aedes aegypti mosquito bite. Vector control remains the most effective measure to protect against this and other arboviral diseases including Zika, chikungunya and (urban) yellow fever, with an established vaccine only available for yellow fever. Although the quinone class shows potential as leading compounds for larvicide development, limited information restricts the development of optimized structures and/or formulations. Thus, in this contribution we investigated the larvicidal and pupicidal activity of three quinone compounds isolated from a Connarus suberosus root wood ethyl acetate extract together with 28 quinones from other sources. Eight quinones demonstrated larvicidal activity, of which tectoquinone (4) proved to be the most active (LC50 1.1 µg/mL). The essential residual effect parameter of four of these quinones was evaluated in laboratory trials, with tectoquinone (4) and 2-ethylanthraquinone (7) presenting the most prolonged activity. In small-scale field residual tests, tectoquinone (4) caused 100% larvae mortality over 5 days, supporting its selection for formulation trials to develop a prototype larvicide to control Ae. aegypti.

The noni anthraquinone damnacanthal is a multi-kinase inhibitor with potent anti-angiogenic effects

The natural bioactive compound damnacanthal inhibits several tyrosine kinases. Herein, we show that -in fact- damancanthal is a multi kinase inhibitor. A docking and molecular dynamics simulation approach allows getting further insight on the inhibitory effect of damnacanthal on three different kinases: vascular endothelial growth factor receptor-2, c-Met and focal adhesion kinase. Several of the kinases targeted and inhibited by damnacanthal are involved in angiogenesis. Ex vivo and in vivo experiments clearly demonstrate that, indeed, damnacanthal is a very potent inhibitor of angiogenesis. A number of in vitro assays contribute to determine the specific effects of damnacanthal on each of the steps of the angiogenic process, including inhibition of tubulogenesis, endothelial cell proliferation, survival, migration and production of extracellular matrix remodeling enzyme. Taken altogether, these results suggest that damancanthal could have potential interest for the treatment of cancer and other angiogenesis-dependent diseases.

Medicinal Plants Used in Mali for the Treatment of Malaria and Liver Diseases

Today, ethno-pharmacology is a very important resource in order to discover new therapies for the current diseases. Moreover, another good justification for the ethno-pharmacological approach is to obtain new, effective, less expensive and simple therapies, limiting at the same time the cost of pharmaceutical research. Two major anti-malarial drugs widely used today, i.e. quinine and artemisinin, came respectively from Peruvian and Chinese ancestral treatments reported in the traditional medicines. In this contest, there is an urgent need for the discovery of new drugs, due to the critical epidemiological situation of this disease and to the growth of resistances. In Mali, malaria and liver diseases remain one of the leading public health problems. Many medicinal plants are often used, in local traditional medicine, for the treatment at the same time of malaria and liver diseases, including hepatic syndromes, jaundice, hepatitis and other hepatic disorders. Moreover, in the local language Bamanan, the word “ Sumaya” is used both for malaria and some liver diseases. In addition, we noted that some of the improved traditional phytomedicines produced by the Department of Traditional Medicine are prescribed by modern doctors both for malaria and liver diseases. In this review, pharmacological, toxicological and phytochemical data on Argemone mexicana L. (Papaveraceae), Cochlospermum tinctorium Perr. ex A. Rich (Cochlospermaceae), Combretum micranthum G.Don (Combretaceae), Entada africana Guillet Perr. (Mimosaceae), Erythrina senegalensis A. DC (Fabaceae), Mitragyna inermis (Willd) Kuntze (Rubiaceae), Nauclea latifolia Smith syn. Sarcocephalus latifolius (Smith) Bruce (Rubiaceae), Securidaca longepedunculata Fresen (Polygalaceae), Trichilia emetica Vahl. (Meliaceae), and Vernonia colorata (Willd) Drake (Asteraceae) are reported. Some of the collected data could be used to improve the actual herbal drugs and to propose new phytomedicines for the management of malaria and liver diseases.

Identification of the Factors Responsible for the Selective in vitro Cytotoxic Activity of Isoprenylated Coumarin Derivatives under Nutrient-deprived Conditions

Pancreatic cancer is one of the most devastating forms of human cancer. The lack of effective clinical treatments for pancreatic cancer has led to one of the lowest five-year survival rates among all cancers. Recently, our laboratory has developed a novel series of isoprenylated coumarin derivatives that have exhibited anti-pancreatic cancer activity exclusively under nutrient-deprived conditions. In this study, we report the effect of the various cell culture medium components on the preferential cytotoxicity of our lead isoprenylated coumarin compound against the pancreatic adenocarcinoma cell line PANC-1. In particular, our findings show a clear link between observed cytotoxicity and glucose deprivation, suggesting that our compound targets a salvage pathway when glycolysis is no longer an option for cancer cell survival. The cytotoxicity of our lead compound was also examined in vitro against two other pancreatic cancer cell lines, BxPC-3 and Capan-2 under both nutrient-rich and nutrient-deprived conditions.

Preferentially Cytotoxic Constituents of Andrographis paniculata and their Preferential Cytotoxicity against Human Pancreatic Cancer Cell Lines

In the course of our search for anticancer agents based on a novel anti-austerity strategy, we found that the 70% EtOH extract of the crude drug Andrographis Herba (aerial parts of Andrographis paniculata), used in Japanese Kampo medicines, killed PANC-1 human pancreatic cancer cells preferentially in nutrient-deprived medium (NDM). Phytochemical investigation of the 70% EtOH extract led to the isolation of 21 known compounds consisting of six labdane-type diterpenes (11, 15, 17-19, 21), six flavones (5, 7, 10, 12, 14, 20), three flavanones (2, 6, 16), two sterols (3, 8), a fatty acid (1), a phthalate (4), a triterpene (9), and a monoterpene (13). Among them, 14-deoxy-11,12-didehydroandrographolide (17) displayed the most potent preferential cytotoxicity against PANC-1 and PSN-1 cells with PC50 values of 10.0 μM and 9.27 μM, respectively. Microscopical observation, double staining with ethidium bromide (EB) and acridine orange (AO), and flow cytometry with propidium iodide/annexin V double staining indicated that 14-deoxy-11,12-didehydroandrographolide (17) triggered apoptosis-like cell death in NDM with an amino acids and/or serum-sensitive mode.

Cytotoxicity of anthraquinones from the roots of Pentas schimperi towards multi-factorial drug-resistant cancer cells

INTRODUCTION

Multidrug resistance in cancer represents a major problem in chemotherapy. The present study was designed to assess the cytotoxicity of anthraquinones from Pentas schimperi, namely damnacanthal (1), damnacanthol (2), 3-hydroxy-2-hydroxymethyl anthraquinone (3) and schimperiquinone B (4) against nine drug-sensitive and multidrug resistant (MDR) cancer cell lines.

METHODS

The resazurin reduction assay was used to evaluate the cytotoxicity of the above compounds, whilst caspase-Glo assay was used to detect the activation of caspases enzymes by compounds 1 and 2. Cell cycle, mitochondrial membrane potential (MMP) and levels of reactive oxygen species were all analyzed via flow cytometry.

RESULTS

Anthraquinones 1 and 2 displayed cytotoxic effects with IC50 values below 81 μM on all the nine tested cancer cell lines whilst 3 and 4 displayed selective activities. The recorded IC50 values for compounds 1 and 2 ranged from 3.12 μM and 12.18 μM (towards leukemia CCRF-CEM cells) and from 30.32 μM and 80.11 μM (towards gliobastoma U87MG.ΔEGFR cells) respectively, and from 0.20 μM (against CCRF-CEM cells) to 195.12 μM (against CEM/ADR5000 cells) for doxorubicin. Compounds 1 and 2 induced apoptosis in CCRF-CEM leukemia cells, mediated by the disruption of the MMP and increase in ROS production.

CONCLUSIONS

Anthraquinones from Pentas schimperi and mostly 1 and 2 are potential cytotoxic natural products that deserve more investigations to develop novel antineoplastic drugs against multifactorial drug resistant cancers.

Anti-austeritic Constituents of the Congolese Medicinal Plant Aframomum melegueta

In the course of our search for anticancer agents based on a novel anti-austerity strategy, we found that the CHCl3 extract of the roots of Aflamomum melegueta (Zingiberaceae), collected in the Democratic Republic of Congo, killed PANC-1 human pancreatic cancer cells preferentially in nutrient-deprived medium (NDM). Phytochemical investigation of the CHCl3 extract led to the isolation of seven known compounds [(-)-buplerol (1), (-)-arctigenin (2), ( E)-14-hydroxy-15-norlabda-8(17),12-dien-16-al (3), labda-8(17),12-dien-15,16-dial (4), 16-oxo-8(17),12( E)-labdadien-15-oic acid (5), 5-hydroxy-7-methoxyflavone (6), and apigenin (7)]. In addition to the previously reported preferentially cytotoxic compound, (-)-arctigenin (2, PC50 0.5 μM), (-)-buplerol (1) also displayed potent preferential cytotoxicity with a PC50 value of 8.42 pM and triggered apoptosis-like PANC-1 cell death in NDM.

Damnacanthal, a noni anthraquinone, inhibits c-Met and is a potent antitumor compound against Hep G2 human hepatocellular carcinoma cells

Damnacanthal, an anthraquinone present in noni plants, targets several tyrosine kinases and has antitumoral effects. This study aims at getting additional insight on the potential of damnacanthal as a natural antitumor compound. The direct effect of damnacanthal on c-Met was tested by in vitro activity assays. Additionally, Western blots of c-Met phosphorylation in human hepatocellular carcinoma Hep G2 cells were performed. The antitumor effects of damnacanthal were tested by using cell growth, soft agar clonogenic, migration and invasion assays. Their mechanisms were studied by Western blot, and cell cycle, apoptosis and zymographic assays. Results show that damnacanthal targets c-Met both in vitro and in cell culture. On the other hand, damnacanthal also decreases the phosphorylation levels of Akt and targets matrix metalloproteinase-2 secretion in Hep G2 cells. These molecular effects are accompanied by inhibition of the growth and clonogenic potential of Hep G2 hepatocellular carcinoma cells, as well as induction of Hep G2 apoptosis. Since c-Met has been identified as a new potential therapeutical target for personalized treatment of hepatocellular carcinoma, damnacanthal and noni extract supplements containing it could be potentially interesting for the treatment and/or chemoprevention of hepatocellular carcinoma through its inhibitory effects on the HGF/c-Met axis.

Muchimangins G-J, fully substituted xanthones with a diphenylmethyl substituent, from Securidaca longepedunculata

Four highly oxygenated xanthones, muchimangins G-J (1-4), have been isolated from the roots of Securidaca longepedunculata collected in Democratic Republic of Congo. Their structures were elucidated by analyses of spectroscopic data to be fully substituted xanthones with a diphenylmethyl substituent at C-2.

Two New Diphenylmethyl-substituted Xanthones from Securidaca longepedunculata

Two new diphenylmethyl-substituted xanthones, named muchimangins K (1) and L (2), have been isolated from the roots of Securidaca longepedunculata (Polygalaceae) collected in the Democratic Republic of Congo. Their structures were established by analyses of the spectral data, including 2D NMR spectra, to be l,3,6,8-tetrahydroxy-2,5-dimethoxy-4-[l-(2,4,5-trimethoxyphenyl)-1-phenylmethyl]xanthone (1) and l,3,6-trihydroxy-4,7-dimethoxy-2-[l-(2,4,5-trimethoxyphenyl)-1-phenylmethyl]xanthone (2).

Traditional use of medicinal plants in south-central Zimbabwe: review and perspectives

BACKGROUND

Traditional medicine has remained as the most affordable and easily accessible source of treatment in the primary healthcare system of resource poor communities in Zimbabwe. The local people have a long history of traditional plant usage for medicinal purposes. Despite the increasing acceptance of traditional medicine in Zimbabwe, this rich indigenous knowledge is not adequately documented. Documentation of plants used as traditional medicines is needed so that the knowledge can be preserved and the utilized plants conserved and used sustainably. The primary objective of this paper is to summarize information on traditional uses of medicinal plants in south-central Zimbabwe, identifying research gaps and suggesting perspectives for future research.

METHODS

This study is based on a review of the literature published in scientific journals, books, reports from national, regional and international organizations, theses, conference papers and other grey materials.

RESULTS

A total of 93 medicinal plant species representing 41 families and 77 genera are used in south-central Zimbabwe. These plant species are used to treat 18 diseases and disorder categories, with the highest number of species used for gastro-intestinal disorders, followed by sexually transmitted infections, cold, cough and sore throat and gynaecological problems. Shrubs and trees (38% each) were the primary sources of medicinal plants, followed by herbs (21%) and climbers (3%). The therapeutic claims made on medicinal plants documented in south-central Zimbabwe are well supported by literature, with 82.8% of the plant species having similar applications in other regions of Zimbabwe as well as other parts of the world and 89.2% having documented biological and pharmacological properties.

CONCLUSION

This study illustrates the importance of traditional medicines in the treatment and management of human diseases and ailments in south-central Zimbabwe. Traditional medicines still play an important role in meeting basic health care of local communities in Zimbabwe.