Ginkgo biloba and ovarian cancer prevention: Epidemiological and biological evidence

Induction of ferroptosis by natural products in non-small cell lung cancer: a comprehensive systematic review

Lung cancer is one of the leading causes of cancer-related deaths worldwide that presents a substantial peril to human health. Non-Small Cell Lung Cancer (NSCLC) is a main subtype of lung cancer with heightened metastasis and invasion ability. The predominant treatment approaches currently comprise surgical interventions, chemotherapy regimens, and radiotherapeutic procedures. However, it poses significant clinical challenges due to its tumor heterogeneity and drug resistance, resulting in diminished patient survival rates. Therefore, the development of novel treatment strategies for NSCLC is necessary. Ferroptosis was characterized by iron-dependent lipid peroxidation and the accumulation of lipid reactive oxygen species (ROS), leading to oxidative damage of cells and eventually cell death. An increasing number of studies have found that exploiting the induction of ferroptosis may be a potential therapeutic approach in NSCLC. Recent investigations have underscored the remarkable potential of natural products in the cancer treatment, owing to their potent activity and high safety profiles. Notably, accumulating evidences have shown that targeting ferroptosis through natural compounds as a novel strategy for combating NSCLC holds considerable promise. Nevertheless, the existing literature on comprehensive reviews elucidating the role of natural products inducing the ferroptosis for NSCLC therapy remains relatively sparse. In order to furnish a valuable reference and support for the identification of natural products inducing ferroptosis in anti-NSCLC therapeutics, this article provided a comprehensive review explaining the mechanisms by which natural products selectively target ferroptosis and modulate the pathogenesis of NSCLC.

The role of Ginkgo Folium on antitumor: Bioactive constituents and the potential mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba L. is a well-known and highly regarded resource in Chinese traditional medicine due to its effectiveness and safety. Ginkgo Folium, the leaf of Ginkgo biloba L., contains biologically active constituents with diverse pharmacological activities. Recent studies have shown promising antitumor effects of the bioactive constituents found in Ginkgo Folium against various types of cancer cells, highlighting its potential as a natural source of antitumor agents. Further research is needed to elucidate the underlying mechanisms and optimize its therapeutic potential.

AIM OF THE REVIEW

To provide a detailed understanding of the pharmacological activities of Ginkgo Folium and its potential therapeutic benefits for cancer patients.

MATERIALS AND METHODS

In this study, we conducted a thorough and systematic search of multiple online databases, including PubMed, Web of Science, Medline, using relevant keywords such as "Ginkgo Folium," "flavonoids," "terpenoids," "Ginkgo Folium extracts," and "antitumor" to cover a broad range of studies that could inform our review. Additionally, we followed a rigorous selection process to ensure that the studies included in our review met the predetermined inclusion criteria.

RESULTS

The active constituents of Ginkgo Folium primarily consist of flavonoids and terpenoids, with quercetin, kaempferol, isorhamnetin, ginkgolides, and bilobalide being the major compounds. These active constituents exert their antitumor effects through crucial biological events such as apoptosis, cell cycle arrest, autophagy, and inhibition of invasion and metastasis via modulating diverse signaling pathways. During the process of apoptosis, active constituents primarily exert their effects by modulating the caspase-8 mediated death receptor pathway and caspase-9 mediated mitochondrial pathway via regulating specific signaling pathways. Furthermore, by modulating multiple signaling pathways, active constituents effectively induce G1, G0/G1, G2, and G2/M phase arrest. Among these, the pathways associated with G2/M phase arrest are particularly extensive, with the cyclin-dependent kinases (CDKs) being most involved. Moreover, active constituents primarily mediate autophagy by modulating certain inflammatory factors and stressors, facilitating the fusion stage between autophagosomes and lysosomes. Additionally, through the modulation of specific chemokines and matrix metalloproteinases, active constituents effectively inhibit the processes of epithelial-mesenchymal transition (EMT) and angiogenesis, exerting a significant impact on cellular invasion and migration. Synergistic effects are observed among the active constituents, particularly quercetin and kaempferol.

CONCLUSION

Active components derived from Ginkgo Folium demonstrate a comprehensive antitumor effect across various levels and pathways, presenting compelling evidence for their potential in new drug development. However, in order to facilitate their broad and adaptable clinical application, further extensive experimental investigations are required to thoroughly explore their efficacy, safety, and underlying mechanisms of action.

New insight into the mechanisms of Ginkgo biloba leaves in the treatment of cancer

BACKGROUND

Ginkgo biloba leaves (GBLs), as an herbal dietary supplement and a traditional Chinese medicine, have been used in treating diseases for hundred years. Recently, increasing evidence reveals that the extracts and active ingredients of GBLs have anti-cancer (chemo-preventive) properties. However, the molecular mechanism of GBLs in anti-cancer has not been comprehensively summarized.

PURPOSE

To systematically summarize the literatures for identifying the molecular mechanism of GBLs in cellular, animal models and clinical trials of cancers, as well as for critically evaluating the current evidence of efficacy and safety of GBLs for cancers.

METHODS

Employing the search terms "Ginkgo biloba" and "cancer" till July 25, 2023, a comprehensive search was carried out in four electronic databases including Scopus, PubMed, Google Scholar and Web of Science. The articles not contained in the databases are performed by manual searches and all the literatures on anti-cancer research and mechanism of action of GBLs was extracted and summarized. The quality of methodology was assessed independently through PRISMA 2020.

RESULTS

Among 84 records found in the database, 28 were systematic reviews related to GBLs, while the remaining 56 records were related to the anticancer effects of GBLs, which include studies on the anticancer activities and mechanisms of extracts or its components in GBLs at cellular, animal, and clinical levels. During these studies, the top six cancer types associated with GBLs are lung cancer, hepatocellular carcinoma, gastric cancer, breast cancer, colorectal cancer, and cervical cancer. Further analysis reveals that GBLs primarily exert their anticancer effects by stimulating cancer cell apoptosis, inhibiting cell proliferation, invasion and migration of cancers, exhibiting anti-inflammatory and antioxidant properties, and modulating signaling pathways. Besides, the pharmacology, toxicology, and clinical research on the anti-tumor activity of GBLs have also been discussed.

CONCLUSIONS

This is the first paper to thoroughly investigate the pharmacology effect, toxicology, and the mechanisms of action of GBLs for anti-cancer properties. All the findings will reinforce the need to explore the new usage of GBLs in cancers and offer comprehensive reference data and recommendations for future research on this herbal medicine.

In vitro evaluation of the anti‑breast cancer properties and gene expression profiles of Thai traditional formulary medicine extracts

Breast cancer is a leading cause of cancer-related deaths worldwide. Moreover, standard treatments are limited, so new alternative treatments are required. Thai traditional formulary medicine (TTFM) utilizes certain herbs to treat different diseases due to their dominant properties including anti-fungal, anti-bacterial, antigenotoxic, anti-inflammatory and anti-cancer actions. However, very little is known about the anti-cancer properties of TTFM against breast cancer cells and the underlying molecular mechanism has not been elucidated. Therefore, the present study, evaluated the metabolite profiles of TTFM extracts, the anti-cancer activities of TTFM extracts, their effects on the apoptosis pathway and associated gene expression profiles. Liquid chromatography with tandem mass spectroscopy analysis identified a total of 226 compounds within the TTFM extracts. Several of these compounds have been previously shown to have an anti-cancer effect in certain cancer types. The MTT results demonstrated that the TTFM extracts significantly reduced the cell viability of the breast cancer 4T1 and MDA-MB-231 cell lines. Moreover, an apoptosis assay, demonstrated that the TTFM extracts significantly increased the proportion of apoptotic cells. Furthermore, the RNA-sequencing results demonstrated that 25 known genes were affected by TTFM treatment in 4T1 cells. TTFM treatment significantly up-regulated Slc5a8 and Arhgap9 expression compared with untreated cells. Moreover, Cybb, and Bach2os were significantly downregulated after TTFM treatment compared with untreated cells. Reverse transcription-quantitative PCR demonstrated that TTFM extract treatment significantly increased Slc5a8 and Arhgap9 mRNA expression levels and significantly decreased Cybb mRNA expression levels. Moreover, the mRNA expression levels of Bax and Casp9 were significantly increased after TTFM treatment in 4T1 cells compared with EpH4-Ev cells. These findings indicated anti-breast cancer activity via induction of the apoptotic process. However, further experiments are required to elucidate how TTFM specifically regulates genes and proteins. This study supports the potential usage of TTFM extracts for the development of anti-cancer drugs.

Synthesis and Bioactivity Evaluation of Nepetaefolin F and Its Analogues

Nepetaefolin F (5), an abietane diterpenoid, showed significant inhibitory activity against human cancer cells in vitro with an IC₅₀ value of 6.3 μM. The syntheses of nepetaefolin F and its analogues are presented herein. The cytotoxicity against various cancer cell lines was evaluated; notably, the cyclopropanecarboxylate ester 42 displayed significant antitumor activity against MGC 803 cells with an IC₅₀ value of 20.9 μM. Further studies revealed that 42 could upregulate the expression of p62, microtubule-associated protein 1 light-chain 3 β (LC3 B-I), cleaved caspase-3, and cleaved caspase-9 and downregulate the expression of Beclin-1 and LC3B-II. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that 42 could modulate multiple signaling pathways, especially for peroxisome proliferator-activated receptor (PPAR) and AMP-activated protein kinase (AMPK), which are closely related to autophagy. These results suggested that compound 42 is a promising lead by inhibiting cell proliferation and autophagy, as inducing cell apoptosis in MGC 803 cells.

Integrative Medicine for Ovarian Cancer

PURPOSE OF REVIEW

Integrative oncology (IO) services provide a wide range of complementary medicine therapies, many of which can augment the beneficial effects of conventional supportive and palliative care for patients with ovarian cancer. This study aims to assess the current state of integrative oncology research in ovarian cancer care.

RECENT FINDINGS

We review the clinical research both supporting the effectiveness of leading IO modalities in ovarian cancer care as well as addressing potential safety-related concerns. There is growing amount of clinical research supporting the use of IO and implementation of integrative gynecological oncology models of care within the conventional supportive cancer care setting. Additional research is still needed in order to create clinical guidelines for IO interventions for the treatment of female patients with ovarian cancer. These guidelines need to address both effectiveness and safety-related issues, providing oncology healthcare professionals with indications for which these patients can be referred to the IO treatment program.

Phytotherapy in Integrative Oncology-An Update of Promising Treatment Options

Modern phytotherapy is part of today's conventional evidence-based medicine and the use of phytopharmaceuticals in integrative oncology is becoming increasingly popular. Approximately 40% of users of such phytopharmaceuticals are tumour patients. The present review provides an overview of the most important plants and nature-based compounds used in integrative oncology and illustrates their pharmacological potential in preclinical and clinical settings. A selection of promising anti-tumour plants and ingredients was made on the basis of scientific evidence and therapeutic practical relevance and included Boswellia, gingko, ginseng, ginger, and curcumin. In addition to these nominees, there is a large number of other interesting plants and plant ingredients that can be considered for the treatment of cancer diseases or for the treatment of tumour or tumour therapy-associated symptoms. Side effects and interactions are included in the discussion. However, with the regular and intended use of phytopharmaceuticals, the occurrence of adverse side effects is rather rare. Overall, the use of defined phytopharmaceuticals is recommended in the context of a rational integrative oncology approach.

ITGB3BP is a potential biomarker associated with poor prognosis of glioma

Despite the growing recognition of ITGB3BP as an essential feature of various cancers, the relationship between ITGB3BP and glioma remains unclear. The main aim of this study was to determine the prognostic and diagnostic value of ITGB3BP in glioma. RNA-Seq and microarray data from 2222 glioma patients were included, and we found that the expression level of ITGB3BP in glioma tissues was significantly higher than that in normal brain tissues. Moreover, ITGB3BP can be considered an independent risk factor for poor prognosis and has great predictive value for the prognosis of glioma. Gene Set Enrichment Analysis results showed that ITGB3BP contributes to the poor prognosis of glioma by activating tumour-related signalling pathways. Some small-molecule drugs were identified, such as hexestrol, which may specifically inhibit ITGB3BP and be useful in the treatment of glioma. The TIMER database analysis results revealed a correlation between the expression of ITGB3BP and the infiltration of various immune cells in glioma. Our findings provide the first evidence that the up-regulation of ITGB3BP correlates with poor prognosis in human glioma. Thus, ITGB3BP is a potential new biomarker that can be used for the clinical diagnosis and treatment of glioma.

Potential effets of ginkgo (Ginkgo biloba, L.) on female reproduction

This minireview will briefly outline the basic knowledge concerning the provenance, biological active constituents of ginkgo (Ginkgo biloba, L.) and its general health effects. Ginkgo has been shown to affect female reproductive functions: it can affect ovarian folliculo- and oogenesis, embryogenesis, promote ovarian granulosa cell apoptosis, reduce their proliferation and the release of ovarian hormones. Usually, ginkgo extract mainly suppresses, but its constituents like amifostine, leuprorelin, quercetin and kaempherol can promote ovarian functions. This may indicate the existence of anti-reproductive ginkgo constituent(s), such as ginkgolide B and allopregnenolone which, like ginkgo extract, can promote ovarian cell apoptosis and suppress ovarian follicullogenesis and oogenesis. Ginkgo effects could be mediated by an action on brain functions, ovarian steroidogenesis, oxidative processes, intracellular regulators of ovarian cell proliferation and apoptosis and GABA receptors. Ginkgo and its molecules, ginkgolide B and allopregnenolone can be useful for prevention and treatment of reproduction-related disorders like ovarian cancer, ovarian ischemia and menopausal syndrome. On the other hand, its constituents amifostine, leuprorelin, quercetin and kaempherol could be potentially applicable as biostimulators of female reproductive processes in human and veterinary medicine and animal production. Nevertheless, application of ginkgo is still limited by insufficient or contradictory knowledge concerning its active constituents, characters, targets and mediators of its action and their functional interrelationships. Impact of ginkgo action on reproductive organs other than ovaries remains largely unknown. Addressing these issues with proper animal and clinical studies could help to understand the distinct efficacy and consequences of medical application of ginkgo.

Phytochemicals in Gynecological Cancer Prevention

Gynecological cancer confers an enormous burden among women worldwide. Accumulating evidence points to the role of phytochemicals in preventing cervical, endometrial, and ovarian cancer. Experimental studies emphasize the chemopreventive and therapeutic potential of plant-derived substances by inhibiting the early stages of carcinogenesis or improving the efficacy of traditional chemotherapeutic agents. Moreover, a number of epidemiological studies have investigated associations between a plant-based diet and cancer risk. This literature review summarizes the current knowledge on the phytochemicals with proven antitumor activity, emphasizing their effectiveness and mechanism of action in gynecological cancer.

Development of Potential Antitumor Agents from the Scaffolds of Plant-Derived Terpenoid Lactones

Naturally occurring terpenoid lactones and their synthetic derivatives have attracted increasing interest for their promising antitumor activity and potential utilization in the discovery and design of new antitumor agents. In the present perspective article, selected plant-derived five-membered γ-lactones and six-membered δ-lactones that occur with terpenoid scaffolds are reviewed, with their structures, cancer cell line cytotoxicity and in vivo antitumor activity, structure-activity relationships, mechanism of action, and the potential for developing cancer chemotherapeutic agents discussed in each case. The compounds presented include artemisinin (ART, 1), parthenolide (PTL, 2), thapsigargin (TPG, 3), andrographolide (AGL, 4), ginkgolide B (GKL B, 5), jolkinolide B (JKL B, 6), nagilactone E (NGL E, 7), triptolide (TPL, 8), bruceantin (BRC, 9), dichapetalin A (DCT A, 10), and limonin (LMN, 11), and their naturally occurring analogues and synthetic derivatives. It is hoped that this contribution will be supportive of the future development of additional efficacious anticancer agents derived from natural products.

Ginkgolide B inhibits lung cancer cells promotion via beclin-1-dependent autophagy

BACKGROUND

Ginkgolide B (GKB) is a major active component of the extracts of Ginkgo biloba leaves, and it has been used as an anti-cancer agent. However, it is unknown whether GKB has the therapeutic effects on lung cancer. Here, we studied the effects of GKB on lung cancer cells.

METHODS

The effects of GKB on lung cancer cell proliferation and invasion were analyzed by cell counting kit (CCK-8) and cell invasion assays, respectively. Apoptosis was detected by flow cytometry. Western blot analysis was used to confirm the expression of autophagy-associated proteins in GKB-treated cells. Immunofluorescence analysis was used to analyze the level of light chain 3B (LC3B).

RESULTS

Treatment with GKB time-dependently inhibited the proliferation and decreased the invasive capacity of A549 and H1975 cells. GKB induced apoptosis of these cells, but there was no significant effect on apoptosis compared to the control treatment. GKB-induced inhibition of cell proliferation and GKB-induced cell death were due to autophagy rather than apoptosis. GKB-induced autophagy of lung cancer cells was dependent on beclin-1, and autophagy-induced inhibition of the NLRP3 inflammasome contributed to the anti-tumor effect of GKB.

CONCLUSIONS

GKB-mediated autophagy of lung cancer cells is beclin-1-dependent and results in inhibition of the NLRP3 inflammasome. Therefore, GKB might be a potential therapeutic candidate for the treatment of lung cancer.

Overview of biological effects of Quercetin on ovary

Over the last few decades, using natural products has been increased to treat different diseases. Today, great attention has been pointed toward the usage of natural products such as flavonoids, especially Quercetin (QUR), in the treatment of diseases. QUR as a natural antioxidant has been traditionally used to prevent or treat a variety of diseases such as cancer, cardiovascular disease, polycystic ovary syndrome (PCOS), obesity, chronic inflammation, and reproductive system dysfunction. Several studies demonstrated that QUR acts as an anti-inflammatory, anti-apoptotic, antioxidant, and anticancer agent. With this in view, in this study, we intended to describe an overview of the biological effects of QUR on the ovary. QUR improves the quality of oocytes and embryos. It affects the proliferation and apoptosis and decreases the oxidative stress in granulosa cells (GCs). Furthermore, QUR can be used as a complementary and alternative therapy in ovarian cancer and it has beneficial effects in the treatment of PCOS patients. It seems that QUR as a supplementary factor has different activities for the treatment of different disorders and it also has bidirectional activities. However, further investigations are needed for understanding the efficacy of QUR in the treatment and improvement of gynecological patients.

Nanoscale drug delivery strategies for therapy of ovarian cancer: conventional vs targeted

Ovarian cancer is the second most common gynaecological malignancy. It usually occurs in women older than 50 years, and because 75% of cases are diagnosed at stage III or IV it is associated with poor diagnosis. Despite the chemosensitivity of intraperitoneal chemotherapy, the majority of patients is relapsed and eventually dies. In addition to the challenge of early detection, its treatment presents several challenges like the route of administration, resistance to therapy with recurrence and specific targeting of cancer to reduce cytotoxicity and side effects. In ovarian cancer therapy, nanocarriers help overcome problems of poor aqueous solubility of chemotherapeutic drugs and enhance their delivery to the tumour sites either by passive or active targeting, and thus reducing adverse side effects to the healthy tissues. Moreover, the bioavailability to the tumour site is increased by the enhanced permeability and retention (EPR) mechanism. The present review aims to describe the current conventional treatment with special reference to passively and actively targeted drug delivery systems (DDSs) towards specific receptors designed against ovarian cancer to overcome the drawbacks of conventional delivery. Conclusively, targeted nanocarriers would optimise the intra-tumour distribution, followed by drug delivery into the intracellular compartment. These features may contribute to greater therapeutic effect.

Carnosic Acid, Tangeretin, and Ginkgolide-B Anti-neoplastic Cytotoxicity in Dual Combination with Dexamethasone-[anti-EGFR] in Pulmonary Adenocarcinoma (A549)

Background:

Traditional chemotherapeutics of low-molecular weight diffuse passively across intact membrane structures of normal healthy cells found in tissues and organ systems in a non-specific unrestricted manner which largely accounts for the induction of most sequelae which restrict dosage, administration frequency, and duration of therapeutic intervention. Molecular strategies that offer enhanced levels of potency, greater efficacy and broader margins-of-safety include the discovery of alternative candidate therapeutics and development of methodologies capable of mediating properties of selective “targeted” delivery.

Materials and Methods:

The covalent immunopharmaceutical, dexamethasone-(C21-phosphoramidate)-[anti- EGFR] was synthesized utilizing organic chemistry reactions that comprised a multi-stage synthesis regimen. Multiple forms of analysis were implemented to vadliate the successful synthesis (UV spectrophotometric absorbance), purity and molar-incorporation-index (UV spectrophotometric absorbance, chemical-based protein determination), absence of fragmentation/polymerization (SDS-PAGE/chemiluminescent autoradiography), retained selective binding-avidity of IgG-immunoglobulin (cell-ELISA); and selectively “targeted” antineoplastic cytotoxicity (biochemistry-based cell vitality/viability assay).

Results:

The botanicals carnosic acid, ginkgolide-B and tangeretin, each individually exerted maximum antineoplastic cytotoxicity levels of 58.1%, 5.3%, and 41.1% respectively against pulmonary adenocarcinoma (A549) populations. Dexamethasone-(C21-phosphoramidate)-[anti-EGFR] formulated at corticosteroid/ glucocorticoid equivalent concentrations produced anti-neoplastic cytotoxicity at levels of 7.7% (10-9 M), 26.9% (10-8 M), 64.9% (10-7 M), 69.9% (10-6 M) and 73.0% (10-5 M). Ccarnosic acid, ginkgolide-B and tangeretin in simultaneous dual-combination with dexamethasone-(C21-phosphoramidate)-[anti-EGFR] exerted maximum anti-neoplastic cytotoxicity levels of 70.5%, 58.6%, and 69.7% respectively.

Discussion:

Carnosic acid, ginkgolide-B and tangeretin botanicals exerted anti-neoplastic cytotoxicity against pulmonary adenocarcinoma (A549) which additively contributed to the anti-neoplastic cytotoxic potency of the covalent immunopharmaceutical, dexamethasone-(C21-phosphoramidate)-[anti-EGFR]. Carnosic acid and tangeretin were most potent in this regard both individually and in dual-combination with dexamethasone-(C21- phosphoramidate)-[anti-EGFR]. Advantages and attributes of carnosic acid and tangeretin as potential monotherapeutics are a wider margin-of-safety of conventional chemotherapeutics which would readily complement the selective “targeted” delivery properties of dexamethasone-(C21-phosphoramidate)-[anti-EGFR] and possibly other covalent immunopharmaceuticals in addition to providing opportunities for the discovery of combination therapies that provide heightened levels of anti-neoplastic efficacy.

Are polyphenol antioxidants at the root of medicinal plant anti-cancer success?

ETHNOPHARMACOLOGICAL RELEVANCE

Given the severe side effects associated with most of the conventional cancer medications, as well as the expanding body of evidence indicating secondary toxicity of these drugs, individuals with cancer are increasingly turning to natural alternatives. Similarly, the pharmaceutical industry is in search of natural products to treat cancer. An understanding of the specific active components in plant products with which anti-cancer efficacy is achieved is required for this research to move forward.

AIM OF THE STUDY

To integrate data from cancer-relatestudies on plant-derived products or extracts, to elucidate whether these products may have similar active ingredients and/or mechanisms of action, that can explain their efficacy. This review also includes a discussion of the methodological complexities and important considerations involved in accurate isolation and characterisation of active substances from plant material.

CONCLUSIONS

From the literature reviewed, most plant products with consistently reported anti-cancer efficacy contains high levels of polyphenols or other potent antioxidants and their mechanisms of action correlate to that reported for isolated antioxidants in the context of cancer. This suggests that natural products may indeed become the panacea against this chronic disease - either as therapeutic medicine strategy or to serve as templates for the design of novel synthetic drugs. The recommendation is made that antioxidant activity of plant actives and especially polyphenols, should be the focus of anti-cancer drug discovery initiatives. Lastly, researchers are advised to exploit current techniques of chemical compound characterisation when investigating polyphenol-rich plants to enable the easy consolidation of research findings from different laboratories.

Cytotoxicity of South-African medicinal plants towards sensitive and multidrug-resistant cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional medicine plays a major role for primary health care worldwide. Cancer belongs to the leading disease burden in industrialized and developing countries. Successful cancer therapy is hampered by the development of resistance towards established anticancer drugs.

AIM

In the present study, we investigated the cytotoxicity of 29 extracts from 26 medicinal plants of South-Africa against leukemia cell lines, most of which are used traditionally to treat cancer and related symptoms.

MATERIAL AND METHODS

We have investigated the plant extracts for their cytotoxic activity towards drug-sensitive parental CCRF-CEM leukemia cells and their multidrug-resistant P-glycoprotein-overexpressing subline, CEM/ADR5000 by means of the resazurin assay. A panel of 60 NCI tumor cell lines have been investigated for correlations between selected phytochemicals from medicinal plants and the expression of resistance-conferring genes (ABC-transporters, oncogenes, tumor suppressor genes).

RESULTS

Seven extracts inhibited both cell lines (Acokanthera oppositifolia, Hypoestes aristata, Laurus nobilis, Leonotis leonurus, Plectranthus barbatus, Plectranthus ciliates, Salvia apiana). CEM/ADR5000 cells exhibited a low degree of cross-resistance (3.35-fold) towards the L. leonurus extract, while no cross-resistance was observed to other plant extracts, although CEM/ADR5000 cells were highly resistant to clinically established drugs. The log10IC50 values for two out of 14 selected phytochemicals from these plants (acovenoside A and ouabain) of 60 tumor cell lines were correlated to the expression of ABC-transporters (ABCB1, ABCB5, ABCC1, ABCG2), oncogenes (EGFR, RAS) and tumor suppressors (TP53). Sensitivity or resistance of the cell lines were not statistically associated with the expression of these genes, indicating that multidrug-resistant, refractory tumors expressing these genes may still respond to acovenoside A and ouabain.

CONCLUSION

The bioactivity of South African medicinal plants may represent a basis for the development of strategies to treat multidrug-resistant tumors either by phytotherapeutic approaches with whole plant preparations or by classical drug development with isolated compounds such as acovenoside A or ouabain.

Quercetin and ovarian cancer: An evaluation based on a systematic review

Some studies have suggested chemopreventive and therapeutic effects of quercetin (Q) on carcinogenesis. The aim of this review was to evaluate the association between Q and ovarian cancer risk among human researches and induced sensitivity to some types of chemotherapeutic drugs and antiproliferative effects of this flavonoid in the animals and cell lines studies. Data for this systematic review were achieved through searches of the MEDLINE (PubMed), Google Scholar, Science Direct, Scopus, Cochrane, SID, and Magiran databases for studies published up to May 2015. Relevant studies were reviewed based on Preferred Reporting Item for Systematic Review and Meta analysis guidelines. From the total number of 220 papers obtained at the initial search, 13 publications including 1 prospective, 2 case -control, 1 animal, and 9 in vitro human and animal cancer cell lines studies were eligible. Despite findings in laboratory settings, results from the epidemiological studies commented that the potentially protective effects of Q not be able to significantly decrease ovarian cancer risk at levels commonly consumed (1.01–31.7 mg/day) in a typical diet. However, animal and in vitro studies suggest that Q exerts anticancer effects via inhibiting tumor growth, and angiogenesis, interrupt the cell cycle, and induce apoptosis. It is highlighted the need for more studies to be conducted.

Traditional Chinese medicine in the prevention and treatment of cancer and cancer metastasis

Traditional Chinese medicine (TCM) has been a major part of healthcare in China, and has extensively affected medicine and healthcare in surrounding countries over a long period of time. In the fight against cancer, certain anticancer remedies using herbs or herbal formulas derived from TCM have been developed for the management of malignancies. Furthermore, there are clinical trials registered for the use of herbal remedies in cancer management. Herbal medicine has been used as part of combined therapies to reduce the side-effects of chemotherapy, including bone marrow suppression, nausea and vomiting. Herbal remedies have also been used as chemopreventive therapies to treat precancerous conditions in order to reduce the incidence of cancer in high-risk populations. Emerging evidence has revealed that herbal remedies can regulate the proliferation, apoptosis, adhesion and migration of cancer cells. In addition to this direct effect upon cancer cells, a number of herbal remedies have been identified to suppress angiogenesis and therefore reduce tumour growth. The inhibition of tumour growth may also be due to modifications of the host immune system by the herbal treatment. However, the precise mechanisms underlying the therapeutic effects of herbal remedies remain poorly understood and are yet to be fully elucidated. The present study aims to summarize the current literature and clinical trial results of herbal remedies for cancer treatment, with a particular focus on the recent findings and development of the Yangzheng Xiaoji capsule.

Appropriate use of complementary and alternative medicine approaches in gynecologic cancers

OPINION STATEMENT

Gynecologic cancer patients frequently desire alternative and/or complementary interventions or medicines to aid in relief of both cancer-related and treatment-related side effects. Furthermore, women also seek treatment to aid in superior outcomes and cure rates. Unfortunately, evidence suggests that the use of complementary and/or alternative medicine (CAM) is underreported or not discussed with physicians providing cancer care. In gynecologic cancer literature, there is a lack of scientific evidence either supporting or negating CAM. Because of the lack of information available, health care providers do not have good information regarding safety, efficacy, and dose of CAM. This leads to miscommunication or absence of communication between providers and patients. Because patients do use CAM to improve quality of life (QOL) during and after treatment, it would be educational for providers to know the specific QOL deficits among patients that require attention. Thus, with the ultimate goal of improving QOL for gynecologic cancer patients, providers should be pushed to investigate CAM and determine an honest support or rejection of these therapies.

Restoring TRAIL mediated signaling in ovarian cancer cells

Ovarian cancer has emerged as a multifaceted and genomically complex disease. Genetic/epigenetic mutations, suppression of tumor suppressors, overexpression of oncogenes, rewiring of intracellular signaling cascades and loss of apoptosis are some of the deeply studied mechanisms. In vitro and in vivo studies have highlighted different molecular mechanisms that regulate tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mediated apoptosis in ovarian cancer. In this review, we bring to limelight, expansion in understanding systematical characterization of ovarian cancer cells has led to the rapid development of new drugs and treatments to target negative regulators of TRAIL mediated signaling pathway. Wide ranging synthetic and natural agents have been shown to stimulate mRNA and protein expression of death receptors. This review is compartmentalized into programmed cell death protein 4, platelet-derived growth factor signaling and miRNA control of TRAIL mediated signaling to ovarian cancer. Mapatumumab and PRO95780 have been tested for efficacy against ovarian cancer. Use of high-throughput screening assays will aid in dissecting the heterogeneity of this disease and increasing a long-term survival which might be achieved by translating rapidly accumulating information obtained from molecular and cellular studies to clinic researches.

Site-specific anticancer effects of dietary flavonoid quercetin

Food-derived flavonoid quercetin, widely distributed in onions, apples, and tea, is able to inhibit growth of various cancer cells indicating that this compound can be considered as a good candidate for anticancer therapy. Although the exact mechanism of this action is not thoroughly understood, behaving as antioxidant and/or prooxidant as well as modulating different intracellular signalling cascades may all play a certain role. Such inhibitory activity of quercetin has been shown to depend first of all on cell lines and cancer types; however, no comprehensive site-specific analysis of this effect has been published. In this review article, cytotoxicity constants of quercetin measured in various human malignant cell lines of different origin were compiled from literature and a clear cancer selective action was demonstrated. The most sensitive malignant sites for quercetin revealed to be cancers of blood, brain, lung, uterine, and salivary gland as well as melanoma whereas cytotoxic activity was higher in more aggressive cells compared to the slowly growing cells showing that the most harmful cells for the organism are probably targeted. More research is needed to overcome the issues of poor water solubility and relatively low bioavailability of quercetin as the major obstacles limiting its clinical use.

Ginkgo May Sensitize Ovarian Cancer Cells to Cisplatin: Antiproliferative and Apoptosis-Inducing Effects of Ginkgolide B on Ovarian Cancer Cells

Ginkgolide B (GB), the primary active component ofGinkgo bilobaextracts, may have antitumor properties. The objective of this study was to determine the effects and possible mechanisms of GB in ovarian cancer cells. In this study, human ovarian cancer cell lines (SKOV3 and CAOV3) were treated with different concentrations of GB alone or in combination with Cis-diaminodichloroplatinum (CDDP). An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was performed to determine cell viability. The apoptosis rates of cells were measured by flow cytometric analysis. The expression of apoptosis-associated and proliferation-associated proteins was detected by Western blot. The cytotoxicity of GB was analyzed using a lactate dehydrogenase assay. Treatment with 100 µM GB for 3 days significantly inhibited SKOV3 and CAOV3 cell proliferation by 57.3% and 63.1% compared with control cells, respectively, as determined by MTT assay. Similarly, the apoptotic cell population was increased when treated with GB in a dose-dependent manner both in SKOV3 and CAOV3 cells. These effects were characterized by the upregulation of p21, p27, cleaved capase-3, and cleaved caspase-8 and downregulation of cyclin D1. In addition, a combined treatment of low concentrations of GB and CDDP showed an additive effect on the inhibition of SKOV3 cell proliferation. Furthermore, GB had significantly less cytotoxicity than CDDP in normal human ovarian surface epithelial cells. This study suggests that GB can be proposed as an effective antiproliferative and apoptosis-inducing agent with interesting translational application in ovarian cancers, used in addition to conventional chemotherapy.

Ginkgolide B inhibits renal cyst development in in vitro and in vivo cyst models

Autosomal dominant polycystic kidney disease (ADPKD) is a common inherited disease characterized by massive enlargement of fluid-filled cysts in the kidney. However, there is no effective therapy yet for this disease. To examine whether ginkgolide B, a natural compound, inhibits cyst development, a Madin-Darby canine kidney (MDCK) cyst model, an embryonic kidney cyst model, and a PKD mouse model were used. Interestingly, ginkgolide B significantly inhibited MDCK cyst formation dose dependently, with up to 69% reduction by 2 μM ginkgolide B. Ginkgolide B also significantly inhibited cyst enlargement in the MDCK cyst model, embryonic kidney cyst model, and PKD mouse model. To determine the underlying mechanisms, the effect of ginkgolide B on MDCK cell viability, proliferation, apoptosis, chloride transporter CFTR activity, and intracellular signaling pathways were also studied. Ginkgolide B did not affect cell viability, proliferation, and expression and activity of the chloride transporter CFTR that mediates cyst fluid secretion. Ginkgolide B induced cyst cell differentiation and altered the Ras/MAPK signaling pathway. Taken together, our results demonstrate that ginkgolide B inhibits renal cyst formation and enlargement, suggesting that ginkgolide B might be developed into a novel candidate drug for ADPKD.

Effects of quercetin on the apoptosis of the human gastric carcinoma cells

Quercetin, a natural constituent abundantly present in grapes, red wine, and other food products, is known to possess potent antiproliferative effects against various malignant cells. The present study aims to investigate the effect of quercetin on the apoptosis and morphology of gastric carcinoma BGC-823 cells, as well as the probable mechanism, in an effort to identify an effective drug as a potential candidate for gastric cancer. Gastric carcinoma BGC-823 cells were treated with quercetin, and cell morphology was determined by light microscopy and transmission electron microscopy. Apoptosis and cell cycle were measured by flow cytometry, using propidium iodide staining. The apoptotic protein expression of caspase-3, Bcl-2 and Bax was detected by Western blot. Quercetin induced apoptosis in BGC-823 cell. Some morphologic features of apoptosis were found, such as cell shrinkage or even apoptosis body. Quercetin changed the apoptotic protein expression. These results indicate that quercetin can induce apoptosis of the BGC-823 cells. A decrease in Bcl-2/Bax ratio with the increased expression of caspase-3 provides evidence that quercetin-induced apoptosis may be mediated via the mitochondrial pathway.

Ginkgolide A-gold nanoparticles inhibit vascular smooth muscle proliferation and migration in vitro and reduce neointimal hyperplasia in a mouse model

BACKGROUND

Neointimal formation is mediated by phenotypic changes in vascular smooth muscle cells (SMC) and is an important mediator of restenosis following arterial reconstruction. We conjugated antioxidant ginkgolide A (GA) to gold nanoparticles (GNP) to determine the effect of GA delivery on neointimal formation.

MATERIALS AND METHODS

GA was conjugated to 80 nm GNP in an overnight incubation. Mouse P53LMAC01 vascular SMC were treated with various doses of GA-GNP, GA alone, GNP alone, and no treatment control. Cell proliferation and migration were analyzed, and superoxide anion levels and the phosphorylation status of ERK1/2 were determined. Mice underwent ligation of the common carotid artery along with local treatment with GNP (control) or GA-GNP. The carotid artery was harvested and subjected to immunohistochemical analysis.

RESULTS

GA-GNP treatment significantly inhibited SMC proliferation and migration in vitro in comparison to GNP treatment alone, and the effect persisted for up to 72 h after treatment. Treatment with GA-GNP also reduced superoxide anion levels in vitro. PDGF-BB substantially induced ERK1/2 phosphorylation in GNP control cells; this PDGE-BB induced ERK1/2 phosphorylation was significantly inhibited in GA-GNP-treated cells compared with GNP only. GA-GNP significantly reduced neointimal hyperplasia after injury in mice, and proliferating cell nuclear antigen (PCNA) staining was reduced substantially in the arteries of mice treated with GA-GNP.

CONCLUSIONS

GA-GNP reduce vascular SMC proliferation and migration in vitro through reduced activation of ERK1/2. Local treatment with GA-GNP in areas of arterial injury reduced neointimal hyperplasia and subsequent stenosis.

Ginkgo biloba and risk of cancer: secondary analysis of the Ginkgo Evaluation of Memory (GEM) Study

PURPOSE

Evidence from in vitro and in vivo studies suggests that Ginkgo biloba has cancer chemopreventive properties, but epidemiological evidence is sparse. We analyzed cancer as a secondary endpoint in the Ginkgo Evaluation of Memory (GEM) Study, the largest randomized, double-blind, placebo-controlled clinical trial of Ginkgo supplementation to date.

METHODS

A total of 3069 GEM participants 75+ years of age were randomized to twice-daily doses of either 120 mg Ginkgo extract (EGb 761) or placebo and followed for a median 6.1 years. We identified hospitalizations for invasive cancer by reviewing hospital admission and discharge records for all reported hospitalizations over follow-up. Using an intention-to-treat approach, we compared the risk of cancer hospitalization between participants assigned to treatment and those assigned to placebo.

RESULTS

During the intervention, there were 148 cancer hospitalizations in the placebo group and 162 in the EGb 761 group (Hazard ratio (HR), 1.09; 95% confidence interval (CI), 0.87-1.36; p = 0.46). Among the site-specific cancers analyzed, we observed an increased risk of breast (HR, 2.15; 95%CI, 0.97-4.80; p = 0.06) and colorectal (HR, 1.62; 95%CI, 0.92-2.87; p = 0.10) cancer, and a reduced risk of prostate cancer (HR, 0.71; 95%CI, 0.43-1.17; p = 0.18).

CONCLUSIONS

Overall, these results do not support the hypothesis that regular use of Ginkgo biloba reduces the risk of cancer.

Cancer prevention with natural compounds

Botanical and nutritional compounds have been used for the treatment of cancer throughout history. These compounds also may be useful in the prevention of cancer. Population studies suggest that a reduced risk of cancer is associated with high consumption of vegetables and fruits. Thus, the cancer chemopreventive potential of naturally occurring phytochemicals is of great interest. There are numerous reports of cancer chemopreventive activity of dietary botanicals, including cruciferous vegetables such as cabbage and broccoli, Allium vegetables such as garlic and onion, green tea, Citrus fruits, soybeans, tomatoes, berries, and ginger, as well as medicinal plants. Several lead compounds, such as genistein (from soybeans), lycopene (from tomatoes), brassinin (from cruciferous vegetables), sulforaphane (from asparagus), indole-3-carbinol (from broccoli), and resveratrol (from grapes and peanuts) are in preclinical or clinical trials for cancer chemoprevention. Phytochemicals have great potential in cancer prevention because of their safety, low cost, and oral bioavailability. In this review, we discuss potential natural cancer preventive compounds and their mechanisms of action.

Activated networking of platelet activating factor receptor and FAK/STAT1 induces malignant potential in BRCA1-mutant at-risk ovarian epithelium

OBJECTIVES

It is essential to understand the molecular basis of ovarian cancer etiology and tumor development to provide more effective preventive and therapeutic approaches to reduce mortality. Particularly, the molecular targets and pathways involved in early malignant transformation are still not clear. Pro-inflammatory lipids and pathways have been reported to play significant roles in ovarian cancer progression and metastasis. The major objective of this study was to explore and determine whether platelet activating factor (PAF) and receptor associated networking pathways might significantly induce malignant potential in BRCA1-mutant at-risk epithelial cells.

METHODS

BRCA1-mutant ovarian epithelial cell lines including (HOSE-636, HOSE-642), BRCA1-mutant ovarian cancer cell (UWB1.289), wild type normal ovarian epithelial cell (HOSE-E6E7) and cancerous cell line (OVCA429), and the non-malignant BRCA1-mutant distal fallopian tube (fimbria) tissue specimens were used in this study. Mutation analysis, kinase microarray, western blot, immune staining, co-immune precipitation, cell cycle, apoptosis, proliferation and bioinformatic pathway analysis were applied.

RESULTS

We found that PAF, as a potent pro-inflammatory mediator, induced significant anti-apoptotic effect in BRCA1-mutant ovarian surface epithelial cells, but not in wild type HOSE cells. With kinase microarray technology and the specific immune approaches, we found that phosphor-STAT1 was activated by 100 nM PAF treatment only in BRCA1-mutant associated at-risk ovarian epithelial cells and ovarian cancer cells, but not in BRCA1-wild type normal (HOSE-E6E7) or malignant (OVCA429) ovarian epithelial cells. Co-immune precipitation revealed that elevated PAFR expression is associated with protein-protein interactions of PAFR-FAK and FAK-STAT1 in BRCA1-mutant ovarian epithelial cells, but not in the wild-type control cells.

CONCLUSION

Previous studies showed that potent inflammatory lipid mediators such as PAF and its receptor (PAFR) significantly contribute to cancer progression and metastasis. Our findings suggest that these potent inflammatory lipids and receptor pathways are significantly involved in the early malignant transformation through PAFR-FAK-STAT1 networking and to block apoptosis pathway in BRCA1 dysfunctional at-risk ovarian epithelium.

Potential of Ginkgo biloba L. leaves in the management of hyperglycemia and hypertension using in vitro models

Leaves from four different Ginkgo biloba L. trees (1 and 2--females; 3 and 4--males), grown at the same conditions, were collected during a period of 5 months (from June to October, 2007). Water and 12% ethanol extracts were analyzed for total phenolics content, antioxidant activity, phenolic profile, and the potential in vitro inhibitory effects on alpha-amylase, alpha-glucosidase, and Angiotensin I-Converting Enzyme (ACE) enzymes related to the management of diabetes and hypertension. The results indicated a significant difference among the trees in all functional benefits evaluated in the leaf extracts and also found important seasonal variation related to the same functional parameters. In general, the aqueous extracts had higher total phenolic content than the ethanolic extracts. Also, no correlation was found between total phenolics and antioxidant activity. In relation to the ACE inhibition, only ethanolic extracts had inhibitory activity.

Perspectives for cancer prevention with natural compounds

Cancer is the second leading cause of death in the United States. Despite the estimated 565,650 deaths in 2008 of Americans as a result of cancer, it is mostly a preventable disease. Simply by modification of diet, maintenance of optimum body weight, and regular physical activity, 30% to 40% of all instances of cancer could be prevented. Modification of diet alone by increasing vegetable and fruit intake could prevent 20% or more of all cases of cancer and may potentially prevent approximately 200,000 cancer-related deaths annually. Because of their safety, low toxicity, antioxidant properties, and general acceptance as dietary supplements, fruits, vegetables, and other dietary elements (phytochemicals and minerals) are being investigated for the prevention of cancer. Extensive research over the past several decades has identified numerous dietary and botanical natural compounds that have chemopreventive potential. In this review, we discuss promising natural chemopreventive compounds, their molecular targets, and their mechanisms, which may help the further design and conduct of preclinical and clinical trials.

FLT1 and its ligands VEGFB and PlGF: drug targets for anti-angiogenic therapy?

Less than 5 years ago, it was still not clear whether anti-angiogenic drugs would prove successful in the clinic. After numerous patients with cancer or age-related macular degeneration have been treated with these drugs, they have now become part of the standard range of therapeutic tools. Despite this milestone, anti-angiogenic therapy still faces a number of clinical hurdles, such as improving efficacy, avoiding escape and resistance, and minimizing toxicity. Hopefully, other agents with complementary mechanisms, such as those that target placental growth factor, will offer novel opportunities for improved treatment.

Ginkgo biloba extract EGb 761 exerts anti-angiogenic effects via activation of tyrosine phosphatases

The standardised Ginkgo biloba extract EGb 761 (Dr. Willmar Schwabe Pharmaceuticals, Karlsruhe, Germany) is one of the most widely used herbal remedies. Indications for this extract range from dementia to peripheral vascular disease, based on well-documented vascular effects. Surprisingly, the actions of EGb 761 on angiogenesis as a function of vascular cells have not been investigated to date. The anti-cancer activity of EGb 761 in vitro and epidemiological data showing reduced risk for ovarian cancer in regular users have prompted us to investigate this issue. We show an anti-angiogenic profile of EGb 761 in vitro (inhibited proliferation, migration and tube formation of endothelial cells) and in vivo in the chicken chorio-allantoic membrane (CAM) assay. An analysis of the underlying mechanisms indicates inhibition of growth factor-induced extracellular signal-regulated kinase (ERK) phosphorylation by EGb 761. Inhibitory effects of EGb 761 on ERK as well as of the upstream kinases map-erk-kinase (MEK) and rapidly growing fibrosarcoma (Raf)-1 could be completely reversed by pre-treatment with sodium vanadate (inhibitor of tyrosine phosphatases). Sodium vanadate also reversed the EGb 761-induced inhibition of endothelial cell migration. Focusing on tyrosine phosphatases upstream of the Raf-MEK-ERK cascade, we identified the tyrosine phosphatase Src homology-2 domain-containing phosphatase 1 (SHP-1) as one target of EGb 761. SHP-1 was rapidly activated by EGb 761, and silencing SHP-1 (siRNA) abrogated reduction of endothelial proliferation by EGb 761. In summary, we identify EGb 761 as a potent anti-angiogenic drug. The underlying mechanism is the activation of protein tyrosine phosphatases, leading to inhibition of the Raf-MEK-ERK pathway. These findings provide a rational basis for using EGb 761 for an additional therapeutic indication: anti-angiogenesis-based tumour prevention and adjuvant therapy.

Activation of platelet-activating factor receptor and pleiotropic effects on tyrosine phospho-EGFR/Src/FAK/paxillin in ovarian cancer

Among the proinflammatory mediators, platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine) is a major primary and secondary messenger involved in intracellular and extracellular communication. Evidence suggests that PAF plays a significant role in oncogenic transformation, tumor growth, angiogenesis, and metastasis. However, PAF, with its receptor (PAFR) and their downstream signaling targets, has not been thoroughly studied in cancer. Here, we characterized the PAFR expression pattern in 4 normal human ovarian surface epithelial (HOSE) cell lines, 13 ovarian cancer cell lines, paraffin blocks (n = 84), and tissue microarrays (n = 230) from patients with ovarian cancer. Overexpression of PAFR was found in most nonmucinous types of ovarian cancer but not in HOSE and mucinous cancer cells. Correspondingly, PAF significantly induced cell proliferation and invasion only in PAFR-positive cells (i.e., OVCA429 and OVCA432), but not in PAFR-negative ovarian cells (HOSE and mucinous RMUG-L). The dependency of cell proliferation and invasion on PAFR was further confirmed using PAFR-specific small interfering RNA gene silencing probes, antibodies against PAFR and PAFR antagonist, ginkgolide B. Using quantitative multiplex phospho-antibody array technology, we found that tyrosine phosphorylation of EGFR/Src/FAK/paxillin was coordinately activated by PAF treatment, which was correlated with the activation of phosphatidylinositol 3-kinase and cyclin D1 as markers for cell proliferation, as well as matrix metalloproteinase 2 and 9 for invasion. Specific tyrosine Src inhibitor (PP2) reversibly blocked PAF-activated cancer cell proliferation and invasion. We suggest that PAFR is an essential upstream target of Src and other signal pathways to control the PAF-mediated cancer progression.

Protective effects of Ginkgo biloba against rat liver carcinogenesis

Ginkgo biloba (EGb) has been proposed as a promising candidate for cancer chemoprevention and has shown protective effects on the liver against chemically induced oxidative injury and fibrosis. The potential beneficial effects of EGb were investigated in two rat liver carcinogenesis bioassays induced by diethylnitrosamine (DEN). In a short-term study for anti-initiating screening, male Wistar rats were fed a basal diet or supplemented diet with 500 or 1000 ppm EGb and initiated 14 days later with a single dose of DEN (100 mg/kg i.p.). The respective groups were killed 24h or 2 weeks after DEN-initiation. Liver samples were collected for the analysis of proliferating cell nuclear antigen (PCNA), transforming growth factor alpha (TGF-alpha), p53, apoptosis and induction of single hepatocytes and minifoci positive for the enzyme glutathione S-transferase P-form (GST-P). In a medium-term study for anti-promoting screening, the animals received a single dose of DEN (200 mg/kg i.p.) and, 2 weeks later, were fed a basal diet or supplemented diet with 500 or 1000 ppm EGb for 6 weeks. All animals underwent 70% partial hepatectomy (PH) at week 3 and killed at week 8. Liver samples were collected to analyze development of preneoplastic foci of altered hepatocytes (FAH) expressing GST-P. In the short-term study, pretreatment of rats with 1000 ppm EGb significantly reduced the rates of cell proliferation, apoptosis and p53, TGF-alpha immunoreactivity and the number of GST-P-positive hepatocytes. In the medium-term study, EGb treatment during the post-initiation stage failed to reduce the development of DEN-induced GST-P-positive foci. Thus, EGb presented inhibitory actions during initiation but not promotion of rat liver carcinogenesis induced by DEN.