Ethical and moral principles for oncology healthcare workers: A brief report from a Bioethics consortium emphasizing on need for education.

The medical sub-specialty of Oncology presents diverse ethical dilemmas, often challenging cancer healthcare workers with difficult-to-handle clinical scenarios that are tough from a personal and professional perspective. Making decisions on patient care in various circumstances is a defining obligation of an oncologist and those duty-based judgments entail more than just selecting the best treatment or solution. Ethics is an essential and inseparable aspect of clinical medicine and the oncologists as well as the allied health care workers are ethically committed to helping the patient, avoiding or minimizing harm, and respecting the patient's values and choices. This review provides an overview of ethics and clinical ethics and the four main ethical principles of autonomy, beneficence, non-maleficence, and justice are stated and explained. At times there are frequently contradictions between ethical principles in patient care scenarios, especially between beneficence and autonomy. In addition, truth-telling, professionalism, empathy, and cultural competence; which are recently considered important in cancer care, are also addressed from an Indian perspective.

Usefulness of Honey as an Adjunct in the Radiation Treatment for Head and Neck Cancer: Emphasis on Pharmacological and Mechanism/s of Actions.

BACKGROUND: In the treatment of head and neck cancer (HNC), ionizing radiation is an important modality in achieving curative objectives. However, the effective use of radiation is compromised by the side effects resulting from the damage to the adjacent normal tissue. Preclinical studies carried out in the recent past have shown that the age-old dietary agent honey, which also possesses myriad medicinal use, is beneficial for mitigating diverse radiation-induced side effects like mucositis, xerostomia, fatigue, weight loss and promoting healing of refractory wounds. OBJECTIVE: The objective of this memoir is to review the beneficial effects of honey in mitigating radiation-induced side effects in HNC and to emphasize on the underlying mechanisms of action for inducing the beneficial effects. METHODS: Two authors searched Google Scholar, PubMed, Embase, and the Cochrane Library for publications up to December 2019 to assess the capability of honey for reducing the severity of radiation-induced ill effects in the treatment of HNC. Subsequently, the adjunct pharmacological effects and mechanism/s responsible were also searched for and appropriately used to substantiate the underlying mechanism/s of action for the beneficial effects. RESULTS: The existing data is suggestive that honey is beneficial in mitigating the radiation-induced mucositis, xerostomia, amd healing of recalcitrant wounds in radiation-exposed regions, and that the multiple pathways mediate the beneficial effects, especially free radical scavenging, antioxidant, wound healing, anticancer, analgesic, anti-inflammatory, anabolic, anti-fatigue and anti-anaemic effects that add additional value to the use of honey as an adjunct in cancer therapy. CONCLUSION: For the first time, this review addresses the underlying pharmacological related to the beneficial effects of honey in radiation-induced damage, and attempts at emphasizing the lacunae that need further studies for optimizing the use of honey as an adjunct in radiotherapy of HNC. The authors suggest that future studies should be directed at understanding the detailed molecular mechanisms responsible for the beneficial effects using validated cell culture and animal models of study. Large multicentric clinical trials with standardised honey also needed to understand the clinical use of honey.

Traditionally Used Natural Products in Preventing Ionizing Radiation-Induced.

In the treatment of cancer, the use of ionizing radiation is an important modality. However, on the downside, radiation, when used for curative purposes, causes acute dermatitis or radiodermatitis at the site of radiation in most individuals. From a clinical viewpoint, severe dermatitis causes a burning and itching sensation is very painful and severely affects the quality of life of the individual undergoing treatment. In worse situations, acute radiation dermatitis can cause gaps or breaks in the planned treatment and this can adversely affect the treatment objective and outcome. BACKGROUND: In various traditional and folk systems of medicine, plants and plant products have been used since time immemorial for treating various skin ailments. Further, many cosmeceutical creams formulated based on knowledge from ethnomedicinal use are marketed and used to treat various ailments. In the current review, an attempt is made at summarizing the beneficial effects of some plants and plant products in mitigating acute radiation dermatitis in humans undergoing curative radiotherapy. Additionally, emphasis is also placed on the mechanisms responsible for the beneficial effects. OBJECTIVE: The objective of this review is to summarize the clinical observations on the prevention of radiodermatitis by plant products. In this review, the protective effects of Adlay (Coix lachryma-jobi L.) bran extract, Aloe vera, Calendula officinalis, Cucumis sativus, green tea constituent the epigallocatechin-3-gallate, honey, Achillea millefolium, Matricaria chamomilla, olive oil, and some polyherbal creams are addressed by also focusing on the mechanism of action for the beneficial effects. METHODS: Two authors' data mined for information in Google Scholar, PubMed, Embase, and the Cochrane Library for publications in the field from 1901 up to July 2020. The focus was on acute radiation dermatitis, ionizing radiation, curative radiotherapy, human cancer. The articles were collected and analyzed. RESULTS: For the first time, this review addresses the usefulness of natural products like adlay bran, Aloe vera, Calendula officinalis, Cucumis sativus, green tea constituent the epigallocatechin-3-gallate, honey, Achillea millefolium, Matricaria chamomilla, olive oil, and some experimentally constituted and commercially available polyherbal creams as skincare agents against the deleterious effects of ionizing radiation on the skin. The protective effects are possibly due to the free radical scavenging, antioxidant, anti-inflammatory, wound healing and skin protective effects. CONCLUSION: The authors suggest that these plants have been used since antiquity as medicinal agents and require in-depth investigation with both clinical and preclinical validated models of study. The results of these studies will be extremely useful to cancer patients requiring curative radiotherapy, the dermatology fraternity, agro-based and pharmaceutical sectors at large.

Generic Anticancer Drugs of the Jan Aushadhi Scheme in India and Their Branded Counterparts: The First Cost Comparison Study.

INTRODUCTION:  In India, the costs of cancer drugs are exorbitant and cause significant financial toxicity to the affected patient and their family members. Considering this, Jan Aushadhi pharmacy stores were established across the country by the government of India with the objective of providing cheap generic medicines to patients. The objective of this study was to perform a cost comparison study of generic chemotherapeutic drugs provided through Jan Aushadhi pharmacies versus their branded counterparts. This will help patients and physicians get first-hand information on the cost variation between generic and branded anticancer drugs in India. MATERIALS AND METHODS:  The cost of Jan Aushadhi generic drugs and the cost of the most expensive and cheapest marketed branded drugs for the same molecule and dose were ascertained and presented in both Indian Rupees (INR) and US Dollars (as of July 2021). Finally, the difference in costs in INR, cost ratio, and cost variance were calculated, comparing the price of the Jan Aushadhi generic drugs with the most expensive and the cheapest branded drug in the same category. RESULTS: Compared to branded drugs, all the Jan Ausadhi generic drugs were cheaper, except one (methotrexate). The highest cost difference was observed for docetaxel, while the least was observed for methotrexate tablets (2.5 mg). The highest cost ratio (22.24) and cost variance (3327.56) were observed for doxorubicin injection (50 mg). CONCLUSION:  The current study compares the cost difference between the marketed branded and Jan Aushadhi generic anticancer drugs for the first time. Replacing the costly branded anticancer drugs with Jan Aushadhi generic drugs can result in substantial cost savings. The information obtained from this cost difference analysis will be helpful for the healthcare fraternity, patients, policymakers, and society at large.

Audit of drug-drug interactions and adverse drug reactions due to polypharmacy in older cancer patients: First report from India.

BACKGROUND: In elderly people, the body's metabolic processes are not optimal and pharmacokinetics and pharmacodynamic profile of drugs are compromised or reduced. Under these conditions, the concomitant use of diverse classes of drugs can potentially increase the risk of adverse reactions and drug interactions. This will consequentially affect the already debilitated organ system. As far as the authors are aware, there are no studies addressing the drug-drug interactions and adverse drug reactions due to polypharmacy in older patients with cancer and therefore, we conducted this study. METHODS: This was an observational chart-based study and was carried out in a tertiary care cancer hospital. The data concerning prescription of all prescribed medications were noted down from the medication chart of the patient in the wards. RESULTS: The most common drug-to-drug interaction that could have happened was due to the combination of theophylline with budesonide (26.10%). Adverse drug reactions were noted during the course of time, the most common being nausea and vomiting (71.9%). CONCLUSIONS: As the geriatric population is increasing, the need to address medical problems among aged patients with cancer is the need of the hour. The adverse drug reactions and drug interactions that have occurred were lesser when compared to published observations.

Honey in oral health and care: A mini review.

BACKGROUND: Honey is a natural product made from the nectar of flowers by honey bees and has over 200 compounds in it, including sugars, water, organic acids, minerals and polyphenols - the exact structure and composition of honey often determined by which plant source(s) the honey bee took the nectar from. Honey has been used in diets and medicines for thousands of years; however, this review, for the first time, aims to look at its place in modern medicine concerning oral health. HIGHLIGHT: The present review for the first time attempted to address the protective effect of honey in the oral care. CONCLUSION: For the first time this review addresses the usefulness of honey against Streptococcus mutans infections, dental plaque and caries, gingivitis and halitosis. Honey was also useful in preventing side effects associated with treatment of cancers of the head and neck, namely, radiation induced mucositis, xerostomia and poor wound healing. This is well supported by evidence in literature and was examined in this review.

Honey Mitigates Radiation-Induced Oral Mucositis in Head and Neck Cancer Patients without Affecting the Tumor Response.

Radiation-induced mucositis is a dose-limiting factor in the effective treatment of head and neck (H & N) cancers. The objective of this study was to understand the efficacy of honey in mitigating radiation-induced mucositis and whether it would interfere with tumor control. This was a single-blinded, randomized, controlled study and was carried out in patients with H & N cancer requiring curative radiotherapy (>62 Gy (Gray)). The patients meeting the inclusion criteria were randomly assigned to receive either honey ( n = 25) or povidone-iodine (active comparator) ( n = 25) during radiotherapy. Oral mucositis was assessed using the RTOG (Radiation Therapy Oncology Group) grading system before the start, during, and at the end of the treatment by an investigator unaware of the treatment. The results indicate that when compared with the active comparator, honey reduced the radiation-induced oral mucositis, decreased the incidence of intolerable mucositis, treatment breaks, loss of treatment days ( p < 0.0001 and < 0.0003) and did not affect the radiation-induced tumor response. The clinical observations indicate that honey mitigates the radiation-induced mucositis and does not interfere with tumor cell killing.

Clinical evaluation of Viscum album mother tincture as an antihypertensive: a pilot study.

Viscum album, an infrequently used antihypertensive in homeopathy, is evaluated by 1-group pretest-posttest model in primary hypertension. The drug was administered for 12 weeks at a dosage of 10 drops 3 times a day. Using paired t test, a significant drop in blood pressure (P < .0001) and serum triglyceride (P < .0001) was observed in the treatment group. This dual effect of Viscum album shows promise in optimizing therapy for primary hypertension.

Scientific validation of the antidiabetic effects of Syzygium jambolanum DC (black plum), a traditional medicinal plant of India.

BACKGROUND: In spite of the tremendous progress achieved in medical sciences in the last century, the management of diabetes mellitus, a disease as old as mankind, is poor. Diabetes is currently the world's largest endocrine disorder, and estimates are that it affects almost 5% of the population. Ayurveda, the Indian traditional system of medicine, is one of the world's oldest systems to have documented the diagnosis and treatment of diabetes. METHODS: Experimental studies performed in accordance with the modern medicine principles have shown that some of the medicinal plants and polyherbal preparations made using the plants used in Ayurveda are effective in preventing both hyperglycemia and its complications. Syzygium jambolanum (Syn Syzygium cumini, Eugenia cumini, Eugenia jambolana), commonly known as black plum and originally indigenous to India, is one of the important antidiabetic plants. RESULTS: Jamun has been used in various complementary and alternative systems of medicine and, before the discovery of insulin, was a frontline antidiabetic medication even in Europe. The brew prepared by boiling the Jamun seeds in boiling water has been used in the various traditional systems of medicine in India. CONCLUSIONS: This review includes the validated antidiabetic effects of Jamun and some of its compounds. Emphasis is also placed on addressing the various mechanisms of action contributing to the pharmacological effects and the aspects that need future investigations for Jamun to be of clinical use.

Zingiber officinale (ginger) as an anti-emetic in cancer chemotherapy: a review.

Despite significant advances and development of novel anti-emetics, nausea and vomiting (emesis) is a major side-effect of cancer chemotherapy. At times, severe nausea and vomiting may also lead to reduction in adherence to the treatment regimen, and this will concomitantly affect the patient's survival. The rhizome of Zingiber officinale, commonly known as ginger, is globally an important spice. It has been used for centuries in the Indian, Chinese, Arabic, Tibetan, Unani, and Siddha systems of traditional medicine to treat nausea and vomiting induced by different stimuli. Preclinical studies with experimental animals (dogs and rats) have shown that the various extracts of ginger and the ginger juice possess anti-emetic effects against chemotherapy-induced nausea and vomiting. Gingerol, the active principle, is also shown to possess anti-emetic effects in minks. However, with regard to humans, while most studies have been supportive of the preclinical observations, a few have been contradictory. The exact mechanism responsible for the anti-emetic effects of ginger is unknown; however, the ginger phytochemicals, especially 6-gingerol, 8-gingerol, 10-gingerol, and 6-shogaol, may function as a 5-hydroxytryptamine (5-HT3) antagonist, NK1 antagonist, antihistaminic, and possess prokinetic effects. The present review for the first time attempts to address the anti-emetic observations and the variability in response of the anti-emetic effects of ginger in cancer chemotherapy. An attempt is also made to address the lacunae in the published studies and emphasize aspects that need further investigations for ginger to be of use in clinics as an anti-emetic agent in the future.

Radioprotective potential of mint: a brief review.

Radiation is an important modality in cancer treatment and estimates are that between one third and one half of all patients will require ionizing irradiation therapy during some point in their clinical management. However, the radiation-induced damage to the normal tissues restricts the therapeutic doses of radiation that can be delivered to tumors and thereby limits the effectiveness of the treatment. The use of chemical compounds (radioprotectors) represents an obvious strategy to improve the therapeutic index in radiotherapy. However, most of the synthetic radioprotective compounds studied have shown inadequate clinical application owing to their inherent toxicity and high cost. These observations necessitated a search for alternative agents that are less toxic and highly effective. Studies in the recent past have shown that some medicinal plants possess radioprotective effects. Two species of the commonly used aromatic herb mint, Mentha piperita and M. arvensis protected mice against the γ-radiation-induced sickness and mortality. Detail investigations have also shown that the aqueous extract of M. piperita protected the vital radiosensitive organs: the testis, gastrointestinal and hemopoetic systems in mice. The radioprotective effects are possibly due to free radical scavenging, antioxidant, metal chelating, anti-inflammatory, antimutagenic, and enhancement of the DNA repair processes. This review for the first time summarizes the observations and elucidates the possible mechanisms responsible for the beneficial effects. The lacunae in the existing knowledge and directions for future research are also addressed.

Selenoprotein deficiency enhances radiation-induced micronuclei formation.

The availability of selenium and the levels of specific selenoproteins might affect cancer risk by influencing the ability of DNA damaging agents to cause genomic instability and mutations. Transgenic mice that express reduced levels of selenoproteins and previously shown to be more susceptible to pathology associated with cancer development were used to study this possibility. These mice were exposed to X-rays and DNA damage assessed in the erythrocytes, where micronuclei formation was higher compared to the same cells obtained from irradiated wild-type controls. To determine whether the selenoprotein glutathione peroxidase-1 (GPx-1) might be involved in this protection, its levels were reduced by siRNA targeting in LNCaP human prostate cells. UV-induced micronuclei frequency was higher in these cells compared to control-transfected cells. These results indicate a role for selenoproteins in protecting DNA from damage and support human data implicating GPx-1 as a possible target of the chemoprotective effect of selenium.

Selenium and GPx-1 overexpression protect mammalian cells against UV-induced DNA damage.

Supplementation of the culture media of human MCF-7 breast carcinoma cells or mouse fibroblasts with low levels of selenium (30 nM) provided as sodium selenite was shown to protect these cells from ultraviolet (UV)-induced chromosome damage, as quantified by micronucleus assay. Selenium supplementation was also effective in reducing UV-induced gene mutations as measured in the lacI shuttle vector model. Protection was dependent on functional BRCA1 activity, a protein implicated in breast cancer risk and DNA damage repair. In addition, overexpression of GPx-1, a selenoprotein with antioxidant activity, also attenuated UV induced micronuclei formation in the absence of selenium supplementation. Combining selenium supplementation with GPx-1 overexpression further reduced UV-induced micronucleus frequency. These data provide evidence that the benefits of selenium supplementation might be either through the prevention or repair of DNA damage, and they implicate at least one selenoprotein (GPx-1) in the process.

Evaluation of the radioprotective effect of Liv 52 in mice.

Liv 52 is a mixture of botanicals that is used clinically to treat various hepatic disorders. In this study, the radioprotective activity of Liv 52 was evaluated in mice given whole-body exposure to different doses of gamma-radiation. In addition, a series of studies was conducted to explore the mechanism of radioprotection. Radioprotection was evaluated by the ability of Liv 52 to reduce both the frequency of bone marrow micronucleated erythrocytes and the lethality produced by (60)Co gamma-radiation. Mice were treated by oral gavage once daily for seven consecutive days with 500 mg/kg body weight Liv 52 or carboxymethylcellulose vehicle prior to radiation. Micronucleated polychromatic erythrocytes (MPCEs), micronucleated normochromatic erythrocytes (MNCEs), and the PCE/NCE ratio were measured at 0.25-14 days after exposure to whole-body radiation doses of 0, 0.5, 1.5, 3.0, or 4.5 Gy; animal survival was monitored after doses of 7, 8, 9, 10, 11, or 12 Gy. Pretreatment of mice with Liv 52 significantly reduced the frequency of radiation-induced MPCEs and MNCEs. Irradiation reduced the PCE/NCE ratio in a dose-related manner for up to 7 days following irradiation; Liv 52 pretreatment significantly mitigated against these reductions. Liv 52 treatment also reduced the symptoms of radiation sickness and increased mouse survival 10 and 30 days after irradiation. Liv 52 pretreatment elevated the levels of reduced glutathione (GSH), increased the activities of glutathione transferase, GSH peroxidase, GSH reductase, superoxide dismutase, and catalase, and lowered lipid peroxidation (LPx) and the activities of alanine amino transferase and aspartate aminotransferase 30 min after exposure to 7 Gy of gamma-radiation. Liv 52 pretreatment also reduced radiation-induced LPx and increased GSH concentration 31 days following the exposure. The results of this study indicate that pretreatment with Liv 52 reduces the genotoxic and lethal effects of gamma-irradiation in mice and suggest that this radioprotection may be afforded by reducing the toxic effects of the oxidative products of irradiation.

Grape seed proanthocyanidins induce apoptosis and inhibit metastasis of highly metastatic breast carcinoma cells.

The strategies available for the treatment of metastatic breast cancer are limited. Dietary botanicals may have a better protective effect on this disease. We therefore investigated the effects of grape seed proanthocyanidins (GSPs) on a highly metastatic mouse mammary carcinoma cell line. In vitro treatment of breast cancer cells, 4T1, MCF-7 and MDA-MB-468, with GSPs resulted in significant inhibition of cellular proliferation and viability, and induction of apoptosis in 4T1 cells in a time- and dose-dependent manner. Further analysis indicated an alteration in the ratio of Bax/Bcl-2 proteins in favor of apoptosis, and the knockdown of Bax using Bax siRNA transfection of 4T1 cells resulted in blocking of GSPs-induced apoptosis. Induction of apoptosis was associated with the release of cytochrome c, increased expression of Apaf-1 and activation of caspase 3 and poly (ADP-ribose) polymerase. Treatment with the pan-caspase inhibitor (Z-VAD-FMK) resulted in partial but significant inhibition of apoptosis in 4T1 cells suggesting the involvement of both caspase activation-dependent and activation-independent pathways in the apoptosis of 4T1 cells induced by GSPs. The effects of dietary GSPs were then examined using an in vivo model in which 4T1 cells were implanted subcutaneously in Balb/c mice. Dietary GSPs (0.2 and 0.5%, w/w) significantly inhibited the growth of the implanted 4T1 tumor cells and increased the ratio of Bax:Bcl-2 proteins, cytochrome c release, induction of Apaf-1 and activation of caspase 3 in the tumor microenvironment. Notably, the metastasis of tumor cells to the lungs was inhibited significantly and the survival of the mice enhanced. These data suggest that GSPs possess chemotherapeutic efficacy against breast cancer including inhibition of metastasis.

Chemoprevention of photocarcinogenesis by selected dietary botanicals.

Epidemiological, clinical and laboratory studies have implicated solar ultraviolet (UV) radiation as a tumor initiator, tumor promoter and complete carcinogen, and their excessive exposure can lead to the development of various skin disorders including melanoma and nonmelanoma skin cancers. Sunscreens are useful, but their protection is not adequate to prevent the risk of UV-induced skin cancer. It may be because of inadequate use, incomplete spectral protection and toxicity. Therefore new chemopreventive methods are necessary to protect the skin from photodamaging effects of solar UV radiation. Chemoprevention refers to the use of agents that can inhibit, reverse or retard the process of skin carcinogenesis. In recent years, considerable interest has been focused on identifying naturally occurring botanicals, specifically dietary, for the prevention of photocarcinogenesis. A wide variety of botanicals, mostly dietary flavonoids or phenolic substances, have been reported to possess substantial anticarcinogenic and antimutagenic activities because of their antioxidant and antiinflammatory properties. This review summarizes chemopreventive effects of some selected botanicals, such as apigenin, curcumin, grape seed proanthocyanidins, resveratrol, silymarin, and green tea polyphenols, against photocarcinogenesis in in vitro and in vivo systems. Attention has also been focused on highlighting the mechanism of chemopreventive action of these dietary botanicals. We suggest that in addition to the use of these botanicals as dietary supplements for the protection of photocarcinogenesis, these botanicals may favorably supplement sunscreens protection and may provide additional antiphotocarcinogenic protection including the protection against other skin disorders caused by solar UV radiation.

Growth inhibitory and antimetastatic effect of green tea polyphenols on metastasis-specific mouse mammary carcinoma 4T1 cells in vitro and in vivo systems.

PURPOSE: Breast cancer is the second leading cause of cancer-related deaths among females. Dietary habits may have a role in breast cancer risk and prevention as well. Here, we examined the effect of green tea polyphenols (GTP) on growth and metastasis of highly metastatic mouse mammary carcinoma 4T1 cells in vitro and in vivo systems. EXPERIMENTAL DESIGN: 4T1 cells were treated with (-)-epigallocatechin-3-gallate (EGCG), and the effect was determined on cellular proliferation, induction of apoptosis, proapoptosis, and antiapoptotic proteins of Bcl-2 family, and caspase 3 and poly(ADP-ribose) polymerase activation following 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, and Western blot analysis. Anticarcinogenic and antimetastatic effect of GTP in 4T1 cells was assessed in immunocompetent BALB/c mice. RESULTS: Treatment of 4T1 cells with EGCG resulted in inhibition of cell proliferation, induction of apoptosis in dose- and time-dependent manner. The increase in apoptosis was accompanied with decrease in the protein expression of Bcl-2 concomitantly increase in Bax, cytochrome c release, Apaf-1, and cleavage of caspase 3 and PARP proteins. Treatment of EGCG-rich GTP in drinking water to 4T1 cells bearing BALB/c mice resulted in reduction of tumor growth accompanied with increase in Bax/Bcl-2 ratio, reduction in proliferating cell nuclear antigen and activation of caspase 3 in tumors. Metastasis of tumor cells to lungs was inhibited and survival period of animals was increased after green tea treatment. CONCLUSION: This study suggests that GTP have the ability to prevent the development of breast cancer and its metastasis; however, further in vivo studies are required to identify the molecular targets.

Silymarin induces apoptosis primarily through a p53-dependent pathway involving Bcl-2/Bax, cytochrome c release, and caspase activation.

Silymarin, a plant flavonoid, has been shown to inhibit skin carcinogenesis in mice. However, the mechanism responsible for the anti-skin carcinogenic effects of silymarin is not clearly understood. Here, we report that treatment of JB6 C141 cells (preneoplastic epidermal keratinocytes) and p53+/+ fibroblasts with silymarin and silibinin (a major constituent of silymarin) resulted in a dose-dependent inhibition of cell viability and induction of apoptosis in an identical manner. Silymarin-induced apoptosis was determined by fluorescence staining (8-64% apoptosis) and flow cytometry (12-76% apoptosis). The silymarin-induced apoptosis was primarily p53 dependent because apoptosis occurred to a much greater extent in the cells expressing wild-type p53 (p53+/+, 9-61%) than in p53-deficient cells (p53-/-, 6-20%). The induction of apoptosis in JB6 C141 cells was associated with increased expression of the tumor suppressor protein, p53, and its phosphorylation at Ser15. The constitutive expression of antiapoptotic proteins Bcl-2 and Bcl-xl were decreased after silymarin treatment, whereas the expression of the proapoptotic protein Bax was increased. There was a shift in Bax/Bcl-2 ratio in favor of apoptotic signal in silymarin-treated cells, which resulted in increased levels of cytochrome c release, apoptotic protease-activating factor-1, and cleaved caspase-3 and poly(ADP-ribose) polymerase in JB6 C141 cells. The shift in Bax/Bcl-2 ratio was more prominent in p53+/+ fibroblasts than in p53-/- cells. Silymarin-induced apoptosis was blocked by the caspase inhibitor (Z-VAD-FMK) in JB6 C141 cells which suggested the role of caspase activation in the induction of apoptosis. These observations show that silymarin-induced apoptosis is primarily p53 dependent and mediated through the activation of caspase-3.

Grape seed proanthocyanidins induce apoptosis through p53, Bax, and caspase 3 pathways.

Grape seed proanthocyanidins (GSP) have been shown to inhibit skin chemical carcinogenesis and photocarcinogenesis in mice. The mechanisms responsible for the anticarcinogenic effects of GSP are not clearly understood. Here, we report that treatment of JB6 C141 cells (a well-developed cell culture model for studying tumor promotion in keratinocytes) and p53+/+ fibroblasts with GSP resulted in a dose-dependent induction of apoptosis. GSP-induced (20-80 g/ml) apoptosis was observed by using immunofluorescence (27-90% apoptosis) and flow cytometry (18-87% apoptosis). The induction of apoptosis by GSP was p53-dependent because it occurred mainly in cells expressing wild-type p53 (p53+/+; 15-80%) to a much greater extent than in p53-deficient cells (p53-/-; 6-20%). GSP-induced apoptosis in JB6 C141 cells was associated with increased expression of the tumor-suppressor protein, p53, and its phosphorylation at Ser15. The antiapoptotic proteins, Bcl-2 and Bcl-xl, were downregulated by GSP, whereas the expression of the pro-apoptotic protein, Bax, and the levels of cytochrome c release, Apaf-1, caspase-9, and cleaved caspase 3 (p19 and p17) were markedly increased in JB6 C141 cells. The downregulation of Bcl-2 and upregulation of Bax were also observed in wild-type p53 (p53+/+) fibroblasts but was not observed in their p53-deficient counterparts. These data clearly demonstrate that GSP-induced apoptosis is p53-dependent and mediated through the Bcl-2, Bax, and caspase 3 pathways.