Protection against radiation oxidative damage in mice by Triphala

Ayurvedic Drug Triphala in Combination with Providone Iodine Mitigates Radiation-Induced Mucositis in Head and Neck Cancer Patients without Affecting the Tumor Response

Radiation-induced mucositis is a dose-limiting concern in the treatment of head and neck cancers (HNC). This study was conducted to determine the effectiveness of the Ayurvedic drug Triphala in reducing radiation-induced mucositis and influencing tumour control when combined with providone iodine. Data from patient files of HNC patients who received Triphala in conjunction with iodine or iodine alone over the course of curative radiotherapy (> 60 Gy) from May 2013 to February 2015 were extracted for this retrospective chart based study. Data was subjected to statistical analysis, X2 and unpaired t test using the Statistical Package for Social Sciences (SPSS), version 17 (IBM, Chicago, USA). When compared to iodine alone, the group that utilised Triphala gargling was very efficient in delaying mucositis, the extent of weight loss (p = 0.038), the incidence (p = 0.03), and the number (p = 0.02) of treatment breaks. However, it had no influence on the radiation-induced tumour response. According to the observations, Triphala coupled with iodine was more successful in preventing radiation mucositis, and without affecting the killing of tumour cells than iodine gargle alone. According to the authors, this is the first observation to demonstrate the value of combining providone iodine with Triphala in preventing radiation-induced oral mucositis.

A Narrative Review of the Herbal Preparation of Ayurvedic, Traditional Chinese, and Kampō Medicines Applied as Radioprotectors

In recent years, there has been growing scientific interest in the search for natural radioprotectors that can be used to mitigate the effects of radiation on patients, healthcare personnel, and even for space travel. This narrative review covers the past fifty years and focuses on herbal preparations of Ayurvedic, Traditional Chinese, and Kampō Medicines that have the potential to reduce or eliminate the harmful effects of radiation. Our findings highlight ten herbal preparations, namely Abana, Amalakyadi Churna, Amritaprasham, Brahma, Bu-zhong-yi-qi-tang (BZYQT), Chyavanaprasha, Cystone, Geriforte, Mentat, and Triphala, which have demonstrated potential radioprotective effects. This review examines their composition, properties, and possible mechanisms of action in relation to their radioprotective properties. Exploring the ethnobotany of traditional Asian medicine is particularly interesting as it may lead to the discovery of new active compounds with radioprotective properties.

Aqueous Extract of Emblica officinalis Linn (Indian gooseberry) in Combination with Iodine is More Efficacious than Iodine Alone in Mitigating Mucositis in Head and Neck Cancer Patients Undergoing Curative Radiotherapy: Retrospective Observations

Mucositis is a very painful unavoidable and common side effect in head and neck cancer patients undergoing curative radiotherapy and can affect the planned treatment. In this study, attempt is made at understanding the efficacy of Emblica officinalis Linn (amla) when combined with providone iodine in mitigating radiation-induced mucositis, weight loss and tumor control. This was a retrospective chart based study and was carried out by extracting the data from the files of patients with cancer of head and neck who used amla in combination with iodine or iodine alone during the course of the curative radiotherapy (> 60 Gy). The data was entered in to Microsoft excel and subjected to statistical analysis using SPSS 17 software. The results indicate that when compared with iodine alone, the group where iodine and amla gargling were used was very effective in delaying mucositis, reduced incidence of intolerable mucositis (P = 0.027), quantitative grade of weight loss (P = 0.016), incidence of severe weight loss (P = 0.03) without affecting tumor response. The results suggest that when compared with iodine alone, amla when combined with iodine was more effective in mitigating radiation mucositis and by not interfering with the tumor cell kill. As far as the authors are aware of this is the first study that shows the usefulness of combining iodine with Amla in mitigating radiation-induced mucositis.

Safety of the Oral Triphala Recipe from Acute and Chronic Toxicity Tests in Sprague-Dawley Rats

BACKGROUND

The Indian Ayurvedic herbal formula Triphala (TPL) is known for its pharmacological properties for immunomodulation, anti-inflammation, antioxidant, and anti-cancer. This study aimed to investigate the acute and chronic toxicities of the Triphala recipe in a rat model.

METHODS

To assess the acute toxicities, 5000 mg/kg of TPL was orally administered to Sprague-Dawley rats. For chronic toxicities, different dose levels of TPL at 600, 1200, and 2400 mg/kg/day were given daily for 270 days. General health and behaviors and the body and organ weights of the rats were monitored. At the end of the experiment, blood samples were evaluated for hematology and biochemistry profiles. The evaluation of the internal organs' appurtenance and necropsy was performed to confirm the tissue histopathology.

RESULTS

The results showed that there was no sign of acute toxicity in the TPL group with a decrease in sex organ weights. No significant differences in the rats' behaviors, physical health, body, or organ weights were found between the controls and the rats receiving the 270/day of oral Triphala at 600, 1200, and 2400 mg/kg/day. However, some alterations in blood chemistries and hematology, including glucose, BUN, red blood cells, Hb, HCT, and MCV, were observed without abnormalities in histopathology.

CONCLUSIONS

It has been demonstrated that the long-term use of TPL in rat models is safe. No toxic effects were found, suggesting possible safety for long-term use in humans.

Exploring scientific validation of Triphala Rasayana in ayurveda as a source of rejuvenation for contemporary healthcare: An update

ETHNOPHARMACOLOGICAL RELEVANCE

Ayurveda remains the classical and comprehensive part of the ancient Indian medicine system for well-being promotive, disease preventive, and revival approach for the human body. Triphala Rasayana is mentioned in Ayurveda, comprising fruits of three plant species viz. Phyllanthus emblica L. (P. emblica), Terminalia chebula Retz (T. chebula), and Terminalia bellirica Roxb (T.bellirica). Triphala Rasayana has been utilized in various traditional medicine systems, viz., Ayurveda, Siddha, and Unani. Traditionally Rasayana based drugs are utilized in different kinds of diseases without pathophysiological associations as indicated by current medication. Various medicinal attributes of Triphala Rasayana include antioxidant, anticancer, antidiabetic, antimicrobial, immunomodulatory, and anticataract and is also considered as a pillar for gastrointestinal treatment, specifically in functional gastrointestinal disorders (FGIDs). Due to Rasayana's accessible mode of administration, availability, and affordability, there is an increase in its global acceptance.

AIM OF REVIEW

This review article summarizes the scientific validation, traditional uses, bioactive compounds, and ethnopharmacological properties of Triphala Rasayana. It also documents recent data on in vivo and in vitro pharmacological studies and clinical effects of Triphala Rasayana.

MATERIAL AND METHOD

A literature review is carried out using PubMed, ScienceDirect, Scopus, web of science, Ayush Research Portal, and Clinical Trials Registry-India. In addition to an electronic search, traditional ayurvedic texts and books were used as sources of information.

RESULTS

Traditionally, "Triphala Rasayana" is classified as a tridoshic rasayana and one of the most well-studied ayurvedic Rasayana. It showed various pharmacological activities such as anticancer, antioxidant, antibacterial, immunomodulatory, cardioprotective, and antidiabetic. Besides this, Rasayana has reported ethnopharmacological activities such as antimicrobial, anticataract, wound healing, and radioprotection. It has shown a good impact on the gastrointestinal tract (GIT) system with the reported pharmacological activities in gastrointestinal disorders such as constipation, gastric ulcer, and inflammatory bowel disease (IBD). Phytochemical studies of Triphala Rasayana revealed chemical constituents like gallic acid, ellagic acid, chebulic acid, chebulinic acid, methyl gallate, emblicanin A, and emblicanin B. Additionally, clinical studies found Triphala Rasayana to be effective against diabetes, constipation, and obesity.

CONCLUSION

The present review revealed that Triphala Rasayana may treat a diverse range of diseases, especially GIT disorders. Considering the beneficial properties of Triphala Rasayana and it's proven non-toxic nature could be a source of rejuvenation in contemporary healthcare. Nevertheless, its clinical data effectively provided precious signals to correlate ayurvedic biology and modern medicine.

Effects of Triphala on Lipid and Glucose Profiles and Anthropometric Parameters: A Systematic Review

Aim.

The efficacy of triphala on lipid profile, blood glucose and anthropometric parameters and its safety were assessed.

Methods.

Databases such as PubMed, ScienceDirect, Web of Science, and Thai Library Integrated System (ThaiLIS) were systematically searched to review current evidence of randomized controlled trials (RCT) on triphala. RCTs investigating the safety and efficacy of triphala on lipid profile, blood glucose and anthropometric parameters were included. Study selection, data extraction, and quality assessment were performed independently by 2 authors.

Results.

Twelve studies on a total of 749 patients were included. The triphala-treated groups showed significantly reduced low-density lipoprotein-cholesterol, total cholesterol and triglyceride in 6 studies. Five RCTs demonstrated triphala-treated groups led to statistically significant decrease in body weight, body mass index and waist circumference of obese patients. Moreover, triphala significantly decreased fasting blood glucose level in diabetic patients but not in people without diabetes. No serious adverse event associated with triphala was reported during treatment.

Conclusions.

This review summarized a current evidence to show triphala might improve the lipid profile, blood glucose, the body weight, body mass index and waist circumference under certain conditions. However, large well-designed RCTs are required to confirm this conclusion.

Turmeric based oral rinse "HTOR-091516" ameliorates experimental oral mucositis

Background:

Prevalence and incidence of oral mucositis (OM) are rigorously increasing and there is no effective treatment. The herbal formulation “HTOR-091516” containing Curcuma longa, Triphala and honey were evaluated for the treatment of OM.

Aim:

The aim of this study was to evaluate the safety and efficacy of HTOR-091516, employing cellular model, human gingival fibroblasts-1 (HGF-1), and 5-fluorouracil (5-FU)-induced mucositis model in rats.

Materials and Methods:

The cell viability was assessed using 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay and the inhibitory effect of HTOR-091516 on tumor necrosis factor-alpha (TNF-α) was evaluated using TNF-α bioassay in lipopolysaccharides-induced HGF-1. 5-FU and glacial acetic acid were used to induce OM in rats. Animals were divided into two groups, group 1 served as mucositis control and group 2 was treated with HTOR-091516 at the dose of 200 μl and TNF-α was estimated in plasma samples.

Results:

The in vitro safety of HTOR-091516 was evaluated in reconstructed human oral epidermis and was found to be nontoxic and exhibited concentration-dependent TNF-α inhibition in HGF-1. The treatment with HTOR-091516 reduced mucositis scores and mortality rate and also decreased the plasma TNF-α level.

Conclusion:

The present data indicate that HTOR-091516 is effective in the treatment of OM.

Oxidative Stress and Cancer: Chemopreventive and Therapeutic Role of Triphala

Oxidative stress, caused by the overproduction of free radicals, leads to the development of many chronic diseases including cancer. Free radicals are known to damage cellular biomolecules like lipids, proteins, and DNA that results in activation of multiple signaling pathways, growth factors, transcription factors, kinases, inflammatory and cell cycle regulatory molecules. Antioxidants, which are classified as exogenous and endogenous, are responsible for the removal of free radicals and consequently the reduction in oxidative stress-mediated diseases. Diet and medicinal herbs are the major source of antioxidants. Triphala, which is a traditional Ayurvedic formulation that has been used for centuries, has been shown to have immense potential to boost antioxidant activity. It scavenges free radicals, restores antioxidant enzymes and non-enzyme levels, and decreases lipid peroxidation. In addition, Triphala is revered as a chemopreventive, chemotherapeutic, immunomodulatory, and radioprotective agent. Accumulated evidence has revealed that Triphala modulates multiple cell signaling pathways including, ERK, MAPK, NF-κB, Akt, c-Myc, VEGFR, mTOR, tubulin, p53, cyclin D1, anti-apoptotic and pro-apoptotic proteins. The present review focuses on the comprehensive appraisal of Triphala in oxidative stress and cancer.

Toxicity and Antigenotoxic Effect of Hispolon Derivatives: Role of Structure in Modulating Cellular Redox State and Thioredoxin Reductase

Hispolon (HS), a bioactive polyphenol, and its derivatives such as hispolon monomethyl ether (HME), hispolon pyrazole (HP), and hispolon monomethyl ether pyrazole (HMEP) were evaluated for comparative toxicity and antigenotoxic effects. The stability of HS derivatives in biological matrices followed the order HS < HP ≈ HME < HMEP. The cytotoxicity analysis of HS derivatives indicated that HP and HMEP were less toxic than HS and HME, respectively, in both normal and tumor cell types. The mechanisms of toxicity of HS and HME involved inhibition of thioredoxin reductase (TrxR) and/or induction of reductive stress. From the enzyme kinetic and docking studies, it was established that HS and HME interacted with the NADPH-binding domain of TrxR through electrostatic and hydrophobic bonds, resulting in inhibition of the catalytic activity. Subsequently, treatment with HS, HP, and HMEP at a nontoxic concentration of 10 μM in Chinese Hamster Ovary (CHO) cells showed significant protection against radiation (4 Gy)-induced DNA damage as assessed by micronuclei and γ-H2AX assays. In conclusion, the above results suggested the importance of phenolic and diketo groups in controlling the stability and toxicity of HS derivatives. The pyrazole derivatives, HP and HMEP, may gain significance in the development of functional foods.

Effect of Low-Dose Selenium Supplementation on the Genotoxicity, Tissue Injury and Survival of Mice Exposed to Acute Whole-Body Irradiation

The aim of the present study is to evaluate the radioprotective effect of low-dose selenium supplementation (multiple administrations) on radiation toxicities and mortality induced by lethal dose of whole-body irradiation (WBI). For this, BALB/c mice received sodium selenite (4 μg/kg body wt) intraperitoneally for five consecutive days and subjected to WBI at an absorbed dose of 8 Gy (⁶⁰Co, 1 Gy/min). Administration of sodium selenite was continued even during the post irradiation days three times a week till the end of the experiment. The radioprotective effect was evaluated in terms of the improvement in 30 days post irradiation survival, protection from DNA damage, and biochemical and histological changes in radiosensitive organs. The results indicated that low-dose sodium selenite administration did not protect the mice from radiation-induced hematopoietic and gastrointestinal injuries and subsequent mortality. However, it significantly prevented the radiation-induced genotoxicity or DNA damage in peripheral leukocytes. Further sodium selenite administration modulated the messenger RNA (mRNA) expression of GPx1, GPx2, and GPx4 in the spleen and intestine differentially and led to a significant increase in GPx activity (∼1.5 to 2-folds) in these organs. In line with this observation, sodium selenite administration reduced the level of lipid peroxidation in the intestine. In conclusion, our study shows that low-dose sodium selenite supplementation can be an effective strategy to prevent WBI-induced genotoxicity but may not have an advantage against mortality sustained during nuclear emergencies.

Therapeutic Uses of Triphala in Ayurvedic Medicine

Aim: The aim of this article is to review the current literature on the therapeutic uses and efficacy of Triphala. Herbal remedies are among the most ancient medicines used in traditional systems of healthcare such as Ayurveda. Triphala, a well-recognized and highly efficacious polyherbal Ayurvedic medicine consisting of fruits of the plant species Emblica officinalis (Amalaki), Terminalia bellerica (Bibhitaki), and Terminalia chebula (Haritaki), is a cornerstone of gastrointestinal and rejuvenative treatment.

Methods: A search of the PubMed database was conducted.

Results: In addition, numerous additional therapeutic uses described both in the Ayurvedic medical literature and anecdotally are being validated scientifically. In addition to laxative action, Triphala research has found the formula to be potentially effective for several clinical uses such as appetite stimulation, reduction of hyperacidity, antioxidant, anti-inflammatory, immunomodulating, antibacterial, antimutagenic, adaptogenic, hypoglycemic, antineoplastic, chemoprotective, and radioprotective effects, and prevention of dental caries. Polyphenols in Triphala modulate the human gut microbiome and thereby promote the growth of beneficial Bifidobacteria and Lactobacillus while inhibiting the growth of undesirable gut microbes. The bioactivity of Triphala is elicited by gut microbiota to generate a variety of anti-inflammatory compounds.

Conclusions: This review summarizes recent data on pharmacological properties and clinical effects of Triphala while highlighting areas in need of additional investigation and clinical development.

Circadian variation of cytotoxicity and genotoxicity induced by an immunosuppressive agent "Mycophenolate Mofetil" in rats

Immunosuppressive drugs such as Mycophenolate Mofetil (MMF) are used to suppress the immune system activity in transplant patients and reduce the risk of organ rejection. The present study investigates whether the potential cytotoxicity and genotoxicity varied according to MMF dosing-time in Wistar Rat. A potentially toxic MMF dose (300 mg/kg) was acutely administered by the i.p. route in rats at four different circadian stages (1, 7, 13 and 19 hours after light onset, HALO). Rats were sacrificed 3 days following injection, blood and bone marrow were removed for determination of cytotoxicity and genotoxicity analysis. The genotoxic effect of this pro-drug was investigated using the comet assay and the micronucleus test. Hematological changes were also evaluated according to circadian dosing time. MMF treatment induced a significant decrease at 7 HALO in red blood cells, in the hemoglobin rate and in white blood cells. These parameters followed a circadian rhythm in controls or in treated rats with an acrophase located at the end of the light-rest phase. A significant, thrombocytopenia was observed according to MMF circadian dosing time. Furthermore, abnormally shaped red cells, sometimes containing micronuclei, poikilocytotic in red cells and hypersegmented neutrophil nuclei were observed with MMF treatment. The micronucleus test revealed damage to chromosomes in rat bone marrow; the comet assay showed significant DNA damage. This damage varied according to circadian MMF dosing time. The injection of MMF in the middle of the dark-activity phase produced a very mild hematological toxicity and low genotoxicity. Conversely, it induced maximum hematological toxicity and genotoxicity when the administration occurred in the middle of the light-rest phase, which is physiologically analogous to the end of the activity of the diurnal phase in human patients.

A randomized, double-blind, placebo-, and positive-controlled clinical pilot study to evaluate the efficacy and tolerability of standardized aqueous extracts of Terminalia chebula and Terminalia bellerica in subjects with hyperuricemia

Objectives

To evaluate the efficacy and tolerability of standardized aqueous extracts of Terminalia chebula and Terminalia bellerica versus febuxostat and placebo on reduction in serum uric acid levels in subjects with hyperuricemia.

Materials and methods

A total of 110 eligible subjects with hyperuricemia were enrolled and randomized to either of the five treatment groups – T. chebula 500 mg twice a day (BID), T. bellerica 250 mg BID, T. bellerica 500 mg BID, placebo BID, and febuxostat 40 mg once daily plus an identical placebo – for a duration of 24 weeks. Serum uric acid levels were measured at baseline and at the end of 4, 8, 12, 16, 20, and 24 weeks. Statistical analysis was done using GraphPad Prism Software 4.

Results and interpretation

All active treatment groups showed a reduction in serum uric acid levels compared to baseline and placebo. Significant reduction in mean serum uric acid levels started as early as 4 weeks following treatment, compared to baseline, with T. bellerica (500 and 250 mg), febuxostat (P<0.001), and T. chebula 500 mg (P<0.01); an increase in serum uric acid levels was seen with placebo (P<0.05). The serum uric acid levels became steady after 16 weeks of treatment and remained the same until the end of 24 weeks. The reduction of serum uric acid levels in the T. bellerica 500 mg group was nearly twice that of the T. chebula 500 mg group as well as T. bellerica 250 mg group at all time points. T. bellerica 500 mg reduced serum uric acid levels from 8.07±0.87 to 5.78±0.25 compared to febuxostat, which reduced serum uric acid levels from 8.53±0.97 to 4.28±0.67 (P<0.001) at the end of 24 weeks. The efficacy of T. bellerica appeared to be dose dependent. All the formulations were well tolerated.

Conclusion

T. bellerica has the potential for treating hyperuricemia as it was devoid of any serious adverse effects in the present study. Further studies are needed to confirm this potential.

Radioprotective effect of epicatechin in cultured human fibroblasts and zebrafish

Radiation-induced normal cell damage limits the delivery of high-dose radiation to targeted cancer. This study investigated the effect of epicatechin (EC), a minor component of green tea extracts, on radiation-induced cellular damage in vitro in primary cultured human fibroblasts and in vivo in a zebrafish model. Cell viability, proliferation and wound-healing efficacy, mitochondrial membrane potential, and reactive oxygen species (ROS) generation as well as changes in the signaling pathway related to apoptosis were investigated in fibroblasts. The therapeutic effects of EC were explored in a zebrafish model. EC increased clonogenic survival and restored the migration ability of the fibroblasts after irradiation. EC inhibited radiation-induced ROS generation, mitochondrial dysfunction and cell death. EC significantly reduced the expression of p-JNK, p-38, and cleaved caspase-3 compared with their significant increase after radiation treatment. EC attenuated the radiation-induced embryotoxicity in a zebrafish model. These results suggest that EC represents an effective means of reducing cellular damage and facilitating wound healing after radiation exposure.

Rasayana drugs from the Ayurvedic system of medicine as possible radioprotective agents in cancer treatment

The use of ionizing radiation, which is the cornerstone of cancer treatment, is compromised by the radiosensitivity of normal tissues. A chemical that can give selective benefit to the normal cells against the deleterious effects of ionizing radiation has been a long-sought goal. However, most of the compounds studied have shown inadequate clinical application owing to their inherent toxicity, undesirable side effects, and high cost. Studies carried out in the past 2 decades have shown that some of the classical Indian Ayurvedic drugs (Amritaprasham, Ashwagandha Rasayana, Brahma Rasayana, Chyavanprasha, Narasimha Rasayana, and Triphala Churna) possess radioprotective effects. In the current review, an attempt is made to summarize the radioprotective observations of these Ayurvedic drugs and the mechanisms responsible for the radioprotective effects.

Evaluation of anti-inflammatory and antinociceptive activity of Triphala recipe

The anti-inflammatory and antinociceptive activities of Triphala recipe were studied in animal models. Triphala recipe (4 mg/ear) significantly exhibited an inhibitory effect on the ear edema formation induced by ethyl phenylpropiolate-induced, but not on the arachidonic acid-induced ear edema in rats. Furthermore, Triphala recipe at the doses of 300, 600 and 1,200 mg/kg significantly reduced carrageenan-induced hind paw edema. Next, the anti-inflammatory action in chronic inflammation was measured using the cotton pellet-induced granuloma formation assay in rats. Triphala recipe (1,200 mg/kg) reduced neither transudative weight nor granuloma formation. It also did not affect on body weight gain and thymus weight indicating that Triphala recipe does not have a steroid-like effect. In antinociceptive study, Triphala recipe (300, 600, 1,200 mg/kg), elicited significant inhibitory effect on both phases, especially in late phase, of the formalin test in mice suggesting that the antinociceptive action of Triphala recipe may be via both peripheral and at least partly centrally acting.

The prospective role of plant products in radiotherapy of cancer: a current overview

Treatment of cancer often requires exposure to radiation, which has several limitations involving non-specific toxicity toward normal cells, reducing the efficacy of treatment. Efforts are going on to find chemical compounds which would effectively offer protection to the normal tissues after radiation exposure during radiotherapy of cancer. In this regard, plant-derived compounds might serve as “leads” to design ideal radioprotectors/radiosensitizers. This article reviews some of the recent findings on prospective medicinal plants, phytochemicals, and their analogs, based on both in vitro and in vivo tumor models especially focused with relevance to cancer radiotherapy. Also, pertinent discussion has been presented on the molecular mechanism of apoptotic death in relation to the oxidative stress in cancer cells induced by some of these plant samples and their active constituents.

Triphala, Ayurvedic formulation for treating and preventing cancer: a review

BACKGROUND

Triphala (Sanskrit tri = three and phala = fruits), composed of the three medicinal fruits Phyllanthus emblica L. or Emblica officinalis Gaertn., Terminalia chebula Retz., and Terminalia belerica Retz. is an important herbal preparation in the traditional Indian system of medicine, Ayurveda. Triphala is an antioxidant-rich herbal formulation and possesses diverse beneficial properties. It is a widely prescribed Ayurvedic drug and is used as a colon cleanser, digestive, diuretic, and laxative. Cancer is a major cause of death, and globally studies are being conducted to prevent cancer or to develop effective nontoxic therapeutic agents. Experimental studies in the past decade have shown that Triphala is useful in the prevention of cancer and that it also possesses antineoplastic, radioprotective and chemoprotective effects.

CONCLUSIONS

This review for the first time summarizes these results, with emphasis on published observations. Furthermore, the possible mechanisms responsible for the beneficial effects and lacunas in the existing knowledge that need to be bridged are also discussed.

The antidiarrheal and spasmolytic activities of Phyllanthus emblica are mediated through dual blockade of muscarinic receptors and Ca2+ channels

AIM OF THE STUDY

This study was aimed at providing the possible mechanisms for the medicinal use of Phyllanthus emblica in diarrhea.

MATERIALS AND METHODS

The in vivo studies were conducted in mice, while isolated rabbit jejunum and guinea-pig ileum were used for the in vitro experiments.

RESULTS

The crude extract of Phyllanthus emblica (Pe.Cr), which tested positive for alkaloids, tannins, terpenes, flavonoids, sterols and coumarins, caused inhibition of castor oil-induced diarrhea and intestinal fluid accumulation in mice at 500-700 mg/kg. In isolated rabbit jejunum, Pe.Cr relaxed carbachol (CCh) and K(+) (80 mM)-induced contractions, in a pattern similar to that of dicyclomine. The preincubation of guinea pig-ileum with Pe.Cr (0.3 mg/mL), caused a rightward parallel shift in the concentration-response curves (CRCs) of acetylcholine without suppression of the maximum response. While at the next higher concentration (1 mg/mL), it produced a non-parallel rightward shift with suppression of the maximum response, similar to that of dicyclomine, suggesting anticholinergic and Ca(2+) channel blocking (CCB)-like antispasmodic effect. The CCB-like activity was further confirmed when pretreatment of the tissue with Pe.Cr, shifted the CRCs of Ca(2+) to the right with suppression of the maximum response, similar to nifedipine or dicyclomine. The activity-directed fractions of Pe.Cr showed a combination of Ca(2+) antagonist and anticholinergic like components in all fractions but with varying potency.

CONCLUSION

These results indicate that the Phyllanthus emblica fruit extract possesses antidiarrheal and spasmolytic activities, mediated possibly through dual blockade of muscarinic receptors and Ca(2+) channels, thus explaining its medicinal use in diarrhea.

Radioprotective activity of Gentiana lutea extract and mangiferin

Radioprotective/sensitizing actions of Gentiana lutea aqueous-ethanol extract and mangiferin on radiation-induced effects on different types of cells were investigated. The study focused on the decreasing survival of normal human immunocompetent cells, the survival of the malignant cells in vitro, and the survival of ex vivo irradiated cells before and after consumption of the extract by healthy volunteers. The in vitro experiments showed that mangiferin could inhibit cytotoxic action of ionizing irradiation (doses of 6 and 8 Gy) only on normal resting human PBMC, not stimulated for proliferation. Orally consumed G. lutea extract showed the potential to reduce the cytotoxic effect of x-ray irradiation on normal human immunocompetent cells PBMC of some healthy people, without changing the susceptibility of malignant cells to be destroyed by irradiation. Since the radioprotective effect was individually dependent, further clinical studies are needed.

Marked changes in endogenous antioxidant expression precede vitamin A-, C-, and E-protectable, radiation-induced reductions in small intestinal nutrient transport

Rapidly proliferating epithelial crypt cells of the small intestine are susceptible to radiation-induced oxidative stress, yet there is a dearth of data linking this stress to expression of antioxidant enzymes and to alterations in intestinal nutrient absorption. We previously showed that 5-14 days after acute γ-irradiation, intestinal sugar absorption decreased without change in antioxidant enzyme expression. In the present study, we measured antioxidant mRNA and protein expression in mouse intestines taken at early times postirradiation. Observed changes in antioxidant expression are characterized by a rapid decrease within 1h postirradiation, followed by dramatic upregulation within 4h and then downregulation a few days later. The cell type and location expressing the greatest changes in levels of the oxidative stress marker 4HNE and of antioxidant enzymes are, respectively, epithelial cells responsible for nutrient absorption and the crypt region comprising mainly undifferentiated cells. Consumption of a cocktail of antioxidant vitamins A, C, and E, before irradiation, prevents reductions in transport of intestinal sugars, amino acids, bile acids, and peptides. Ingestion of antioxidants may blunt radiation-induced decreases in nutrient transport, perhaps by reducing acute oxidative stress in crypt cells, thereby allowing the small intestine to retain its absorptive function when those cells migrate to the villus days after the insult.

Radioprotection of plasmid and cellular DNA and Swiss mice by silibinin

The radioprotective effect of a non-toxic bioactive component in plant milk thistle, silibinin against genotoxicity induced by gamma-irradiation was investigated in vivo/in vitro. Under in vitro conditions of irradiation, silibinin protected plasmid pBR322 DNA against gamma-radiation-induced strand breaks in a concentration dependent manner (0-200microM). Under cellular conditions of radiation exposure (3Gy), silibinin offered protection to lymphocyte DNA as evidenced from reduction in DNA damage and micronuclei formation, which showed correlation to the extent of intracellular reactive oxygen species reduction. Our extended animal studies suggest that oral administration of silibinin (70mg/kg for 3 days) to mice prior to whole-body gamma-exposure (7.5Gy) resulted in significant protection to radiation-induced mortality and DNA damage in blood leukocytes. However, silibinin treatment after irradiation was not as effective as pre-administration. In conclusion, present study indicated that silibinin has a strong potential to prevent radiation-induced DNA damage under both in vitro and in vivo.

Triphala inhibits both in vitro and in vivo xenograft growth of pancreatic tumor cells by inducing apoptosis

BACKGROUND

Triphala is commonly used in Ayurvedic medicine to treat variety of diseases; however its mechanism of action remains unexplored. This study elucidates the molecular mechanism of Triphala against human pancreatic cancer in the cellular and in vivo model.

METHODS

Growth-inhibitory effects of Triphala were evaluated in Capan-2, BxPC-3 and HPDE-6 cells by Sulphoradamine-B assay. Apoptosis was determined by cell death assay and western blotting. Triphala was administered orally to nude mice implanted with Capan-2 xenograft. Tumors were analyzed by immunohistochemistry and western blotting.

RESULTS

Exposure of Capan-2 cells to the aqueous extract of Triphala for 24 h resulted in the significant decrease in the survival of cells in a dose-dependent manner with an IC50 of about 50 microg/ml. Triphala-mediated reduced cell survival correlated with induction of apoptosis, which was associated with reactive oxygen species (ROS) generation. Triphala-induced apoptosis was linked with phosphorylation of p53 at Ser-15 and ERK at Thr-202/Tyr-204 in Capan-2 cells. Above mentioned effects were significantly blocked when the cells were pretreated with an antioxidant N-acetylcysteine (NAC), suggesting the involvement of ROS generation. Pretreatment of cells with pifithrin-alpha or U0126, specific inhibitors of p53 or MEK-1/2, significantly attenuated Triphala-induced apoptosis. Moreover, NAC or U0126 pretreatment significantly attenuated Triphala-induced p53 transcriptional activity. Similarly, Triphala induced apoptosis in another pancreatic cancer cell line BxPC-3 by activating ERK. On the other hand, Triphala failed to induce apoptosis or activate ERK or p53 in normal human pancreatic ductal epithelial (HPDE-6) cells. Further, oral administration of 50 mg/kg or 100 mg/kg Triphala in PBS, 5 days/week significantly suppressed the growth of Capan-2 pancreatic tumor-xenograft. Reduced tumor-growth in Triphala fed mice was due to increased apoptosis in the tumors cells, which was associated with increased activation of p53 and ERK.

CONCLUSION

Our preclinical studies demonstrate that Triphala is effective in inhibiting the growth of human pancreatic cancer cells in both cellular and in vivo model. Our data also suggests that the growth inhibitory effects of Triphala is mediated by the activation of ERK and p53 and shows potential for the treatment and/or prevention of human pancreatic cancer.

Radiosensitization by diospyrin diethylether in MCF-7 breast carcinoma cell line

The development of radio-resistant tumor cells might be overcome by the use of tumor selective cytotoxic agents in combination with radiation treatment of cancer. Thus, we are exploring the radiomodifying potential of D7, a tumor-inhibitory compound derived from a plant product, diospyrin, in breast carcinoma cells, MCF-7. The present study indicated that D7 could enhance the radiation-induced cytotoxicity and apoptosis through down-regulation of the anti-apoptotic Bcl-2 and COX-2 gene expression, and up-regulation of pro-apoptotic genes, like p53 and p21. The higher expression of PUMA, a pro-apoptotic protein was also observed in the combination treatment. Effect of D7 on up-regulation of p21 expression in irradiated MCF-7 cells was concomitant with the cell cycle arrest in the G1 phase. Thus, it was concluded that D7 could sensitize the effect of radiation in breast carcinoma by regulating the gene expression involved in cell cycle and apoptosis.