Development of a Critical Appraisal Tool (AIMRDA) for the Peer-Review of Studies Assessing the Anticancer Activity of Natural Products: A Step towards Reproducibility.

The journal of APJCP (Asian Pacific Journal of Cancer Prevention) focuses to gather relevant and up-to-date novel information's related to cancer sciences. The research methodologies and approaches adopted by the researcher are prone to variation which may be desirable in the context of novel scientific findings however, the reproducibility for these studies needs to be unified and assured. The reproducibility issues are highly concerned when preclinical studies are reported in cancer, for natural products in particular. The natural products and medicinal plants are prone to a wide variation in terms of phytochemistry and phyto-pharmacology, ultimately affecting the end results for cancer studies. Hence the need for specific guidelines to adopt a best-practice in cancer research are utmost essential. The current AIMRDA guidelines aims to develop a consensus-based tool in order to enhance the quality and assure the reproducibility of studies reporting natural products in cancer prevention. A core working committee of the experts developed an initial draft for the guidelines where more focus was kept for the inclusion of specific items not covered in previous published tools. The initial draft was peer-reviewed, experts-views provided, and improved by a scientific committee comprising of field research experts, editorial experts of different journals, and academics working in different organization worldwide. The feedback from continuous online meetings, mail communications, and webinars resulted a final draft in the shape of a checklist tool, covering the best practices related to the field of natural products research in cancer prevention and treatment. It is mandatory for the authors to read and follow the AIMRDA tool, and be aware of the good-practices to be followed in cancer research prior to any submission to APJCP. Though the tool is developed based on experts in the field, it needs to be further updated and validated in practice via implementation in the field.

Thymoquinone (2-Isoprpyl-5-methyl-1, 4-benzoquinone) as a chemopreventive/anticancer agent: Chemistry and biological effects.

Cancer remains the topmost disorders of the mankind and number of cases is unceasingly growing at unprecedented rates. Although the synthetic anti-cancer compounds still hold the largest market in the modern treatment of cancer, natural agents have always been tried and tested for potential anti-cancer properties. Thymoquinone (TQ), a monoterpene and main ingredient in the essential oil of Nigella sativa L. has got very eminent rankings in the traditional systems of medicine for its anti-cancer pharmacological properties. In this review we summarized the diverse aspects of TQ including its chemistry, biosynthesis, sources and pharmacological properties with a major concern being attributed to its anti-cancer efficacies. The role of TQ in different aspects involved in the pathogenesis of cancer like inflammation, angiogenesis, apoptosis, cell cycle regulation, proliferation, invasion and migration have been described. The mechanism of action of TQ in different cancer types has been briefly accounted. Other safety and toxicological aspects and some combination therapies involving TQ have also been touched. A detailed literature search was carried out using various online search engines like google scholar and pubmed regarding the available research and review accounts on thymoquinone upto may 2019. All the articles reporting significant addition to the activities of thymoquinone were selected. Additional information was acquired from ethno botanical literature focusing on thymoquinone. The compound has been the centre of attention for a long time period and researched regularly in quite considerable numbers for its various physicochemical, medicinal, biological and pharmacological perspectives. Thymoquinone is studied for various chemical and pharmacological activities and demonstrated promising anti-cancer potential. The reviewed reports confirmed the strong anti-cancer efficacy of thymoquinone. Further in-vitro and in-vivo research is strongly warranted regarding the complete exploration of thymoquinone in ethnopharmacological context.

Glycyrrhizic acid suppresses 1,2-dimethylhydrazine-induced colon tumorigenesis in Wistar rats: Alleviation of inflammatory, proliferation, angiogenic, and apoptotic markers.

OBJECTIVES: Colon cancer is the major health disease related with high mortality. Glycyrrhizic acid (GA) is an active constituent of licorice with anti-inflammatory and anticarcinogenesis effects. We investigated the chemopreventive potential of GA against 1,2-dimethylhydrazine (DMH)-induced colon tumorigenesis in Wistar rats. METHODS: Glycyrrhizic acid was administered orally at the dose of 15 mg/kg b.wt. and DMH was administered at the dose of 20 mg/kg b.wt. once a week for first 15 weeks. All the rats were euthanized after 30 weeks. GA supplementation significantly inhibited the tumor incidence and multiplicity. RESULTS: Glycyrrhizic acid treatment reduced the expression of Ki-67, proliferating cell nuclear antigen (PCNA), nuclear factor-kappa B (NF-kB), cyclooxygenase-2 (COX-2), induced nitric oxide synthase (iNOS), and vascular endothelial growth factor (VEGF) while enhanced the expression of p53, connexin-43, b-cell lymphoma-2 (Bcl-2), survivin, and cleaved caspase-3. Glycyrrhizic acid also significantly ameliorated DMH-induced decreased activities of caspase-9 and caspase-3. Furthermore, GA treatment reduced mast cells infiltration, attenuated the shifting of sialomucin to sulphomucin as well the levels of pro-inflammatory cytokines. CONCLUSION: The findings of the study suggest that GA has chemopreventive potential against DMH-induced colon tumorigenesis plausibly through the attenuation of hyperproliferative responses, pro-inflammatory cytokines level, inflammatory and angiogenic markers, and apoptotic responses.

Alleviation of 5-fluorouracil-induced intestinal mucositis in rats by vitamin E via targeting oxidative stress and inflammatory markers.

BackgroundIntestinal mucositis is a major concern related with cancer therapy. It is well established that overproduction of reactive oxygen species and inflammatory mediators plays vital role in the pathogenesis of mucositis. The aim of the study was to investigate the modulatory effect of vitamin E (vit. E) on 5-fluorouracil (5-FU)-induced intestinal mucositis by targeting oxidative stress and inflammatory markers in rats. MethodsRats were randomly divided into four groups of six animals each. All four-group animals received normal standard diet and water throughout the experimental period which last up to 10 days. Rats were gavaged with vit. E (300 mg/kg b. wt.) daily for 10 days (day 1-10) and were given intraperitoneal injection of 5-FU (150 mg/kg b. wt.) or saline (control) on day 8 to induce mucositis. Results We found that vit. E supplementation ameliorated 5-FU-induced lipid peroxidation, myeloperoxidase activity, activation of nuclear factor κB, expression of cyclooxygenase-2, inducible nitric oxide synthase and mucin depletion. Vit. E administration also attenuated 5-FU-induced histological anomalies such as neutrophil infiltration, loss of cellular integrity, villus and crypt deformities. ConclusionsFindings of the study suggest that vit. E inhibits 5-FU-induced mucositis via modulation of oxidative stress, activation of redox sensitive transcription factor and its downstream targets.

Moringa oleifera as an Anti-Cancer Agent against Breast and Colorectal Cancer Cell Lines.

In this study we investigated the anti-cancer effect of Moringa oleifera leaves, bark and seed extracts. When tested against MDA-MB-231 and HCT-8 cancer cell lines, the extracts of leaves and bark showed remarkable anti-cancer properties while surprisingly, seed extracts exhibited hardly any such properties. Cell survival was significantly low in both cells lines when treated with leaves and bark extracts. Furthermore, a striking reduction (about 70-90%) in colony formation as well as cell motility was observed upon treatment with leaves and bark. Additionally, apoptosis assay performed on these treated breast and colorectal cancer lines showed a remarkable increase in the number of apoptotic cells; with a 7 fold increase in MD-MB-231 to an increase of several fold in colorectal cancer cell lines. However, no significant apoptotic cells were detected upon seeds extract treatment. Moreover, the cell cycle distribution showed a G2/M enrichment (about 2-3 fold) indicating that these extracts effectively arrest the cell progression at the G2/M phase. The GC-MS analyses of these extracts revealed numerous known anti-cancer compounds, namely eugenol, isopropyl isothiocynate, D-allose, and hexadeconoic acid ethyl ester, all of which possess long chain hydrocarbons, sugar moiety and an aromatic ring. This suggests that the anti-cancer properties of Moringa oleifera could be attributed to the bioactive compounds present in the extracts from this plant. This is a novel study because no report has yet been cited on the effectiveness of Moringa extracts obtained in the locally grown environment as an anti-cancer agent against breast and colorectal cancers. Our study is the first of its kind to evaluate the anti-malignant properties of Moringa not only in leaves but also in bark. These findings suggest that both the leaf and bark extracts of Moringa collected from the Saudi Arabian region possess anti-cancer activity that can be used to develop new drugs for treatment of breast and colorectal cancers.

Ascorbic acid attenuates antineoplastic drug 5-fluorouracil induced gastrointestinal toxicity in rats by modulating the expression of inflammatory mediators.

Damage to the mucous membrane is a serious issue associated with chemotherapy. Gastrointestinal (GI) toxicity is complex and multistep process and unregulated production of reactive oxygen species (ROS) and inflammatory mediators play vital role in the development of GI toxicity. In the present study we have investigated the attenuating potential of vitamin C (vit. C) on 5 fluorouracil (5-FU) induced GI toxicity by targeting oxidative stress and inflammatory markers in Sprague Dawley (SD) rats. Rats were gavaged with vit. C (500 mg/kg b. wt.) or vehicle daily (day 1-10) and were given intraperitoneal injection of 5-FU (150 mg/kg b. wt.) or saline (control) on day 8 to induce mucositis. We found that vit. C supplementation attenuated 5-FU induced lipid peroxidation, myeloperoxidase (MPO) activity, activation of NF-kB and expression of COX-2. Histological observations further supported the protective potential of vit. C against 5-FU induced intestinal anomalies such as neutrophil infiltration, loss of cellular integrity, villus and crypt deformities. Thus the biochemical, molecular and histological findings of the present study demonstrate that oxidative stress and inflammation play vital role in 5-FU induced GI toxicity and the inhibitory potential of vit. C is may be due to the modulation of oxidative stress, activation of redox sensitive transcription factor and also its downstream target molecules.

Tannic acid mitigates the DMBA/croton oil-induced skin cancer progression in mice.

Skin cancer is the most common malignancy in the world and also one of the major causes of death worldwide. The toxic environmental pollutant 7,12-dimethylbenz[a]anthracene (DMBA) is a skin-specific carcinogen. Tannic acid (TA) is reported to be effective against various types of chemical-induced toxicities and carcinogenesis as well. In the present study, we have evaluated the therapeutic potential of tannic acid in DMBA + croton oil-induced skin cancer in Swiss albino mice. Protective effect of TA against skin cancer was evaluated in terms of antioxidant enzymes activities, lipid peroxidation, histopathological changes and expression of inflammation and early tumour markers. DMBA + croton oil causes depletion of antioxidant enzymes (p < 0.001) and elevation of early inflammatory and tumour promotional events. TA prevents the DMBA + croton oil-induced toxicity through a protective mechanism that involves the reduction of oxidative stress as well as COX-2, i-NOS, PCNA protein expression and level of proinflammatory cytokine such as IL-6 release at a very significant level (p < 0.001). It could be concluded from our results that TA attenuates DMBA + croton oil-induced tumour promotional potential possibly by inhibiting oxidative and inflammatory responses and acts as antioxidant, anti-inflammatory and antiproliferative agent.

Assessment of Augmented Immune Surveillance and Tumor Cell Death by Cytoplasmic Stabilization of p53 as a Chemopreventive Strategy of 3 Promising Medicinal Herbs in Murine 2-Stage Skin Carcinogenesis.

Cancer is the final outcome of a plethora of events. Targeting the proliferation or inducing programmed cell death in a proliferating population is a major standpoint in the cancer therapy. However, proliferation is regulated by several cellular and immunologic processes. This study reports the inhibition of proliferation by augmenting immune surveillance, silencing acute inflammation, and inducing p53-mediated apoptosis of skin cancer by 3 promising medicinal extracts. We used the well-characterized model for experimental skin carcinogenesis in mice for 32 weeks to study the chemopreventive effect of the methanolic extracts of Trigonella foenumgraecum, Eclipta alba, and Calendula officinalis. All 3 extracts reduced the number, incidence, and multiplicity of tumors, which was confirmed by the pathologic studies that showed regressed tumors. There was a significant reduction in the PCNA+ nuclei in all treatment groups 32 weeks after the initiation. Mechanistic studies revealed that proliferative population in tumors is diminished by the restoration of the endogenous antioxidant defense, inhibition of the stress-related signal-transducing element NFκB, reduction of inflammation, enhancement of immunosurveillance of the genetically mutated cells, along with silencing of the cell cycle progression signals. Finally, all 3 medicinal extracts induced stable expression of p53 within the tumors, confirmed by the CFDA-Cy3 apoptosis assay. Results of our study confirm that these extracts not only limit the rate of proliferation by inhibition of the processes integral to cancer development but also induce stable cytoplasmic expression of p53-mediated apoptosis, leading to fewer and regressed tumors in mice.

Glycyrrhizic acid suppresses the development of precancerous lesions via regulating the hyperproliferation, inflammation, angiogenesis and apoptosis in the colon of Wistar rats.

BACKGROUND: Colon carcinogenesis is a multistep process and it emanates from a series of molecular and histopathological alterations. Glycyrrhizic acid (GA) is a natural and major pentacyclic triterpenoid glycoside of licorice roots extracts. It has several pharmacological and biological properties such as anti-inflammatory, anti-viral, and anti-cancer. In the present study, we investigated the chemopreventive potential of GA against 1,2-dimethyhydrazine (DMH)-induced precancerous lesions i.e., aberrant crypt foci (ACF) and mucin depleted foci (MDF), and its role in regulating the hyperproliferation, inflammation, angiogenesis and apoptosis in the colon of Wistar rats. METHODS: Animals were divided into 5 groups. In group III, IV and V, GA was administered at the dose of 15 mg/kg b. wt. orally while in group II, III and IV, DMH was administered subcutaneously in the groin at the dose of 20 mg/kg b.wt once a week for first 5 weeks and animals were euthanized after 9 weeks. RESULTS: GA supplementation suppressed the development of precancerous lesions and it also reduced the infiltration of mast cells, suppressed the immunostaining of Ki-67, NF-kB-p65, COX-2, iNOS and VEGF while enhanced the immunostaining of p53, connexin-43, caspase-9 and cleaved caspase-3. GA treatment significantly attenuated the level of TNF-α and it also reduced the depletion of the mucous layer as well as attenuated the shifting of sialomucin to sulphomucin. CONCLUSION: Our findings suggest that GA has strong chemopreventive potential against DMH-induced colon carcinogenesis but further studies are warranted to elucidate the precise mechanism of action of GA.

Androgen deprivation by flutamide modulates uPAR, MMP-9 expressions, lipid profile, and oxidative stress: amelioration by daidzein.

The growth and development of prostate gland is governed by testosterone. Testosterone helps in maintaining the adipose tissue stores of the body. It is well documented that with advancing age there has been a gradual decline in testosterone levels. Our aim was to study the protective role of daidzein on flutamide-induced androgen deprivation on matrix degrading genes, lipid profile and oxidative stress in Wistar rats. Sub-chronic (60 days) flutamide (30 mg/kg b.wt) administration resulted in marked increase in expressions of matrix degrading genes [matrix metalloproteases 9 and urokinase plasminogen activation receptor]. Additionally, it increased the levels of low density lipoproteins, total cholesterol, triglycerides, and lowered the levels of high density lipoproteins and endogenous antioxidant levels. Oral administration of daidzein (20 and 60 mg/kg b.wt) restituted the levels to normal. Daidzein administration resulted in amelioration of the prostate atrophy, degeneracy and invasiveness induced by flutamide. Our findings suggest that the daidzein may be given as dietary supplement to patients who are on androgen deprivation therapy, to minimize the adverse effects related to it and also retarding susceptibility of patients to cardiovascular diseases.

Soy isoflavones (daidzein & genistein) inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cutaneous inflammation via modulation of COX-2 and NF-κB in Swiss albino mice.

It is well established that aberrant production of inflammatory mediators has been associated with most the toxic manifestations and the genesis of different chronic diseases including cancer. The basic aim of the present study is to investigate the effects of soy isoflavones (SIF) on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cutaneous inflammatory responses and to explore the underlying molecular mechanisms. We have studied the protective effects of SIF against TPA induced oxidative stress, pro-inflammatory cytokines level, activation of NF-κB, expression of COX-2 and ki-67 in mouse skin. Animals were divided into five groups I-V (n=6). Groups II, III and IV received topical application of TPA at the dose of 10 nmol/0.2 ml of acetone/animal/day, for 2 days. Animals of the groups III and IV were pre-treated with SIF 1.0 µg (D1) and 2.0 µg (D2) topically 30 min prior to each TPA administration, while groups I and V were given acetone (0.2 ml) and SIF (D2), respectively. We have found that SIF pretreatment significantly inhibited TPA induced oxidative stress, proinflammatory cytokines production and activation of NF-κB. SIF also inhibited the expression of COX-2 and ki-67. Histological findings further supported the protective effects of SIF against TPA-induced cutaneous damage. Thus, our results suggest that inhibitory effect of SIF on TPA-induced cutaneous inflammation includes inhibition of proinflammatory cytokines, attenuation of oxidative stress, activation of NF-κB and expression of COX-2.

Chrysin abrogates cisplatin-induced oxidative stress, p53 expression, goblet cell disintegration and apoptotic responses in the jejunum of Wistar rats.

Cisplatin (cis-diamminedichloroplatinum (II) (CDDP)) is a commonly used chemotherapeutic drug for the treatment of numerous forms of cancer, but it has pronounced adverse effects, namely nephrotoxicity, ototoxicity, neurotoxicity, hepatotoxicity, diarrhoea and nausea. CDDP-induced emesis and diarrhoea are also marked toxicities that may be due to intestinal injury. Chrysin (5,7-dihydroxyflavone), a natural flavone commonly found in many plants, possesses multiple biological activities, such as antioxidant and anti-inflammatory properties. In the present study, we investigated the protective effect of chrysin against CDDP-induced jejunal toxicity. The plausible mechanism of CDDP-induced jejunal toxicity includes oxidative stress, p53 and apoptosis via up-regulating the expression of caspase-6 and -3. Chrysin was administered to Wistar rats orally in maize oil. A single intraperitoneal injection of CDDP was given and the animals were killed after 24 h of CDDP injection. Chrysin ameliorated CDDP-induced lipid peroxidation, increase in xanthine oxidase activity, glutathione depletion, decrease in antioxidant (catalase, glutathione reductase, glutathione peroxidase and glucose-6-phosphate dehydrogenase) and phase-II detoxifying (glutathione-S-transferase and quinone reductase) enzyme activities. Chrysin attenuated CDDP-induced goblet cell disintegration, enhanced expression of p53 and apoptotic tissue damage. Histological findings further substantiated the protective effects of chrysin against CDDP-induced damage in the jejunum. The results of the present study demonstrate that oxidative stress and apoptosis are closely associated with CDDP-induced toxicity and chrysin shows the protective efficacy against CDDP-induced jejunum toxicity possibly via attenuating the oxidative stress and apoptotic tissue damage.