Azadirachta indica acts as a pro-oxidant and modulates cell cycle associated proteins during DMBA/TPA induced skin carcinogenesis in mice

Induction of apoptosis in A431 cells via ROS generation and p53-mediated pathway by chloroform fraction of Argemone mexicana (Pepaveraceae)

Argemone mexicana(Pepaveraceae) is an important medicinal plant commonly known as 'maxican prickly poppy' and is traditionally used to treat skin diseases. In the present study, the extract/fractions of aerial parts of A. mexicana after carrying out the organoleptic characteristics were sequentially extracted with the solvents of increasing polarities. Total fractions were examined for their radical scavenging activities in DPPH and DNA nicking assays. Among all, maximum antioxidant activity was shown by chloroform fraction (AmC) in DPPH assay with IC50 of 26.12 μg/ml, and DNA nicking assay showed 80.91% protective potential. The AmC fraction was analyzed for its antibacterial, cytotoxic potential, cell cycle analysis, mitochondrial membrane potential (MMP) and accumulation of reactive oxygen species (ROS) using A431 cell line. The AmC fraction exhibited remarkable antibacterial activity against bacterial strains in the order Klebsiella pneumoniae> Bacillussubtilis> Salmonella typhi> Staphylococcus epidermidis. The cytotoxic potential of the AmC fraction was analyzed in skin epidermoid carcinoma (A431) cells, osteosarcoma (MG-63) and cervical (HeLa) cell lines with a GI50 value of 47.04 μg/ml, 91.46 μg/ml and 102.90 μg/ml, respectively. The AmC fraction was extended further to explore its role in cell death using A431 cell line. Phase contrast and scanning electron microscopic studies on A431 cells exhibited all the characteristics indicative of apoptosis, viz., viability loss, cell shrinkage, cell rounding-off, DNA fragmentation and formation of apoptotic bodies. Flow cytometric analysis revealed enhanced ROS level, decreased MMP and arrest cell cycle at the G0/G1 phase further strengthened cell death by apoptosis. Increased expressions of apoptotic markers (p53, PUMA, cyt c, Fas and Apaf-1) were confirmed by RT-qPCR analysis. Furthermore, the AmC fraction was subjected to ultra-high-performance liquid chromatography, which revealed the presence of different polyphenols in the order: caffeic acid> epicatechin> kaempferol> chlorogenic acid> gallic acid> catechin> ellagic acid >umbeliferone> quercetin> coumaric acid. A critical analysis of results revealed that the AmC fraction induced cell death in epidermoid carcinoma cells via ROS and p53-mediated apoptotic pathway which may be ascribed to the presence of polyphenols in it.

Calcium Fructoborate Prevents Skin Cancer Development in Balb-c Mice: Next Part, Reverse Inflammation, and Metabolic Alteration

Metabolic alterations and inflammation are regarded as hallmarks of cancer. Glycolytic flux and intermediate accumulation lead to the production of building blocks and NADPH which is important in protecting the cell from oxidative damage. Inflammation causes the release of mediators responsible for regulating molecular mechanism affecting metabolic pathways. CaFB due to its cis-diol-rich feature may have the potential to interact with molecules taking part in cancer development. This study was aimed to investigate the effects of CaFB on metabolic alterations and inflammation in 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin cancer. For this purpose, 92 Balb-c mice were distributed into 6 groups as control, CaFB, DMBA/TPA (D-T), treatment 1 (T1), 2 (T2), and 3(T3). Apart from control and CaFB in other groups, tumors initiated with 97.5-nmol DMBA and 6.5-nmol TPA. Treatment groups received 3 mg/kg/day CaFB with DMBA (T1), with TPA (T2), and after tumor formation (T3). In the D-T group, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity, 6-phosphogluconate dehydrogenase (PGD), glutathione (GSH), interleukin 6 (IL-6), (IL-1β), tumor necrosis factor-α (TNF-α) levels increased (p < 0.001) while malondialdehyde (MDA) levels decreased (p < 0.001) compared with that in control. CaFB application ameliorated DMBA-TPA effect according to the distribution time. It is noteworthy to consider CaFB as a potential preventive agent in skin cancer development.

Altered presence of extra cellular matrix components in murine skin cancer: Modulation by Azadirachta indica leaf extract

BACKGROUND AND AIM

Although, the anticancer potential of Aqueous Azadirachta indica leaf extract (AAILE) has been robustly established against cutaneous squamous cell carcinoma (SCC) in mice, however, its ability in modulating tumor associated extra cellular matrix (ECM) is largely unknown. Therefore, the present study was conceived to explore changes in ECM during murine skin cancer and its chemoprevention by AAILE.

EXPERIMENTAL PROCEDURE

Skin tumors were induced using a two-stage model of carcinogenesis employing topical application of 7,12-Dimethylbenz(a)anthracene (DMBA) and 12-O-tetradecanoyl phorbol-13-acetate (TPA) as carcinogen and promoter respectively. AAILE was administered orally to the animals. Male Laca mice were divided into four groups: control, AAILE, DMBA/TPA and AAILE + DMBA/TPA.

RESULTS

The tumors obtained in DMBA/TPA and AAILE + DMBA/TPA groups were histologically identified as SCC. Tumor induction in these groups was accompanied by raised serum carcinoembryonic antigen (CEA) levels when compared to control counterparts. Assessment of hydroxyproline levels and histochemical staining with sirius red and trichrome stain revealed an increase in collagen in tumors of DMBA/TPA group. An increase in glycosaminoglycans (GAGs) levels was also observed in DMBA/TPA group as made evident by biochemical studies and histochemical staining using mucicarmine and alcian blue-periodic acid schiff's stain. Administration of AAILE to DMBA/TPA treated animals caused a decrease in collagen and GAG levels along with a decrease in serum CEA levels.

CONCLUSION

Skin tumors exhibited altered presence of ECM components which is indicative of a modified ECM. AAILE administration antagonised tumor associated ECM alterations which may be contributing to its chemopreventive activity as reported previously.

Lycopene enriched tomato extract suppresses chemically induced skin tumorigenesis in mice

Abstract. The present study revealed the effects of Lycopene enriched tomato extract (LycT) on chemically induced skin cancer in mice. Skin tumors were induced by topical application of 7,12-Dimethylbenz(a)anthracene (DMBA) [500 nmol/100 ul of acetone, twice a week for two weeks] and 12-O-tetradecanoyl phorbol-13-acetate (TPA) [1.7 nmol/100 ul of acetone, twice a week for eighteen weeks] and LycT (5 mg/kg b.w.) was administered orally. Male Balb/c mice were divided into four groups (n = 15 per group): control, DMBA/TPA, LycT and LycT + DMBA/TPA. The chemopreventive response of LycT to skin tumorigenesis was evident by inhibition in tumor incidence, number, size, burden and volume in LycT + DMBA/TPA group when compared to DMBA/TPA group. This was associated with inhibition of cell proliferation in LycT + DMBA/TPA group as observed by the decrease in epidermal morphometric parameters and mRNA and protein expression of proliferating cell nuclear antigen when compared to DMBA/TPA group (p ≤ 0.05). LycT decreased (p ≤ 0.05) the mRNA and protein expression of angiogenic genes (vascular endothelial growth factor, angiopoietin-2, basic fibroblast growth factor) in LycT + DMBA/TPA group, suggesting its anti-angiogenic effects. The increase (p ≤ 0.05) in protein expression of connexin-32 and 43 in LycT + DMBA/TPA group suggests improved inter cellular communication when compared to DMBA/TPA group. Histochemical studies demonstrated that the components of extracellular matrix (fibrous proteins and mucopolysaccharides) were also modulated during skin carcinogenesis and its chemoprevention by LycT. The decrease in cell proliferation parameters and expression of angiogenesis associated genes, modulation of ECM components and increase in expression of connexins suggest that LycT improved multiple dysregulated processes during chemoprevention of skin cancer.

Maternal folic acid depletion during early pregnancy increases sensitivity to squamous tumor formation in the offspring in mice

Gestational nutrition is widely recognized to affect an offspring's future risk of lifestyle-related diseases, suggesting the involvement of epigenetic mechanisms. As folic acid (FA) is a nutrient essential for modulating DNA methylation, we sought to determine how maternal FA intake during early pregnancy might influence tumor sensitivity in an offspring. Dams were maintained on a FA-depleted (FA(-)) or normal (2 mg FA/kg; FA(+)) diet from 2 to 3 days before mating to 7 days post-conception, and their offspring were challenged with chemical tumorigenesis using 7,12-dimethylbenz[a)anthracene and phorbol 12-myristate 13-acetate for skin and 4-nitroquinoline N-oxide for tongue. In both squamous tissues, tumorigenesis was more progressive in the offspring from FA(-) than FA(+) dams. Notably, in the skin of FA(-) offspring, the expression and activity of cylindromatosis (Cyld) were decreased due to the altered DNA methylation status in its promoter region, which contributed to increased tumorigenesis coupled with inflammation in the FA(-) offspring. Thus, we conclude that maternal FA insufficiency during early pregnancy is able to promote neoplasm progression in the offspring through modulating DNA methylation, such as Cyld. Moreover, we propose, for the first time, "innate" utero nutrition as the third cause of tumorigenesis besides the known causes-hereditary predisposition and acquired environmental factors.

Folic Acid Modulates DMBA/TPA-Induced Changes in Skin of Mice: A Study Relevant to Carcinogenesis

The present study was aimed at investigating the modulatory effects of folic acid (FA) on early stages of chemically induced skin cancer. For this, a two-stage model of skin tumorigenesis was employed. 7,12-Dimethylbenz(a)anthracene (DMBA, 500 nmol/100 ul of acetone) was applied topically for two weeks (twice weekly), followed by phorbol-12-myristate-13-acetate (TPA, 1.7 nmol/100 ul) twice weekly for six weeks on the depilated skin of mice, and FA was administered orally at a dose of 40 microgram/animal for 10 weeks daily. Balb/c mice were divided into four groups depending upon the treatment they received (control, DMBA/TPA, FA, and FA+DMBA/TPA). DMBA/TPA treatment led to the formation of papillomas in DMBA/TPA and FA+DMBA/TPA groups. Ornithine decarboxylase (ODC), proliferating cell nuclear antigen (PCNA), epidermal thickness, and cell count were evaluated to assess the beneficial effects in the early stages. FA exhibited its ameliorative potential as indicated by decreased epidermal thickness and cell count in FA+DMBA/TPA group when compared to DMBA/TPA group. Concomitantly, FA decreased the expression of ODC and PCNA in skin and activity of serum lactate dehydrogenase, suggesting inhibitory effects on cell proliferation and cell damage. Differential modulation in lipid peroxidation and reduced glutathione was observed in response to DMBA/TPA treatment and its intervention with FA. Although these findings suggest the inhibitory potential of FA during initial stages of murine skin cancer, detailed studies are warranted considering the ambiguous reports available in literature regarding the association of FA and cancer.

A Systematic Review on the Implication of Minerals in the Onset, Severity and Treatment of Periodontal Disease

Periodontal disease is an inflammatory disease with high prevalence in adults that leads to destruction of the teeth-supporting tissues. Periodontal therapy has been traditionally directed at reduction of the bacterial load to a level that encourages health-promoting bacteria and maintenance of oral-hygiene. The role of nutrition in different chronic inflammatory diseases has been the subject of an increasing body of research in the last decades. In this sense, there has been an important increase in the volume of research on role of nutrition in periodontitis since the diet has known effects on the immune system and inflammatory cascades. Minerals play a key role in all these processes due to the multiple pathways where they participate. To clarify the role of the different minerals in the establishment, progression and/or treatment of this pathology, a systemically review of published literature cited in PubMed until May 2016 was conducted, which included research on the relationship of these elements with the onset and progression of periodontal disease. Among all the minerals, calcium dietary intake seems important to maintain alveolar bone. Likewise, dietary proportions of minerals that may influence its metabolism also can be relevant. Lastly, some observations suggest that all those minerals with roles in immune and/or antioxidant systems should be considered in future research.

Pro-Oxidant Role of Silibinin in DMBA/TPA Induced Skin Cancer: 1H NMR Metabolomic and Biochemical Study

Silibinin, a major bioactive flavonolignan in Silybum marianum, has received considerable attention in view of its anticarcinogenic activity. The present study examines its anticancer potential against 7, 12-dimethylbenz(a)anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) induced skin cancer. Male LACA mice were randomly segregated into 4 groups: Control, DMBA/TPA, Silibinin and Silibinin+DMBA/TPA. Tumors in DMBA/TPA and Silibinin+DMBA/TPA groups were histologically graded as squamous cell carcinoma. In the Silibinin+DMBA/TPA group, significant reduction in tumor incidence (23%), tumor volume (64.4%), and tumor burden (84.8%) was observed when compared to the DMBA/TPA group. The underlying protective mechanism of Silibinin action was studied at pre-initiation (2 weeks), post-initiation (10 weeks) and promotion (22 weeks) stages of the skin carcinogenesis. The antioxidant nature of Silibinin was evident at the end of 2 weeks of its treatment. However, towards the end of 10 and 22 weeks, elevated lipid peroxidation (LPO) levels indicate the pro-oxidative nature of Silibinin in the cancerous tissue. TUNEL assay revealed enhanced apoptosis in the Silibinin+DMBA/TPA group with respect to the DMBA/TPA group. Therefore, it may be suggested that raised LPO could be responsible for triggering apoptosis in the Silibinin+DMBA/TPA group. ¹H Nuclear Magnetic Resonance (NMR) spectroscopy was used to determine the metabolic profile of the skin /skin tumors. Dimethylamine (DMA), glycerophosphocholine (GPC), glucose, lactic acid, taurine and guanine were identified as the major contributors for separation between the groups from the Principal Component Analysis (PCA) of the metabolite data. Enhanced DMA levels with no alteration in GPC, glucose and lactate levels reflect altered choline metabolism with no marked Warburg effect in skin tumors. However, elevated guanine levels with potent suppression of taurine and glucose levels in the Silibinin+DMBA/TPA group are suggestive of the pro-oxidative nature of Silibinin in regressing tumors. Thus, supporting the theory of augmented LPO levels resulting in increased apoptosis in the skin tumors treated with Silibinin.

Plants used to treat skin diseases

Skin diseases are numerous and a frequently occurring health problem affecting all ages from the neonates to the elderly and cause harm in number of ways. Maintaining healthy skin is important for a healthy body. Many people may develop skin diseases that affect the skin, including cancer, herpes and cellulitis. Some wild plants and their parts are frequently used to treat these diseases. The use of plants is as old as the mankind. Natural treatment is cheap and claimed to be safe. It is also suitable raw material for production of new synthetic agents. A review of some plants for the treatment of skin diseases is provided that summarizes the recent technical advancements that have taken place in this area during the past 17 years.