Role of nutraceutical starch and proanthocyanidins of pigmented rice in regulating hyperglycemia: Enzyme inhibition, enhanced glucose uptake and hepatic glucose homeostasis using in vitro model.

Dysregulation of glucose homeostasis result in hyperglycemia and pigmented rice, unique combination of high quality starch and phenolics has the potential in regulating it. In this study, pigmented rice was characterized in terms of nutraceutical starch (NS) and phenolic content. Further the effect of rice phenolics on carbolytic enzyme inhibition, glucose uptake, hepatic glucose homeostasis and anti-glycation ability was analyzed in vitro. The most relevant effect on enzyme inhibition (α-amylase: IC50-42.34 µg/mL; α-glucosidase: IC50:63.89 µg/mL), basal uptake of glucose (>39.5%) and anti-glycation ability (92%) was found in red rice (RR), than black rice (BR). The role of RR phenolics in regulating glucose homeostasis was deciphered using hepatic cell line system, which found up-regulation of glucose transporter 2 (GLUT2) and glycogen synthase 2 (GYS2); while expression of gluconeogenic genes were found down regulated. To our knowledge this study is the first report validating the role of starch-phenolic quality towards anti-hyperglycemic effect of RR.

Bio-guided fractionation and isolation of active component from Tragopogon graminifolius based on its wound healing property.

ETHNOPHARMACOLOGICAL RELEVANCE: Tragopogon graminifolius (T. graminifolius) from Asteraceae family has been used as a remedy in Persian traditional medicine for the treatment of various disorders such as wound healing. AIM OF THE STUDY: The purpose of this study is to investigate the compounds of T. graminifolius, which are responsible for its wound healing activity. MATERIALS AND METHODS: The experiment was performed in three phases; each phase consisted of fractionation of extracts followed by scratch assay. The results of the scratch assay were expressed using scratch closure index (SCI), representing the contraction of scratch. RESULTS: In phase I, Ethyl acetate fraction (E) showed the maximum SCI (61.7 ±â€¯3.5) that was selected for more fractionation in the next phase. In phase II, 12 fractions were obtained and labeled as fractions E- A to L, respectively. Based on the SCI of fractions, EF (SCI=68.9 ±â€¯0.6) was the most active fraction in phase II and selected for further fractionation in phase III. In phase III, 8 fractions were resulted by fractionation of EF and labeled as EF- 1-8. Fraction EF5 with the highest SCI (30.8 ±â€¯3.0) was the most effective fraction and Luteolin was the main component. Luteolin significantly improved viability of fibroblast cells and increased cell population that was accompanied by decreased cell apoptosis. Luteolin-induced cell number increase in the S and G2M phases of the cell cycle, further confirms the proliferative effect of this compound. CONCLUSION: The results showed that the total extract and fractions of T. graminifolius stimulate proliferation and migration of skin fibroblast cells and Luteolin is one of the active compounds responsible for these effects.

Effect of selenylation modification on antitumor activity of peptidoglycan from Lactobacillus acidophilus.

Selenium is an essential trace element for human with the antitumor properties. In the present study, the peptidoglycan (PG) derived from Lactobacillus acidophilus was modified by selenylation with the HNO3-Na2SeO3 method. Reaction temperature, reaction duration and the selenide content were optimized according to orthogonal design of three-factors. In addition, the molecular structure of selenizing peptidoglycan (Se-PG) was determined by infrared spectroscopy analysis. Furthermore, the antitumor activity of Se-PG was also investigated in HT-29 cells. The results showed that Se-PG exerted a greater antitumor activity than non-modified PG in a dose-dependent manner. These findings indicated that selenylation modification can enhance the antitumor activity of PG, and Se-PG could achieve its potential in antitumor activity.

Synergistic cytotoxic effects of combined δ-tocotrienol and jerantinine B on human brain and colon cancers.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Tabernaemontana has widespread distribution throughout tropical and subtropical parts of the world, i.e. Africa, Asia and America which has long been used for treatments of different disease conditions including tumours, wounds, syphilis, stomach ache and headache. Some Tabernaemontana species are used for treatment of piles, spleen and abdominal tumours in India. In particular, the leaf of Tabernaemontana corymbosa is used for treatment of tumours in Bangladesh. Parts of the plant or whole plants are used as decoctions, steam bath, powder and ointments. AIM OF STUDY: The present study was undertaken to study the mechanism of apoptosis induction in human glioblastoma (U87MG) and colorectal adenocarcinoma (HT-29) cancer cells by a novel indole alkaloid, jerantinine B isolated from T. corymbosa, δ-tocotrienol and the combined low-dose treatments of δ-tocotrienol with IC20 dose of jerantinine B. MATERIALS AND METHODS: Cell viability, isobologram and combinational index (CI) analyses were used to determine the pharmacological interaction between combined treatments based on the IC50 values obtained. Fluorescence and histochemical staining techniques as well as comet assay were used for evaluating the morphological changes and DNA damage pattern, respectively. The effects of treatments on microtubules, caspase activity and cell death were determined using immunofluorescence technique, caspase colorimetric and neutral red uptake assays, respectively. RESULTS: Jerantinine B, δ-tocotrienol and combined low-dose treatments induced a dose-dependent growth inhibition against U87MG and HT-29 cells selectively with less toxicity acted towards the normal MRC5 cells. Synergistic growth inhibition observed with CI values of 0.85 and 0.77 for U87MG and HT-29 cells, resulting in up to 2-fold and 3.8-fold dose reduction of δ-tocotrienol and jerantinine B, respectively. U87MG and HT-29 cells exhibited morphological features of apoptosis and double stranded DNA breaks. Individual and combined treatments induced caspase 8 and 3 activities and cell death independent of caspase activation on U87MG and HT-29 cells. An increased caspase 9 activity was also evident on U87MG and HT-29 treated with combined treatments and HT-29 cells treated with jerantinine B. Jerantinine B and combined low-dose treatments with δ-tocotrienol undoubtedly disrupted the microtubule networks. CONCLUSION: The present study demonstrated the mechanism for cytotoxic potency of δ-tocotrienol and jerantinine B against U87MG and HT-29 cells. Furthermore, combined low-dose treatments induced concurrent synergistic inhibition of cancer cell growth with concomitant dose reduction thus minimizing toxicity to normal cells and improving potency of δ-tocotrienol and jerantinine B.

Antimutagenicity and induction of antioxidant defense by flavonoid rich extract of Myrcia bella Cambess. in normal and tumor gastric cells.

ETHNOPHARMACOLOGICAL RELEVANCE: The Brazilian "Cerrado" is an important source of natural products, such as Myrcia bella Cambess (MB, also known as "mercurinho"). MB leaves are popularly used for the treatment of diabetes and gastrointestinal disorders; however, only its hypoglycemic activity has been experimentally described. AIM OF THE STUDY: Because MB is used to treat gastrointestinal disorders, the present study characterized biological activities of hydroalcoholic MB extract in human normal and tumor gastric cells. MATERIALS AND METHODS: Cytotoxic, antiproliferative, genotoxic and protective effects were evaluated, as well as the effects of the MB extract on gene expression. RESULTS: The MB extract induced cytotoxicity in tumor cells at lower concentrations compared with normal cells as assessed by the MTT assay. Moreover, the MB extract induced necrosis based on acridine orange/ethidium bromide staining. An antiproliferative effect was evidenced through an arrest in the G2/M phase detected by flow cytometry and a decrease in the nuclear division index using the cytokinesis-block micronucleus cytome assay. Cells treated with MB extract combined with doxorubicin (DXR) showed increased NUBDs, which may be related to the gene amplification of CCND1. Antimutagenic effects were also observed and may be associated with the antioxidant activities detected using the CM-H2DCFDA probe. CONCLUSIONS: Our findings showed the following: (a) high concentrations of MB induced cytotoxicity and cell death by necrosis; (b) its antiproliferative effect was associated with G2/M arrest; and (c) its antioxidant activity could be responsible for the observed antimutagenic effects and for protective effects against gastrointestinal disorders previously described to MB. Although these effects are not specific to normal or tumor cells, they provide a panel of biological activities for further exploration.

Protective effects of Zhibai Dihuang Wan on renal tubular cells affected with gentamicin-induced apoptosis.

ETHNOPHARMACOLOGICAL RELEVANCE: Zhibai Dihuang Wan (ZDW) is an ancient traditional Chinese medicine composed of eight herbal ingredients and has been used to treat chronic kidney inflammation and diabetes for thousands of years. Nonetheless, the influence of ZDW on acute kidney injury is still unknown. We intended to identify the influence of ZDW on cell growth and gentamicin-induced apoptotic injury in renal tubular cells. MATERIALS AND METHODS: We extracted ZDW with artificial intestinal fluid and treated rat renal tubular cells (NRK-52E) with various concentrations of the ZDW extraction. Cell proliferation and gentamicin-induced apoptosis of NRK-52E cells were evaluated using real-time proliferation monitoring and annexin V staining, respectively. Western blotting was used to evaluate the levels of Bcl-2 and caspase-3 expression. The effect of ZDW on gentamicin-induced kidney injury was also monitored in mice using the terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL) assay, and the measurement of serum creatinine and blood urea nitrogen. RESULTS: We found that 30 µg/ml of ZDW promoted cell proliferation of the rat renal tubular cells. ZDW also expressed a dose-dependent protective effect against gentamicin-induced apoptosis in the cells. Pretreatment with 3 µg/ml or 30 µg/ml of ZDW maximally increased Bcl-2 and decreased cleaved caspase-3 in the gentamicin-treated NRK-52E cells. Among the herbal ingredients of ZDW, only Phellodendron amurense Rupr., bark (Cortex Phellodendri), and Anemarrhena asphodeloides Bunge, rhizome inhibited both the gentamicin-induced Bcl-2 decrease and cleaved caspase-3 increase. Phellodendron amurense Rupr., bark and Anemarrhena asphodeloides Bunge, rhizome also inhibited gentamicin-induced apoptosis at particular concentrations; however, these two ingredients were less effective than ZDW. In the mouse model of gentamicin-induced nephropathy, the ZDW treatment significantly reduced apoptotic cells in the renal cortex and improved renal function. CONCLUSIONS: Our results suggest that ZDW at adequate doses attenuates gentamicin-induced apoptotic injury in renal tubular cells and also protects kidneys from gentamicin-induced injury in mice.

Ligand modulation of a dinuclear platinum compound leads to mechanistic differences in cell cycle progression and arrest.

Despite similar structures and DNA binding profiles, two recently synthesized dinuclear platinum compounds are shown to elicit highly divergent effects on cell cycle progression. In colorectal HCT116 cells, BBR3610 shows a classical G2/M arrest with initial accumulation in S phase, but the derivative compound BBR3610-DACH, formed by introduction of the 1,2-diaminocyclohexane (DACH) as carrier ligand, results in severe G1/S as well as G2/M phase arrest, with nearly complete S phase depletion. The origin of this unique effect was studied. Cellular interstrand crosslinking as assayed by comet analysis was similar for both compounds, confirming previous in vitro results obtained on plasmid DNA. Immunoblotting revealed a stabilization of p53 and concomitant transient increases in p21 and p27 proteins after treatment with BBR3610-DACH. Cell viability assays and cytometric analysis of p53 and p21 null cells indicated that BBR3610-DACH-induced cell cycle arrest was p21-dependent and partially p53-dependent. However, an increase in the levels of cyclin E was observed with steady state levels of CDK2 and Cdc25A, suggesting that the G1 block occurs downstream of CDK/cyclin complex formation. The G2/M block was corroborated with decreased levels of cyclin A and cyclin B1. Surprisingly, BBR3610-DACH-induced G1 block was independent of ATM and ATR. Finally, both compounds induced apoptosis, with BBR3610-DACH showing a robust PARP-1 cleavage that was not associated with caspase-3/7 cleavage. In summary, BBR3610-DACH is a DNA binding platinum agent with unique inhibitory effects on cell cycle progression that could be further developed as a chemotherapeutic agent complementary to cisplatin and oxaliplatin.