RESUMO
Rice (Oryza sativa L.) is the main source of energy for humans and a staple food of high cultural significance for much of the world's population. Rice with highly resistant starch (RS) is beneficial for health and can reduce the risk of disease, especially type II diabetes. The identification of loci affecting starch properties will facilitate breeding of high-quality and health-supportive rice. A genome-wide association study (GWAS) of 230 rice cultivars was used to identify candidate loci affecting starch properties. The apparent amylose content (AAC) among rice cultivars ranged from 7.04 to 33.06%, and the AAC was positively correlated with RS (R2 = 0.94) and negatively correlated with rapidly available glucose (RAG) (R2 = -0.73). Three loci responsible for starch properties were detected on chromosomes 1, 6, and 11. On chromosome 6, the most significant SNP corresponded to LOC_Os06g04200 which encodes granule-bound starch synthase I (GBSSI) or starch synthase. Two novel loci associated with starch traits were LOC_Os01g65810 and LOC_Os11g01580, which encode an unknown protein and a sodium/calcium exchanger, respectively. The markers associated with GBSSI and LOC_Os11g01580 were tested in two independent sets of rice populations to confirm their effect on starch properties. The identification of genes associated with starch traits will further the understanding of the molecular mechanisms affecting starch in rice and may be useful in the selection of rice varieties with improved starch.
RESUMO
This study aims to evaluate the potency of ethanol extract of red okra pods (EEROP) in inhibiting growth of cervical cancer cells through repression of the cell cycle-associated oncogenes. The EEROP treatment was given to HeLa cells cultured with RPMI medium and incubated at 37°C with 5% CO2. The MTT method was used to measure HeLa cell growth and IC50 values. The mRNA levels of the three cell cycle-associated oncogenes (MYC, TYMS, and MDM2) were evaluated by qRT-PCR to determine the effect of EEROP treatment on the cell cycle. The lowest percentage of viable cells at 24, 48, and 72 hours after EEROP treatment was in the dose of 1000 µg/mL with a growth percentage of 71.60% at 24 hours, 55.61% at 48 hours, and 46.97% at 72 hours. The IC50 values were 2845, 1153, and 776.8 µg/mL for 24, 48, and 72 hours, respectively. The three oncogenes at a dose of 1000 µg/mL significantly decreased the lowest mRNA levels compared to other doses with MYC oncogene that experienced the greatest decrease. The mRNA level of dose 1000 µg/mL EEROP at the MYC oncogene was 0.014-fold changes, at the TYMS oncogene was 0.097-fold changes, and at the MDM2 oncogene was 0.028-fold changes. The EEROP has been shown to decrease the expression of three cell cycle-associated oncogenes. This is also supported by the growth of HeLa cells that did not increase throughout 24, 48, and 72 hours. However, further research is needed on the main active components in red okra that function as anticancer, so that in the future, okra can not only stop cancer cell growth but also induce cancer cell death.
