مقالات پذیرفته شده در نهمین کنگره بین المللی زیست پزشکی
Antioxidant and anticancer potential of methanolic rhizome extract of Polygonum bistorta L. against HT-29 colon cancer cells
Antioxidant and anticancer potential of methanolic rhizome extract of Polygonum bistorta L. against HT-29 colon cancer cells
Sayeh Jafari Marandi,1,*Sara Ramezani,2Sedigheh Arbabian,3Fahimeh Salimpour,4
1. Department of Biology, NT.C., Islamic Azad University, Tehran, Iran 2. Department of Biology, NT.C., Islamic Azad University, Tehran, Iran 3. Department of Biology, NT.C., Islamic Azad University, Tehran, Iran 4. Department of Biology, NT.C., Islamic Azad University, Tehran, Iran
Introduction: Colorectal cancer is one of the most common cancers worldwide and is still a leading cause of cancer deaths. Despite progress in surgery, chemotherapy, and radiotherapy, the prognosis for advanced cases remains poor. Because of this, interest has grown in natural products, especially medicinal plants, as safer and more accessible therapeutic options. Polygonum bistorta L., a perennial herb from the Polygonaceae family, has long been used in traditional medicine for its astringent and anti-inflammatory effects. It contains phenolic and flavonoid compounds, which are often associated with antioxidant and anticancer activities. In this study, we examined the potential of methanolic extracts from the rhizome and leaf of P. bistorta against HT-29 human colorectal cancer cells.
Methods: Methanolic extracts (80% methanol) were prepared from both rhizome and leaf and analyzed for their phytochemical contents. Total phenolics were measured using the Folin–Ciocalteu method (mg GAE/g DW) and flavonoids by the aluminum chloride method (mg QE/g DW). Antioxidant activity was assessed by the DPPH assay, and IC₅₀ values were calculated. For cytotoxicity, HT-29 cells were exposed to extract concentrations of 50–800 μg/mL for 24, 48, and 72 hours, and cell viability was determined by the MTT assay. Apoptosis was examined by flow cytometry, and qRT-PCR was used to analyze the expression of P53, Bax, and Bcl2, with β-actin as control.
Results: The rhizome extract contained more bioactive compounds (phenolics: 8.98 mg GAE/g DW; flavonoids: 6.31 mg QE/g DW) compared with the leaf (6.41 and 2.38, respectively). Antioxidant results confirmed this, as the rhizome extract showed a lower IC₅₀ (1963 μg/mL) than the leaf (4472 μg/mL). Cytotoxicity assays also indicated stronger activity for the rhizome: after 72 h, cell survival dropped to 45.7% compared with 65.2% in the leaf group. The IC₅₀ of the rhizome extract decreased sharply from 1279 μg/mL (24 h) to 580 μg/mL (72 h). Gene expression studies showed marked upregulation of P53 and Bax and strong downregulation of Bcl2 in rhizome-treated cells. Flow cytometry confirmed significantly higher apoptosis in this group.
Conclusion: our results highlight the methanolic rhizome extract of P. bistorta as a potent natural source with superior antioxidant and anticancer activities compared to the leaf. By upregulating P53 and Bax and suppressing Bcl2, the rhizome extract effectively promotes apoptosis in HT-29 cells. These findings not only support its potential as a promising candidate for colorectal cancer therapy but also encourage further in vivo investigations and the exploration of its bioactive constituents for possible drug development.