Chemopreventive potential of sorghum with different phenolic profiles /
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| Other Authors: | |
| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2010]
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| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| Abstract: | Epidemiological evidence has correlated consumption of sorghum with reduced incidences of gastrointestinal (GI) tract cancer, especially esophageal cancer. There is little evidence on how phenols of sorghum may affect chemoprevention. Seventeen sorghum varieties were screened for phenolic profiles and antioxidant capacity. The ability of crude sorghum extracts to induce NAD(P)H:quinone oxidoreductase (QR, a phase II protective enzyme), and inhibit proliferation of colon (HT-29) and esophageal (OE33) carcinoma cells using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide) and PicoGreen assays, were determined in vitro. 3- Deoxyanthocyanidins, apigeninidin, luteolinidin and their methoxylated derivatives were also investigated for antioxidant capacity, QR inducing and antiproliferative potential. Tannin sorghum generally showed higher antioxidant capacity than non-tannin sorghum varieties. Sorghum varieties containing extractable condensed tannins did not show any significant QR inducing potential; on the other hand, non-tannin sorghums increased QR activity by 1.5-2.7 times; black sorghum (Tx430) was most potent (doubled QR activity at 25 [mu]g/mL, 2.7-fold increase at 100 [mu]g/mL). All sorghum extracts showed relatively strong antiproliferation activity with IC₅₀s (the concentration needed to inhibit cancer cell growth by 50%) of 49.7-883 [mu]g/mL. Tannin-containing sorghums had stronger cancer cell proliferation inhibitory potential (IC₅₀s 49.7-131 [mu]g/mL) than non-tannin sorghums (IC₅₀s 141-883 [mu]g/mL). Total phenol content and antioxidant capacity of crude sorghum extracts positively correlated with their antiproliferative potential (r² 0.71-0.97). Among tested 3-deoxyanthocyanidins, methoxylation on A-ring improved QR inducing potency. 5,7-Dimethoxyluteolinidin had the greatest QR inducing potency (4.3- fold at 100 [mu]M). Methoxylation also improved their antiproliferation potential; the IC₅₀s trend was di-methoxylated (8.3-105 [mu]M) > mono-methoxylated (40.1-192 [mu]M) > apigeninidin and luteolinidin (81.5-284 [mu]M). This study provides information for how phenolic compositions of sorghum and 3-deoxyanthocyanidin structure affect their capacity to induce QR activity and inhibit GI tract cancer cell proliferation. The information is useful to promote the utilization of sorghum in functional foods, beverages, dietary supplements, and other health-related industries. Further study will focus on, fractioned and isolated sorghum phenols, the effect of food processing on their chemopreventive potential, as well as cellular mechanisms involved. |
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| Item Description: | "Major Subject: Food Science and Technology" Title from author supplied metadata (automated record created 2010-08-20 08:31:34). Electronic resource. |
| Physical Description: | 1 online resource. |
| Bibliography: | Includes bibliographical references. |