Antiproliferative Activity and Cytotoxicity of Solanum jamesii Tuber Extracts on Human Colon and Prostate Cancer Cellsin Vitro

Abstract

Some tuber-bearing wild potato species are reportedly higher in potential health-promoting traits, such as antioxidant activity (AOA) and total phenolic content (TP), than commercial cultivars; therefore, they could be used as parental material in breeding for high AOA and TP. However, using wild species might result in progenies that are toxic for human consumption because of the presence of high total glycoalkaloids (TGAs) and other unknown compounds. Therefore, wild potato accessions should be screened for cytotoxicity before their introduction into breeding programs. The objective of this study was to investigate antiproliferative activity and cytotoxicity of tuber extracts from 15 Solanum jamesii accessions on human HT-29 colon and LNCaP prostate cancer cell lines in vitro. Also, correlations among AOA, TP, TGA, and antiproliferative activity were determined. The tuber extracts significantly inhibited proliferation of HT-29 and LNCaP cell lines and were not cytotoxic to the cells compared to the control (DMSO). The antiproliferative activity exhibited by tuber extracts was not due to necrosis, because the amount of lactate dehydrogenase (LDH) released from cells incubated with the extracts was not significantly different from that released from cells incubated without extracts (control). Colon cancer cells were more responsive to tuber extract treatment than prostate cancer cells. In both HT-29 and LNCaP cells, there were no observable significant correlations between antioxidant activity (DPPH and ABTS) and inhibition of cell proliferation or between TP and cell proliferation inhibition. Also, glycoalkaloids did not exhibit significant correlations with the inhibition of cancer cell proliferation. Findings of this study show that S. jamesii accessions probably pose no cytotoxic effects when used as parental material in improving the nutritional value of potato cultivars. Correlation results, along with cell proliferation data, suggest that not only the compounds measured in this study but also other bioactive compounds present in the matrix acting additively or synergistically may be more responsible for the antiproliferative effects of potato tuber extracts than higher concentrations of a single or group of compounds.

Antioxidant, Antiproliferative, and Pro-Apoptotic Activities of a Saponin Extract Derived from the Roots of Panax notoginseng (Burk.) F.H. Chen

“…Leakage of lactate dehydrogenase (LDH) into the media indicating cell plasma membrane injury was detected using a commercial assay assay kit ( Jiancheng BioEngineering, Nanjing, China) 21 following the manufacturer's directions.…”

“…1,21,22 Early and late apoptotic changes in LoVo cells were determined using an annexin V-FITC/PI apoptosis detection kit (BestBio, Shanghai) following the manufacturer's instructions. In brief, cells (1 · 10 6 ) were collected, washed twice with PBS, and suspended in 400 lL of binding buffer (adding 5 lL of annexin V-FITC and 10 lL of PI).…”

Diversity Relationships Among Wild Potato Collections from Seven “Sky Island” Mountain Ranges in the Southwest USA

“…One led to the description of the mutant which is the only reported example of complete lack of purple pigment in series Longipedicellata. Similar collecting efforts for the second potato species in the USA, Solanum jamesii, captured populations whose tubers have extreme dormancy, remaining viable for over 8 years in cold storage (Bamberg 2010), and others whose tubers inhibit the growth of prostate cancer (Nzaramba et al 2009). …”

Evaluation of Salicin Isolated from Salix subserrata as a Radioprotector against Gamma Irradiation Induced Ultrastructural and Electrophoretic Changes in Spleen Tissue in Rats

“…It belonged to the phenolic compounds which are believed to work synergistically to promote healthy conditions through a variety of different mechanisms, such as enhancing antioxidant activity, impacting cellular processes associated with apoptosis, platelet aggregation, blood vessel dilation, and enzyme activities associated with carcinogen activation and detoxification 31,32 .…”