Anticancer and Antifolate Activities of Extracts of Six Saudi Arabian Wild Plants Used in Folk Medicine

Abstract

Six indigenous folk medicinal plants growing wild in the area of Tabuk, Saudi Arabia which were selected for the study of their phytochemistry as well as their biological activities as antitumor and antifolate agents. Antitumor activities of methanol extracts of the six plants were measured in vitro using three human tumor cell lines (breast, lung and CNS cancers) while antifolate activities were assessed using commercial dihyrofolate reductase obtained from Sigma Co. Among the six plant extracts tested, the most remarkable were those of Caralluma sinaica and Fagonia tenuifolia. Caralluma extract showed strong antitumor activity (low GI 50 ) against the three human tumor cell lines. Fagonia extract, on the other hand, was quite inhibitory to the growth of CNS cancer and breast cancer cell lines but much less so against lung cancer cells. Extracts of both Sonchus oleraceus and Caralluma sinaica were strongly inhibitory to DHFR. These results suggest that the mechanism of anticancer activity of Caralluma plant is through DHFR inhibition but that of Fagonia may follow a different path.

Untitled

“…It also showed activity against Klebsiella pneumoniae and Enterobacter arerogenes but did not prevent any cell growth 59 . Similar studies were done by Gouda et al, 2014 andAlbalawi et al, 2015 in Saudi Arabia. The methanol extract of Verbesina encelioides was tested for their in-vitro antimicrobial activity and in-vitro cytotoxicity on different human cancer cell lines.…”

“…The plant had remarkable antibacterial activity but not promising cytotoxicity against different cancer cell lines 60,61 . Al-Oqail et al, 2016 screened the extracts of V. encelioides for anticancer potential against human lung cancer (A-549), breast cancer (MCF-7) and liver cancer (HepG2) cell lines.…”

“…Verbesina encelioides had shown strong activity against many bacteria and fungi but not promising activity against different cancer cell lines 8,10,25,49,59,60,61,62 . Cell cultures of V. encelioides were established from seeds on MS basal medium 49 .…”

“…The cell cycle analysis and comet assay showed that V. encelioides considerably induced G2/M arrests and DNA damage 62 . The hydroalcoholic extracts of the aerial branches, roots, and flowers of V. encelioides were cytotoxic against hepatocellular carcinoma and active against Gram +ve bacteria (Staphylococcus aureus and Bacillus subtilis), Gram -ve bacteria (Escherichia coli) and fungi (Aspergillus fumigatus and Candida albicans) 61 . According to Ramakrishnan et al, 2017 proteins from the young leaves of V. encelioides exhibits moderate antimicrobial activity against various bacterial and fungal species 25 .…”

DHFR Inhibitors: Reading the Past for Discovering Novel Anticancer Agents

“…Since Caralluma sinaica extracts are active in both antitumor and antifolate assays, they could assume that the anticancer activity of this plant proceeds through DHFR inhibition. Thus, this study provides scientific support for the use of Caralluma sinaica as a medicinal anticancer plant [59].…”