Extraction and purification of total flavonoids from pine needles of Cedrus deodara contribute to anti-tumor in vitro

Cedrus deodara is one of the traditional Chinese medicinal herbs that exhibits a line of biological activities. The current study extracted the total flavonoids from the pine needles of Cedrus deodara (TFPNCD), and investigated its anti-cancer effects in tumor cell lines.

The TFPNCD, in which the contents of total flavonoid reached up to 54.28 %, and the major ingredients of myricetin, quercetin, kaempferol and isorhamnetin in TFPNCD were 1.89, 2.01, 2.94 and 1.22 mg/g, respectively. The MTT assays demonstrated that TFPNCD inhibited the growth of HepG2 cells in a dose-dependent manner, with the IC₅₀ values of 114.12 μg/mL. By comparison, TFPNCD inhibited the proliferation to a less extent in human cervical carcinoma HeLa, gastric cancer MKN28 cells, glioma SHG-44 cells and lung carcinoma A549 than HepG2 cells. We found that even at the lower doses, the total flavonoids effectively inhibited the proliferation of HepG2 cells. Comparison of IC₅₀ values implicated that HepG2 cells might be more sensitive to the treatment with total flavonoids. TFPNCD was able to increase the population of HepG2 cells in G0 /G1 phase. Meanwhile, TFPNCD treatment increased the percentage of apoptotic HepG2 cells.

These data suggested that TFPNCD might have therapeutic potential in cancer through the regulation of cell cycle and apoptosis.