Phenylethanoid Glycoside-Enriched Extract Prepared from Clerodendrum chinense Leaf Inhibits A549 Lung Cancer Cell Migration and Apoptosis Induction through Enhancing ROS Production

Abstract

This study aims to investigate the antioxidant and anti-cancer activities of Clerodendrum chinense leaf ethanolic extract. The phenylethanoid glycoside-enriched extract, namely verbascoside and isoverbascoside, was determined in the ethanolic C. chinense leaf extract using the validated HPLC method. The ethanolic extract showed DPPH and ABTS free radical scavenging activities with the IC50 values of 334.2 ± 45.48 μg/mL and 1012.77 ± 61.86 µg/mL, respectively, and a FRAP value of 88.73 ± 4.59 to 2480.81 ± 0.00 µM. C. chinense leaf extract exhibited anti-proliferative activity against A549 lung cancer cells in a dose- and time-dependent manner, with the IC50 value of 340.63 ± 89.43, 210.60 ± 81.74, and 107.08 ± 28.90 µg/mL after treatment for 24, 48, and 72 h, respectively. The IC50 values of verbascoside, isoverbascoside, and hispidulin were 248.40 ± 15.82, 393.10 ± 15.27, and 3.86 ± 0.87 µg/mL, respectively, indicating that the anti-proliferative effects of the C. chinense leaf extract mainly resulted from hispidulin and verbascoside. The selectivity index (SI) of C. chinense leaf extract against A549 lung cancer cells vs. normal keratinocytes were 2.4 and 2.8 after incubation for 24 and 48 h, respectively, suggesting the cytotoxic selectivity of the extract toward the cancer cell line. Additionally, the C. chinense leaf extract at 250 µg/mL induced late apoptotic cells up to 21.67% with enhancing reactive oxygen species (ROS) induction. Furthermore, the lung cancer cell colony formation was significantly inhibited after being treated with C. chinense leaf extract in a dose-dependent manner. The C. chinense leaf extract at 250 µg/mL has also shown to significantly inhibit cancer cell migration compared with the untreated group. The obtained results provide evidence of the anti-lung cancer potentials of the C. chinense leaf ethanolic extract.

Clerodendrum chinense Stem Extract and Nanoparticles: Effects on Proliferation, Colony Formation, Apoptosis Induction, Cell Cycle Arrest, and Mitochondrial Membrane Potential in Human Breast Adenocarcinoma Breast Cancer Cells

“…Several factors may have influenced the yield, including the temperature of extraction, extraction time, extraction solvent polarity, and the source of C. chinense stem [21]. The yield of C. chinense stem extraction was lower compared with C. chinense leaf (11.4%) and flower (11.2%) [18,19].…”

“…Among different parts of the plants, ethanolic extract of C. chinense leaf offered the highest TPC (1.03 g GAE/g extract), followed by stem extract (0.553 g GAE/g extract) and flower extract (0.487 g GAE/g extract) [18,19]. The results of total flavonoid content analysis showed that the stem of C. chinense exhibited the lowest concentration of total flavonoid content, followed by the leaf and flower [18,19]. These results indicated that each part of C. chinense contained different amounts of phenolic compounds and flavonoids.…”

“…The filtrate extract was dried to a crude extract using a rotary evaporator and stored in the vacuum desiccator for further studies. The yield (%w/w) of the extract was calculated using the following equation [19]:…”

“…The filtrate extract was dried to a crude extract using a rotary evaporator and stored in the vacuum desiccator for further studies. The yield (%w/w) of the extract was calculated using the following equation [19]: In the analysis of C. chinense stem extract, the bioactive compounds verbascoside, isoverbascoside, and hispidulin were identified and quantified. The identification and quantification were achieved through the implementation of a validated HPLC method employing an RP-C18 column (ACE 5 C18-AR, 250 × 4.6 mm, 5 µm) [42].…”

“…The ethyl acetate fraction had the lowest IC 50 value and was classified as moderately active against lung cancer. Previously, we reported the anticancer activities of C. chinense leaf and flower extracts against MCF-7, A549, and HeLa cells [18,19]. The leaf and flower extract of C. chinense have undergone extensive research in various cancer cell lines; however, there remains a gap in the existing knowledge, as the anticancer activities of the stem extract in relation to a breast cancer cell line have never been investigated.…”