Gallotannin-Enriched Fraction from Quercus infectoria Galls as an Antioxidant and Inhibitory Agent against Human Glioblastoma Multiforme

Abstract

In recent years, herbal medicine has experienced rapid development in the search for alternative anticancer compounds. Various phytochemicals present in Quercus infectoria (QI) galls have been reported to trigger cytotoxic effects on many types of cancer cells. However, a specific active constituent of QI galls with the potential to inhibit highly invasive stage IV malignant brain tumor, glioblastoma multiforme (GBM), is yet to be discovered. In this study, a two-phase system composed of aqueous soxhlet extraction and methanolic enrichment fractionation was employed to extract an anticancer compound, gallotannin, from the QI galls. This optimized two-phase system successfully generated a fraction (F4) with ~71% gallotannin, verified by the TLC and HPLC assays. Astoundingly, this fraction showed significantly higher (~1.15-fold) antioxidant activities compared to its crude extract, as well as to a commercial synthetic pure gallotannin. The F4 was also found to significantly suppress GBM cell growth, better than the synthetic pure gallotannin and the QI gall crude extract, probably related to its significantly higher antioxidant property. Moreover, the inhibitory effects exerted by the F4 treatment on GBM cells were comparable to the effects of two clinically used chemo-drugs (Temozolomide and Tamoxifen), indicating its high efficiency in combating human cancer. In conclusion, this study pioneered the development of an optimized extraction procedure for enriched yield of the natural gallotannin metabolite from the galls of the QI medicinal plant with high antioxidant potential and inhibitory effects on human GBM cells.

New Avenues and Major Achievements in Phytocompounds Research for Glioblastoma Therapy

“…Another group of compounds with high anti-GBM activity is gallotanins, for example, found in Quercus infectoria galls [102,103]. Kamarudin et al obtained the fractioned extract rich in gallotanins and showed its high cytotoxicity (IC 50 15.0 µg/mL) in the in vitro tests using the DBTRG-05MG cell line.…”

Glioblastoma Multiforme: Molecular Biology and Updated Systematic Review on Natural Extract and Phytochemical Efficacy In-vitro

“…Additionally, more studies need to assess the efficacy of phytochemicals against TMZ, the current therapeutic standard of care for GBM. From the studies included in this review, only four studies compared the cytotoxicity of phytochemicals to TMZ [140,159,161]. Mann Whitney-U testing demonstrated a statistically significant difference between the concentrations of natural extracts and phytochemicals required to reach IC50 versus TMZ.…”

Review of Malaysian Medicinal Plants with Potential Anticancer Activity

“…In this study, it was found that the result of anticancer activity of the methanolic extract of the stem bark of Senna alata (Gelenggang) varied between previous studies due to different types of cancer cell lines used by both studies: MCF-7 breast cancer cells and PC-3 prostate cancer cell lines which then resulting in two different cytotoxic effects which are moderate and weak with IC 50 values at 47.11 µg/mL and 427.77 µg/mL, respectively (Madankumar et al, 2020;Kamarudin et al, 2021). Another study also reported that the different anticancer activity of ethanolic extract of Morinda citrifolia (Mengkudu) fruit on different cancer cell lines: THP-1 human monocyte cell and MDA-MB-231 breast cancer cell line resulting in different IC 50 values at 0.39 µg/mL (highly active) and 49.72 µg/mL (moderately active), respectively (Tsao et al, 2020;Vyn et al, 2020).…”