Extreme effects of Seabuckthorn extracts on influenza viruses and human cancer cells and correlation between flavonol glycosides and biological activities of extracts

Abstract

Seabuckthorn is a medicinal plant that is used to prevent cold. It was tested for its metabolic content followed by activity against cancer and virus. The metabolic distribution of different polarity solvent extractions from the leaves was analyzed by LC-MS/MS. Flavonol glycoside contents in EA and Bu extracts were higher than MeOH and DW was observed. MeOH and EA extracts recorded high activity against influenza A/PR virus with IC₅₀ of 7.2 μg/mL and 10.3 μg/mL compared with known drug Oseltamivir of 60.3 μg/mL. A similar trend showed in influenza A/Victoria virus. In case of influenza B viruses such as B/Lee and B/Maryland, EA extract (2.87 μg/mL and 4.5 μg/mL of IC₅₀) emerged strongest among other extracts and Oseltamivir (103.73 μg/mL and 71.6 μg/mL). Each extract showed potent anticancer activities. Interestingly, Bu extract showed stronger anticancer activity against human cancer cells such as NCL-H1299, HeLa, SKOV and Caski (8.2 μg/mL, 8.6 μg/mL, 18.2 μg/mL and 9.2 μg/mL of IC₅₀) respectively. Correlation study reveals that aglycones and flavonol mono-glycosides highly correlated with anti-influenza activities but not correlated with anticancer activities. Reversely, di-glycosides and tri-glycosides have a high correlation with cytotoxic effect with both normal and cancer cells. Therefore, this study provides significant information concerning Seabuckthorn for further medicinal drug development.

Keywords: Cancer; Influenza; Metabolite correlation; SRB assay; Seabuckthorn leaf.

Figure 1

Total flavonoid and total polyphenol content of different extracts of Seabuckthorn leaf. (A) Total flavonoid content; (B) total polyphenol content. Each value was obtained from an average of three independent experiments’ standard deviation.

Figure 2

Free radical scavenging potential of different extractions of Seabuckthorn leaf. (A) ABTS radical scavenging activity, (B) DPPH radical scavenging activity. Each value was obtained from an average of three independent experiments’ standard deviation.

Figure 3

Flavonol glycosides variation of Seabuckthorn leaf extracts. (MeOH) Methanol, (EA) ethyl acetate, (Bu) butanol and (DW) water extract.

Figure 4

Effect of Seabuckthorn leaf extracts on influenza A/PR infected MDCK cells in a concentration of 10 μg/mL. (A) A/PR virus infected cells; (B) A/PR virus infected cells with MeOH extract; (C) A/PR virus infected cells with EA extract; (D) A/PR virus infected cells with Bu extract; (E) A/PR virus infected cells with DW extract; (F) A/PR virus infected cells with Oseltamivir; (G) non-infected cells; (H) non-infected cells with MeOH extract; (I) non-infected cells with EA extract; (J) non-infected cells with Bu extract; (K) non-infected cells with DW extract; (L) non-infected cells with Oseltamivir.

Figure 5

Effect of Seabuckthorn leaf extracts on the NCL-H1299 lung cancer cell line. NCL-H1299 cells seeded onto 96 well plates and maintained at 37 °C, 5% of CO₂ and humidified incubator. After 24 h incubation, media was removed and washed with PBS solution. Then MeOH, EA, Bu and DW extracts or Berberine concentrations such as 1, 10 and 100 μg/mL. After incubation 48 h, the morphology of cells was observed under microscope 20× magnification, and a photograph taken. (A) MeOH extract; (B) EA extract; (C) Bu extract; (D) DW extract; (E) Berberine; (F) control, non-treated NCL-H1299 cells.

Figure 6

Correlation heat map between flavonol glycosides and biological activities such as antioxidant, antiviral, anticancer and cytotoxicity.