In vitro evaluation of novel antiviral activities of 60 medicinal plants extracts against hepatitis B virus

Abstract

Currently, >35 Saudi Arabian medicinal plants are traditionally used for various liver disorders without a scientific rationale. This is the first experimental evaluation of the anti-hepatitis B virus (HBV) potential of the total ethanolic and sequential organic extracts of 60 candidate medicinal plants. The extracts were tested for toxicity on HepG2.2.15 cells and cytotoxicity concentration (CC₅₀) values were determined. The extracts were further investigated on HepG2.2.15 cells for anti-HBV activities by analyzing the inhibition of HBsAg and HBeAg production in the culture supernatants, and their half maximal inhibitory concentration (IC₅₀) and therapeutic index (TI) values were determined. Of the screened plants, Guiera senegalensis (dichloromethane extract, IC₅₀=10.65), Pulicaria crispa (ethyl acetate extract, IC₅₀=14.45), Coccinea grandis (total ethanol extract, IC₅₀=31.57), Fumaria parviflora (hexane extract, IC₅₀=35.44), Capparis decidua (aqueous extract, IC₅₀=66.82), Corallocarpus epigeus (total ethanol extract, IC₅₀=71.9), Indigofera caerulea (methanol extract, IC₅₀=73.21), Abutilon figarianum (dichloromethane extract, IC₅₀=99.76) and Acacia oerfota (total ethanol extract, IC₅₀=101.46) demonstrated novel anti-HBV activities in a time- and dose-dependent manner. Further qualitative phytochemical analysis of the active extracts revealed the presence of alkaloids, tannins, flavonoids and saponins, which are attributed to antiviral efficacies. In conclusion, P. crispa, G. senegalensis and F. parviflora had the most promising anti-HBV potentials, including those of C. decidua, C. epigeus, A. figarianum, A. oerfota and I. caerulea with marked activities. However, a detailed phytochemical study of these extracts is essential to isolate the active principle(s) responsible for their novel anti-HBV potential.

Keywords: Abutilon figarianum; Acacia oerfota; Capparis deciduas; Coccinea grandis; Corallocarpus epigeus; Fumaria parviflora; Guiera senegalensis; Indigofera coerulea; Pulicaria crispa; anti-hepatitis B virus plants; hepatitis B virus.

Figure 1.

Time-course anti-HBV activity of selected plant extracts (50 µg/ml each). (A) Abutilon figarianum; (B) Acacia oerfota; (C) Capparis decidua; (D) Coccinia grandis; (E) Corallocarpus epigeus; (F) Fumaria parviflora; (G) Guiera senegalensis; (H) Indigofera caerulea; (I) Pulicaria crispa. ELISA showing inhibitions of HBsAg expression in HepG2.2.15 culture supernatants at days 1, 3 and 5 post-treatment. Lamivudine (2.0 µM) was used as a reference anti-HBV drug. Values (y-axis): means of three determinations. HBV, hepatitis B virus; Aqua, aqueous; DCM, dichloromethane; EtAc, ethyl acetate; EtOH, ethanol; Hex, hexane; MeOH, methanol; LAM, lamivudine.

Figure 2.

Time-course anti-HBV activity of the plants extracts with anti-HBV potential (50 µg/ml each). ELISA showing inhibitions of HBeAg expression in HepG2.2.15 culture supernatants at days 1, 3 and 5 post-treatment. Lamivudine (2.0 µM) was used as a reference anti-HBV drug. Values (y-axis): means of three determinations. HBV, hepatitis B virus; Aqua, aqueous; DCM, dichloromethane; EtAc, ethyl acetate; EtOH, ethanol; Hex, hexane; MeOH, methanol; LAM, lamivudine.