Inhibition of the DNA polymerase and RNase H activities of HIV-1 reverse transcriptase and HIV-1 replication by Brasenia schreberi (Junsai) and Petasites japonicus (Fuki) components

Abstract

Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) possesses two distinct enzymatic activities: those of RNA- and DNA-dependent DNA polymerases and RNase H. In the current HIV-1 therapy, all HIV-1 RT inhibitors inhibit the activity of DNA polymerase, but not that of RNase H. We previously reported that ethanol and water extracts of Brasenia schreberi (Junsai) inhibited the DNA polymerase activity of HIV-1 RT [Hisayoshi et al. (2014) J Biol Macromol 14:59-65]. In this study, we screened 43 edible plants and found that ethanol and water extracts of Brasenia schreberi and water extract of Petasites japonicus strongly inhibit not only the activity of DNA polymerase to incorporate dTTP into poly(rA)-p(dT)15 but also the activity of RNase H to hydrolyze the RNA strand of an RNA/DNA hybrid. In addition, these three extracts inhibit HIV-1 replication in human cells, with EC50 values of 1-2 µg/ml. These results suggest that Brasenia schreberi and Petasites japonicus contain substances that block HIV-1 replication by inhibiting the DNA polymerase activity and/or RNase H activity of HIV-1 RT.

Antiprotozoal Activity of Plants Used in the Management of Sleeping Sickness in Angola and Bioactivity-Guided Fractionation of Brasenia schreberi J.F.Gmel and Nymphaea lotus L. Active against T. b. rhodesiense

“…Interestingly, these two Nymphaeales are being used in combination in a traditional preparation for the management of sleeping sickness in the northern part of Angola. While this is the first investigation of their antitrypanosomal constituents, B. schreberi and N. lotus have been investigated for several other bioactivities such as antioxidant [75] and anti-inflammatory [48,76], anti-bacterial [77][78][79], anti-algal [80], anti-adipogenic [49] as well as lowering cholesterol [81] and inhibition of HIV-1 reverse transcriptase [82,83].…”

Antitrypanosomal Constituents from <em>Brasenia schreberi</em> and <em>Nymphaea lotus</em> Used in a Single Herbal Preparation against Sleeping Sickness in Angola

“…Interestingly, these two Nymphaeales are being used in combination in a traditional preparation for the management of sleeping sickness in the northern part of Angola. While this is the first investigation of their antitrypanosomal constituents, B. schreberi and N. lotus have been investigated for several other bioactivities such as antioxidant [88] and anti-inflammatory [61,89], antibacterial [41,42,90], antialgal [43], anti-adipogenic [62] as well as cholesterol lowering [91] and inhibition of HIV-1 reverse transcriptase [92,93].…”

Polysaccharides from Brasenia schreberi with Great Antioxidant Ability and the Potential Application in Yogurt

“…In traditional folklore, B. schreberi was used as a dietary salad ingredient. Recent studies have highlighted its wide-ranging properties, demonstrating not only antioxidant and anti-inflammatory attributes but also revealing an inhibitory effect on HIV [ 1 , 2 ]. These findings have sparked significant scientific interest, particularly in the fields of nutritional and pharmaceutical research.…”