In vitro antiviral activities of extracts derived from Daucus maritimus seeds.

The antiviral activities of extracts from Daucus maritimus seeds were investigated against the reverse transcriptase of human immunodeficiency virus (HIV) type 1 and a panel of RNA-dependent RNA polymerases of dengue virus, West Nile virus (WNV) and hepatitis C virus (HCV). The extracts showed moderate to potent inhibition rates against the four viral polymerases. The ethyl acetate extract exhibited a potent inhibitory effect against WNV's RdRp, with an IC50 value of 8 µg mL⁻¹. The F2 fraction exhibited potent inhibitory activity against WNV and HCV's RdRps, with IC50 values 1 and 5 µg mL⁻¹, respectively. The P2 fraction also showed potent inhibitory effects on WNV and HCV's RdRps, with IC50 values 2.7 and 4 µg mL⁻¹, respectively. The results suggest that these extracts are candidates for the development of new anti-WNV RpDp and anti-HCV RpDp agents.

[Dengue virus: viral targets and antiviral drugs]. / Le virus de la dengue : cibles virales et antiviraux.

This work reviews the opportunities and scientific bases in the development of anti-dengue drugs. The timeliness of anti-dengue drug development is addressed in the context of the growing impact of dengueworldwide and existing strategies to fight the virus. The antiviral approach in therapy or prophylaxis during an epidemic as well as the impact of recent technological advances in drug-discovery and antiviral chemotherapy on the development of anti-dengue drugs are discussed. An analysis of current sources of synthetic or natural drugs is provided. Finally, we summarize the current knowledge on dengue virus proteins, which are currently considered the most viable as drug targets, as the envelop protein E and non-structural proteins NS3 and NS5 carrying protease, helicase, RNA triphosphatase, methyltransferase and RNA-dependent RNA polymerase activities. Other viral proteins proposed to be part of the replication complex and the complex itself are considered as potential targets of anti-dengue drugs. State-of-the-art methods are listed, that are expected to allow the discovery, design, and characterisation of anti-dengue drugs effective against the four serotypes.

Why are pharmacokinetic data summarized by arithmetic means?

The main aim of many studies in clinical pharmacology is to describe the pharmacokinetic activity of a given compound. This pharmacokinetic activity for an individual is then evaluated through a series of summary parameters, such as area under the concentration-time curve (AUC), maximum concentration (Cmax) and the rate constant lambda, and it is evaluated across individuals by descriptive statistics of these parameters, such as the mean and range and a measure of spread such as the standard deviation. How the pharmacokinetic parameters are derived is described here. It is demonstrated that the assumption of an exponential half-life is often fundamental to the derivation of pharmacokinetic parameters. Given this fact, one would think it logical that data are analyzed with the appropriate statistics on the log-scale and not by summary statistics, such as arithmetic means, on the original scale. Why arithmetic means are used to describe the data is explored and the special nature of the log-transformation highlighted.