Herpesviruses (HV) are pathogens causing infections in humans and animals worldwide. Since it shares many common features with other HV, bovine HV type 1 (BoHV-1) was selected as a model to test the anti-herpesviral activity of medicinal plants.
Fifteen plants were chosen in this study for their medical, antibacterial and antiviral properties. The aim was to investigate ethanolic extracts from the selected medicinal plants for anti-BoHV-1 activity. The virucidal activities were evaluated by comparing the effect of noncytotoxic concentrations of extracts on BoHV-1 strain 1640 replication in Madin-Darby bovine kidney (MDBK) cells. Virucidal activity was determined by means of virus titration after exposure to the extracts. The extract of Desmodium canadense was found to be the most effective virucide – the 50% tissue culture infective dose (TCID50) after exposure was 3.75 log10 and the virus reduction factor was ≥5.0±0.25 log10. The extract of D. canadense was therefore chosen for further studies. Virus yield reduction assays showed that D. canadense extract had time-dependent and dose-dependent effects. It effectively reduced virus titre from 8.33 log10 to 4.67 log10 (p<0.01). The virucidal activity was also confirmed by real-time polymerase chain reaction (real-time PCR), where the number of threshold cycles (Ct) was inversely proportional to the virus titre in TCID50 The virucidal activity was also confirmed by real-time polymerase chain reaction (real-time PCR). This method showed that the number of threshold cycles (Ct) was inversely proportional to the virus titre (direct correlation with exposure time R=0.9321). The extract of D. canadense showed a high virus reduction capacity. In future, such active substances should be identified for the development of effective antivirals.
Injection of lymphokine activated killer (LAK) cells is known as useful for activation of cellular immune system. Although the effect of LAK cells has been clarified in human or mice, this effect on function of immune cells has not been examined in calves. Healthy ten Holstein calves were injected with the LAK cells 2 days after birth (LAK Group), and another eight calves were observed as controls (Control Group). All calves received the colostrum formulation on the day of birth, and then, were inoculated with a live attenuated vaccine of bovine herpesvirus (BHV)-1 at 2 (the first vaccination) and 6 (the second vaccination) weeks after birth. Peripheral blood of their dam obtained 3 weeks before calving was used for preparation of LAK cells. Blood samples were taken prior to vaccine inoculation and 3 days after the first inoculation, as well as 3 and 6 days after the second vaccination from all calves. Numbers of CD8+ and CD21+ cells increased significantly after the second vaccination in the LAK Group compared with Control Group. The present study suggested the improved effect of injecting LAK cells originated from dams on immune cells function of young calves after BHV-1 live vaccine.
In the present study on Bubalus bubalis of the Campania Region (Italy) the serum levels of derivatives of reactive oxygen metabolites (d-ROMs), anti-ROM and oxidative stress index (Osi) were evaluated. These data were then related to the seropositive status of the animals against alpha-herpesviruses, precisely Bubaline herpesvirus 1 (BuHV-1) and Bovine herpesvirus 1 (BoHV-1). Clinically healthy Mediterranean buffaloes were selected for this study. The serum samples of these animals were taken, and d-ROMs, anti-ROM and Osi were measured using commercially available tests. The preliminary data demonstrated that animals seropositive to both BuHV-1 and BoHV-1 present more oxidative stress than seronegative animals, as revealed by a significant increase in d-ROMs. Our results provide, for the first time, insight into the reac- tive oxygen species (ROS) modulation induced by the herpesvirus in Bubalus bubalis.