Multiple Antiviral Activities of Endemic Medicinal Plants Used by Berber Peoples of Morocco

Abstract

We investigated the antiviral activities of methanol extracts of 75 Moroccan plants (64 genera of 35 families), used traditionally to treat diseases that could be caused by viruses and microbes. The plants included many endemic to Morocco and used by Berber as well as Arab peoples. They were evaluated against three mammalian viruses: herpes simplex virus, Sindbis virus and poliovirus, at non-cytotoxic concentrations. Five extracts were very active against the three viruses, 16 were active against two viruses, and 24 were only active against one virus. Thirty-two extracts showed light enhanced and two showed light-dependent activities. Punica granatum extract, which was the most active, inhibited all three viruses at a concentration of only 1.5 µg/ml, although these activities were not light enhanced. The extracts of Acacia gummifera, Juglans regia, Thymus maroccanus, Lawsonia inermis, Pinus halepensis, and Rosa canina inhibited Sindbis virus at a minimum concentration of 1.5 µg/ml. Thymus maroccanus and Rosa canina activities were light enhanced. Pistacia lentiscus and Thymus maroccanus were very active against herpes simplex virus. The extracts most active against poliovirus were those from Pinus halepensis and Punica granatum. These were active at minimum concentrations of 6.5 µg/ml, but were not light enhanced. These results indicate that some of these plants are potential potent medicines against infectious diseases caused by viruses. Their discriminatory effect against specific microorganisms suggests the presence of different chemical compounds. Light is a determining factor in the activity of photosensitizers and should be definitely taken into account in this kind of test.