Anthelminthic medicinal plants in veterinary ethnopharmacology: A network meta-analysis following the PRISMA-P and PROSPERO recommendations

Medicinal plants may be effective against helminthic infestation in animals, but to date few studies have investigated the real impact of anthelminthic medicinal plants in veterinary ethnopharmacology. The aim of this study was to assess the geographical use of anthelminthic medicinal plants in livestock in European Union (EU), and to quantify the anthelminthic efficacy of medicinal plants in comparison with anthelminthic drugs. Surveys on the use of anthelminthic traditional medicinal plants in livestock in the EU were included in the qualitative synthesis. Studies that investigated the efficacy of anthelminthic traditional medicinal plants in animals, compared with negative control and/or anthelminthic drugs, were included in the quantitative synthesis (network meta-analysis). Twelve surveys (9 in Italy, 2 in Spain, 1 in Austria) reported the use of anthelminthic medicinal plants in livestock living in EU Countries. Data obtained from 256 animals and extracted from 6 studies were included in the network meta-analysis. Medicinal plants and drugs were more effective than negative control (standardized mean difference [SMD]: -0.60 95%CrI -0.88 to -0.31, -0.73 95%CrI -1.08 to -0.38, respectively, P < 0.001). Overall, no difference was detected between anthelminthic medicinal plants and anthelminthic drugs, namely albendazole, ivermectin, fenbendazole, and doramectin (SMD: 0.26 95%CrI -0.02 to 0.55, P > 0.05). The most effective anthelminthic medicinal plants were Artemisia absintihium, Allium sativum, and Duranta erecta. There is the strong medical need of performing adequately powered randomized controlled trials in different livestock species aimed to improve the quality of the current evidence concerning the anthelminthic efficacy of medicinal plants compared to that of the currently available antiparasitic drugs.