RESUMO
In this study, a combination therapy of several natural products was evaluated in vivo in the Giardia duodenalis infection model. G. duodenalis infected mice were treated as follows: distilled water (infected control C+), BIOintestil® (BIO; natural products of Cymbopogon martinii and Zingiber officinale), MicrobiomeX® (MBX; extract of Citrus sinensis and Citrus paradisi), MBX + BIO, Camellia sinensis tea (CPR; black tea). These natural compounds were administered in a dose of 100 mg/day and were compared to G. duodenalis-infected mice treated with albendazole (ALB; 50 mg/Kg/day) and metronidazole (MET; 500 mg/Kg/day), the conventional therapies used to this day. One group remained un-infected and untreated as our control group (C-). Treatment started 8 days after infection, and after 5 days of treatment (7 days for MET), all animals were followed for 15 days. We continuously checked for the presence of G. duodenalis by Faust method, in association with detection of the parasite by PCR from feces, as well for the presence of trophozoites in the intestinal mucosa after sacrifice. Animals treated with MBX, BIO and MBX + BIO presented an undetectable parasitic load until the 15th day of monitoring, while animals treated with CPR, MET and ALB continued to release cysts. Animals in the MBX, MBX + BIO, ALB groups consumed lower feed, MBX, CPR, MET had greater weight and MBX, MBX + BIO, BIO, CPR, C- consumed more water when compared to infected-group control. MBX and BIO alone or associated eliminated G. duodenalis without apparent adverse effects and animals of these groups showed better clinical performance in relation to those with high parasitic load. MET, ALB and CPR only decreased the number of cysts, indicating limitations and therapeutic failure.