Antimicrobial properties of Peganum harmala L. seeds’ smoke in indoors: applications and prospects

Peganum harmala L., known as Harmal or African, Syrian Rue, Espand (in Iranian culture), and Ozallaik (in Turkey), is a perennial herbaceous glabrous plant, which offers many antimicrobial activities in indoor air. In this regard, in the present study, we aimed at evaluating the disinfectant effects of Peganum harmala L. (PHL) seed smoke on microbial load in air. For this reason, the effects of four doses of PHL seeds (5, 10, 15, and 20 g) and various sampling times in the range of 0–30 min were examined on its antibacterial and antifungal effects. The experiments were conducted at two different areas including a classroom located at the health faculty of Ahvaz University of Medical Sciences and a residential area with a similar volume of 60 m 3 . Tryptic soy agar (TSA) was applied as a specific bacterial culture medium, and sabouraud dextrose agar (SDA) was used as a specific fungal culture medium. The concentration of bacteria and fungi in the indoor air of the residential area decreased by 71.4 and 94.7%, respectively. In the educational area, the concentration of bacteria and fungi decreased by 92.8 and 88.9%, respectively. In conclusion, the PHL smoke showed antibacterial and antifungal effects, which may be due to its alkaloids harmine properties, while it causes an increase in the concentration of particles in the air of indoor environments. Therefore, it can be used as an indoor air disinfectant for decreasing the load of bacteria and viruses in a closed space.