• Anti-oxidant, anti-bacterial, and anti-fungi potential of redroot pigweed's allelochemicals
  • Hamideh Bakhshayeshan-Agdam,1,* Fatemeh Khodaie,2 Seyed Yahya Salehi-Lisar ,3 Gholamreza Zarrini ,4
    1. Department of Plant Sciences, Faculty of Natural Sciences, University of Tabriz, Tabriz-5166616471, Iran
    2. Department of Animal Sciences, Faculty of Natural Sciences, University of Tabriz, Tabriz-5166616471, Iran
    3. Department of Plant Sciences, Faculty of Natural Sciences, University of Tabriz, Tabriz-5166616471, Iran
    4. Department of Animal Sciences, Faculty of Natural Sciences, University of Tabriz, Tabriz-5166616471, Iran


  • Introduction: Redroot pigweed (Amaranthus retroflexus L.) is a weed plant with well-known allelopathic effects worldwide. Its allelochemicals belongs to different groups of plants secondary matabolites. Dom which some compounds such 5 alpha pregnane, carvacrol, thymol, and sabinene have therapeutic effects. Interestingly, the majority of these allelochemicals are the excellent anti-oxidant compounds as well. Current research aimed to assessment the anti-bacterial and anti-fungal potential of redroot pigweed’s allelochemicals and subsequently evaluation its anti-oxidant capacity.
  • Methods: In order to, MIC (at different concentration including 1000, 500, 250, 125, 62.5, 31.25, 15.6, and 7.81 µl/ml) and DPPH assay with estimation total phenolics, flavonoids, and anthocyanins were used. Strains that used in this research were including combination of gram-positive, gram-negative bacteria and saccharomycete fungi.
  • Results: The redroot pigweed's allelochemicals showed an excellent anti-bacterial effect on gram-positive bacteria and Candida fungi, but they have less effective on gram-negative bacteria and can be considered as candidates in the anti-biotics production for gram-positive bacteria especially S.aureus and S.epidermidis and Candida fungi. DPPH assay revealed that amaranth allelochemicals inhibit the superoxide radical production in a dose-dependent manner and 400µg/ml of allelochemical's extract showed the highest free radical scavenging activity (87.35%). Total phenols, flavonoids, and anthocyanins contents of this extract were 4.81, 1.56 and 0.52 mg/g DW, respectively. Therefore, based on the literature, total phenolics, flavonoids, and anthocyanins contents of redroot pigweed extract were in the moderately level. But, according to the DPPH assay results, probably other anti-oxidant metabolites such terpenoid compounds were involving in the free radicals scavenging. GC-MS analysis results of redroot pigweed's allelochemicals profile supported this interpretation.
  • Conclusion: Redroot pigweed is one of the most invasive weed worldwide that reduce crops yield. Yearly, large quantities of poisons are used as herbicides to combat whit this weed. Apart from the economic costs of production, these compounds are toxic substances that impose irreparable effects on the environment and are also hazardous to humans and livestock. Therefore, using this plant to produce medicines can reduce the environmental damage. According to the literature using allelochemicals derived from the various organisms as anti-bacterial and anti-cancer agents are increased day-by-day and this event represents the most promising to application of amaranth allelochemicals as an anti-biotics.
  • Keywords: Anti-bacterial, anti-oxidant, anti-fungi, redroot pigweed, DPPH assay