Document Type : Research Paper
Authors
1 Student Research Comittee, Iran University of Medical Sciences, Tehran, Iran
2 Department of Pharmacognosy and Pharmaceutical Biotechnology, Iran University of Medical Sciences, Tehran, Iran
3 Student of Research Committee, Iran University of Medical Sciences, Tehran, Iran
4 Department of Pharmacology and Toxicology, Iran University of Medical Sciences, Tehran, Iran
5 Department of Pharmacognosy and Pharmaceutical Biotechnology, Iran University of Medical Sciences
Abstract
Background and Objectives: Urinary tract infection (UTI) is one of the most common infections in humans and imposes a significant therapeutic and economic burden on healthcare systems. Although antibiotics remain the mainstay of treatment, the growing threat of antimicrobial resistance highlights the need for alternative or adjunctive therapies. Stachys schtschegleevii has traditionally been used in Iranian folk medicine to treat infectious diseases. This study evaluated the therapeutic effect of the methanolic extract of the aerial parts of this plant on UTI in an animal model, with particular emphasis on reducing microbial load and urinary nitrite levels.
Methodology: A total of 500 g of powdered aerial parts of S. schtschegleevii was extracted with methanol by percolation at room temperature. The extract was concentrated and dried. Phytochemical screening was performed to identify the major bioactive constituents, including alkaloids, tannins, saponins, flavonoids, cyanogenic glycosides, and steroids. To assess anti-infective activity, 42 female Wistar rats weighing 200–250 g were randomly allocated to six groups: a healthy control (no infection or treatment), a negative control (infection without treatment), three treatment groups receiving extract doses of 500, 750, and 1000 mg/kg/day orally, and a positive control group treated with gentamicin (10 mg/kg/day intraperitoneally). UTI was induced by direct inoculation of 10⁵ CFU of Escherichia coli. Treatment continued for 21 days. Urine samples were collected on days 0 and 21 and analyzed for bacterial count and nitrite levels. Statistical analyses were performed using GraphPad Prism 5 software.
Results: Phytochemical analyses revealed tannins and flavonoids in the methanolic extract of S. schtschegleevii, whereas alkaloids, saponins, steroids, and cyanogenic glycosides were not detected. Pharmacological evaluation showed that after 21 days of treatment, rats receiving the extract at 500, 750, and 1000 mg/kg, as well as those treated with gentamicin, had significantly lower urinary bacterial counts than the negative control group. The greatest reduction in microbial load occurred in the group receiving 1000 mg/kg of the extract. Urinary nitrite assessment also confirmed a dose-dependent effect of the extract. In the 500 mg/kg group, two of seven rats tested negative; in the 750 mg/kg group, three tested negative; and in the 1000 mg/kg group, four rats tested negative for urinary nitrite. In contrast, only one rat in the gentamicin group remained nitrite-positive, whereas all rats in the negative control group remained nitrite-positive, indicating that the extract reduced UTI severity.
Conclusion: The findings suggest that the methanolic extract of Stachys schtschegleevii exhibits dose-dependent antibacterial activity, with the 1000 mg/kg dose showing the most promising results. Although its efficacy was lower than that of gentamicin, the extract showed significant therapeutic potential and could be considered an adjunct or preventive option in UTI management. Tannins are likely responsible for this effect. Future studies should isolate and purify the active constituents, investigate potential synergistic effects with antibiotics, and evaluate the pharmacokinetic and safety profiles of the extract.
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