Polyphenolic Profile and Multimodal Biological Activity of Ajuga turkestanica Extract: From In vitro Antioxidant Potential to In vivo Antihypoxic Protection
Abstract
Natural adaptogens are increasingly evaluated for their ability to mitigate environmental stress, yet the non-ecdysteroid components of Ajuga turkestanica remain poorly characterized. The present study aimed to characterize the polyphenolic profile of Ajuga turkestanica and to evaluate its antioxidant, antihypoxic, and antimicrobial activities using integrated phytochemical and biological approaches. The ethanolic extract was systematically examined for total phenolics, flavonoids, and phenolic acids using spectrophotometric methods. Quantitative assessment demonstrated a total phenolic content of 10.03 ± 1.68 mg GAE/g, accompanied by flavonoid levels of 0.46 ± 0.02 mg QE/g and total phenolic acids amounting to 0.96 ± 0.12 mg CAE/g. In vitro antioxidant assays demonstrated robust radical scavenging activity, with an IC50 for DPPH at 0.42 mg/mL and significant hydroxyl radical inhibition (IC50 = 0.04 mg/mL). In vivo studies demonstrated that the extract significantly enhanced survival under hypoxic conditions in outbred white mice and reduced alloxan-induced oxidative stress in outbred white rats. Hemic hypoxia models showed the strongest response to the extract; a 120 mg/kg dose extended survival by 38.7% (19.7 ± 1.0 min vs 14.2 ±1.1 min in control, p = 0.01). Furthermore, the extract exhibited broad-spectrum antimicrobial activity, particularly against Candida species, with inhibition zones up to 10.33 ± 0.58 mm for C. glabrata and C. krusei. Acute toxicity tests confirmed a high safety profile (LD50 > 10,000 mg/kg), classifying the extract as a low-toxicity substance. These observations indicate the potential applicability of A. turkestanica extract as a natural adjuvant in conditions involving acute oxygen deprivation, such as high-altitude exposure or ischemic events.