Anti-diabetic properties and bioactive compounds of Teucrium polium L

Diabetes mellitus is a common metabolic disease with considerable morbidity and mortality. Untreated or improperly-treated diabetes can be associated with several long-term complications that necessitate an effective way to manage diabetes. Due to the side effects of synthetic glucose-lowering agents, alternative therapeutic modalities such as medicinal plants have attracted notable attention. Teucrium polium L. is a medicinal herb with antioxidant, antinociceptive, anti-inflammatory, hypolipidemic, hepatoprotective, and hypoglycemic properties. In vitro and in vivo studies have been conducted to characterize the anti-diabetic properties of Teucrium polium L. and its bioactive compounds. We conducted a literature study using Scopus, PubMed, and Google Scholar including the keywords 'diabetes' and 'Teucrium polium'. We also scanned all the references cited by the retrieved articles. According to this review, Teucrium polium administration displayed anti-diabetic effects by targeting different mechanisms and pathways, such as enhancement of insulin secretion and insulin level, improvement of oxidative damage, regeneration of pancreatic β-cells, and promotion of glucose uptake in muscle tissues by increasing GLUT-4 translocation as well as inhibiting α-amylase activity. Although Teucrium polium has been widely regarded as a traditional method, the pharmacological studies on anti-diabetic effects are not sufficient, most studies are either in-vivo or in-vitro. The preclinical and clinical studies are further required to confirm the efficacy of Teucrium polium.

Effects of neonatal capsaicin treatment on stress induced analgesia and hyperalgesia in Tail-Flick test in male rats

Background & Objective: It is reported that acute forced swimming stress induces analgesia immediately, and chronic stress induces hyperalgesia. Whereas in response to nociceptive stimulation, small-diameter C-fibers of the excitatory system in the dorsal horn of the spinal cord are activated, therefore, in the present study, the effects of C-fiber lesion in stress and dexamethasone-induced analgesia and hyperalgesia in acute and chronic forms were investigated using Tail-Flick test. Methods: Adults Wistar male rats (180-200 g) were assigned into three groups (n=7): C-normal (intact C-fibers), sham (received capsaicin vehicle at neonate stage) and C-lesion (received capsaicin at neonate stage). Forced swim stress (10 min/day) in water (18±1 ºC) was considered as acute stress and repeated daily forced swim stress as chronic stress, also single-dose of dexamethasone (2 mg/kg, i.p.) was considered as acute dexamethasone and repeated for three days as chronic dexamethasone. Neonatal capsaicin treatment was used for C-fibers depletion. The nociceptive thermal threshold was assessed using Tail-Flick test. Results: In C-lesion group, thermal pain sensitivity was reduced (P<0.001). Acute stress in C-normal group, reduced pain (P<0.001) and in C-lesion group, it caused deeper antinociception in Tail-Flick (P<0.001). Chronic stress and acute-chronic dexamethasone in C-normal group, created hyperalgesia (P<0.001) and induced analgesia in C-lesion groups (P<0.01). Conclusion: It seems that presence of C-fiber is so important in thermal pain transmission in Tail-Flick test; therefore, C-fiber lesion, reduces pain sensitivity (analgesia), increases antinociception effects of acute stress, decreases hyperalgesia of chronic-stress and acute-chronic dexamethasone

effects of hydroalchoholic extract of Teucrium polium L. on hypertension induced by angiotensin II in rats

Antispasmodic and vasorelaxant effects of Teucrium polium L. [TP] were mentioned in former studies, so we attempted to evaluate the eventual preventive effect of TP in an acute experimental model of hypertension induced by angiotensin II [Ang II]. Forty-eight male Wistar rats were divided randomly into six groups [n = 8]; control Group [C], which received only saline, group Ang II; which received Ang II [300 ng/min, IV], group losartan [Los]; which received Los [10 mg/kg, IV] before Ang II injection, three groups of TP 100, TP 200, and TP 400; which received different doses of TP extract [100, 200 and 400 mg/kg, IP, respectively] before Ang II application. After cannulation of the femoral artery, mean arterial blood pressure [MAP] and heart rate [HR] was continuously measured and recorded during the experiments. Comparisons were performed using t test with SPSS software, version 16 [SPSS, Chicago, IL]. MAP and HR in Ang group were significantly higher than the control group [P < 0.001], MAP in group Los significantly was lower than Ang group [P < 0.001] and pretreatment with three doses of TP extract also inhibited increasing of MAP after Ang II injection [P < 0.001]. Los also inhibited the increase of HR due to Ang II [P < 0.001], but none of three doses of TP extract had a protective effect on tachycardia induced by Ang II. It seems TP extract could be effective in preventing of high blood pressure induced by Ang II pathway activation but could not have remarkable efficacy for improving the created tachycardia