Laboratory Neurotoxicity and Psychopharmacology, Graduate Program in Biological Sciences: Toxicological Biochemistry, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria, RS, Brazil.
School of Pharmaceutical Sciencies of Ribeirão Preto- University of São Paulo (FCFRP-USP), Ribeirão Preto, SP, Brazil.
Biomed Pharmacother. 2019 Jan;109:646-657. doi: 10.1016/j.biopha.2018.10.132. Epub 2018 Nov 4.
Tabernaemontana catharinensis, popularly known as snakeskin, is used in traditional medicine to treat skin inflammatory disorders. To confirm the topical anti-inflammatory effect of T. catharinensis leaves, we evaluated the therapeutic effect of crude extract (TcE) and its different fractions on irritant contact dermatitis model in mice and verified its anti-inflammatory action mechanism.
The qualitative phytochemical analysis of TcE and its dichloromethane, n-butanol and ethyl acetate fractions was performed by UHPLC-ESI-HRMS. The gel accelerated stability was performed to ensure the effectiveness formulation. We investigated the TcE' inhibitory effect, its fractions and a gel formulation containing TcE in irritant contact dermatitis models induced by unique (1000 μg/ear) and multiple (400 μg/ear) croton oil application, evaluated by the ear edema formation, inflammatory cell infiltration (MPO activity measurement and histological procedure) and pro-inflammatory cytokines levels. The action glucocorticoid-like of TcE was investigated using a glucocorticoid receptor antagonist (mifepristone; 50 mg/kg, s.c.).
The treatments (10 μg/ear) reduced the ear edema and MPO activity by 100% and 94 ± 3% (TcE) 85 ± 4% and 88 ± 3% (dichloromethane fraction), 83 ± 6% and 73 ± 11% (n-butanol fraction) and 86 ± 6% and 93 ± 4% (ethyl acetate fraction) and 100% (dexamethasone solution), respectively to the acute ICD model. The TcE and dexamethasone gel (15 mg/ear) also reduced by 66 ± 6% and 70 ± 5% the ear edema and by 58 ± 14% and 84 ± 4% the MPO activity, respectively. To the chronic ICD model, the TcE and dexamethasone (10 μg/ear) also reduced the ear edema (66 ± 6% and 70 ± 5%) and the MPO activity (58 ± 14% and 84 ± 4%); on the 9th day of the experiment. TcE and dexamethasone also reduced the pro-inflammatory cytokines (MIP-2, IL-1β and TNF-α) levels in acute ICD model induced by croton oil. Besides, mifepristone prevented the topical anti-edematogenic effect of TcE' and dexamethasone' solutions by 97 ± 9% to TcE and 75 ± 15% to dexamethasone. The accelerated stability study of T.catharinensis gels showed no relevant changes at low temperatures. The dereplication of the TcE and fractions revealed the presence of indole alkaloids, triterpenes, and flavonoids by UHPLC-ESI-HRMS. These classes of compounds are known in the literature for present potential anti-inflammatory action, supporting the results obtained.
The results confirm the topical popular use ofT.catharinensis leaves in the treatment of skin inflammation and demonstrate the TcE' potential for the development of a promising topical anti-inflammatory agent to treat inflammatory disorders.
Tabernaemontana catharinensis，俗称蛇皮，在传统医学中用于治疗皮肤炎症性疾病。为了证实 Tabernaemontana catharinensis 叶的局部抗炎作用，我们评估了粗提取物（TcE）及其不同部分对小鼠刺激性接触性皮炎模型的治疗效果，并验证了其抗炎作用机制。
采用 UHPLC-ESI-HRMS 对 TcE 及其二氯甲烷、正丁醇和乙酸乙酯部分进行定性植物化学分析。进行凝胶加速稳定性测试，以确保有效配方。我们研究了 TcE、其馏分和含有 TcE 的凝胶配方在独特（1000μg/耳）和多次（400μg/耳）巴豆油应用诱导的刺激性接触性皮炎模型中的抑制作用，通过耳肿胀形成、炎症细胞浸润（MPO 活性测量和组织学程序）和促炎细胞因子水平进行评估。使用糖皮质激素受体拮抗剂（米非司酮；50mg/kg，sc）研究了 TcE 的类糖皮质激素作用。
（10μg/耳）的治疗方法将急性 ICD 模型中的耳肿胀和 MPO 活性分别降低了 100%和 94±3%（TcE）、85±4%和 88±3%（二氯甲烷馏分）、83±6%和 73±11%（正丁醇馏分）和 86±6%和 93±4%（乙酸乙酯馏分）以及 100%（地塞米松溶液）。TcE 和地塞米松凝胶（15mg/耳）也分别降低了 66±6%和 70±5%的耳肿胀和 58±14%和 84±4%的 MPO 活性。对于慢性 ICD 模型，TcE 和地塞米松（10μg/耳）也降低了耳肿胀（66±6%和 70±5%）和 MPO 活性（58±14%和 84±4%）；在实验的第 9 天。TcE 和地塞米松还降低了急性 ICD 模型中由巴豆油诱导的促炎细胞因子（MIP-2、IL-1β 和 TNF-α）水平。此外，米非司酮将 TcE 和地塞米松溶液的局部抗水肿作用分别预防了 97±9%（TcE）和 75±15%（地塞米松）。Tcatharinensis 凝胶的加速稳定性研究表明，在低温下没有发现相关变化。TcE 和馏分的去重复揭示了吲哚生物碱、三萜类和类黄酮的存在，通过 UHPLC-ESI-HRMS 进行鉴定。这些类化合物在文献中已知具有潜在的抗炎作用，支持了所获得的结果。
结果证实了 Tabernaemontana catharinensis 叶在治疗皮肤炎症中的局部应用，并证明了 TcE 开发有前途的局部抗炎药物治疗炎症性疾病的潜力。
