背景:千层属(桃金娘科)包含数十种富含精油(EO)的物种,这些物种因其各种药用价值而在世界范围内受到赞赏。此外,它们在传统医学中以抗菌闻名,抗真菌药,和其他与皮肤相关的活动。当前的研究调查了首次在埃及种植的M.subulata(Cheel)Craven(SynonymCallistemonsubulatus)叶片中挥发性成分的化学特征和与皮肤相关的活性。
方法:使用加氢蒸馏(HD)提取挥发性成分,顶部空间(HS),和超临界流体(SF)。实施GC/MS和Kovat的保留指数来识别挥发性化合物,同时使用主成分分析和层次聚类分析评估成分之间的差异。使用2,2-二苯基-1-吡啶酰肼(DPPH)评估自由基清除活性,氧自由基吸收能力(ORAC)和β-胡萝卜素测定。此外,使用抗弹性蛋白酶评估抗衰老效果,和抗胶原酶,而抗菌潜力是从琼脂扩散和肉汤微量稀释试验中推断出来的。最后,使用DiscoveryStudio4.5中的C-docker方案进行了分子对接研究,以合理化与靶向酶的结合亲和力.
结果:SF提取方法提供了最高的EO产率,为0.75%。根据GC/MS分析,单萜烃是HD油样品中最丰富的挥发性类别(54.95%),α-pine烯是最丰富的成分(35.17%)。相反,HS和SF挥发性成分率先使用含氧单萜(72.01和36.41%),桉树脑和异戊烯酮是最公认的成分,分别占67.75%和23.46%,分别。化学计量学分析表明,三种提取方法与α-pine烯的分离聚类,桉树脑,和异宝乐酮作为主要的鉴别植物标志物。关于生物活性的背景,SF和HD-EOs在ORAC和β-胡萝卜素漂白方面均表现出抗氧化作用。HD-EO显示出有效的抗酪氨酸酶活性,而SF-EO表现出显著的抗弹性蛋白酶特性。此外,SF-EO显示对革兰氏阳性皮肤病原体的选择性活性,尤其是金黄色葡萄球菌.最终,分子对接显示挥发性成分的结合得分;类似于对接的参考药物。
结论:M.Subulata叶构成生物活性挥发性成分,可作为管理皮肤老化和感染的生物活性物质,尽管建议进一步的体内研究。
BACKGROUND: The genus Melaleuca (Myrtaceae) comprises dozens of essential oil (EO)-rich species that are appreciated worldwide for their various medicinal values. Additionally, they are renowned in traditional medicine for their antimicrobial, antifungal, and other skin-related activities. The current study investigated the chemical profile and skin-related activities of volatile constituents derived from M. subulata (Cheel) Craven (Synonym Callistemon subulatus) leaves cultivated in Egypt for the first time.
METHODS: The volatile components were extracted using hydrodistillation (HD), headspace (HS), and supercritical fluid (SF). GC/MS and Kovat\'s retention indices were implemented to identify the volatile compounds, while the variations among the components were assessed using Principal Component Analysis and Hierarchical Cluster Analysis. The radical scavenging activity was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC) and β-carotene assays. Moreover, the anti-aging effect was evaluated using anti-elastase, and anti-collagenase, while the antimicrobial potential was deduced from the agar diffusion and broth microdilution assays. Lastly, the molecular docking study was executed using C-docker protocol in Discovery Studio 4.5 to rationalize the binding affinity with targeted enzymes.
RESULTS: The SF extraction approach offered the highest EO yield, being 0.75%. According to the GC/MS analysis, monoterpene hydrocarbons were the most abundant volatile class in the HD oil sample (54.95%), with α-pinene being the most copious component (35.17%). On the contrary, the HS and SF volatile constituents were pioneered with oxygenated monoterpenes (72.01 and 36.41%) with
eucalyptol and isopulegone being the most recognized components, representing 67.75 and 23.46%, respectively. The chemometric analysis showed segregate clustering of the three extraction methods with α-pinene,
eucalyptol, and isopulegone serving as the main discriminating phytomarkers. Concerning the bioactivity context, both SF and HD-EOs exhibited antioxidant effects in terms of ORAC and β-carotene bleaching. The HD-EO displayed potent anti-tyrosinase activity, whereas the SF-EO exhibited significant anti-elastase properties. Moreover, SF-EO shows selective activity against gram-positive skin pathogens, especially S. aureus. Ultimately, molecular docking revealed binding scores for the volatile constituents; analogous to those of the docked reference drugs.
CONCLUSIONS: M. subulata leaves constitute bioactive volatile components that may be indorsed as bioactive hits for managing skin aging and infection, though further in vivo studies are recommended.