Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química y Metabolismo del Fármaco (IQUIMEFA), Buenos Aires, Argentina; Cátedra de Farmacognosia, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química y Metabolismo del Fármaco (IQUIMEFA), Buenos Aires, Argentina; Cátedra de Farmacognosia, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
J Ethnopharmacol. 2022 Oct 5;296:115429. doi: 10.1016/j.jep.2022.115429. Epub 2022 May 31.
Larrea divaricata Cav. (Zygophyllaceae) (jarilla) is a native plant of South America widely distributed across Argentina and used in popular medicine to treat diabetes and hypercholesterolemia by the Diaguita-Calchaquí, Amaichas, and Quilmes indigenous communities and by non-indigenous population (criollos) of Calamuchita, in the province of Córdoba, Argentina. L. divaricata has also proved to have anti-inflammatory properties. However, the antidiabetic effects and the nutritional properties of the aqueous extract (AE) of this plant remain to be scientifically determined.
The aim of the present work was to evaluate the capacity of an aqueous extract of L. divaricata (AE) and its main compound nordihydroguaiaretic acid (NDGA) to modulate the glucose, cholesterol, triglycerides and oxidative stress levels in STZ-induced diabetes in mice. The general objective of the present work was to search for extracts that can be used as adjuvant therapy in for diabetes. The suitability of the extract to be used as a dietary supplement was also assessed by determining the proximate amount of fibre, lipids, proteins, and minerals.
Diabetes was induced in mice by administration of streptozotocin (STZ). AE and NDGA were administered by the oral route. The animals' glycaemia was periodically monitored in blood samples obtained from the tail vein. The glucose dehydrogenase method was used. The effect of the AE on cholesterol, triglycerides, oxidative stress, lipid peroxidation and reduced glutathione (GSH) levels were determined in plasma samples by spectrophotometric assays.
In STZ-treated mice, AE significantly decreased glucose (33%, ****p < 0.0001) and cholesterol levels (32%, **p < 0.01). AE and NDGA decreased lipid peroxidation (30% and 38%, respectively, ****p < 0.0001), and increased GSH levels (20%, **p < 0.01). The effects of AE on glucose and lipid levels could not be ascribed to NDGA; however, this compound was involved in the extract antioxidant effects. The overall effects of AE were probably related to its antioxidant activity and to the anti-hyperglycaemic effect mainly mediated by flavonoids, fibre (carbohydrates) and mineral elements such as potassium, calcium, magnesium, and zinc. The AE protein content also confers the extract nutritional properties.
These results support the hypothesis that AE could be used as a therapeutic adjuvant or as a nutritional supplement to control glucose levels and lipid metabolism in metabolic syndrome-associated diseases. Moreover, these results scientifically reinforce the popular use of the plant.
Larrea divaricata Cav.（Zygophyllaceae）（刺桐）是一种原产于南美洲的植物，广泛分布于阿根廷，并在当地民间医学中用于治疗糖尿病和高胆固醇血症，使用群体包括 Diaguita-Calchaquí、Amaichas 和 Quilmes 土著社区以及阿根廷科尔多瓦省 Calamuchita 的非土著居民（criollos）。刺桐还被证明具有抗炎特性。然而，这种植物的水提物（AE）的抗糖尿病作用和营养特性仍有待科学确定。
本研究的目的是评估 Larrea divaricata 的水提物（AE）及其主要化合物 NDGA 对链脲佐菌素（STZ）诱导的糖尿病小鼠葡萄糖、胆固醇、甘油三酯和氧化应激水平的调节能力。本研究的总体目标是寻找可用于糖尿病辅助治疗的提取物。还通过测定纤维、脂质、蛋白质和矿物质的含量来评估提取物作为膳食补充剂的适用性。
通过给予链脲佐菌素（STZ）诱导小鼠糖尿病。AE 和 NDGA 通过口服途径给药。定期监测从尾静脉采集的血液样本中的动物血糖。使用葡萄糖脱氢酶法。通过分光光度法测定血浆样品中 AE 对胆固醇、甘油三酯、氧化应激、脂质过氧化和还原型谷胱甘肽（GSH）水平的影响。
在 STZ 处理的小鼠中，AE 显著降低了血糖（33%，****p<0.0001）和胆固醇水平（32%，**p<0.01）。AE 和 NDGA 降低了脂质过氧化（分别为 30%和 38%，****p<0.0001），并增加了 GSH 水平（20%，**p<0.01）。AE 对葡萄糖和脂质水平的影响不能归因于 NDGA；然而，这种化合物参与了提取物的抗氧化作用。AE 的整体作用可能与其抗氧化活性以及主要由类黄酮、纤维（碳水化合物）和矿物质元素（如钾、钙、镁和锌）介导的抗高血糖作用有关。AE 的蛋白质含量也赋予了提取物的营养特性。
这些结果支持了这样一种假设，即 AE 可用于作为治疗辅助剂或营养补充剂，以控制代谢综合征相关疾病中的血糖水平和脂质代谢。此外，这些结果从科学上加强了该植物的民间应用。
