Antioxidant, Anti-Inflammatory and Anti-Diabetic Activities of <i>Tectona grandis</i> Methanolic Extracts, Fractions, and Isolated Compounds

• Main Authors: Mei Han (Author), Fengxian Yang (Author), Kun Zhang (Author), Jiyan Ni (Author), Xia Zhao (Author), Xuelin Chen (Author), Zhennan Zhang (Author), Hanlei Wang (Author), Jing Lu (Author), Yumei Zhang (Author)
• Format: Book
• Published: MDPI AG, 2023-03-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

<i>Tectona grandis</i> is a traditional Dai medicine plant belonging to the Lamiaceae family, which can be used to treat malaria, inflammation, diabetes, liver disease, bronchitis, tumors, cholelithiasis, jaundice, skin disease and as an anti-helminthic. To find more novel therapeutic agents contained in this medicinal plant, the antioxidant, anti-inflammatory and anti-diabetic activities of <i>T. grandis</i> methanolic extract, fractions and compounds were evaluated. In this study, 26 compounds were isolated from the leaves and branches of <i>T. grandis</i>. Their structures were identified based on extensive spectral experiments, including NMR, ESI-MS and comparison with published spectral data. Among them, compounds <b>1</b>-<b>2</b>, <b>4</b>-<b>6</b>, <b>9</b>-<b>14</b> and <b>16</b>-<b>22</b> were reported for the first time for this plant. The antioxidant activity screening results showed that compounds <b>5</b>, <b>15</b> and <b>23</b> had potent antioxidant capacities, with SC₅₀ values from 0.32 to 9.92 µmol/L, 0.92 to 1.10 mmol Trolox/L and 1.02 to 1.22 mmol Trolox/L for DPPH, ABTS and FRAP, respectively. In addition, their anti-inflammatory effects were investigated by releasing TNF-<i>α</i>, IL-1<i>β</i> and IL-6 through the use of mouse monocytic macrophages (RAW 264.7). Compounds <b>1</b>, <b>13</b>, <b>18</b> and <b>23</b> had the effects of reducing the expression of inflammatory factors. Compounds <b>13</b> and <b>18</b> were reported for the first time for their anti-inflammatory activities. Furthermore, the methanolic extract (ME), petroleum ether extract (PEE) and EtOAc extract (EAE) of <i>T. grandis</i> showed significant glucose uptake activities; compounds <b>21</b> and <b>23</b> significantly promoted glucose uptake of 3T3-L1 adipocytes at 40 µM. Meanwhile, compounds <b>4</b>, <b>5</b> and <b>7</b> showed significant inhibitory activities against α-glucosidase, with IC₅₀ values of 14.16 ± 0.34 µmol/L, 19.29 ± 0.26 µmol/L and 3.04 ± 0.08 µmol/L, respectively. Compounds <b>4</b> and <b>5</b> were reported for the first time for their <i>α</i>-glucosidase inhibitory activities. Our investigation explored the possible therapeutic material basis of <i>T. grandis</i> to prevent oxidative stress and related diseases, especially inflammation and diabetes.

Item Description

10.3390/antiox12030664
2076-3921