Four tetrahydroxanthone dimers (1-4) and four biogenetically related monomers (5-8), including the new derivatives 4-6, were isolated from the endophyte Phomopsis longicolla. The absolute configurations of 2-4 were established for the first time by TDDFT electronic circular dichroism calculations, and that of phomoxanthone A (1) was revised by X-ray crystallography. Phomoxanthone A (1) showed the strongest pro-apoptotic activity when tested against a panel of human cancer cell lines, including cisplatin-resistant cells, whereas it was up to 100-fold less active against healthy blood cells. It was also the most potent activator of murine T lymphocytes, NK cells, and macrophages, suggesting an activation of the immune system in parallel to its pro-apoptotic activity. This dual effect in combating cancer cells could help in fighting resistance during chemotherapy. Preliminary structure-activity studies of isolated compounds and derivatives obtained by semisynthesis (9a-11) hinted at the location of the biaryl axis and the presence of acetyl groups as important structural elements for the biological activity of the studied tetrahydroxanthones.
Pain is an unpleasant sensory and emotional experience in many diseases and is often caused by intense or damaging stimuli. Pain negatively affects the quality of life and increases high health expenditures. Drugs with analgesic properties are commonly used to relieve pain, but these Western medications could be overwhelmed by side effects including tolerance and addiction. Herbal medicines may provide alternative measures for pain management. In this review paper, after introduction of Chinese medicine theory and treatment modality, emphasis is placed on the application of Chinese herbs and herbal formulations in pain management. Three of the most commonly used herbs, i.e., Corydalis yanhusuo, Ligusticum chuanxiong, and Aconitum carmichaeli, are reviewed. Subsequently, using this ancient medical remedy, Chinese herbal formulation in treating common medical conditions associated with pain, such as headache/migraine, chest pain, abdominal pain, low back pain, neuropathic pain, osteoarthritis, and cancer pain, is presented. Chinese herbal medicines could be considered as a complementary and integrative approach in the modern armamentarium in combating pain.
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