Scyphocephalione A isolated from the stem bark of Scyphocephalium ochocoa (Myristicaceae) attenuate acute and chronic pain through the antiinflammatory activity.

In the treatment of cancer, patients that receive anti-cancer drugs such as Vincristine develop peripheral neuropathic pain. Scyphocephalione A is a new bioactive compound isolated from Scyphocephalium ochocoa (Myristicaceae), a medicinal plant traditionally used in African countries. Recently, an in vitro study has shown its anti-inflammatory and cytotoxic activities on MCF-7 cell line of mammary carcinoma. The purpose of the present study was to assess the in vitro anti-inflammatory and in vivo anti-nociceptive activities of Scyphocephalione A. In vitro tests were carried out on cyclooxygenase and 5-lipoxygenase activities, and on protein denaturation; while in vivo tests were performed on acute and chronic pain models. It was noticed that Scyphocephalione A (1000 µg/ml), inhibits proteins denaturation, cyclooxygenase and 5-lipoxygenase activities respectively by 74.21%, 75.80% and 64.43%. The dose 50 mg/kg of Scyphocephalione A, inhibits acetic acid (63.43%, p < 0.001) and formalin (42.12%, p < 0.001) within first phase and 67.53% (p < 0.001) within second phase)-induced pains. At the same dose, Scyphocephalione A significantly inhibited mechanical and heat hyperalgesia, as well as cold allodynia induced by vincristine. In addition, the compound restored haematological, biochemical and oxidative stress parameters which were altered following Vincristine administration. These results suggest that Scyphocephalione A is endowed with anti-inflammatory potential and antinociceptive properties. Therefore, Scyphocephalione A can be classified as a promising molecule for the management of peripheral neuropathic pain triggered by anti-cancer drug.

Antihypernociceptive and neuroprotective effects of Combretin A and Combretin B on streptozotocin-induced diabetic neuropathy in mice.

Painful diabetic neuropathy (PDN) is known to adversely affect psychosocial functioning by enhancing levels of anxiety and depression. This study was designed to verify the antihypernociceptive, anxiolytic, and antidepressant-like effects of Combretin A and Combretin B (two triterpenes cycloartane-type isolated from the leaves of Combretum fragrans) in streptozotocin-induced diabetic neuropathy in mice. PDN was induced in mice by the administration of streptozotocin (STZ, 200 mg/kg, i.p.). The effect of oral administration of Combretin A (25 and 50 mg/kg) and Combretin B (25 and 50 mg/kg) on nociception (mechanical allodynia, thermal hyperalgesia, cold allodynia, and chemical hyperalgesia), anxiety (elevated plus maze, light-dark box test, social interaction), and depressant (open field test, forced swimming test, tail suspension test) was evaluated. Combretin A (25 and 50 mg/kg) and Combretin B (25 and 50 mg/kg) caused antihypernociceptive, anxiolytic, and antidepressant-like effects in in STZ-induced diabetic neuropathy in mice. Both compounds also caused a decrease in blood glucose and improved body weight in treated animals. They also significantly (p < 0.001) reduced tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1ß), malondialdehyde (MDA), and nitric oxide (NO) production in serum and sciatic nerves, and, significantly (p < 0.001) increased superoxide dismutase (SOD) and catalase (CAT) activity in serum, sciatic nerves, and brain. Combretin A and Combretin B also showed a great systemic effect, conserving values of evaluated parameters close to normal in treated mice. The results of this study confirm the antihypernociceptive, antianxiety, and antidepressant activities of Combretin A and Combretin B.