Olatunji T L, Siebert F, Adetunji A E, Harvey B H, Gericke J, Hamman J H, Van der Kooy F
Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa.
School of Life Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
J Ethnopharmacol. 2022 Apr 6;287:114711. doi: 10.1016/j.jep.2021.114711. Epub 2021 Nov 8.
Sceletium tortuosum (L.) N.E.Br., the most sought after and widely researched species in the genus Sceletium is a succulent forb endemic to South Africa. Traditionally, this medicinal plant is mainly masticated or smoked and used for the relief of toothache, abdominal pain, as a mood-elevator, analgesic, hypnotic, anxiolytic, thirst and hunger suppressant, and for its intoxicating/euphoric effects. Sceletium tortuosum is currently of widespread scientific interest due to its clinical potential in treating anxiety and depression, relieving stress in healthy individuals, and enhancing cognitive functions. These pharmacological actions are attributed to its phytochemical constituents referred to as mesembrine-type alkaloids.
The aim of this review was to comprehensively summarize and critically evaluate recent research advances on the phytochemistry, pharmacokinetics, biological, pre-clinical and clinical activities of the medicinal plant S. tortuosum. Additionally, current ongoing research and future perspectives are also discussed.
All relevant scientific articles, books, MSc and Ph.D. dissertations on botany, behavioral pharmacology, traditional uses, and phytochemistry of S. tortuosum were retrieved from different databases (including Science Direct, PubMed, Google Scholar, Scopus and Web of Science). For pharmacokinetics and pharmacological effects of S. tortuosum, the focus fell on relevant publications published between 2009 and 2021.
Twenty-five alkaloids belonging to four structural classes viz: mesembrine, Sceletium A4, joubertiamine, and tortuosamine, have been identified from S. tortuosum, of which the mesembrine class is predominant. The crude extracts and commercially available standardized extracts of S. tortuosum have displayed a wide spectrum of biological activities (e.g. antimalarial, anti-oxidant, neuromodulatory, immunomodulatory, anti-HIV, neuroprotection) in in vitro or in vivo studies. While the plant has been studied in clinical populations, this has only been in healthy subjects, so that further study in pathological states remains to be done. Nevertheless, the aforementioned studies have demonstrated that S. tortuosum has potential for enhancing cognitive function and managing anxiety and depression.
As an important South African medicinal plant, S. tortuosum has garnered many research advances on its phytochemistry and biological activities over the last decade. These scientific studies have shown that S. tortuosum has various bioactivities. The findings have further established the link between the phytochemistry and pharmacological application, and support the traditional use of S. tortuosum in the indigenous medicine of South Africa.
弯果草（Sceletium tortuosum (L.) N.E.Br.）是弯果草属中最受追捧且研究广泛的物种，是南非特有的肉质草本植物。传统上，这种药用植物主要是咀嚼或吸食，用于缓解牙痛、腹痛，作为情绪提升剂、镇痛药、催眠药、抗焦虑药、抑制口渴和饥饿，以及产生陶醉/欣快感。由于弯果草在治疗焦虑和抑郁、缓解健康个体的压力以及增强认知功能方面的临床潜力，目前它受到了广泛的科学关注。这些药理作用归因于其被称为美登木碱型生物碱的植物化学成分。
本综述的目的是全面总结并批判性评价弯果草这种药用植物在植物化学、药代动力学、生物学、临床前和临床活性方面的最新研究进展。此外，还讨论了当前正在进行的研究和未来展望。
从不同数据库（包括科学Direct、PubMed、谷歌学术、Scopus和科学网）检索了所有关于弯果草的植物学、行为药理学、传统用途和植物化学的相关科学文章、书籍、硕士和博士论文。对于弯果草的药代动力学和药理作用，重点关注2009年至2021年期间发表的相关出版物。
已从弯果草中鉴定出属于四个结构类别的25种生物碱，即：美登木碱、弯果草A4、朱贝蒂胺和弯果胺，其中美登木碱类占主导。弯果草的粗提物和市售标准化提取物在体外或体内研究中显示出广泛的生物活性（如抗疟疾、抗氧化、神经调节、免疫调节、抗HIV、神经保护）。虽然该植物已在临床人群中进行研究，但仅针对健康受试者，因此在病理状态下的进一步研究仍有待开展。然而，上述研究表明弯果草具有增强认知功能以及治疗焦虑和抑郁的潜力。
作为一种重要的南非药用植物，弯果草在过去十年中在植物化学和生物活性方面取得了许多研究进展。这些科学研究表明弯果草具有多种生物活性。这些发现进一步确立了植物化学与药理学应用之间的联系，并支持弯果草在南非本土医学中的传统用途。
