Diterpenes and their derivatives have many biological activities, including anti-inflammatory and immunomodulatory effects. To date, several diterpenes, diterpenoids, and their laboratory-derived products have been demonstrated for antiarthritic activities. This study summarizes the literature about diterpenes and their derivatives acting against rheumatoid arthritis (RA) depending on the database reports until 31 August 2021. For this, we have conducted an extensive search in databases such as PubMed, Science Direct, Google Scholar, and Clinicaltrials.gov using specific relevant keywords. The search yielded 2708 published records, among which 48 have been included in this study. The findings offer several potential diterpenes and their derivatives as anti-RA in various test models. Among the diterpenes and their derivatives, andrographolide, triptolide, and tanshinone IIA have been found to exhibit anti-RA activity through diverse pathways. In addition, some important derivatives of triptolide and tanshinone IIA have also been shown to have anti-RA effects. Overall, findings suggest that these substances could reduce arthritis score, downregulate oxidative, proinflammatory, and inflammatory biomarkers, modulate various arthritis pathways, and improve joint destruction and clinical arthritic conditions, signs, symptoms, and physical functions in humans and numerous experimental animals, mainly through cytokine and chemokine as well as several physiological protein interaction pathways. Taken all together, diterpenes, diterpenoids, and their derivatives may be promising tools for RA management.

Nelumbo nucifera (sacred lotus), locally known as Poddo, has been used as food and traditional remedy in Ayurvedic system in India and Traditional Chinese Medicine for a wide range of diseases. During past two decades, there are numerous scientific studies and general reviews have been published on its phytochemistry and pharmacology. However, in this paper, we aim to make a survey on neuropharmacological effects, as well as psychoactivities, of N. nucifera, identifying the active constituents and their proposed mechanism of actions which has not been systematically documented in the literature. Several online databases, including Google Scholar, PubMed, Web of Science, Science Direct, and Scopus were employed to conduct this survey. Previous studies have demonstrated that N. nucifera has potential neuropharmacological effects in various test systems, including in vivo animal models and in vitro cultured cells or enzymes through various mechanistic pathways, including 5-HT2A receptor blockade, GABAergic system, regulating the NCAM and GAP-43 expression levels, regulating for skolinstimulated cAMP production, and many more. Our survey showed that many alkaloids isolated from N. nucifera demonstrated antidepressant, sedative-hypnotic, anxiolytic, analgesia-potentiating action, anticonvulsant, antipsychotic, and memory enhancer activities. Although many studies have showed potential neurotherapeutic benefits of this plant and many of its constituents, but the focus of research towards clinical trial in human is rather very limited. Dhaka Univ. J. Pharm. Sci. 20(3): 347-358, 2022 (June) Centennial Special Issue