Essential oil composition, anti-tyrosinase activity, and molecular docking studies of Knema intermedia Warb. (Myristicaceae).

Knema is one of the genera in the Myristicaceae family. The genus includes 60 species in Southeast Asia and is traditionally used for treating skin disorders. Here, for the first time, the essential oil, anti-tyrosinase, and molecular docking studies of Knema intermedia were evaluated. The essential oil was obtained by hydrodistillation and fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Anti-tyrosinase activity was evaluated against mushroom tyrosinase, whereas molecular docking studies were performed using Autodock vina embedded in PyRx to evaluate the binding interactions of major components. A total of 37 components (97.3%) were successfully identified in the essential oil, which was characterized by high amounts of t-muurolol (20.1%), α-copaene (14.4%), δ-cadinene (13.9%), germacrene B (9.5%), and δ-selinene (7.0%). The essential oil displayed moderate inhibitory activity towards tyrosinase with an IC50 value of 70.2 µg/mL. The best docking energy was observed with δ-selinene (-7.8 kcal/mol), and it also forms interactions with His85, His263, and His244 which are important amino acid residues of the tyrosinase receptor. Hence, this study provides valuable scientific data on K. intermedia as potential candidate for the development of natural antiaging formulations.

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.

Biochemical metabolism of young plants of Ucuúba (Virola surinamensis) in the presence of cadmium.

Virola surinamensis is a forest species widely distributed in the estuaries of the Amazon. These ecosystems are susceptible to contamination by Cadmium (Cd), indicating that the plant has strategies for tolerating this metal. The aim of this study was to assess the nitrogen and carbon metabolism of young plants of Ucuúba (Virola surinamensis) in the presence of cadmium with the perspective of the phytoremediation of contaminated environments. The used experimental design was a completely randomized design with five Cd concentrations (0, 15, 30, 45, and 60 mg L- 1), for 60 days. In general, Cd did not affect nitrate concentration in the root but had a positive effect on leaves. The reduction of nitrate reductase (NR) in plants exposed to Cd was followed by a decrease in ammonia, total soluble amino acids (TSA), and total soluble proteins (TSP). Cd promoted an increase in the concentration of total soluble carbohydrates (TSC), proline, sucrose, and reducing sugars in the plants. The increase in TSC, sucrose and proline, suggests a metabolic regulatory mechanism of V. surinamensis against Cd stress.

Antidiabetic potential of phytochemicals isolated from the stem bark of Myristica fatua Houtt. var. magnifica (Bedd.) Sinclair.

Phytochemical investigation of the stem bark of Myristica fatua Houtt. led to the isolation of a new compound 1 (3-tridecanoylbenzoic acid), along with six known acylphenols (2-7). All the compounds displayed moderate inhibitory activity on α-amylase and significant activity on α-glucosidase; however malabaricone B (6) and C (7) were identified as potent α-glucosidase inhibitors with IC50 values of 63.70 ±â€¯0.546, and 43.61 ±â€¯0.620 µM respectively. Acylphenols (compounds 3-7) also showed significant antiglycation property. The molecular docking and dynamics simulation studies confirmed the efficient binding of malabaricone C with C-terminus of human maltase-glucoamylase (2QMJ). Malabaricone B also enhanced the 2-NBDG [2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxy glucose] uptake in L6 myotubes. These findings demonstrate that acylphenols isolated from Myristica fatua Houtt. can be considered as a lead scaffold for the treatment of type II diabetes mellitus.