Immunosuppressive Effects of Annona muricata L. Leaf Extract on Cellular and Humoral Immune Responses in Male Wistar Rats.

BACKGROUND: Annona muricata L. (Annonaceae) (AM)'s remarkable anti-inflammatory and anti-cancer activities make it a targeted plant to be explored for its immunomodulatory properties. Traditional practitioners have employed various components of AM to cure a variety of ailments, including cancer, diabetes, and inflammation. OBJECTIVE: The present study evaluated the immunosuppressive effects of 80% ethanol extract of of AM leaves in male Wistar rats on different parameters of humoral and cellular immune responses. METHODS: AM leaf extract (AMLE) was analyzed using UHPLC-MS/MS to profile its secondary metabolites. AMLE was rich in polyphenols which include (epi)catechin-(epi)catechin-(epi) catechin, caffeic acid, coumaroylquinic acid, hyperin, kaempferol, quinic acid and rutin. The rats were administered 100, 200 and 400 mg/kg bw of the extract daily for 14 days. The effects of AMLE on innate immune responses were determined by evaluating phagocytosis, neutrophils migration, reactive oxygen species (ROS) release, CD11b/CD18 integrin expression, and ceruloplasmin, lysozyme and myeloperoxidase (MPO) levels. The adaptive immune parameters were evaluated by immunizing the rats with sheep red blood cells (sRBC) on day 0 and administered orally with AMLE for 14 days. RESULTS: AMLE established significant immunosuppressive effects on the innate immune parameters by inhibiting the neutrophil migration, ROS production, phagocytic activity and expression of CD11b/CD18 integrin in a dose-dependent pattern. AMLE also suppressed ceruloplasmin, MPO and lysozyme expressions in the rat plasma dose-dependently. AMLE dose-dependently inhibited T and B lymphocytes proliferation, Th1 and Th2 cytokine production, CD4+ and CD8+ co-expression in splenocytes, immunoglobulins (IgM and IgG) expression and the sRBC-induced swelling rate of rat paw in delayed-type hypersensitivity (DTH). CONCLUSION: The strong inhibitory effects on the different parameters of humoral and cellular responses indicate that AMLE has potential to be an important source of effective immunosuppressive agents.

Pharmacological activities and mechanisms of action of hypophyllanthin: A review.

Hypophyllanthin is a major lignan present in various Phyllanthus species and has been used as one of the bioactive chemical markers for quality control purposes as it contributes to their diverse pharmacological activities. The objective of this study is to compile up-to-date data on the pharmacological actions and mechanisms of hypophyllanthin. This review also includes the extracts of Phyllanthus species whose pharmacological actions have been partially attributed to hypophyllanthin. The scientific findings on the compound are critically analyzed and its potential as a lead molecule for the discovery of drug candidates for the development of therapeutics to treat diverse diseases is highlighted. Data collection was mainly through the exploration of Ovid-MEDLINE, Scopus, Science Direct, and Elsevier databases. Studies conducted in vitro and in vivo showed that hypophyllanthin had potent immunomodulating properties as well as a variety of other pharmacological properties, including anti-inflammatory, hepatoprotective, anti-tumor, anti-allergic, anti-hypertensive, and phytoestrogenic properties. Several mechanisms of action on the effects of hypophyllanthin on the immune system, in cancer and other disease states, were presented to provide some insights into its pharmacological effects. Before being submitted to clinical investigations, additional animal studies utilising different animal models are necessary to analyse its bioavailability, pharmacokinetics, and pharmacodynamic properties, as well as its toxicity, to determine its efficacy and safety. Understanding its potential as a lead molecule for the discovery of therapeutic candidates, particularly for the development of therapies for inflammatory and immune-related disorders, requires an understanding of its pharmacological activities and mechanisms of action. An insight into its pharmacological activities and mechanisms of action will provide an understanding of its potential as a lead compound for the discovery of drug candidates, especially for the development of therapies for inflammatory and immune related diseases.

Exploring the Leaves of Annona muricata L. as a Source of Potential Anti-inflammatory and Anticancer Agents.

The use of anti-inflammatory natural products to treat inflammatory disorders for cancer prevention and therapy is an appealing area of interest in the last decades. Annona muricata L. is one of the many plant extracts that have been explored owing to their anti-inflammatory and anticancer effects. Different parts of A. muricata especially the leaves have been used for various ethnomedicinal purposes by traditional healers to treat several diseases including cancer, inflammation, diabetes, liver diseases, and abscesses. Some of these experience-based claims on the use of the plant have been transformed into evidence-based information by scientific investigations. The leaves of the plant have been extensively investigated for its diverse pharmacological aspects and found eminent for anti-inflammatory and anticancer properties. However, most studies were not on the bioactive isolates which were responsible for the activities but were based on crude extracts of the plant. In this comprehensive review, all significant findings from previous investigations till date on the leaves of A. muricata, specifically on their anti-inflammatory and anticancer activities have been compiled. The toxicology of the plant which has been shown to be due to the presence of neurotoxic annaceous acetogenins and benzyltetrahydro-isoquinoline alkaloids has also been updated to provide recent information on its safety aspects. The present knowledge of the plant has been critically assessed, aimed at providing direction toward improving its prospect as a source of potential anti-inflammatory and anticancer agents. The analysis will provide a new path for ensuring research on this plant to discover new agents to treat inflammatory diseases and cancer. Further in vitro and in vivo studies should be carried out to explore the molecular mechanisms underlying their anti-inflammatory responses in relation to anticancer activity and more detail toxicity study to ensure they are safe for human consumption. Sufficient preclinical data and safety data generated will allow clinical trials to be pursued on this plant and its bioactive compounds.

Magnoflorine Enhances LPS-Activated Pro-Inflammatory Responses via MyD88-Dependent Pathways in U937 Macrophages.

Magnoflorine, a major bioactive metabolite isolated from Tinospora crispa, has been reported for its diverse biochemical and pharmacological properties. However, there is little report on its underlying mechanisms of action on immune responses, particularly on macrophage activation. In this study, we aimed to investigate the effects of magnoflorine, isolated from T. crispa on the pro-inflammatory mediators generation induced by LPS and the concomitant NF-κB, MAPKs, and PI3K-Akt signaling pathways in U937 macrophages. Differentiated U937 macrophages were treated with magnoflorine and the release of pro-inflammatory mediators was evaluated through ELISA, while the relative mRNA expression of the respective mediators was quantified through qRT-PCR. Correspondingly, western blotting was executed to observe the modulatory effects of magnoflorine on the expression of various markers related to NF-κB, MAPK and PI3K-Akt signaling activation in LPS-primed U937 macrophages. Magnoflorine significantly enhanced the upregulation of TNF-α, IL-1ß, and PGE2 production as well as COX-2 protein expression. Successively, magnoflorine prompted the mRNA transcription level of these pro-inflammatory mediators. Magnoflorine enhanced the NF-κB activation by prompting p65, IκBα, and IKKα/ß phosphorylation as well as IκBα degradation. Besides, magnoflorine treatments concentration-dependently augmented the phosphorylation of JNK, ERK, and p38 MAPKs as well as Akt. The immunoaugmenting effects were further confirmed by investigating the effects of magnoflorine on specific inhibitors, where the treatment with specific inhibitors of NF-κB, MAPKs, and PI3K-Akt proficiently blocked the magnoflorine-triggered TNF-α release and COX-2 expression. Magnoflorine furthermore enhanced the MyD88 and TLR4 upregulation. The results suggest that magnoflorine has high potential on augmenting immune responses.

Natural cholinesterase inhibitors from Myristica cinnamomea King.

A new acylphenol, malabaricone E (1) together with the known malabaricones A-C (2-4), maingayones A and B (5 and 6) and maingayic acid B (7) were isolated from the ethyl acetate extract of the fruits of Myristica cinnamomea King. Their structures were determined by 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Compounds 3 (1.84±0.19 and 1.76±0.21µM, respectively) and 4 (1.94±0.27 and 2.80±0.49µM, respectively) were identified as dual inhibitors, with almost equal acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibiting potentials. The Lineweaver-Burk plots of compounds 3 and 4 indicated that they were mixed-mode inhibitors. Based on the molecular docking studies, compounds 3 and 4 interacted with the peripheral anionic site (PAS), the catalytic triad and the oxyanion hole of the AChE. As for the BChE, while compound 3 interacted with the PAS, the catalytic triad and the oxyanion hole, compound 4 only interacted with the catalytic triad and the oxyanion hole.

Quorum Sensing Inhibitory Activity of Giganteone A from Myristica cinnamomea King against Escherichia coli Biosensors.

Malabaricones A-C (1-3) and giganteone A (4) were isolated from the bark of Myristica cinnamomea King. Their structures were elucidated and characterized by means of NMR and MS spectral analyses. These isolates were evaluated for their anti-quorum sensing activity using quorum sensing biosensors, namely Escherichia coli [pSB401] and Escherichia coli [pSB1075], whereby the potential of giganteone A (4) as a suitable anti-quorum sensing agent was demonstrated.