AIM OF THE STUDY: This review is an attempt to assess the anti-inflammatory activity of Polyalthia species by giving critical appraisal and establishing evidences of their traditional uses. Moreover this review will highlight the lead compounds for future drug development that can serve as a potential anti-inflammatory drug with comparative efficacy and minimum side effects.
MATERIALS AND METHODS: An extensive literature review, focusing the anti-inflammatory potential of Polyalthia species was conducted using the following databases: PubMed, ScienceDirect, SpringerLink, Ovid, Scopus and ProQuest, as well as the locally available books, journals and relevant documents. The reference lists of retrieved papers were also searched for additional studies.
RESULTS: The Polyalthia species have shown significant anti-inflammatory activity through various mechanism of action. The most significant anti-inflammatory mechanism includes the inhibition of nuclear factor kappa B (NF-κB), prostaglandins (PGs), pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS). The data suggests that hydroxycleroda-3,13-dien-15,16-olide and 16-oxocleroda-3,13-dien-15-oic acid, quercetin, rutin, spinasterol, α-spinasterol, goniothalamin and (-)-5-hydroxygoniothalamin are the most potent anti-inflammatory compounds from Polyalthia species with comparable IC50 with positive controls.
CONCLUSIONS: Numerous pharmacological studies have supported the use of Polyalthia species against pain, rheumatic fever, haemorrhages and inflammation in traditional medicine. Flavonoids, diterpenoids, sterols and styrylpyrones from genus Polyalthia are the most significant class of compounds with potent anti-inflammatory activity. Secondary metabolites from these classes should be brought into further research to fill the gaps of knowledge in pharmacokinetics, pharmacodynamics, bioavailability, and toxicity in order to convert the pre-clinical results into clinical data for further investigation.
METHODS: A systematic search of the literature up to May 2020 was conducted in PubMed, Ovid Medline, EBSCOhost, Scopus, and the Cochrane Library to identify relevant published studies on quercetin and cardiac function using standardized criteria. Meta-analyses were performed on animal studies of pressure overload and ischemia-reperfusion (I/R) injury.
RESULTS: The effects of quercetin on cardiac function in both models were qualitatively reported in 14 studies. The effects of quercetin in four pressure-overload model studies involving 73 rodents and eight I/R-injury model studies involving 120 rodents were quantitatively assessed by meta-analysis. Quercetin improved the overall cardiac function in both pressure overload (n = 4 studies, n = 73 rodents; SMD = - 1.50; 95% CI: - 2.66 to - 0.33; P
Objective: To evaluate the inhibitory effects of three M. pumilum varieties on the secretion of lipopolysaccharide (LPS)- and monosodium urate crystal (MSU)-induced cytokines and plasma prostaglandin E2 (PGE2) in vitro.
Materials and Methods: The leaves and roots of M. pumilum var. alata (MPA), M. pumilum var. pumila (MPP), and M. pumilum var. lanceolata (MPL) were successively extracted with dichloromethane (DCM), methanol, and water. Human peripheral blood mononuclear cells and ELISA technique were used for the cytokine assay, whereas human plasma and radioimmunoassay technique were used in the PGE2 assay. Flavonoids content was determined using a reversed-phase high-performance liquid chromatography.
Results: DCM extract of MPL roots showed the highest inhibition of LPS-stimulated cytokine secretion with IC50 values of 29.87, 7.62, 5.84, 25.33, and 5.40 μg/mL for interleukin (IL)-1α, IL-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α, respectively; while that of plasma PGE2 secretion was given by DCM extract of MPP roots (IC50 31.10 μg/mL). Similarly, the DCM extract of MPL roots demonstrated the highest inhibition against MSU-stimulated IL-1α, IL-1β, IL-6, IL-8, TNF-α, and PGE2 secretion with IC50 values of 11.2, 8.92, 12.29, 49.51, 9.60, and 31.58 μg/mL, respectively. Apigenin in DCM extracts of MPL (0.051 mg/g) and MPP (0.064 mg/g) roots could be responsible for the strong inhibitory activity against IL-1β, IL-6, TNF-α, and PGE2.
Conclusion: The results suggested that DCM extracts of MPL and MPP roots are potential anti-inflammatory agents by inhibiting the secretion of LPS- and MSU-stimulated pro-inflammatory cytokines and PGE2.
SUMMARY: Amongst 18 tested extracts, DCM extracts of MPL and MPP roots remarkably inhibited LPS- and MSU-stimulated pro-inflammatory cytokines and PGE2 secretionPhytochemical analysis was performed for the active extracts using RP-HPLC systemThe presence of flavonoids particularly apigenin could be responsible for the anti-inflammatory activity. Abbreviations used: BSA: Bovine serum albumin, COX-2: Cyclooxygenase-2, CPM: Count per minute, DAMP: Danger-associated molecular pattern, DCM: Dichloromethane, DMSO: Dimethyl sulfoxide, ELISA: Enzyme-linked immunosorbent assay, FBS: Fetal bovine serum, H2O: Water, HEPES: 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid, HMC-1: Human mast cell-1, HMGB1: High-mobility group box 1, ICAM: Intercellular adhesion molecule, IFN: Interferon, IgG: Immunoglobulin G, IKK: IkB kinase, IL: Interleukin, iNOS: Inducible nitric oxide synthase, LPS: Lipopolysaccharide, MeOH: Methanol, MPA: Marantodes pumilum var. alata, MPL: Marantodes pumilum var. lanceolata, MPP: Marantodes pumilum var. pumila, MSU: Monosodium urate, MTT: Methylthiazole tetrazolium, NF-κB: Nuclear factor-kappa B, NLR: NOD-like receptor, NLRP3: NLR family pyrin domain containing protein 3, NO: Nitric oxide, NOD: Nucleotide-binding oligomerization domain, NSAID: Nonsteroidal anti-inflammatory drug, PAMP: Pathogen-associated molecular pattern, PBMC: Peripheral blood mononuclear cell, PBS: Phosphate buffered saline, PGE2: Prostaglandin E2, PMACI: Phorbol-12-myristate 13-acetate and calcium ionosphere A23187, PRR: Pathogen recognition receptor, PTFE: Polytetrafluoroethylene, RIA: Radioimmunoassay, RIG: Retinoic acid-inducible gene I, RLR: RIG I-like receptor, RP-HPLC: Reversed-phase high-performance liquid chromatography, RPMI-1640: Roswell Park Memorial Institute-1640, TLR: Toll-like receptor, TNF: Tumor necrosis factor, VCAM: Vascular cell adhesion molecule.