Inocalophyllins A, B and their methyl esters from the seeds of Calophyllum inophyllum

Characteristic chromanone acids from Calophyllum membranaceum: Determination of C-3 configuration and anti-inflammatory activity

One undescribed homologous furanochromanone (1) featuring a 6/6/5/3 tetracyclic skeleton and four highly oxidized pyranochromanones (2-5), along with a set of four pyranochromanone stereoisomers [(±)-6a and (±)-6b], were isolated from the leaves of Calophyllum membranaceum Gardn. Et Champ. Their structures were elucidated by using spectroscopic data, Snatzke's method, quantum-chemical calculations, and X-ray crystallographic analysis. The correlation of characteristic Cotton effects and specific chemical shifts with C-3 configuration provided a convenient approach to assign the C-3 configuration of 2,3-dimethylchromanones. The stereochemical assignments of 3-OH substituted pyranochromanones by quantum-based NMR methods following single/double MTPA derivatization were consistent with the ECD/NMR prediction, which verified the feasibility and reliability of the proposed empirical rule. The underlying mechanism was further clarified by conformational and molecular orbital analyses. Moreover, biological evaluation and binding assays demonstrated that compound 3 (KD = 0.45 μM) tightly binds to the TLR4-MD2 target, thereby inhibiting the TLR4/MyD88-dependent and -independent signal pathways. This study provides the first evidence that Calophyllum chromanones are a novel structural type of TLR4 inhibitors, exerting their anti-inflammatory effects by disrupting the binding between TLR4 and MD2.

Identification of Antioxidant Metabolites from Five Plants (Calophyllum inophyllum, Gardenia taitensis, Curcuma longa, Cordia subcordata, Ficus prolixa) of the Polynesian Pharmacopoeia and Cosmetopoeia for Skin Care

Oxidative stress contributes to impairment of skin health, the wound healing process, and pathologies such as psoriasis or skin cancer. Five Polynesian medicinal plants, among the most traditionally used for skin care (pimples, wounds, burns, dermatoses) are studied herein for their antioxidant properties: Calophyllum inophyllum, Gardenia taitensis, Curcuma longa, Cordia subcordata, and Ficus prolixa. Plant extracts were submitted to in vitro bioassays related to antioxidant properties and their bioactive constituents were identified by a metabolomic analytical approach. High performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) analysis was performed leading to the characterization of 61 metabolites. Compounds annotated for F. prolixa and C. subcordata extracts were reported for the first time. Antioxidant properties were evaluated by total phenolic content (TPC), free radical scavenging DPPH (1,1-diphenyl-2-picryl-hydrazyl), and Ferric Reducing Antioxidant Power activity (FRAP) assays. F. prolixa extract was the most active one and showed antioxidant intracellular activity on keratinocytes by Anti Oxydant Power 1 assay. Online HPLC-DPPH allowed the identification of phenolic bioactive compounds such as quercetin-O-rhamnoside, rosmarinic acid, chlorogenic acid, procyanidins, epicatechin, 5-O-caffeoylshikimic acid, and curcumin as being responsible for the scavenging properties of these plant extracts. These results highlight the potential of F. prolixa aerial roots as a source of antioxidants for skin care applications.

A new chromanone acid derivative from the nut oil resin of Calophyllum inophyllum

One novel chromanone acid derivative, namely inocalophylline C (1), together with one known compound calophyllolide (2), were isolated from the methanolic extract of nut oil resin of Calophyllum inophyllum L., a medicinal plant widely distributed in Vietnam. The isolated compound structures were elucidated by spectroscopic methods and the absolute configuration of 1 was established by the single-crystal X-ray crystallography as ethyl (R) 3-((2 R,3R,6R)-4-hydroxy-2,3-dimethyl-6-((R)-5-methyl-2-(prop-1-en-2-yl)hex-4-en-1-yl)-6-(3-methylbut-2-en-1-yl)-5,7-dioxo-3,5,6,7-tetrahydro-2H-chromen-8-yl)-3-phenylpropanoate.

Indigenous Uses, Phytochemical Analysis, and Anti-Inflammatory Properties of Australian Tropical Medicinal Plants

Australian tropical plants have been a rich source of food (bush food) and medicine to the first Australians (Aboriginal people), who are believed to have lived for more than 50,000 years. Plants such as spreading sneezeweed (Centipeda minima), goat’s foot (Ipomoea pes-caprae), and hop bush (Dodonaea viscosa and D. polyandra) are a few popular Aboriginal medicinal plants. Thus far, more than 900 medicinal plants have been recorded in the tropical region alone, and many of them are associated with diverse ethnomedicinal uses that belong to the traditional owners of Aboriginal people. In our effort to find anti-inflammatory lead compounds in collaboration with Aboriginal communities from their medicinal plants, we reviewed 78 medicinal plants used against various inflammation and inflammatory-related conditions by Aboriginal people. Out of those 78 species, we have included only 45 species whose crude extracts or isolated pure compounds showed anti-inflammatory properties. Upon investigating compounds isolated from 40 species (for five species, only crude extracts were studied), 83 compounds were associated with various anti-inflammatory properties. Alphitolic acid, Betulinic acid, Malabaric acid, and Hispidulin reduced proinflammatory cytokines and cyclooxygenase enzymes (COX-1 and 2) with IC₅₀ values ranging from 11.5 to 46.9 uM. Other promising anti-inflammatory compounds are Brevilin A (from Centipeda minima), Eupalestin, and 5′-methoxy nobiletin (from Ageratum conyzoides), Calophyllolide (from Calophyllum inophyllum), and Brusatol (from Brucea javanica). D. polyandra is one example of an Aboriginal medicinal plant from which a novel anti-inflammatory benzoyl ester clerodane diterpenoid compound was obtained (compound name not disclosed), and it is in the development of topical medicines for inflammatory skin diseases. Medicinal plants in the tropics and those associated with indigenous knowledge of Aboriginal people could be a potential alternative source of novel anti-inflammatory therapeutics.

Improving the Antioxidant Properties of Calophyllum inophyllum Seed Oil from French Polynesia: Development and Biological Applications of Resinous Ethanol-Soluble Extracts

Tamanu oil from Calophyllum inophyllum L. has long been used in traditional medicine. Ethanol extraction was found the best strategy for recovering bioactive compounds from the resin part of Tamanu oil, yielding two neutral and acidic resins fractions with high phenolics, flavonoids and pyranocoumarins concentrations. A further cascade of LPLC/HPLC separations of neutral and acidic resin fractions allowed identifying fifteen metabolites, and among them, calanolide D and 12-oxocalanolide A (both in neutral fraction) were first identified from a natural source. All these extracts, subfractions and isolated metabolites demonstrated increased free radical scavenging, antioxidant, anti-inflammatory, antimicrobial and antimycobacterial activity compared to Tamanu oil and its de-resinated lipid phase. Overall, these results could promote resinous ethanol-soluble Tamanu oil extracts as a useful multifaceted and renewable medicinal resource.

The Genus Calophyllum: Review of Ethnomedicinal Uses, Phytochemistry and Pharmacology

The species of genus Calophyllum have been reported for several ethnomedicinal uses in the traditional systems of medicine. The scientific study of the genus Calophyllum revealed that it is a rich source of bioactive secondary metabolites. These phytochemicals have shown a wide range of biological activities. Some of these have reached to the clinical developmental stage. The Calophyllum inophyllum seed oil has been proved to be an acceptable sustainable source of biodiesel. Few species of the genus are endangered and have been included in the red list of threatened species by the IUCN Red List. Owing to the importance of the genus a review of its ethnomedicinal uses, phytochemistry, and pharmacology has been carried out. It will further help to explore the molecular mechanism of phytochemicals for health benefits.

Caseinate-Stabilized Emulsions of Black Cumin and Tamanu Oils: Preparation, Characterization and Antibacterial Activity

Caseinate-stabilized emulsions of black cumin (Nigella sativa) and tamanu (Calophyllum inophyllum) oils were studied in terms of preparation, characterization, and antibacterial properties. The oils were described while using their basic characteristics, including fatty acid composition and scavenging activity. The oil-in-water (o/w) emulsions containing the studied oils were formulated, and the influence of protein stabilizer (sodium caseinate (CAS), 1-12 wt%), oil contents (5-30 wt%), and emulsification methods (high-shear homogenization vs sonication) on the emulsion properties were investigated. It was observed that, under both preparation methods, emulsions of small, initial droplet sizes were predominantly formed with CAS content that was higher than 7.5 wt%. Sonication was a more efficient emulsification procedure and was afforded emulsions with smaller droplet size throughout the entire used concentration ranges of oils and CAS when compared to high-shear homogenization. At native pH of ~ 6.5, all of the emulsions exhibited negative zeta potential that originated from the presence of caseinate. The antibacterial activities of both oils and their emulsions were investigated with respect to the growth suppression of common spoilage bacteria while using the disk diffusion method. The oils and selected emulsions were proven to act against gram positive strains, mainly against Staphylococcus aureus (S. aureus) and Bacillus cereus (B. cereus); regrettably, the gram negative species were fully resistant against their action.

In vivo antiarthritic activity of the ethanol extracts of stem bark and seeds of Calophyllum inophyllum in Freund's complete adjuvant induced arthritis

CONTEXT

Calophyllum inophyllum Linn. (Clusiaceae) (CI) is traditionally used to treat pain, inflammation, eye disorders and rheumatism.

OBJECTIVE

The present study evaluates the antiarthritic activity of the ethanol extract of the stem bark (ESBCI) and seeds (ESCI) of Calophyllum inophyllum in Freund's adjuvant induced arthritic Wistar albino rat model.

MATERIALS AND METHODS

ESBCI and ESCI were screened for in vitro anti-inflammatory activity by proteinase inhibition and membrane stabilization assays. Acute oral toxicity studies were conducted according to OECD-425 guidelines. Antiarthritic activity of ESBCI and ESCI at the dose of 250 mg/kg/p.o. was evaluated by Freund's adjuvant induced arthritic rat model.

RESULTS

ESBCI and ESCI have shown maximum inhibition at 250 μg/mL in proteinase inhibition and haemolysis assays. The LD₅₀ of ESBCI and ESCI was found to be greater than 5000 and 2000 mg/kg/p.o., respectively. In Freund's adjuvant induced arthritic rat model ESBCI, ESCI and Diclofenac treatment have shown 28.57, 36.36, and 43.51% as maximum reduction in rat paw oedema volume respectively when compared with the arthritic control rats. ESBCI and ESCI treatment at the dose level of 250 mg/kg/p.o. normalized the altered haematological and biochemical parameters of arthritic control rats. Histological and radiological evaluation confirmed the antiarthritic effect of ESBCI and ESCI.

DISCUSSION

ESBCI and ESCI were found to show significant antiarthritic activity evidenced with clinical, biochemical, histological and radiological evaluations.

CONCLUSION

The present study indicates the antiarthritic activity of ESBCI and ESCI, however its mechanism of action has to be studied in the future.

Anti-inflammatory and wound healing activities of calophyllolide isolated from Calophyllum inophyllum Linn

Due to the high-cost and limitations of current wound healing treatments, the search for alternative approaches or drugs, particularly from medicinal plants, is of key importance. In this study, we report anti-inflammatory and wound healing activities of the major calophyllolide (CP) compound isolated from Calophyllum inophyllum Linn. The results showed that CP had no effect on HaCaT cell viability over a range of concentrations. CP reduced fibrosis formation and effectively promoted wound closure in mouse model without causing body weight loss. The underlying molecular mechanisms of wound repair by CP was investigated. CP markedly reduced MPO activity, and increased M2 macrophage skewing, as shown by up-regulation of M2-related gene expression, which is beneficial to the wound healing process. CP treatment prevented a prolonged inflammatory process by down-regulation of the pro-inflammatory cytokines—IL-1β, IL-6, TNF-α, but up-regulation of the anti-inflammatory cytokine, IL-10. This study is the first to indicate a plausible role for CP in accelerating the process of wound healing through anti-inflammatory activity mechanisms, namely, by regulation of inflammatory cytokines, reduction in MPO, and switching of macrophages to an M2 phenotype. These findings may enable the utilization of CP as a potent therapeutic for cutaneous wound healing.

Calophyllolide content in Calophyllum inophyllum at different stages of maturity and its osteogenic activity

Calophyllum inophyllum is a coastal plant rich in natural substances. Its ingredients have been used for the development of an anti-human immunodeficiency virus (HIV) drug. In this study, we collected C. inophyllum fruit, and the ethanol extract of the fruit was chromatographically separated using silica gel and Sephadex LH-20 columns to obtain the major compound, calophyllolide. The fruits were harvested from September to December in 2011; a quantitative analysis of the calophyllolide content was conducted using HPLC to explore the differences between the different parts of the fruit during the growing season. The results showed that in fruits of C. inophyllum, calophyllolide exists only in the nuts, and dried nuts contain approximately 2 mg·g⁻¹ of calophyllolide. The calophyllolide levels in the nuts decreased during maturity. In addition, calophyllolide dose-dependently enhanced alkaline phosphatase (ALP) activity in murine osteoblastic MC3T3-E1 cells, without significant cytotoxicity. The expression of osteoblastic genes, ALP and osteocalcin (OCN), were increased by calophyllolide. Calophyllolide induced osteoblasts differentiation also evidenced by increasing mineralization and ALP staining.