Antioxidant, anti-inflammatory, antiproliferative and antimycobacterial activities of the essential oil of Psidium guineense Sw. and spathulenol

Abstract

Ethnopharmacological relevance: Leaves from Psidium guineense Sw. are used in popular medicine for the treatment of inflammatory disease. However, there is no scientific evidence demonstrating this activity.

Aim of the study: To evaluate the antioxidant, anti-inflammatory, antiproliferative and antimycobacterial activities of the essential oil of P. guineense and spathulenol (a major constituent). The study was conducted in part to provide evidence supporting the ethnobotanical use of the leaves of this species.

Material and methods: The essential oil (EOPG) was extracted from the leaves of P. guineense by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC-MS). The major compound, spathulenol (PG-1), was isolated in a chromatographic column and characterized by nuclear magnetic resonance (NMR). EOPG and PG-1 were evaluated in vitro for antioxidant activity by DPPH, ABTS and MDA methods; anti-inflammatory potential was assessed using two models, including pleurisy and oedema, in mice. The impact of EOPG and PG-1 on cell proliferation was determined via spectrophotometric quantification of the cellular protein content using a sulforhodamine B assay, and anti-Mycobacterium tuberculosis activity was determined using the REMA method.

Results: A total of 38 components were identified from the EOPG, with the sesquiterpenic alcohol spathulenol (PG-1) (80.7%) being the major constituent. EOPG and PG-1 exhibited the highest antioxidant activities in the DPPH and MDA system compared with reference standard, with IC₅₀ values ranging from 26.13 to 85.60μg/mL. Oral administration of EOPG and PG-1 showed significant inhibition in the Cg-induced mice paw oedema and pleurisy model. The EOPG (GI₅₀ = 0.89μg/mL) and PG-1 (GI₅₀ = 49.30μg/mL) were particularly effective against the ovarian cancer cell line. Both showed moderate antimycobacterial activity.

Conclusion: For the first time, this study demonstrated the antioxidant, anti-inflammatory, antiproliferative and antimycobacterial properties of the essential oil of P. guineense (leaves were collected in Dourados-MS) and spathulenol, collaborating the etnhopharmacologycal use of this plant due to its an anti-inflammatory effect.

Keywords: (1)H NMRProton nuclear magnetic resonance of hydrogen; (13)C NMRCarbon-13 nuclear magnetic resonance; 786-0Renal; AA%Antioxidant activity; ABTS2,2′-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid); Anti-Mycobacterium tuberculosis; Antioxidant; Antiproliferative; Araçá; BHTButylated hydroxytoluene; CCColumn chromatography; CDCl(3)Deuterated chloroform; CO(2)Carbon dioxide; Cgλ–carrageenan; DEXADexamethasone; DMSODimethylsulfoxide; DOXDoxorubicin; DPPH2,2-Diphenyl-1-picrylhydrazyl; EOPG-1Essential oil of P. guineense-sub-fraction 1; EOPG-4Essential oil of P. guineense-sub-fraction 4; EOPG-7Essential oil of P. guineense-sub-fraction 7; EOPGEssential oil of Psidium guineense; GC-MSGas chromatograph - mass spectrometry; GI(50)Growth inhibitory for 50% of cell; HT-29Colon cell line; HaCaTKeratinocytes; I%Inhibition percentage; IC(50)Concentration resulting in 50% inhibition; IL-1βInterleukin-1 beta; IL-6Interleukin-6; IL-8Interleukin-8; IPPIsopentenyl pyrophosphate; K-562Leukaemia; LC(50)Concentration killing 50% of cells; MCF-7Breast; MDAMalondialdehyde; MHzMegahertz; MICConcentration inhibition minimum; MM-1Matriz metalloproteinase-1; MTBMycobacterium tuberculosis; NCI-ADR/RESOvarian expressing the phenotype of multiple drug resistance; NCI-H460Lung; NCINational câncer institute; NONitric oxide; OVCAR-3Ovarian; Oedema; PBSPhosphate buffered saline; PCO-3Prostate; PG-1Compound spathulenol; Pleurisy; REMAResazurin microtiter assay; RPMI-1640Roswell park memorial institute 1640 medium; TGIGrowth inhibitory for 50% of cell; TLCThin-layer chromatography; TMSTetramethylsilane; TNF-αTumour necrosis factors-alpha; U251Glioma.