Inhibitory effect of garcinol against 12-O-tetradecanoylphorbol 13-acetate-induced skin inflammation and tumorigenesis in mice

Garcinia kola: a critical review on chemistry and pharmacology of an important West African medicinal plant

Garcinia kola Heckel (Clusiaceae) is a tree indigenous to West and Central Africa. All plant parts, but especially the seeds, are of value in local folklore medicine. Garcinia kola is used in treatment of numerous diseases, including gastric disorders, bronchial diseases, fever, malaria and is used to induce a stimulating and aphrodisiac effect. The plant is now attracting considerable interest as a possible source of pharmaceutically important drugs. Several different classes of compounds such as biflavonoids, benzophenones, benzofurans, benzopyran, vitamin E derivatives, xanthones, and phytosterols, have been isolated from G. kola, of which many appears to be found only in this species, such as garcinianin (found in seeds and roots), kolanone (fruit pulp, seeds, roots), gakolanone (stem bark), garcinoic acid, garcinal (both in seeds), garcifuran A and B, and garcipyran (all in roots). They showed a wide range of pharmacological activities (e.g. analgesic, anticancer, antidiabetic, anti-inflammatory, antimalarial, antimicrobial, hepatoprotective and neuroprotective effects), though this has only been confirmed in animal models. Kolaviron is the most studied compound and is perceived by many studies as the active principle of G. kola. However, its research is associated with significant flaws (e.g. too high doses tested, inappropriate positive control). Garcinol has been tested under better conditions and is perhaps showing more promising results and should attract deeper research interest (especially in the area of anticancer, antimicrobial, and neuroprotective activity). Human clinical trials and mechanism-of-action studies must be carried out to verify whether any of the compounds present in G. kola may be used as a lead in the drug development.

Evaluation of the healing properties of Garcinia brasiliensis extracts in a cutaneous wound model

ETHNOPHARMACOLOGICAL RELEVANCE

Wound healing is a complex process that can leave pathological scars, especially in case of infections from opportunistic microorganisms. In this context, herbal medicines open up great possibilities for investigation. One of the species of interest native to Brazil is Garcinia brasiliensis ("bacupari"). Traditionally known for treating wounds and ulcers, G. brasiliensis presents anti-inflammatory, antioxidant and antimicrobials properties. But, its wound healing profile in experimental models, in order to validate its efficacy, is still litle studied.

AIM OF THE STUDY

Thus, the objective of this work was to evaluate, in an infected cutanous wound model, the potential of formulations incorporated with G. brasiliensis leaves extracts.

MATERIALS AND METHODS

Crude extract (CE), Ethyl Acetate Fraction (EAF) and Hexanic Fraction (HF) were submitted to phytochemical assays, high performance thin layer chromatography (HTPLC) and cytotoxicity studies. CE and EAF were also tested for microbicidal properties and incorporated in cream and gel formulations at 10% concentration. After stability testing, the gel formulations with CE or EAF at 10% were selected and applied to skin wounds infected or not with Staphylococcus aureus in Wistar rats. The healing potenttial of the extracts was verified by the expression of the protein Annexin A1 (AnxA1), related to the processes of inflammation and antifibrotic function, the cells immunostaining for Gasdermin-D (GSDM-D), a marker of pyroptotic cell death, and the dosage of interleukin-10 (IL-10) and monocyte chemotactic protein (MCP)-1 inflammatory mediators.

RESULTS

Phytochemical studies indicated the presence of compounds of pharmacological interest, including Catechin, Quercetin and Berberine in addition to low cytotoxicity of CE and EAF at 10%. After the 6-day topical treatments, CE and EAF gel formulations demonstrated to control the pruritus formation process. The treatments decreased AnxA1 expression and the amount of cells immunostained for GSDM-D, and increased the expression of MCP-1 in infected wounds.

CONCLUSIONS

Together, the results show important anti-inflammatory profile and skin healing potential of CE and EAF from G. brasiliensis leaves, even in infected lesions, with therapeutic perspectives.

Cytotoxic and Antiangiogenetic Xanthones Inhibiting Tumor Proliferation and Metastasis from Garcinia xipshuanbannaensis

Eight prenylated xanthones including four new analogues were extracted and purified from the leaves of Garcinia xipshuanbannaensis. Multiple techniques including UV, 1D and 2D NMR, and HRESIMS were used to determine the structures of the isolated xanthones. These xanthones were evaluated for their cytotoxicity toward human cancer cells, and compound 4 exhibited activity against HeLa cells. A cytotoxic mechanism examination revealed the active compound induced cell apoptosis by arresting the cell cycle, increasing the levels of ROS, and inhibiting the expression of p-STAT3 in HeLa cells. In in vivo zebrafish experiments, compound 4 was found to block tumor proliferation and migration and have antiangiogenetic activity, and thus seems worthy of further laboratory evaluation.

Medicinal Potential of Garcinia Species and Their Compounds

Garcinia is a genus of Clusiaceae, distributed throughout tropical Asia, Africa, New Caledonia, Polynesia, and Brazil. Garcinia plants contain a broad range of biologically active metabolites which, in the last few decades, have received considerable attention due to the chemical compositions of their extracts, with compounds which have been shown to have beneficial effects in several diseases. Our work had the objective of reviewing the benefits of five Garcinia species (G. brasiliensis, G. gardneriana, G. pedunculata, G. cambogia, and G. mangstana). These species provide a rich natural source of bioactive compounds with relevant therapeutic properties and anti-inflammatory effects, such as for the treatment of skin disorders, wounds, pain, and infections, having demonstrated antinociceptive, antioxidant, antitumoral, antifungal, anticancer, antihistaminic, antiulcerogenic, antimicrobial, antiviral, vasodilator, hypolipidemic, hepatoprotective, nephroprotective, and cardioprotective properties. This demonstrates the relevance of the genus as a rich source of compounds with valuable therapeutic properties, with potential use in the prevention and treatment of nontransmissible chronic diseases.

β-Elemene inhibits 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate-induced skin tumorigenesis through suppression of NF-κB-associated signaling events in the mouse skin model

β-Elemene (1-methyl-1-vinyl-2,4-diisopropenyl-cyclohexane), a natural sesquiterpene-derived curcumae radix, exhibits a variety of pharmacologic properties including anticancer. However, the molecular action of β-elemene in chemical-induced skin carcinogenesis remains unclear. Therefore, the present study executes to investigate a possible effect of β-elemene in the 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted skin tumor model. The experimental mice were subjected to execute two-stage skin carcinogenesis and it has been initiated by the addition of DMBA on the dorsal portion of the mouse skin. One week after, for chemical carcinogen of mice, topical exposure of DMBA has been induced following with TPA (5 nmol) in acetone (200 μL) given weekly twice for 20 weeks respectively. After completion of the experimental period, we noticed that 100% of tumor incidence, histopathological changes, decreased lipid peroxidation (LPO), and decreased antioxidant levels in DMBA/TPA-promoted skin carcinogenesis. Furthermore, enhanced activity of inflammatory protein markers (nuclear factor [NF]-κB, tumor necrosis factor-α, interleukin-6, cyclooxygenase-2, and nitric oxide synthase) and cell-proliferative messenger RNA markers (PCNA, cyclin D1), and increased antiapoptotic protein Bcl-2; decreased proapoptotic protein marker events Bax and caspase 3 and 9 expressions were noticed in DMBA/TPA promoted skin tissue. In this study, we noticed that β-elemene noticeably reversed the histopathological changes and antioxidant levels in tumor-bearing mice. Conversely, β-elemene effectively inhibits inflammation, cell proliferation events, and enhances proapoptotic factors, by suppression of NF-κB transcriptional activation in DMBA/TPA animals. Thus, we concluded that β-elemene prevents DMBA/TPA promoted skin carcinogenesis through its antioxidant and abate inflammation markers and cell-proliferative markers also activating proapoptotic molecules.

Anti-Arthritic Effect of Garcinol Enriched Fraction Against Adjuvant Induced Arthritis

Background:

Garcinia indica also known as kokum is used in traditional system of medicine for relieving inflammation and rheumatic pain. Garcinol, a benzophenone obtained from its fruit rind is reported to have anti-inflammatory effect via modulating arachidonic acid metabolism, suppressing iNOS expression, NF-κB activation and COX-2 expression. It has also been studied for antioxidant and anti-cancer activity. Apart from these, few patents claim that garcinol also has anti-obesity and hepatoprotec-tive effect and has a potential to be used for the treatment of renal disorders, endometriosis and cardiac dysfunction.

Objective:

Garcinol Enriched Fraction (GEF) from the fruit rind of Garcinia indica should be effective in the treatment of arthritis, one of the chronic inflammatory disorder owing to its anti-inflammatory property as indicated by earlier experiments.

Methods:

GEF was prepared from the fruit rind of Garcinia indica and quantified using LC-MS/MS. It was found to contain 89.4% w/w of garcinol. GEF was evaluated at the dose of 10mg/kg for its efficacy against Complete Freund’s Adjuvant (CFA) induced arthritis in Wistar albino rats. Paw volumes of both sides were measured by Plethysmometer and body weight was recorded on 0, 1, 5, 12 and 21^st day. The hyperalgesic response was also measured by motility test and stair climbing test.

Results:

GEF showed a significant reduction in paw swelling (p < 0.0001) and arthritis index (p < 0.0001) exhibiting anti-inflammatory potential. It also improves the motility and stair climbing ability of experimental animals (p < 0.05), thus reducing hyperalgesia.

Conclusion:

Garcinol enriched fraction shows anti-arthritic activity in experimental animals.

Chemical and Biological Aspects of Garcinol and Isogarcinol: Recent Developments

The natural polyisoprenylated benzophenone derivatives garcinol and isogarcinol are secondary plant metabolites isolated from various Garcinia species including Garcinia indica. This review takes stock of the recent chemical and biological research into these interesting natural compounds over the last five years. New biological sources and chemical syntheses are discussed followed by new insights into the activity of garcinol and isogarcinol against cancer, pathogenic bacteria, parasite infections and various inflammatory diseases.

Research Progress of Polycyclic Polyprenylated Acylphloroglucinols

Polycyclic polyprenylated acylphloroglucinols (PPAPs) are a class of hybrid natural products sharing the mevalonate/methylerythritol phosphate and polyketide biosynthetic pathways and showing considerable structure and bioactivity diversity. This review discusses the progress of research into the chemistry and biological activity of 421 natural PPAPs in the past 11 years as well as in-depth studies of biological activities and total synthesis of some PPAPs isolated before 2006. We created an online database of all PPAPs known to date at http://www.chem.uky.edu/research/grossman/PPAPs . Two subclasses of biosynthetically related metabolites, spirocyclic PPAPs with octahydrospiro[cyclohexan-1,5'-indene]-2,4,6-trione core and complicated PPAPs produced by intramolecular [4 + 2] cycloadditions of MPAPs, are brought into the PPAP family. Some PPAPs' relative or absolute configurations are reassigned or critically discussed, and the confusing trivial names in PPAPs investigations are clarified. Pharmacologic studies have revealed a new molecular mechanism whereby hyperforin and its derivatives regulate neurotransmitter levels by activating TRPC6 as well as the antitumor mechanism of garcinol and its analogues. The antineoplastic potential of some type B PPAPs such as oblongifolin C and guttiferone K has increased significantly. As a result of the recent appearances of innovative synthetic methods and strategies, the total syntheses of 22 natural PPAPs including hyperforin, garcinol, and plukenetione A have been accomplished.

Assessment of Toxicity and Beneficiary Effects of Garcinia pedunculata on the Hematological, Biochemical, and Histological Homeostasis in Rats

This study was undertaken to investigate the toxicological profile of a methanolic extract of Garcinia pedunculata fruit in rats by conducting hematological, biochemical, and histopathological examinations. Long Evans rats were divided into four groups, each with 6 animals, and were treated with three oral doses (250, 500, and 1000 mg/kg) once daily for 21 days. The extract did not cause significant changes in body and relative organ weight, percent water content, or hematological parameters at any administered doses. However, a significant dose-dependent positive effect in serum lipid profile and all atherogenic indices including the cardiac risk ratio, Castelli's risk index-2, and the atherogenic coefficient were observed. Significant increases in the levels of iron and decreases in serum alkaline phosphatase, alanine transaminase, and lactate dehydrogenase activities and the levels of serum glucose were noted when the extract was administered at the highest dose (1000 mg/kg). Histopathological examination of the target tissues further confirmed that the extract was safe and had no observed toxicological features. Our study indicates that G. pedunculata fruit is nontoxic, has the potential to be effective against atherosclerosis, and may be used as a hepatoprotectant. The fruit extract is also beneficial to those with iron deficiency and hyperglycemia.