Effects of barakol from Cassia siamea on neuroblastoma SH-SY5Y cell line: A potential combined therapy with doxorubicin.

Management of neuroblastoma is challenging because of poor response to drugs, chemotherapy resistance, high relapse, and treatment failures. Doxorubicin is a potent anticancer drug commonly used for neuroblastoma treatment. However, doxorubicin induces considerable toxicities, particularly those caused by oxidative-related damage. To minimize drug-induced adverse effects, the combined use of anticancer drugs with natural-derived compounds possessing antioxidant properties has become an interesting treatment strategy. Barakol is a major compound found in Cassia siamea, an edible plant with antioxidant and anticancer properties. Therefore, barakol could potentially be used in combination with doxorubicin to synergize the anticancer effect, while minimizing the oxidative-related toxicities. Herein, the potential of barakol (0.0043-43.0 µM) to synergize the anticancer effect of low-dose doxorubicin (0.5 and 1.0 µM) was investigated. Results indicated that barakol could enhance the cytotoxic effect of low-dose doxorubicin by affecting the cell viability of the treated cells. Furthermore, the co-treatment with barakol and low-dose doxorubicin decreased the levels of intracellular ROS when compared with the control. Moreover, the antimetastatic effect of the barakol itself was studied through its ability to inhibit metalloproteinase-3 (MMP-3) activity and prevent cell migration. Results revealed that the barakol inhibited MMP-3 activity and prevented cell migration in time- and dose-dependent manners. Additionally, barakol was a non-cytotoxic agent against the normal tested cell line (MRC-5), which suggested its selectivity and safety. Taken together, barakol could be a promising compound to be further developed for combination treatment with low-dose doxorubicin to improve therapeutic effectiveness but decrease drug-induced toxicities. The inhibitory effects of barakol on MMP-3 activity and cancer cell migration also supported its potential to be developed as an antimetastatic agent.

Protective Efficacy of Spilanthes acmella Murr. Extracts and Bioactive Constituents in Neuronal Cell Death.

Spilanthes acmella Murr., a well-known Thai traditional medicine, has been used for treatment of toothache, rheumatism, and fever. Diverse pharmacological activities of S. acmella Murr. have been reported. In this study, antioxidative and neuroprotective effects of S. acmella Murr. extracts as well as bioactive scopoletin, vanillic acid, and trans-ferulic acid found in the aerial parts of this plant species have been described. Protective effect of S. acmella Murr. extracts and bioactive compounds on dexamethasone-induced neuronal cell death was investigated. Different plant crude ethyl acetate (EtOAc) and methanol (MeOH) extracts including pure compounds of S. acmella Murr. were evaluated in human neuroblastoma SH-SY5Y cells. Cytotoxic effects were performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Mechanisms involved in the antioxidant effects of S. acmella Murr. regarding the activation of antioxidant marker proteins such as superoxide dismutase 2 (SOD2) and sirtuin 3 (SIRT3) were determined using 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) assay, Western blot analysis, and immunocytochemistry. Dexamethasone significantly caused the decrease of SH-SY5Y cell viability. Conversely, the increases in reactive oxygen species (ROS), autophagy, and apoptosis were observed in dexamethasone-treated cells. S. acmella Murr. MeOH and EtOAc extracts, as well as the bioactive compounds, reversed the toxic effect of dexamethasone by increasing the cell viability, SIRT3 protein expression but reducing the ROS, autophagy, and apoptosis. This study demonstrated that S. acmella Murr. may exert its protective effects against ROS through SOD2 and SIRT3 signaling pathways in dexamethasone-induced neurotoxicity. S. acmella Murr. may be a candidate therapy for neuroprotection.

Spilanthes acmella Murr. ameliorates chronic stress through improving mitochondrial function in chronic restraint stress rats.

Chronic stress is a risk factor for the development of psychiatric illnesses through impairment of the ability to appropriately regulate physiological and behavioral responses, but the molecular events that lead to damage of hippocampal neurons remain unclear. The medicinal herb Spilanthes acmella Murr. has been used as a traditional medicine for various diseases and its extracts exhibit antioxidant activity. The present study explored the molecular signals of mitochondrial dynamics and investigated the beneficial effects of S. acmella Murr. An ethyl acetate extract of this plant was used to assess mitochondrial dynamics in response to chronic restraint stress (CRS) in male Sprague-Dawley rats. The results demonstrated that the S. acmella Murr. extract reduced the expression of mitochondrial fission protein but induced HSP60, MnSOD and ATPsynthase in the hippocampus of the CRS rats. In addition, S. acmella Murr. extract reversed depressive symptoms in the forced swim test. Our findings suggested that S. acmella Murr. extract provides a potential treatment of chronic stress, and that the mechanism is associated with the alleviation of neuronal injury and maintenance of mitochondrial function.

Mitochondrial Dynamics Impairment in Dexamethasone-Treated Neuronal Cells.

Dexamethasone is an approved steroid for clinical use to activate or suppress cytokines, chemokines, inflammatory enzymes and adhesion molecules. It enters the brain, by-passing the blood brain barrier, and acts through genomic mechanisms. High levels of dexamethasone are able to induce neuronal cell loss, reduce neurogenesis and cause neuronal dysfunction. The exact mechanisms of steroid, especially the dexamethasone contribute to neuronal damage remain unclear. Therefore, the present study explored the mitochondrial dynamics underlying dexamethasone-induced toxicity of human neuroblastoma SH-SY5Y cells. Neuronal cells treatment with the dexamethasone resulted in a marked decrease in cell proliferation. Dexamethasone-induced neurotoxicity also caused upregulation of mitochondrial fusion and cleaved caspase-3 proteins expression. Mitochondria fusion was found in large proportions of dexamethasone-treated cells. These results suggest that dexamethasone-induced hyperfused mitochondrial structures are associated with a caspase-dependent death process in dexamethasone-induced neurotoxicity. These findings point to the high dosage of dexamethasone as being neurotoxic through impairment of mitochondrial dynamics.

Neuroprotective effect of Spilanthes acmella Murr. on pesticide-induced neuronal cells death.

OBJECTIVE: To investigate protective effects of Spilanthes acmella (S. acmella) Murr. extracts against pesticide-induced neuronal cells death and to elucidate the underlying molecular mechanism in dopaminergic (SH-SY5Y) cells lines. METHODS: Cell viability of SH-SY5Y cells was studied by treating the cells with various concentration of pirimicarb for 24 h. Neuroprotective effect of S. acmella Murr. extracts was investigated by adding the plant extracts to the medium for 24 h prior to the incubation with 100 µM H2O2 or with pirimicarb for 24 h. Control-untreated cells were incubated with the culture medium. Cell viability was measured by MTT assay, calpain and calpastatin expressions were analyzed by Western blotting and immunocytochemistry. RESULTS: Pretreatment of SH-SY5Y cells with S. acmella Murr. extracts (1 µg/mL) for 24 h significantly increased the dopaminergic neurons in pirimicarb-induced neurotoxicity. In addition, pretreatment with the S. acmella Murr. extracts led to decreased calpain but increased calpastatin protein levels. CONCLUSION: S. acmella Murr. extracts exerted neuroprotective effect, via an alteration of calcium homeostasis, against pirimicarb induced neurotoxicity. The S. acmella Murr. might be a potential natural candidate with neuroprotective activity.

High therapeutic potential of Spilanthes acmella: A review.

Spilanthes acmella, a well known antitoothache plant with high medicinal usages, has been recognized as an important medicinal plant and has an increasingly high demand worldwide. From its traditional uses in health care and food, extensive phytochemical studies have been reported. This review provides an overview and general description of the plant species, bioactive metabolites and important pharmacological activities including the preparation, purification and in vitro large-scale production. Structure-activity relationships of the bioactive compounds have been discussed. Considering data from the literature, it could be demonstrated that S. acmella possesses diverse bioactive properties and immense utilization in medicine, health care, cosmetics and as health supplements. As a health food, it is enriched with high therapeutic value with high potential for further development.

Bioactive 4-hydroxycinnamide and bioactivities of Polyalthia cerasoides.

Constituents from Polyalthia cerasoides, stem bark methanol extract, were previously documented. This study reports the first isolation of bioactive N-(4-hydroxy-ß-phenethyl)-4-hydroxycinnamide (1) from ethyl acetate extract of the plant species including stigmasterol and a mixture of triterpenes from hexane and dichloromethane extracts. Trace essential elements were found in the hexane extract in ppm level. The plant extracts were evaluated for their antimicrobial and antioxidative activities. The dichloromethane extract displayed the highest activity against Corynebacterium diphtheriae NCTC 10356 with MIC of 32 µg/mL, as well as, the highest SOD activity with an IC50 of 4.51 µg/mL.

Bioactive azafluorenone alkaloids from Polyalthia debilis (Pierre) Finet & Gagnep.

This study investigated bioactive extracts of Polyalthia debilis (Annonaceae) with antimicrobial, antimalarial and cytotoxic activities. Extensive chromatographic isolations provided azafluorenone alkaloids; onychine (1) and 7-methoxyonychine (2) together with a mixture of beta-sitosterol and stigmasterol. The two alkaloids were isolated from the P. debilis for the first time. Isolated fractions containing a mixture of triterpenoids (C7, C8 and C9) exhibited the most potent antimicrobial activity against many bacterial strains with minimum inhibitory concentration of 64 microg/mL. Fractions with antimalarial and cytotoxic activities were also observed. The findings suggest the potential use of P. debilis in medicinal applications.

Bioactive metabolites from Spilanthes acmella Murr.

Spilanthes acmella Murr. (Compositae) has been used as a traditional medicine for toothache, rheumatism and fever. Its extracts had been shown to exhibit vasorelaxant and antioxidant activities. Herein, its antimicrobial, antioxidant and cytotoxic activities were evaluated. Agar dilution method assays against 27 strains of microorganisms were performed. Results showed that fractions from the chloroform and methanol extracts inhibited the growth of many tested organisms, e.g. Corynebacterium diphtheriae NCTC 10356 with minimum inhibitory concentration (MIC) of 64-256 mg/mL and Bacillus subtilis ATCC 6633 with MIC of 128-256 mg/mL. The tested fractions all exhibited antioxidant properties in both DPPH and SOD assays. Potent radical scavenging activity was observed in the DPPH assay. No cytotoxic effects of the extracts against KB and HuCCA-1 cell lines were evident. Bioassay-guided isolation resulted in a diverse group of bioactive compounds such as phenolics [vanillic acid (2), trans-ferulic acid (5) and trans-isoferulic acid (6)], coumarin (scopoletin, 4) and triterpenoids like 3-acetylaleuritolic acid (1), b-sitostenone (3), stigmasterol and stigmasteryl-3-O-b-D-glucopyranosides, in addition to a mixture of stigmasteryl-and b-sitosteryl-3-O-b-D-glucopyranosides. The compounds 1-6 represent bioactive metabolites of S. acmella Murr. that were never previously reported. Our findings demonstrate for the first time the potential benefits of this medicinal plant as a rich source of high therapeutic value compounds for medicines, cosmetics, supplements and as a health food.

Antimicrobial and antioxidative activities of bioactive constituents from Hydnophytum formicarum Jack.

Hydnophytum formicarum Jack. (Rubiaceae) is a medicinal plant whose tubers possesses cardiovascular, anti-inflammatory and antiparasitic effects and have been used for the treatment of hepatitis, rheumatism and diarrhea. Herein we report the isolation of its active constituents and the testing of their antimicrobial activity against 27 strains of microorganisms using an agar dilution method and of their antioxidative activity using the DPPH and SOD assays. The results show that the crude hexane, dichloromethane, ethylacetate and methanol extracts exert such activities. Particularly, the crude ethyl acetate extract exhibits antigrowth activity against many Gram-positive and Gram-negative bacteria with MIC 256 microg/mL. Shewanella putrefaciens ATCC 8671 is completely inhibited at a lower MIC (128 microg/mL). Interestingly, Corynebacterium diphtheriae NCTC10356 is inhibited by all the tested extracts. Significantly, the ethyl acetate extract is also the most potent antioxidant, showing 83.31% radical scavenging activity with IC50 8.40 microg/mL in the DPPH assay. The other extracts display weak to moderate antioxidative activities, ranging from 28.60-56.80% radical scavenging. The SOD assay shows that methanol extract exhibits the highest activity (74.19% inhibition of superoxide radical). The dichloromethane and ethyl acetate extracts display comparable SOD activity. The promising bioactivities of the crude ethyl acetate extract guided the first isolation of bioactive flavonoid and phenolic compounds: isoliquiritigenin (2), protocatechualdehyde(3), butin (4) and butein (5) from this species. Their structures have been fully established by 1D and 2D NMR. In addition, stigmasterol was isolated from the crude hexane and dichloromethane extracts. The antimicrobial and cytotoxic activities of compounds 3-5 were evaluated. The tested compounds were inactive against HuCCA-1 and KB cell lines,showing ED50> 10 microg/mL. Protocatechualdehyde (3) completely inhibits the growth of Plesiomonas shigelloides with MIC