Wogonin, an active ingredient of Chinese herb medicine Scutellaria baicalensis, inhibits the mobility and invasion of human gallbladder carcinoma GBC-SD cells by inducing the expression of maspin

Ethnopharmacological relevance

A traditional Chinese medicine Scutellaria baicalensis is prescribed for the treatment of a variety of inflammatory diseases and tumors in clinic in China. However, the detailed mechanism of anti-metastasis effect of wogonin, a main active ingredient of Scutellaria baicalensis, remains elusive.

Aim of the study

The present study was designed to investigate the action and mechanism of wogonin on the mobility and invasion of human gallbladder carcinoma GBC-SD cells.

Materials and methods

Viability, apoptosis, mRNA and protein expression of tumor cells were analyzed by MTT, Annexin V staining, real-time PCR and Western blot, respectively. The migration and invasion assay was used to evaluate the anti-metastasis effect of wogonin. Knockdown of maspin was performed by specific small interference RNA.

Results

Wogonin at the dose of 1-10 μM, which did not induce apoptosis, significantly inhibited the mobility and invasion activity of human gallbladder carcinoma GBC-SD cells. In addition, the expressions of matrix metalloproteinase (MMP)-2, MMP-9 and phosphorylated extracellular regulated protein kinase 1/2 (ERK1/2) but not phosphorylated Akt were dramatically suppressed by wogonin in a concentration-dependent manner. Furthermore, the metastasis suppressor maspin was confirmed as the downstream target of wogonin. Both maspin mRNA and protein were upregulated by wogonin. Interestingly, the knockdown of maspin resulted in almost completely blocking of wogonin-induced inhibition of MMP-2, MMP-9 and phosphorylated ERK1/2 as well as the mobility and invasion activity of GBC-SD cells.

Conclusions

These findings suggest that wogonin inhibits cell mobility and invasion by upregulating the metastasis suppressor maspin. Together, these data provide novel insights into the chemoprotective effect of wogonin, a main active ingredient of Chinese medicine Scutellaria baicalensis.     

Inhibitory effects of Scutellaria baicalensis extract on hepatic stellate cells through inducing G2/M cell cycle arrest and activating ERK-dependent apoptosis via Bax and caspase pathway

Ethnopharmacological relevance

The bioactive components extracted from Scutellaria baicalensis Georgi (SB) have been widely used for anti-cancer, anti-oxidation, anti-inflammation and modulating the immune response.

Aim of the study

The purpose of this study is to verify the inhibitory effect and the underlying mechanisms of Scutellaria baicalensis ethanol extract (SBEE) on activated hepatic stellate cells which play a central role in liver fibrogenesis.

Materials and methods

Dimethylnitrosamine (DMN)-administrated rat model was applied to evaluate the anti-fibrotic effect of SBEE in vivo. Flow cytometric analysis and immunoblotting were then used to further investigate the molecular mechanisms by which Scutellaria baicalensis extract induces HSC-T6 cell death.

Results

Hepatic collagen contents and alpha-smooth muscle actin levels were remarkably reduced by treating with SBEE. 100 μg/mL SBEE-induced apoptosis of HSC-T6 cell was characterized with elevated levels of activated caspase-3, poly-(ADP-ribose) polymerase (PARP) cleavage, and release of cytochrome c into the cytosol in a time-dependent manner. A 24 h treatment of SBEE induced G₂/M cell cycle arrest with increased expression of p21 and downregulation of cdc2 and cyclin B1 protein levels. Again, SBEE induced bax expression with concomitant decrease of bcl-2 and upregulated the p53 and MAPK signaling in HSC-T6 cells.

Conclusions

These findings demonstrated that SBEE could prevent hepatic fibrosis by promoting ERK-p53 pathways which may in turn cause G₂/M cell cycle arrest and activate caspase system resulting in final apoptosis of HSC-T6 cells.     

Effects of Scutellaria baicalensis on chronic cerebral hypoperfusion-induced memory impairments and chronic lipopolysaccharide infusion-induced memory impairments

Ethnopharmacological relevance

Extracts of the roots of Scutellaria baicalensis Georgi (Labiatae) have been widely used to relieve fever related to bacterial infection and inflammatory diseases in traditional Korean medicine and have been reported to be effective in brain diseases.These experiments were conducted to examine the effects of oral administration of Scutellaria baicalensis extracts on the rescue of memory impairments induced by chronic cerebral hypoperfusion or chronic lipopolysaccharide (LPS) infusion. In addition, the underlying mechanisms of these effects were investigated.

Materials and methods

In the first experiment, chronic cerebral hypoperfusion was induced in male Wister rats by bilateral common carotid artery occlusion (BCCAo). Daily administration of Scutellaria baicalensis extracts was started on 20 day after BCCAo and given for 40 days. A Morris water maze was then used to evaluate the status of the hippocampal-dependent spatial learning and hippocampal mitogen-activated protein kinase (MAPK) signaling was examined in control rats, rats with chronic cerebral hypoperfusion, and rats with chronic cerebral hypoperfusion that was administered Scutellaria baicalensis. In the second experiment, hippocampal microglial activation was induced by chronic infusions of LPS into the fourth ventricle of Fisher-344 rat brains. Daily administration of Scutellaria baicalensis extracts was started on 7 day after the surgery of LPS infusion and given for 32 days. Spatial memory and hippocampal microglial activation was then examined in control rats with an artificial cerebrospinal fluid infusion, rats with chronic LPS infusion, and rats with chronic LPS infusion that were administered Scutellaria baicalensis.

Results

Rats that received chronic cerebral hypoperfusion or chronic LPS infusion showed spatial memory impairments relative to their control rats; however, these symptoms were reduced by daily administration of Scutellaria baicalensis. Administration of Scutellaria baicalensis mitigated alterations of hippocampal MAPK signaling by chronic cerebral infusion and microglial activation by chronic LPS infusion.

Conclusions

These results indicate that Scutellaria baicalensis may possess therapeutic potential for the prevention of Alzheimer's disease and vascular dementia.     

Memory improvement in ibotenic acid induced model rats by extracts of Scutellaria baicalensis

Ethnopharmacological relevance

Scutellaria baicalensis Georgi (Labiatae) extracts have been used as traditional Korean medicine, to treat cerebral ischemia in addition to bacterial infection and inflammatory diseases.

Aim of the study

The improvement effect on learning and memory by the administration of Scutellaria baicalensis extracts was evaluated and the underlying mechanisms were investigated.

Materials and methods

Memory behavior was tested by the passive avoidance test and Y-maze test. We also investigated the cells expressing neuronal markers related to memory processes by immunofluorescence staining analysis in memory deficient animal model (Ibo model) rats and in hippocampal progenitor cells.

Results

We found neuronal cells immunoreactive to choline acetyltransferase (ChAT), a marker for cholinergic neurons were increased in the hippocampus, while cells producing GABA and glutamate were not after 30 mg/kg Scutellaria baicalensis administration. Futhermore, Scutellaria baicalensis extracts enhanced the survival of a hippocampal progenitor cell line, HiB5 and its differentiation to ChAT immunoreactive cells. The increased expression of memory related neurotransmitter, NMDA receptor and a reduction of activated microglia in the hippocampus were also observed in the Ibo model when administrated Scutellaria baicalensis extracts.

Conclusions

These results imply that Scutellaria baicalensis has significant neuroprotective effects in the Ibo model.     

Toona sinensis (leaf extracts) inhibit vascular endothelial growth factor (VEGF)-induced angiogenesis in vascular endothelial cells

Aim of the study

Toona sinensis is well known as a traditional Chinese medicine; also, it has been shown to exhibit anticancer and anti-inflammatory effects. This study was aimed at evaluating the anti-angiogenesis effect of the aqueous extracts of Toona sinensis (TS extracts) or gallic acid, a major component of TS extracts, against both VEGF-induced EA.hy 926 and human umbilical vein endothelial cells (HUVECs).

Materials and methods

Anti-proliferative activity of TS extracts or gallic acid, was determined against EA.hy 926 and HUVECs by trypan blue exclusion method. Invasion, tube formation and chick chorioallantoic membrane assay were carried out to determine the in vitro and in vivo anti-angiogenic effects.

Results

Non-cytotoxic concentration of TS extracts (50-100 μg/mL) and gallic acid (5 μg/mL) inhibited the proliferation of VEGF-stimulated EA.hy 926 and HUVECs. Inhibitory effects of TS extracts and gallic acid on angiogenesis were assessed by VEGF-induced migration/invasion and capillary-like tube formation by EA.hy 926 and HUVECs. Additionally, gelatin zymography assays showed that TS extracts and gallic acid suppressed the activity of metalloproteinase (MMP)-9 and MMP-2 activated by VEGF. In vivo, TS extracts and gallic acid strongly suppressed neovessel formation in the chorioallantoic membrane of chick embryos. Flow cytometry analyses and Western blot demonstrated that treatment with TS extracts and gallic acid induced G₀/G₁ arrest in VEGF-stimulated EA.hy 926 cells via a reduction in the amounts of cyclin D1, cyclin E, CDK4, hyperphosphorylated retinoblastoma protein (pRb), VEGFR-2, and eNOS.

Conclusions

These results support an anti-angiogenic activity of Toona sinensis that may contribute critically to its cancer and inflammation chemopreventive potentials.     

Baicalein, isolated from Scutellaria baicalensis, protects against endothelin-1-induced pulmonary artery smooth muscle cell proliferation via inhibition of TRPC1 channel expression

Ethnopharmacological relevance

We investigated the antiproliferative effects of baicalein, isolated from Scutellaria baicalensis (Huang-qin), on ET-1-mediated pulmonary artery smooth muscle cells (PASMCs) proliferation and the mechanisms underlying these effects.

Materials and methods

Intrapulmonary artery smooth muscle cells were isolated and cultured from female Sprague-Dawley rats and used during passages 3-6. The proliferation of PASMCs was quantified by cell counting and XTT assay. The protein expression of TRPC1 and PKCα were determined by western blotting. The cell cycle pattern was assayed by flow cytometry. The intracellular calcium concentrations ([Ca²⁺]_i) were measured using the fluorescent indicator fura-2-AM and flow cytometry.

Results

Baicalein (0.3-3 μM) inhibited PASMCs proliferation, promoted cell cycle progression, enhanced [Ca²⁺]_i levels, increased capacitative Ca²⁺ entry (CCE), upregulated the canonical transient receptor potential 1 (TRPC1) channel and membrane protein kinase Cα (PKCα) expression induced by ET-1 (0.1 μM). The PKC activator PMA (1 μM) reversed the inhibitory effects of baicalein on ET-1-induced upregulation of TRPC1 expression and S phase accumulation, while the PKC inhibitor chelerythrine (1 μM) potentiated baicalein-mediated G₂/M phase arrest and TRPC1 channel inhibition.

Conclusion

Our findings suggest that baicalein protects against ET-1-induced PASMCs proliferation via modulation of the PKC-mediated TRPC channel.     

HY253, a novel decahydrofluorene analog,from Aralia continentalis, induces cell cycle arrest at the G1 phase and cytochrome c-mediated apoptosis in human lung cancer A549 cells

Aim of the study

In the course of our screening for novel modulators on cell cycle progression and apoptosis as anticancer drug candidates, we isolated a novel compound HY253 with the molecular structure of 7,8a-divinyl-2,4a,4b,5,6,7,8,8a,9,9a-decahydro-1H-fluorene-2,4a,4b,9a-tetraol from the roots of Aralia continentalis. This study was designed to evaluate the detailed mechanisms of cell cycle arrest and the apoptotic induction of HY253 in human lung cancer A549 cells.

Materials and methods

To investigate the effects of HY253 on cell cycle progression in A549 cells, we measured DNA content of A549 cells treated with 35 μM of HY253 using flow cytometric analysis. Furthermore, TUNEL assay was used to examine apoptotic induction in A549 cells treated with 70 μM of HY253 for 24 and 48 h. The effects of HY253 on apoptosis-associated and cell cycle regulatory proteins in A549 cells were examined using Western blot analysis.

Results

The flow cytometric analysis revealed an appreciable G₁ phase arrest in A549 cells treated with 35 μM of HY253. This HY253-induced G₁ phase arrest is associated with decreased expression of cyclin D and up-regulation of p21^CIP1, via p53 phosphorylation at Ser-15, which resulted in increased hypophosphorylated pRb in A549 cells. Furthermore, TUNEL assay and Western blot analysis revealed an appreciable apoptotic induction in A549 cells treated with 70 μM of HY253 for 48 h. This apoptotic induction in HY253-treated A549 cells is also associated with cytochrome c release from mitochondria which in turn resulted in the activation of caspase-9 and -3, and the cleavage of poly(ADP-ribose) polymerase (PARP).

Conclusions

These results demonstrate that HY253, a novel antiproliferative compound isolated from the roots of Aralia continentalis, induces cell cycle arrest at the G₁ phase and apoptosis in A549 cells. Based on these results, we suggest that HY253 may be a potent cancer chemotherapeutic candidate for use in treating human lung cancer cells via up-regulation and activation of p53 gene.     

Exploring Tagetes erecta Linn flower for the elastase, hyaluronidase and MMP-1 inhibitory activity

Ethnopharmacological relevance

Traditionally Tagetes erecta Linn flower is claimed to treat skin diseases like sores, burns, wounds, ulcers, eczema and several other skin ailments. The aim of the present experiment was to evaluate the anti-wrinkle potential of standardized flower extract of Tagetes erecta.

Materials and methods

The Tagetes erecta extract and fractions were screened for hyaluronidase, elastase and matrix metalloproteinase (MMP-1) inhibitory activity compared with the activity of standard oleanolic acid. Syringic acid and β-amyrin were obtained from the extract and quantified through RP-HPLC. Also the compounds were evaluated for anti-wrinkle activity.

Results

The methanol extract showed significant (^aP < 0.05) hyaluronidase and elastase inhibition with IC50 of 11.70 ± 1.79 μg mL⁻¹ and 4.13 ± 0.93 μg mL⁻¹ respectively and better MMP-1 inhibition compared to standard oleanolic acid. The isolated compounds syringic acid and β-amyrin found to inhibit enzymes comparable to oleanolic acid. The RP-HPLC analysis revealed that good amounts of syringic acid and β-amyrin (2.30%, w/w and 0.06%) are present in Tagetes erecta.

Conclusion

Tagetes erecta flower showed effective inhibition of hyaluronidase, elastase and MMP-1. Therefore, this experiment further rationalizes the traditional uses of this plant, which may be useful as an anti-wrinkle agent.     

Simulated gastrointestinal tract metabolism and pharmacological activities of water extract of Scutellaria baicalensis roots

Ethnopharmacological relevance

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Scutellaria baicalensis

Georgi (Labiatae) is a well-known traditional Chinese medicine to treat inflammation, cardiovascular diseases, respiratory and gastrointestinal infections, etc. The present study was to understand the metabolism of the root of Scutellaria baicalensis (a.k.a. Huangqin in Chinese) in the gastrointestinal tract and the correlation between the metabolites and their respective pharmacological activities.

Materials and methods

The water extract of the root of Scutellaria baicalensis (WESB) was incubated with simulated gastric and intestinal juices, and human fecal microflora for 24 h at 37 °C. The HPLC–DAD analysis was used to monitor the in vitro metabolic process and identify its metabolites by comparing their absorption spectrum and retention time with those of chemical references. The in vitro anticomplementary and antimicrobial activity was evaluated with hemolysis assay, agar disc-diffusion method and MIC value, respectively.

Results

Main constituents of WESB remain unchanged during the incubation with simulated gastric juice (pH=1.5) and intestinal juice (pH=6.8), whereas four flavones, baicalin, wogonoside, oroxyloside and norwogonoside were metabolized into their respective aglycons by human intestinal bacteria. All four metabolites were demonstrated to have higher anticomplementary and antimicrobial activity than those of WESB. The anticomplementary active metabolites were identified to be baicalein, oroxylin A and norwogonin, among them, norwogonin is the most active compound.

Conclusion

The presence of intestinal bacteria is demonstrated to play an important role in the gastrointestinal metabolism of WESB, and the pharmacological effects of Scutellaria baicalensis may be dependent on the intestinal bacteria metabolism.     

Paeonia lactiflora Pall inhibits bladder cancer growth involving phosphorylation of Chk2 in vitro and in vivo

Ethnopharmacological relevance

Extracts of Paeonia lactiflora Pall (RPA), a traditional Chinese medicines has been shown to treat cancers.

Aim of the study

The purpose of this study is to evaluate the anticancer effect of RPA in urinary bladder carcinoma in vitro and in vivo.

Materials and methods

The cell viability was analyzed with DAPI. Flow cytometry and Western blot were used to study the apoptosis and cell cycle related mechanism. A rat model of bladder cancer was induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (OH-BBN). Tumors were analyzed with immunohistochemical analysis.

Results

Our data suggested that RPA inhibits growth of bladder cancer via induction of apoptosis and cell cycle arrest. Treatment of TSGH-8301 cells with RPA resulted in G2-M phase arrest that was associated with a marked decline in protein levels of cdc2, cyclin B1, cell division cycle 25B (Cdc25B) and Cdc25 C. We also reported that RPA-mediated growth inhibition of TSGH-8301 cells was correlated with activation of checkpoint kinase 2 (Chk2). Herein, we further evaluated urinary bladder cancer using a model of bladder cancer induced by OH-BBN. Analysis of tumors from RPA-treated rats showed significant decrease in the expression of Bcl2, cyclin D1, and PCNA, and increase in the expression of p-Chk2 (Thr-68), Bax, and Cip1/p21.

Conclusion

Our data provide the experimental evidence that RPA could modulate apoptosis in models of bladder cancer.     

Inhibition effect of Gynura procumbens extract on UV-B-induced matrix-metalloproteinase expression in human dermal fibroblasts

Ethnopharmacological relevance

Gynura procumbens Merr. (Asteraceae) has been used as a traditional remedy for various skin diseases in certain areas of Southeast Asia.

Aim of the study

In order to evaluate the protective activity of Gynura procumbens extract on skin photoaging and elucidate its mode of action.

Materials and methods

Matrix-metalloproteinase (MMP)-1 and -9 expressions were induced by UV-B irradiation in human primary dermal fibroblasts. MMP-1 expression level was measured by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Zymography was employed for evaluating the enzymatic activity of MMP-9. Anti-inflammatory activity and anti-oxidative capacity of the extract were evaluated by ELISA and dichlorodihydrofluorescein diacetate (DCF-DA) assay.

Results

The ethanolic extract of Gynura procumbens inhibited MMP-1 expression up to 70% compare to negative control group. The enzymatic activity of MMP-9 was inhibited around 73% by the treatment of 20 μg/mL of the extract. The extract markedly reduced the production of reactive oxygen species (ROS). Gynura procumbens extract showed an inhibitory effect on releasing pro-inflammatory cytokines (IL-6 and IL-8) in human HaCat keratinocyte.

Conclusion

The ethanolic extract of Gynura procumbens inhibited MMP-1 and MMP-9 expressions induced by UV-B irradiation via inhibition of pro-inflammatory cytokine mediator release and ROS production.     

(2S)-naringenin from Typha angustata inhibits vascular smooth muscle cell proliferation via a G0/G1 arrest

Ethnopharmacological relevance

Typha angustata is used in traditional Chinese medicine for a variety of clinical disorders. Its pharmacological actions include beneficial effects on hyperlipidemia and myocardial infarction, as well as labor-inducing and antibacterial effects.

Aim of the study

We investigated the mechanism underlying the ability of (2S)-naringenin, an active compound from Typha angustata, to inhibit the proliferation of vascular smooth muscle cells (VSMCs).

Materials and methods

After measuring the antiproliferative effect of (2S)-naringenin on VSMC proliferation using cell proliferation and viability assays, the possible involvement of a signaling pathway associated with platelet-derived growth factor receptor β (PDGF-Rβ), extracellular signal regulated kinase 1/2 (ERK1/2), phosphatidylinositol 3-kinase (PI3K)-linked protein kinase B (Akt/PKB), or phospholipase C-γ1 (PLCγ1) was investigated by immunoblotting. Moreover, the effect of (2S)-naringenin on DNA synthesis and the cell cycle was examined using a [³H]-thymidine incorporation assay and flow cytometry.

Results

(2S)-Naringenin significantly inhibited PDGF-BB-induced VSMC proliferation in a concentration-dependent manner, but did not affect signaling pathways associated with PDGF-Rβ, Akt/PKB, ERK1/2, or PLCγ1. However, (2S)-naringenin suppressed DNA synthesis via a G₀/G₁ cell cycle arrest. Accordingly, the expression of cyclins D1 and E and cyclin-dependent kinases 2 and 4 was inhibited in a concentration-dependent manner; moreover, the phosphorylation of retinoblastoma protein was suppressed.

Conclusions

Our results show that (2S)-naringenin inhibited the PDGF-BB-induced proliferation of VSMCs via a G₀/G₁ arrest; thus, (2S)-naringenin may be valuable as a therapeutic agent for managing atherosclerosis and/or vascular restenosis.     

Effect of Emblica officinalis (fruit) against UVB-induced photo-aging in human skin fibroblasts

Ethnopharmacological relevance

Emblica officinalis fruit (EO), commonly known as Amla is a reputed traditional medicine and functional food used in Indian subcontinent. It has long been used in Indian folk medicine to treat liver diseases, stomach ulcers, inflammatory diseases, metabolic disorders, geriatric complaints, skin disorders and beauty care.

Aim of the study

Recently, it has been shown to promote pro-collagen content and inhibit matrix metalloproteinase levels in skin fibroblast. The aim of the present study was to investigate the efficacy of EO to inhibit UVB-induced photo-aging in human skin fibroblasts.

Materials and methods

Mitochondrial activity of human skin fibroblasts was measured by MTT-assay. Quantifications of pro-collagen 1 and matrix metalloproteinase 1 (MMP-1) release were performed by immunoassay techniques. Hyaluronidase inhibition assay was studied in vitro using bovine testicular hyaluronidase and human umbilical cord hyaluronic acid. Cell cycle analysis was performed by flowcytometry using propidium iodide.

Results

EO stimulated, the otherwise UVB inhibited cellular proliferation and protected pro-collagen 1 against UVB-induced depletion via inhibition of UVB-induced MMP-1 in skin fibroblasts (10-40 μg/mL, p > 0.001). EO exhibited inhibitory activity of hyaluronidase (10-40 μg/mL, p > 0.001). Treatment with EO also prevented UVB disturbed cell cycle to normal phase.

Conclusion

The results of the present study suggests that EO effectively inhibits UVB-induced photo-aging in human skin fibroblast via its strong ROS scavenging ability and its therapeutic and cosmetic applications remain to be explored.     

Synergistic effects of baicalein with ciprofloxacin against NorA over-expressed methicillin-resistant Staphylococcus aureus (MRSA) and inhibition of MRSA pyruvate kinase

Ethnopharmacological relevance

Baicalein, the active constituent derived from Scutellaria baicalensis Georgi., has previously been shown to significantly restore the effectiveness of β-lactam antibiotics and tetracycline against methicillin-resistant Staphylococcus aureus (MRSA). With multiple therapeutic benefits, the antibacterial actions of baicalein may also be involved in overcoming other bacterial resistance mechanisms. The aim of the present study was to further investigate antibacterial activities of baicalein in association with various antibiotics against selected Staphylococcus aureus strains with known specific drug resistance mechanisms.

Material and methods

A panel of clinical MRSA strains was used for further confirmation of the antibacterial activities of baicalein. The effect of baicalein on inhibiting the enzymatic activity of a newly discovered MRSA-specific pyruvate kinase (PK), which is essential for Staphylococcus aureus growth and survival was also examined.

Results

In the checkerboard dilution test and time-kill assay, baicalein at 16 μg/ml could synergistically restore the antibacterial actions of ciprofloxacin against the NorA efflux pump overexpressed SA-1199B, but not with the poor NorA substrate, pefloxacin. Moreover, synergistic effects were observed when baicalein was combined with ciprofloxacin against 12 out of 20 clinical ciprofloxacin resistant strains. For MRSA PK studies, baicalein alone could inhibit the enzymatic activity of MRSA PK in a dose-dependent manner.

Conclusion

Our results demonstrated that baicalein could significantly reverse the ciprofloxacin resistance of MRSA possibly by inhibiting the NorA efflux pump in vitro. The inhibition of MRSA PK by baicalein could lead to a deficiency of ATP which might further contribute to the antibacterial actions of baicalein against MRSA.     

Cytotoxic and genotoxic effects of defence secretion of Ulomoides dermestoides on A549 cells

Ethnopharmacological relevance

Ulomoides dermestoides (Fairmaire, 1893) is a cosmopolitan tenebrionid beetle reared by Argentine people who consume them alive as an alternative medicine in the treatment of different illnesses such as asthma, Parkinson's, diabetes, arthritis, HIV and specially cancer.

Aim of the study

To evaluate the cytotoxicity and DNA damage of the major volatile components released by Ulomoides dermestoides on human lung carcinoma epithelial cell line A549.

Materials and methods

The defence compounds of Ulomoides dermestoides were extracted with dichloromethane and analyzed and quantified by capillary gas chromatography. The toxicity effects of the beetle's extract against A549 cell line were evaluated. Cytotoxicity was evaluated by MTT test and Trypan blue assay and genotoxicity was evaluated by the comet assay. The synthetic compounds, individually or combined, were also tested in A549 cells and normal mononuclear human cells.

Results

The defence compounds of Ulomoides dermestoides extracted with dichloromethane (methyl-1,4-benzoquinones, ethyl-1,4-benzoquinones and 1-pentadecene as major components) showed cytotoxic activity on A549 cells demonstrated by MTT test and Trypan blue assay, with IC₅₀ values of 0.26 equivalent/ml and 0.34 equivalent/ml, respectively (1 equivalent = amount of components extracted per beetle). The inhibition of A549 cell proliferation with the synthetic blend (1,4-benzoquinone and 1-pentadecene) or 1,4-benzoquinone alone was similar to that obtained with the insect extract. 1-Pentadecene showed no inhibitory effect. Low doses of insect extract or synthetic blend (0.15 equivalent/ml) inhibited mononuclear cell proliferation by 72.2 ± 2.7% and induced significant DNA damage both in tumor and mononuclear cells.

Conclusion

Results of this study demonstrated that defence compounds of Ulomoides dermestoides reduced cell viability and induced DNA damage. We also concluded that the insect benzoquinones are primarily responsible for inducing cytotoxicity and genotoxicity in culture cells.     

Acalypha wilkesiana extracts induce apoptosis by causing single strand and double strand DNA breaks

Ethnopharmacological relevance

The seeds of Acalypha wilkesiana have been used empirically by traditional healers in Southwest Nigeria together with other plants as a powder mixture to treat patients with breast tumours and inflammation.

Aim of the study

There is an increasing interest among researchers in searching for new anticancer drugs from natural resources, particularly plants. This study aimed to investigate the anticancer properties of Acalypha wilkesiana extracts and the characteristics of DNA damage against brain and lung cancer cells.

Materials and methods

The antiproliferative activity of Acalypha wilkesiana extracts (ethyl acetate, hexane, and ethanol) was examined on human glioma (U87MG), human lung carcinoma (A549), and human lung fibroblast (MRC5) cells.

Results

Cell viability MTT assay revealed that ethyl acetate extract of the plant possessed significant antiproliferative effects against both U87MG (GI₅₀ = 28.03 ± 6.44 μg/ml) and A549 (GI₅₀ = 89.63 ± 2.12 μg/ml) cells (p value < 0.0001). The hexane extract was found to exhibit crucial antiproliferative effects on U87MG (GI₅₀ = 166.30 ± 30.50 μg/ml) (p value < 0.0001) but not on A549 cells. Neither plant extract possessed noticeable antiproliferative effects on the non-cancerous MRC5 cells (GI₅₀ > 300 μg/ml). The ethanol extract showed no antiproliferative effects on any cell line examined. Haematoxylin &; Eosin (H &; E) staining and single cell gel electrophoresis (SCGE) comet assay confirmed that plant extract-treated cells underwent apoptosis and not necrosis. SCGE comet assays confirmed that plant extracts caused both single strand (SSB) and double strand (DSB) DNA breaks that led to the execution of apoptosis.

Conclusion

The extracts (especially ethyl acetate and hexane) of Acalypha wilkesiana possess valuable cytotoxic effects that trigger apoptosis in U87MG and A549 cancer cells through induction of DNA SSBs and DSBs.