Anti-angiogenic activity of methanol extract of Phellinus linteus and its fractions

Aim of the study

The aim of the present study was to investigate the effects of MeOH extract of PL (PLME) and its fractions on angiogenesis.

Materials and methods

PLME and its subsequent fractions (methylene chloride, ethyl acetate, n-butanol and aqueous fractions) were evaluated in vitro. Specifically, the anti-angiogenic activities of PLME and its fractions were investigated by measuring their effects on the proliferation, migration, tube formation and phosphorylation of vascular endothelial growth factor receptor (VEGFR)-2 in human umbilical vein endothelial cells (HUVECs). In addition, the in vivo Matrigel plug model was applied to evaluate new vessel formation.

Results

The results revealed that PLME and its subsequent fractions, except for the aqueous fraction, led to significant inhibition of the proliferation, migration, tube formation and VEGFR-2 phosphorylation of HUVECs as well as in vivo angiogenesis.

Conclusions

These findings indicate the potential for the use of PLME in pathological situations involving stimulated angiogenesis, such as inflammation and tumor development.     

Gender-dependent pharmacokinetics of lignans in rats after single and multiple oral administration of Schisandra chinensis extract

Ethnopharmacological relevance

Schisandra chinensis (S. chinensis), a traditional Chinese medicine, has been widely used as sedatives and tonics in clinic. Schisandra lignans are believed to be the major bioactive components in S. chinensis. However, there is a lack of information about the effects of gender and repeated-dose on the pharmacokinetic properties of the schisandra lignans.

Aim of the study

The study was performed to investigate the influence of gender on the pharmacokinetics of schisandra lignans after administration of S. chinensis extract and to compare their pharmacokinetic behaviors between single and multiple administration.

Materials and methods

Two groups of rats (half male and half female) were received a single dose or multiple doses of S. chinensis extract, respectively. A liquid chromatography–tandem mass spectrometry method was developed and validated to determine the plasma concentrations of schisandra lignans.

Results

The pharmacokinetic parameters of schisandrin, schisandrol B, deoxyschisandrin, γ-schisandrin and schisantherin A were significantly different by gender difference. The t_1/2 of all the tested schisandra lignans in female rats were 2–9 times longer than the corresponding values in male rats. The C_max and AUC_0−t of these schisandra lignans except schisantherin A in female rats were 5–50 times higher than those in male rats. The pharmacokinetic profiles of schisandrin, schisandrol B, deoxyschisandrin and schisantherin A in both gender rats after multiple doses were similar to the corresponding profile after single dose.

Conclusion

All the tested schisandra lignans showed slower elimination and higher bioavailability in female rats after single or multiple administration of S. chinensis extract compared with male rats. Their pharmacokinetic profiles were not affected by repeated-dose except γ-schisandrin, which was eliminated more slowly in female rats after multiple administration.     

The protective effects of total saponins from Ornithogalum saundersiae (Liliaceae) on acute hepatic failure induced by lipopolysaccharide and d-galactosamine in mice

Ethnopharmacological relevance

This study examined the protective effects of total saponins from Ornithogalum saundersiae (Liliaceae) on d-galactosamine (d-GalN) and lipopolysaccharide (LPS) - induced fulminant hepatic failure.

Materials and methods

Total saponins of Ornithogalum saundersiae (Liliaceae) (OC) were prepared with ethyl alcohol extract from bulbs of the plant. Mice were given an intraperitoneal injection of d-GalN (700 mg/kg)/LPS (10 μg/kg). OC (100 mg/kg, 200 mg/kg and 300 mg/kg) was administered orally for 3 days continuously, and at the last day at 1 h before the d-GalN/LPS injection. Mice were sacrificed at 8 h after the d-GalN/LPS injection. The liver injury was assessed biochemically, investigating aspartate aminotransferase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA), glutathione (GSH) activities, and the expressions of caspase-3 and hypoxia inducible factor-1α (HIF-1α) as well. Tumor necrosis factor (TNF-α) content was measured after d-GalN/LPS induced 1 h by ELISA assay. The survival rates after application of OC in 24 h also were observed.

Results

d-GalN/LPS increased the serum aminotransferase levels and lipid peroxidation, while decreased the reduced glutathione level. The pretreatment with OC attenuated these changes in a dose-dependent manner. Elevation of TNF-α level and activation of caspase-3, HIF-1α were observed in the d-GalN/LPS group, which was attenuated by OC. The survival rate of the OC groups was significantly higher than that of the d-GalN/LPS group.

Conclusions

Protection afforded by OC against d-GalN/LPS-induced fulminant hepatic failure is the result of reduced oxidative stress, inhibited expression of caspase-3, HIF-1α, and anti-apoptotic activity.     

Sedative, hypnotic and anticonvulsant activities of the ethanol fraction from Rhizoma Pinelliae Praeparatum

Ethnopharmacological relevance

Rhizoma Pinelliae Praeparatum is the product of raw Rhizoma Pinellia processed with alkaline solution and Licorice, which had been widely used for treatment of insomnia in traditional Chinese medicine. The present study aimed to investigate the sedative, hypnotic and anticonvulsant activities of ethanol fraction from Rhizoma Pinelliae Praeparatum (EFRP) and to determine whether these effects were related to GABAergic mechanism.

Materials and methods

The sedative, hypnotic and anticonvulsant activities of EFRP were investigated with locomotion activity, pentobarbital-induced sleeping and nikethamide (NKTM)-induced convulsion tests, respectively. Additionally, the effects of flumazenil (an antagonist of GABA_A receptor) and l-malic acid (blocker of synthetic enzyme for GABA) on the hypnotic activity of EFRP were evaluated.

Results

EFRP at dose of 12 g/kg significantly inhibited the locomotion activity of mice. EFRP showed synergic effect on pentobarbital-induced sleeping by increased numbers of mice falling asleep, reduced the sleep latency and prolonged the sleeping time. l-malic acid and flumazenil inhibited the augment effects of EFRP on pentobarbital-induced sleeping. EFRP promoted a significant protection to NKTM-induced convulsion, by prolonged the death latency and decreased mortality.

Conclusion

EFRP possessed sedative, hypnotic and anticonvulsant activities and these activities may be related to the GABAergic system.     

Effects of lignans extracted from Eucommia ulmoides and aldose reductase inhibitor epalrestat on hypertensive vascular remodeling

Aim of the study

To investigate the effects of lignans extracted from Eucommia ulmoides and epalrestat on vascular remodeling in spontaneously hypertensive rats.

Materials and methods

Ten-week-old male spontaneously hypertensive rats were randomly divided into 3 groups (12 rats each group), and treated orally with 100 mg/kg/d of captopril (an angiotensin-converting enzyme inhibitor), 100 mg/kg/d of epalrestat (an aldose reductase inhibitor) and 300 mg/kg/d of lignans by gavage daily for 16 weeks, respectively. Sex-, age-, and number-matched spontaneously hypertensive rats and normotensive Wistar Kyoto rats, were treated with distilled water (vehicle) as controls. The rats were weighed weekly. Mean arterial blood pressure and heart rate were measured periodically by non-invasive blood pressure monitoring. They were sacrificed at the end of experiment (26-week-old). Superior mesenteric artery and aorta were isolated for determination of histomorphometry and the expression of aldose reductase by immunohistochemistry.

Results

Captopril and lignans, but not epalrestat, decreased mean arterial blood pressure in spontaneously hypertensive rats. Vascular remodeling was improved in all three treated groups by histomorphometry.

Conclusions

Both lignans and epalrestat reversed hypertensive vascular remodeling. Aldose reductase played a vital role in the pathologic process of hypertensive vascular remodeling rather than elevation of blood pressure. These data suggested that aldose reductase could be a new therapeutic target for the treatment of cardiovascular diseases.     

Protective effects of Eucommia lignans against hypertensive renal injury by inhibiting expression of aldose reductase

Aim of the study

To investigate the protective effects and the underlying mechanism of Eucommia lignans against hypertensive renal injury.

Material and methods

Ten-week-old Wistar Kyoto rats and age matched spontaneously hypertension rats were used in the study. The SHR were randomly divided into 4 groups (n = 7 for each group) and received different treatment for 16 weeks, which including saline, Captopril, Epalrestat and Eucommia lignans, respectively. System blood pressures of the rats were monitored once every 4 weeks. N-Acetyl-β-d-glucosaminidase (NAG) activity and the ratio of albumin and urinary creatinine were chosen as the indices of kidney function. Then the structure and renal collagen type III expression of glomerular basement membrane were observed by microscopy and the renal aldose reductase (AR) expression was measured by immunohistochemistry. In vitro, the proliferation of mesangial cells induced by AngII was assayed by MTT, and the mRNA expression of AR was measured by RT-real-time PCR.

Results

The renal function, evaluated by NAG enzyme activity and the ratio of albumin to urinary creatinine, was significantly ameliorated by Eucommia lignans treatment. Meanwhile, Eucommia lignans decreased both the protein (P < 0.05) and the mRNA expressed lever of AR (P < 0.05). Eucommia lignans also decreased the high expression of collagen type III in SHR (P < 0.05) and inhibited the proliferation of renal mesangial cells induced by AngII (P < 0.05).

Conclusion

Eucommia lignans have protective effects against hypertensive renal injury, and the protective effects may be partly due to inhibition of aldose reductase.     

Permeability of rosmarinic acid in Prunella vulgaris and ursolic acid in Salvia officinalis extracts across Caco-2 cell monolayers

Ethnopharmacological relevance

Rosmarinic acid (RA), a caffeic acid-related compound found in high concentrations in Prunella vulgaris (self-heal), and ursolic acid (UA), a pentacyclic triterpene acid concentrated in Salvia officinalis (sage), have been traditionally used to treat inflammation in the mouth, and may also be beneficial for gastrointestinal health in general.

Aim of the study

To investigate the permeabilities of RA and UA as pure compounds and in Prunella vulgaris and Salvia officinalis ethanol extracts across human intestinal epithelial Caco-2 cell monolayers.

Materials and methods

The permeabilities and phase II biotransformation of RA and UA as pure compounds and in herbal extracts were compared using Caco-2 cells with HPLC detection.

Results

The apparent permeability coefficient (P_app) for RA and RA in Prunella vulgaris extracts was 0.2 ± 0.05 × 10⁻⁶ cm/s, significantly increased to 0.9 ± 0.2 × 10⁻⁶ cm/s after β-glucuronidase/sulfatase treatment. P_app for UA and UA in Salvia officinalis extract was 2.7 ± 0.3 × 10⁻⁶ cm/s and 2.3 ± 0.5 × 10⁻⁶ cm/s before and after β-glucuronidase/sulfatase treatment, respectively. Neither compound was affected in permeability by the herbal extract matrix.

Conclusion

RA and UA in herbal extracts had similar uptake as that found using the pure compounds, which may simplify the prediction of compound efficacy, but the apparent lack of intestinal glucuronidation/sulfation of UA is likely to further enhance the bioavailability of that compound compared with RA.     

Panax notoginseng saponins inhibit Zymosan A induced atherosclerosis by suppressing integrin expression, FAK activation and NF-κB translocation

Ethnopharmacological significance

Panax notoginseng saponins (PNS) are ingredients extracted from traditional Chinese medicinal herb Panax notoginseng. It has been demonstrated that PNS have extensive effects on the cardiovascular system, including inhibition of platelet aggregation, increasing blood flow, improving left ventricular diastolic function in hypertensive patients and anti-inflammatory effect.

Aim of study

Recent researches indicated that PNS administration inhibited foam cells’ formation. The present study was designed to study the effects of PNS on atherogenesis and to explore the relevant molecular mechanisms.

Materials and methods

The Zymosan A induced atherosclerosis models were used to investigate the anti-atherosclerosis effects of PNS. The integrin express array was used to check the changes of integrins. The foam cell formation was observed with transmission electron microscope. The effect of PNS on phosphorylation of FAK on threonine 397 and protein level of NF-κB was also evaluated in vitro.

Results

PNS treated rats had less plaque spots on the aortas compared with Zym induced group. The formation of foam cell was inhibited by PNS. Compared with Zym treated group, the expression of most integrin families decreased except Itgav and Itgb2 after PNS treatment. PNS inhibited phosphorylation of FAK on threonine 397 and translocation of NF-κB.

Conclusion

High fat diet together with Zym induces atherogenesis of rat. PNS inhibits zymosan A induced atherogenesis by suppressing FAK phosphorylation, integrins expression and NF-κB translocation.     

Influences of Fructus evodiae pretreatment on the pharmacokinetics of Rhizoma coptidis alkaloids

Ethnopharmacological relevance

Rhizoma coptidis is a traditional Chinese medicine with pharmacological properties. It is usually prescribed with Fructus evodiae as traditional Chinese medicine (TCM) formulas. Here we report the influences of Fructus evodiae on the pharmacokinetics of the Rhizoma coptidis alkaloids and propose possible mechanisms.

Materials and methods

Pharmacokinetic experiments were performed in rats. In vitro absorption experiments were performed in everted rat gut sacs, while in vitro metabolism experiments and determination of hepatic UDP-glucuronosyltransferase (UGT) 1A1 mRNA expression were performed in rat liver microsomes.

Results

Pretreatment with Fructus evodiae extract for two weeks decreased the systemic exposure of the Rhizoma coptidis alkaloids. This effect was not due to inhibition of absorption or enhanced hepatic phase I metabolism of the Rhizoma coptidis alkaloids. However, Fructus evodiae pretreatment enhanced both the activity and expression of hepatic UGT1A1.

Conclusions

The results showed that Fructus evodiae pretreatment decreased the systemic exposure of the Rhizoma coptidis alkaloids by inducing hepatic UGT1A1.     

Acute and subacute toxicity of ethanol extracts from Salvia przewalskii Maxim in rodents

Aim

The present investigation was carried out to evaluate the safety of the lipid-soluble ethanol extracts from rhizome of Salvia przewalskii Maxim (SPM) by determining its potential toxicity after acute and subacute administration in rodents.

Materials and methods

For the acute study, SPM extract was administered to mice in single doses given by gavage, intramuscular and intraperitoneal route. General behavior adverse effects and mortality were determined for up to 14 days. In the subacute study, the extract was administered orally at doses of 0, 50 and 250 mg/kg daily for 30 days to rats. Body weight, heart rate, blood pressure, biochemical and hematological parameters were determined at the end of 0, 15 and 30 days of daily administration.

Results

In acute study, SPM extract caused dose-dependent general behavior adverse effects and mortality. The no-observed adverse effect levels (NOAEL) of the extract were 1723, 288 and 500 mg/kg, when given by gavage, intramuscular and intraperitoneal routes, respectively, and the lowest-observed adverse effect levels (LOAEL) were 1981, 840 and 781 mg/kg. Mortality increased with increasing doses, with LD₅₀ of 2547.8, 901.3 and 780.8 mg/kg for the oral, intramuscular and intraperitonal administration. In subacute study, daily oral administration of SPM extract for up to 30 days did not result in death or significant changes in the body weight, heart rate and blood pressure, hematological and mainly biological parameters. In biological analysis, some significant changes occurred, including total protein and albumin, glucose and triglycerides, indicating that SPM extract has lipid-modulating activity.

Conclusions

SPM extract was found to be low or non-toxic when acute toxicities and subacute toxicities in rodents. In view of the doses of the components consumed in traditional medicine, there is a wide margin of safety for the therapeutic use.     

Effects of Curcuma comosa on the expression of atherosclerosis-related cytokine genes in rabbits fed a high-cholesterol diet

Aim of the study

Curcuma comosa has been known to have potential use in cardiovascular diseases, but its immunoregulatory role in atherosclerosis development and liver toxicity has not been well studied. We therefore investigated the effects of Curcuma comosa on the expression of atherosclerosis-related cytokine genes in rabbits fed a high-cholesterol diet.

Materials and methods

Twelve male New Zealand White rabbits were treated with 1.0% cholesterol for one month and were subsequently treated with 0.5% cholesterol either alone, or in combination with 5 mg/kg/day of simvastatin or with 400 mg/kg/day of Curcuma comosa powder for three months. The expression of IL-1, MCP-1, TNF-α, IL-10, and TGF-β in the isolated abdominal aorta and liver were determined by real-time RT-PCR. Liver toxicity was determined by hepatic enzyme activity.

Results

Curcuma comosa significantly decreased the expression of pro-inflammatory cytokines, leading to a stronger reduction in IL-1, MCP-1, and TNF-α expression compared to that was suppressed by simvastatin treatment. However, neither Curcuma comosa nor simvastatin affected the expression of anti-inflammation cytokines. In the liver, Curcuma comosa insignificantly decreased the expression of pro-inflammatory cytokines and significantly increased the expression of the anti-inflammatory cytokine IL-10 without altering the activity of hepatic enzymes. In contrast, simvastatin significantly increased the MCP-1 and TNF-α expressions and serum ALT level, without affecting the expression of anti-inflammatory cytokines.

Conclusions

In this study, we demonstrated that Curcuma comosa exerts anti-inflammatory activity in the aorta and liver without causing liver toxicity, indicating that Curcuma comosa is a potential candidate as an alternative agent in cardiovascular disease therapy.     

Bacopa monniera leaf extract up-regulates tryptophan hydroxylase (TPH2) and serotonin transporter (SERT) expression: implications in memory formation

Aim of the study

To examine the effect of Bacopa monniera leaf ethanolic extract (BMEE) on the serotonergic system of postnatal rats with reference to learning and memory.

Materials and methods

From postnatal day (PND)-15-29, rats were treated with BMEE (40 mg/kg BW + 0.5% gum acacia) by oral gavage. Behavioural tests (Y-maze, hole-board and passive avoidance) were used to evaluate their learning (PND-32-37) and retention of memory (PND-47-53). Effect of BMEE on neurotransmitter system was analyzed by ELISA and semi-quantitative polymerase chain reaction (PCR).

Results

Oral administration of BMEE improved learning and retention of memory significantly in all behavioural tasks. Following BMEE treatment, the level of serotonin (5-HT) increased while dopamine (DA) decreased significantly. We also found variation in the level of acetylcholine (ACh). However, no significant changes were observed in the level of ACh and glutamate (Glu). The level of 5-HT was significantly elevated up to PND-37 and was then restored to normal level on PND-53. Interestingly, concomitant up-regulation was recorded in the mRNA expression of serotonin synthesizing enzyme tryptophan hydroxylase-2 (TPH2) and serotonin transporter (SERT) on PND-29 and PND-37, which was restored on PND-53.

Conclusions

The results suggest that BMEE treatment significantly enhances the learning and retention of memory in postnatal rats possibly through regulating the expression of TPH2, 5-HT metabolism and transport.     

Comparison of the chemical profiles and anti-platelet aggregation effects of two "Dragon's Blood" drugs used in traditional Chinese medicine

Ethnopharmacological relevance

“Dragon's Blood” has been used as a medicine since ancient times by many cultures. In traditional Chinese medicine, the resin obtained from Daemonorops draco (RDD) and the resin from Dracaena cochinchinensis (RDC) are equally prescribed as “Dragon's Blood” for facilitating blood circulation.

Aim of the study

To verify the traditional efficacy and elucidate the mechanism, the present study compared the chemical profiles and the pharmacological effects of two species of “Dragon's Blood” mainly used in China.

Materials and methods

A UPLC-MS fingerprinting method was developed to compare the chemical profiles of the two medicines. The anti-platelet aggregation effects of the two medicines induced by arachidonic acid (AA) were investigated.

Results

The chemical profiles of these two species of “Dragon's Blood” were significantly different. The characteristic constituents were found to be: flavanes in RDD and stilbenes in RDC. In the in vivo platelet inhibition test, performed with the dose of 200 mg/kg on rats, the peak inhibitory effects of RDD and RDC were 35.8% and 27.6%, respectively, compared with the control group. With the in vitro concentrations of 0.2, 0.4 and 0.8 mg/ml, RDD exerted significant inhibition of aggregation by 18.7%, 20.0%, and 61.6%, respectively, and RDC exerted significant inhibition of aggregation by 13.3%, 20.2%, and 31.6%, respectively.

Conclusion

The fingerprinting method used here is suitable for distinguishing them. All pharmacological tests indicated that RDD was more potent than RDC against platelet aggregation.     

Anti-diabetic activity of Chiliadenus iphionoides

Ethnopharmacological relevance

Chiliadenus iphionoides (Boiss. & Blanche) Brullo (Asteraceae), a small aromatic shrub found throughout Israel, is used traditionally in the treatment of diabetes mellitus. In this study, Chiliadenus iphionoides anti-diabetic activity was characterized using cellular and animal models.

Materials and methods

Pancreatic β cells, adipocytes, and skeletal myotubes were treated with an ethanolic extract of Chiliadenus iphionoides to study the extract's effects on insulin secretion and glucose uptake. The sand rat (Psammomys obesus) was used to study Chiliadenus iphionoides acute and long term effects in vivo. An oral starch tolerance test was performed as well as a 30 day feeding study.

Results

Chiliadenus iphionoides extract increased insulin secretion in β cells as well as glucose uptake in adipocytes and skeletal myotubes. The extract also displayed hypoglycemic activity in the diabetic sand rat.

Conclusions

Chiliadenus iphionoides exhibits considerable anti-diabetic activity, although the mechanism of action remains to be determined.     

Inhibitory effect of Aralia continentalis on the cariogenic properties of Streptococcus mutans

Ethnopharmacological relevance

Aralia continentalis has been used in traditional Korean medicine for dental diseases such as toothache, dental caries, periodontal disease and gingivitis, and also has been used for neuralgia, analgesia, sweating, and as an antirheumatic.

Aim of the study

The present study was designed to investigate the inhibitory effect of Aralia continentalis extract on cariogenic properties of Streptococcus mutans, which is one of the most important bacteria in the formation of dental caries and dental plaque.

Materials and methods

The inhibitory effects of Aralia continentalis extract on the growth, acid production, water-insoluble glucan synthesis, and adhesion were investigated in Streptococcus mutans. The biofilm formation of Streptococcus mutans was determined by scanning electron microscopy (SEM) and safranin staining.

Results

The ethanol extract of Aralia continentalis showed concentration dependent inhibitory activity on the growth of Streptococcus mutans and significant inhibition of acid production at the concentrations of 0.25, 0.5, 1, 2 and 4 mg/ml compared to the control group. The synthesis of water-insoluble glucan by glucosyltransferase (GTFase) was decreased in the presence of 0.5-4 mg/ml of the extract of Aralia continentalis. The extract markedly inhibited Streptococcus mutans adherence to saliva-coated hydroxyapatite beads (S-HAs). The extract of Aralia continentalis has an inhibitory effect on the formation of Streptococcus mutans biofilms at the concentrations higher than 2 mg/ml.

Conclusions

These results suggest that Aralia continentalis may inhibit cariogenic properties of Streptococcus mutans, and also may support the scientific rationale that native inhabitants used the extract for the treatment of dental diseases.     

Antidiabetic and antioxidant effects of extracts from Potentilla discolor Bunge on diabetic rats induced by high fat diet and streptozotocin

Aim of the study

Potentilla discolor Bunge, commonly found at the north temperate and boreal zone, has been used for diabetes in China for a long time. Flavonoids and triterpenoids are two major types of compounds in P. discolor. This study was designed primarily to investigate the effects of total flavonoids extract (TFE) and total triterpenoids extract (TTE) of P. discolor Bunge on blood glucose, lipid profiles and antioxidant parameters on diabetic rats induced by high fat diet and streptozotocin.

Materials and methods

High fat diet-fed and streptozotocin-induced diabetic rats were treated with the TFE and TTE for 15 days, respectively. A range of parameters were tested including fasting blood glucose (FBG), serum insulin (SI), blood lipid profile, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), glycosylated serum protein (GSP), and nitric oxide (NO).

Results

Diabetic rats treated with TFE or TTE had decreased concentration of FBG and GSP compared with the control group. Meanwhile, the levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-c) in the TFE or TTE treated diabetic rats were lower, and the high-density lipoprotein cholesterol (HDL-c) level was higher than in the control diabetic rats. Furthermore, the extracts treatment decreased the MDA and NO level, while increased SOD and GSH levels in diabetic rats. Histopathologic examination also showed that the extracts have protective effects on β-cells in diabetic rats which are supported by the increase of SI.

Conclusions

All these experimental results highlighted the hypoglycemic and hypolipidemic properties of the two extracts from Potentilla discolor Bunge on diabetes and its complications, possibly through a strong antioxidant activity and a protective action on β-cells.     

In vitro antimicrobial synergism within plant extract combinations from three South African medicinal bulbs

Ethnopharmacological relevance

Tulbaghia violacea, Hypoxis hemerocallidea and Merwilla plumbea are used in South African traditional medicine for the treatment of some infectious diseases and other ailments.

Aim of the study

The study aimed at investigating the antimicrobial efficacies of independent and various within-plant extract combinations of three medicinal bulbs to understand the possible pharmacological interactions.

Materials and methods

Bulb and leaf extracts of the three medicinal plants, independently and in combinations, were comparatively assessed for antimicrobial activity against two Gram-positive and two Gram-negative bacteria and Candida albicans using the microdilution method. The fractional inhibitory concentration indices (FIC) for two extract combinations were determined.

Results

At least one extract combination in each plant sample demonstrated good antimicrobial activity against all the test organisms. The efficacies of the various extract combinations in each plant sample varied, with the strongest synergistic effect exhibited by the proportional extract yield combination of PE and DCM extracts in Merwilla plumbea bulb sample against Staphylococcus aureus (FIC index of 0.1). Most extract combinations demonstrated either a synergistic, additive or indifferent interaction effect against the test bacteria with only a few exhibiting antagonistic effects.

Conclusion

The observed antimicrobial efficacy and synergistic interactions indicate the beneficial aspects of combination chemotherapy of medicinal plant extracts in the treatment of infectious diseases.     

Phaleria macrocarpa (Scheff.) Boerl fruit aqueous extract enhances LDL receptor and PCSK9 expression in vivo and in vitro

Ethnopharmacological relevance

Phaleria macrocarpa (Scheff.) Boerl (Pm) has been shown to reduce cholesterol level in vitro and in vivo experiment.

Aim of the study

This study investigated the effects of Pm fruit on weight control and mechanistic basis of its anti-hypercholesterolemic effect in both in vivo and in vitro.

Materials and method

In the in vivo study, thirty six male Sprague Dawley were randomized to six groups. Five groups were induced into hypercholesterolemia by giving 3% cholesterol enriched-diet for 52 days while one group acted as control. The rats were then treated with Pm extract (0, 20, 30 and 40 mg/ml) or simvastatin for 84 days. The following parameters were determined: (1) body weight, (2) blood lipid profile (total cholesterol, triglyceride, HDL and LDL) and (3) hepatic LDL receptor (160 kDa and 120 kDa) and PCSK9 proteins. In the in vitro study, HepG2 cells were cultured in serum-free RPMI supplemented with 0.2% BSA with or without LDL and in the presence of Pm extract (0, 0.1, 2, 40 and 1000 μg/ml) or simvastatin (4.60 μg/ml) for 24 h. The abundance of both LDL receptor and PCSK9 proteins and mRNA were investigated.

Results

Pm extract significantly (P < 0.05) reduced body weight gain, total cholesterol, triglycerides, HDL LDL levels and upregulated hepatic LDL receptor as well as PCSK9 proteins of hypercholesterolemic rats. These results were supported by studies in HepG2 cells whereby Pm extract also significantly upregulated both LDL receptor and PCSK9 at protein and mRNA levels.

Conclusion

This study enhances the potential usage of Pm fruit for controlling the body weight of obese people and for treating hypercholesterolemia.     

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.