The cytotoxic effect of Baeckea frustescens extracts in eliminating hypoxic breast cancer cells

BACKGROUND

Adaptive metabolic response towards a low oxygen environment is essential to maintain rapid tumour proliferation and progression. The vascular network that surrounds the tumour develops an intermittent hypoxic condition and stimulates hypoxia-inducing factors. Baeckea frutescens is used in traditional medicine and known to possess antibacterial and cytoprotective properties. In this study, the cytotoxic effect of B. frutescens leaves and branches extracts against hypoxic human breast cancer (MCF-7) was investigated.

METHOD

The extracts were prepared using Soxhlet apparatus for ethanol and hexane extracts while the water extracts were freeze-dried. In vitro cytotoxic activities of B. frutescens extracts of various concentrations (20 to 160 μg/mL) at 24, 48, and 72 hours time points were studied using MTT in chemically induced hypoxic condition and in 3-dimensional in vitro cell culture system. An initial characterisation of B. frutescens extracts was carried out using Fourier-transform Infrared- Attenuated Total Reflection (FTIR-ATR) to determine the presence of functional groups.

RESULTS

All leaf extracts except for water showed IC50 values ranging from 23 -158 μg/mL. Hexane extract showed the lowest IC50 value (23 μg/mL), indicating its potent cytotoxic activity. Among the branch extracts, only the 70% ethanolic extract (B70) showed an IC50 value. The hexane leaf extract tested on 3- dimensional cultured cells showed an IC50 value of 17.2 μg/mL. The FTIR-ATR spectroscopy analysis identified various characteristic peak values with different functional groups such as alcohol, alkenes, alkynes, carbonyl, aromatic rings, ethers, ester, and carboxylic acids. Interestingly, the FTIR-ATR spectra report a complex and unique profile of the hexane extract, which warrants further investigation.

CONCLUSION

Adaptation of tumour cells to hypoxia significantly contributes to the aggressiveness and chemoresistance of different tumours. The identification of B. frutescens and its possible role in eliminating breast cancer cells in hypoxic conditions defines a new role of natural product that can be utilised as an effective agent that regulates metabolic reprogramming in breast cancer.

Anti-inflammatory activity of raw and processed stingless bee honey

The anti-inflammatory activity of raw and processed Kelulut stingless bee honey was investigated for its ability to inhibit nitric oxide (NO) production in lipopolysaccharidestimulated RAW 264.7 cells. Raw honey was optimally processed by thermal processing and thermosonication at 90°C. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) cell viability assay showed that Kelulut honey from 7.8 to 500 µg/mL was not cytotoxic to RAW 264.7 cells as it resulted in at least 80% viable cells after 24 hr. Both raw and processed honey from 10 to 300 µg/mL displayed an increase and decrease in NO concentrations, suggesting a mixed effect of NO inhibition and enhancement. Maximum NO inhibition of 17.5% was recorded from 20 µg/mL of thermally processed honey while the highest NO enhancement of 7.8% was from 10 µg/mL of thermosonicated honey. The NO effects were independent of honey concentration and processing techniques, suggesting its potential robustness in medicinal properties as part of the diet.

In vitro characterization of chicken bone marrow-derived dendritic cells following infection with very virulent infectious bursal disease virus

Infectious bursal disease is caused by infectious bursal disease virus (IBDV), an immunosuppressive virus that targets immune cells such as B cells and macrophages. However, the involvement of dendritic cells (DCs) during IBDV infection is not well understood. In this study the in vitro effects of live and inactivated very virulent IBDV (vvIBDV) UPM0081 on bone marrow-derived DCs (BM-DC) were characterized and compared with BM-DC treated with lipopolysaccharide (LPS). Morphologically, BM-DC treated with LPS and vvIBDV showed stellate shape when compared to immature BM-DC. In addition, LPS-treated and both live and inactivated vvIBDV-infected BM-DC expressed high levels of double positive CD86 and major histocompatibility complex class II antigens (>20%). vvIBDV-infected BM-DC showed significantly higher numbers of apoptotic cells compared to LPS. Replication of vvIBDV was detected in the infected BM-DC as evidenced by the increased expression of VP3 and VP4 IBDV antigens based on flow cytometry, real-time polymerase chain reaction and immunofluorescence tests. Levels of different immune-related genes such as interleukin-1β (IL-1β), CXCLi2 (IL-8), IL-18, interferon gamma (IFN-γ, IL-12α, CCR7 and Toll-like receptor-3 (TLR3) were measured after LPS and vvIBDV treatments. However, marked differences were noticed in the onset and intensity of the gene expression between these two treatment groups. LPS was far more potent than live and inactivated vvIBDV in inducing the expression of IL-1β, IL-18 and CCR7 while expression of Th1-like cytokines, IFN-γ and IL-12α were significantly increased in the live vvIBDV treatment group. Meanwhile, the expression of TLR3 was increased in live vvIBDV-infected BM-DC as compared to control. Inactivated vvIBDV-treated BM-DC failed to stimulate IFN-γ, IL-12α and TLR3 expressions. This study suggested that BM-DC may serve as another target cells during IBDV infection which require further confirmation via in vivo studies.

Phytochemical analysis of Andrographis paniculata and Orthosiphon stamineus leaf extracts for their antibacterial and antioxidant potential

Leaves of Andrographis paniculata and Orthosiphon stamineus were extracted with water, ethanol, methanol and chloroform to assess their potential as antibacterial and antioxidant agents. High performance liquid chromatography analysis showed that the methanolic extracts of A. paniculata and O. stamineus leaves gave the highest amounts of andrographolide and rosmarinic acid, respectively. These leaf extracts exhibited antimicrobial and antioxidant activities and, at the highest concentration tested (200 mg/mL), showed greater inhibitory effects against the Gram positive bacteria Bacillus cereus and Staphylococcus aureus than 10% acetic acid. Andrographis paniculata and O. stamineus methanolic and ethanolic leaf extracts also showed the strongest antioxidant activity as compared with the other extracts tested. The bioactive compounds present in these leaf extracts have the potential to be developed into natural antibacterial and antioxidant agents that may have applications in animal and human health.

Involvement of monoaminergic system in the antidepressant-like effect of aqueous extract of Channa striatus in mice

BACKGROUND

In our previous study, the aqueous extract of Channa striatus (family: Channidae) fillet (AECSF) showed an antidepressant-like effect in mice. However, the mechanism of the antidepressant-like effect is unknown.

AIM

The objective of this study was to explore the involvement of monoamines in the antidepressant-like effect of AECSF in mice.

MATERIALS AND METHODS

AECSF was prepared by steaming the fillets of C. striatus. The male ICR mice were pretreated with various monoaminergic antagonists viz., p-chlorophenylalanine (100 mg/kg, i.p.), prazosin (1 mg/kg, i.p.) and yohimbine (1 mg/kg, i.p.), SCH23390 (0.05 mg/kg, s.c.) and sulpiride (50 mg/kg, i.p.) followed by treatment with AECSF and tested in tail suspension test (TST). Two-way ANOVA with Tukey test were used at p < 0.05 for significance.

RESULTS

The pretreatments with p-chlorophenylalanine, prazosin and yohimbine, but not with SCH23390 and sulpiride, were able to reverse the antidepressant-like effect of AECSF in TST.

CONCLUSIONS

The antidepressant-like effect of AECSF may be mediated through the serotonergic and noradrenergic systems and not through the dopaminergic system.

Antidepressant-like effect of aqueous extract of Channa striatus fillet in mice models of depression

BACKGROUND AND OBJECTIVES

Channa (C.) striatus (Malay-Haruan), is a fresh water snakehead fish, consumed as a rejuvenating diet in post-parturition period in local Malay population. The aqueous extract of C. striatus fillet (AECSF) was reported to act through serotonergic receptor system in a previous study. There is no scientific report on neuropharmacological effects of C. striatus. Based on these data, the antidepressant-like effect of C. striatus was evaluated in mice models of depression.

MATERIALS AND METHODS

AECSF was prepared by steaming the fillets as described previously. Antidepressant activity was studied in male ICR mice using forced swimming test (FST) and tail suspension test (TST). Open-field test was used to evaluate any psychomotor stimulant activity. AECSF was administered intraperitoneally at the concentrations of 30%, 40% and 50% w/v at the dosage of 10 ml/kg. Amitriptyline (10 mg/kg) was used as positive control.

RESULTS

All the three concentrations of AECSF (30%, 40% and 50% w/v) significantly reduced the immobility time (p < 0.001) in FST and TST. All the three concentrations of AECSF (30%, 40% and 50% w/v) significantly (p < 0.001) reduced locomotor activity in a dose-dependent manner in open-field test.

CONCLUSIONS

AECSF produced significant reduction of immobility time in both FST and TST. Amitriptyline produced a significant reduction of immobility time in both FST and TST similar to previous findings. The AECSF produced a dose-dependent decrease in locomotor activity in the open-field test. This hypolocomotion effect indicated the absence of any psychomotor stimulant activity thereby supporting the antidepressant-like effect of the AECSF. The pharmacological mechanisms of the observed antidepressant-like effect and hypolocomotion effect are not understood from our study. Hence, further studies are required.

Moringa oleifera Enhances Liver Antioxidant Status via Elevation of Antioxidant Enzymes Activity and Counteracts Paracetamol-induced Hepatotoxicity

This study investigated the role of antioxidant enzyme system following crude hydroethanolic extract of Moringa oleifera leaves (MO) in acute paracetamol (PCM) induced hepatotoxicity. Hydroethanolic extract (80%) of MO (200 mg/kg and 800 mg/kg; p.o) was pre-administered before a single oral dose of 3 g/kg PCM intoxication to male Sprague-Dawley rats. Pre-treatment of the extract was found to have reduced lipid peroxidation level when compared to the group treated with PCM only. The level of glutathione peroxidase (GPx), glutathione-Stransferase (GST) and glutathione reductase (GR) was restored to near normal in groups that were pre-treated with MO. Histopathological studies have further confirmed the hepatoprotective activity of MO compared to group treated with PCM only. The results obtained were comparable to silymarin (200 mg/kg; p.o). The MO extract was found to have significantly protected the liver against toxicity following PCM intoxication by enhancing the level of antioxidant enzyme activity.

Effects of mitragynine from Mitragyna speciosa Korth leaves on working memory

AIM OF THE STUDY

Mitragyna speciosa Korth from Rubiaceae family is a tropical plant indigenous to Southeast Asia particularly in Thailand, Peninsular of Malaysia and Indonesia. The leaves have been used by natives for their opium-like effect and cocaine-like stimulant ability to combat fatigue and enhance tolerance to hard work. However there is no scientific information about the effect of mitragynine on the cognitive performances. This study is designed to examine the working memory effects of mitragynine which is extracted from Mitragyna speciosa mature leaves.

MATERIALS AND METHODS

The cognitive effect was studied using object location task and the motor activity in open-field test. Mitragynine 5, 10 and 15 mg/kg and were administered by intraperitoneal (IP) for 28 consecutive days and evaluated on day 28 after the last dose treatment. Scopolamine was used as the control positive drug.

RESULTS

In this study there is prominent effects on horizontal locomotor activity was observed. Mitragynine significantly reduced locomotor activity in open-field test compared with vehicle. In object location task mitragynine (5, 10 and 15 mg/kg) did not showed any significances discrimination between the object that had changed position than the object that had remain in a constant position.

CONCLUSION

Our results suggest that chronic administration of mitragynine can altered the cognitive behavioral function in mice.

Morphological alteration in mitochondria following diclofenac and ibuprofen administration

This study was conducted to identify and to compare the mitochondrial morphological alterations in livers of rats treated with various doses of diclofenac and ibuprofen. Hundred and forty-four male Sprague Dawley rats were dosed with 3, 5 and 10 mg kg(-1) diclofenac and ibuprofen in saline via intraperitoneal injection for 15 days. The control group was administered with saline in a similar manner. Four rats were euthanised every 3 days until day 15. While 200 mg kg(-1) diclofenac and ibuprofen-treated rats (n = 4) were euthanized 10 h posttreatment. The livers were removed, cleaned and a section across the right lobe was taken and fixed in 4% (v/v) glutaraldehyde for electron microscopy analysis and the remaining samples were kept at -80 degrees C for Western blot analysis. Five milligram per kilogram and 10 mg kg(-1) diclofenac-administered rats for 15 days revealed the presence of enlarged mitochondria, irregular and ruptured mitochondrial membranes. While rats administered with 10 mg kg(-1) ibuprofen also showed the presence of mitochondria with irregular membrane structure and ruptured membranes. Western blotting analysis of mitochondrial fractions revealed the expression of cytochrome c in all samples and complete absence of cytochrome c expression in the cytosolic fraction of all samples after day 15. Analysis in 200 mg kg(-1) diclofenac and ibuprofen-treated groups, revealed expression of cytochrome c in both mitochondrial and cytosolic fractions. This observation indicates that both diclofenac and ibuprofen may alter the morphology of mitochondria, leading to cytochrome c release into the cytosol. Further studies needs to be conducted to investigate on the activity of the mitochondria following both treatments.

Moringa oleifera Lam prevents acetaminophen induced liver injury through restoration of glutathione level

Initiation of acetaminophen (APAP) toxicities is believed to be promoted by oxidative stress during the event of overdosage. The aim of the present study was to evaluate the hepatoprotective action of Moringa oleifera Lam (MO), an Asian plant of high medicinal value, against a single high dose of APAP. Groups of five male Sprague-Dawley rats were pre-administered with MO (200 and 800 mg/kg) prior to a single dose of APAP (3g/kg body weight; p.o). Silymarin was used as an established hepatoprotective drug against APAP induced liver injury. The hepatoprotective activity of MO extract was observed following significant histopathological analysis and reduction of the level of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in groups pretreated with MO compared to those treated with APAP alone. Meanwhile, the level of glutathione (GSH) was found to be restored in MO-treated animals compared to the groups treated with APAP alone. These observations were comparable to the group pretreated with silymarin prior to APAP administration. Group that was treated with APAP alone exhibited high level of transaminases and ALP activities besides reduction in the GSH level. The histological hepatocellular deterioration was also evidenced. The results from the present study suggested that the leaves of MO can prevent hepatic injuries from APAP induced through preventing the decline of glutathione level.