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Fulltext Effects of xanthorrhizol on 3T3-L1 adipocyte hyperplasia and hypertrophy [Abstract]

Seok Fang Oon, Meenakshii Nallappan, Mohd Shazrul Fazry Sa’ariwijaya, Nur Kartinee Kassim, Shamarina Shohaimi, Thiam Tsui Tee, et al.

Malaysian Journal of Medicine and Health Sciences, 2019;15(102):41-41.
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ABSTRACTS FOR INTERNATIONAL HEALTH AND MEDICAL SCIENCES CONFERENCE 2019 (IHMSC 2019). Accelerating Innovations in Translational and Precision Medicine. Held at Taylor’s University Lakeside Campus, Subang Jaya, Selangor, Malaysia. 8-9th March, 2019
Introduction: According to the National Health and Morbidity Survey (NHMS) 2015, 47.7% of the Malaysian population are either obese or overweight. The increased obesity prevalence has caused major health problems including cardiovascular diseases and diabetes. Although several anti-obesity drugs have been developed, they are limited due to adverse side effects. Previous studies demonstrated that xanthorrhizol (XNT) reduced the levels of serum free fatty acid and triglyceride in vivo, but the detailed anti-obesity activities and its related mechanisms are yet to be reported. Thus, this study aims to evaluate its abilities to inhibit adipocyte hyperplasia and hypertrophy employing 3T3-L1 adipocytes.
Methods: Statistical significance was established by one-way ANOVA, where p < 0.05 was considered statistically significant.
Results: In this study, the IC50 value of XNT (98.3% purity) from Curcuma xanthorrhiza Roxb. in 3T3-L1 adipocytes was 35 ± 0.24 μg/mL. The loss of cell viability was due to 20.01 ± 2.77% of early apoptosis and 24.13 ± 2.03% of late apoptosis. XNT elicited apoptosis via up-regulation of caspase-3 and cleaved PARP-1 protein expression for 4.09-fold and 3.12-fold, respectively. Moreover, XNT decreased adipocyte differentiation for 36.13 ± 3.64% and reduced GPDH activity to 52.26 ± 4.36%. The underlying mechanism was due to impaired expression of PPARγ to 0.36-fold and FAS to 0.38-fold, respectively. On the other hand, XNT increased glycerol release by 45.37 ± 6.08% compared to control. During lipolysis, XNT up-regulated the leptin protein for 2.08-fold but down-regulated the protein level of insulin to 0.36-fold. These results indicated that XNT reduced the volume of adipocytes through modulation of leptin and insulin.
Conclusion: To conclude, XNT exerted its anti-obesity mechanisms by suppression of adipocyte hyperplasia through induction of apoptosis and inhibition of adipogenesis whilst reduction of adipocyte hypertrophy through stimulation of lipolysis. Thus, XNT could be developed as a potential anti-obesity agent in the future.
Contrasting sirtuin and poly(ADP-ribose)polymerase activities of selected 2,4,6-trisubstituted benzimidazoles

Yeong KY, Tan SC, Mai CW, Leong CO, Chung FF, Lee YK, et al.

Chem Biol Drug Des, 2018 01;91(1):213-219.
PMID: 28719017 DOI: 10.1111/cbdd.13072

Both sirtuin and poly(ADP-ribose)polymerase (PARP) family of enzymes utilize NAD+ as co-substrate. Inhibitors of sirtuins and PARPs are important tools in drug discovery as they are reported to be linked to multiple diseases such as cancer. New potent sirtuin inhibitors (2,4,6-trisubstituted benzimidazole) were discovered from reported PARP inhibitor scaffold. Interestingly, the synthesized compounds have contrasting sirtuin and PARP-1 inhibitory activities. We showed that modification on benzimidazoles may alter their selectivity toward sirtuin or PARP-1 enzymes. This offers an opportunity for further discovery and development of new promising sirtuin inhibitors. Molecular docking studies were carried out to aid the rationalization of these observations. Preliminary antiproliferative studies of selected compounds against nasopharyngeal cancer cells also showed relatively promising results.
Fulltext Cytotoxic and apoptotic effects of heat killed Mycobacterium indicus pranii (MIP) on various human cancer cell lines

Subramaniam M, In LL, Kumar A, Ahmed N, Nagoor NH

Sci Rep, 2016;6:19833.
PMID: 26817684 DOI: 10.1038/srep19833

Mycobacterium indicus pranii (MIP) is a non-pathogenic mycobacterium, which has been tested on several cancer types like lung and bladder where tumour regression and complete recovery was observed. In discovering the potential cytotoxic elements, a preliminary test was carried out using four different fractions consisting of live bacteria, culture supernatant, heat killed bacteria and heat killed culture supernatant of MIP against two human cancer cells A549 and CaSki by 3-(4,5-dimethyl thiazol)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis was investigated in MCF-7 and ORL-115 cancer cells by poly-(ADP-ribose) polymerase (PARP) and DNA fragmentation assays. Among four MIP fractions, only heat killed MIP fraction (HKB) showed significant cytotoxicity in various cancer cells with inhibitory concentration, IC50 in the range 5.6-35.0 μl/(1.0 × 10(6) MIP cells/ml), while cytotoxicity effects were not observed in the remaining fractions. HKB did not show cytotoxic effects on non-cancerous cells contrary to cancerous cells, suggesting its safe usage and ability to differentially recognize between these cells. Evaluation on PARP assay further suggested that cytotoxicity in cancer cells were potentially induced via caspase-mediated apoptosis. The cytotoxic and apoptotic effects of MIP HKB have indicated that this fraction can be a good candidate to further identify effective anti-cancer agents.
Benzimidazole derivatives as potential dual inhibitors for PARP-1 and DHODH

Abdullah I, Chee CF, Lee YK, Thunuguntla SSR, Satish Reddy K, Nellore K, et al.

Bioorg Med Chem, 2015 Aug 01;23(15):4669-4680.
PMID: 26088338 DOI: 10.1016/j.bmc.2015.05.051

Poly (ADP-ribose) polymerases (PARPs) play diverse roles in various cellular processes that involve DNA repair and programmed cell death. Amongst these polymerases is PARP-1 which is the key DNA damage-sensing enzyme that acts as an initiator for the DNA repair mechanism. Dihydroorotate dehydrogenase (DHODH) is an enzyme in the pyrimidine biosynthetic pathway which is an important target for anti-hyperproliferative and anti-inflammatory drug design. Since these enzymes share a common role in the DNA replication and repair mechanisms, it may be beneficial to target both PARP-1 and DHODH in attempts to design new anti-cancer agents. Benzimidazole derivatives have shown a wide variety of pharmacological activities including PARP and DHODH inhibition. We hereby report the design, synthesis and bioactivities of a series of benzimidazole derivatives as inhibitors of both the PARP-1 and DHODH enzymes.
Matrine enhances the inhibitory effect of 5-fu on sw480 cells in vitro and in vivo

Xu-hui Zhang, Lei Liang, Xiao-yan Wang, Li Zhang, Yan-xin Zheng, Hong-zhu Deng, et al.

Sains Malaysiana, 2016;45:109-113.

We investigated the antitumor effects of the combination of matrine-a purified alkaloid extracted from Sophora flavescence-and 5-fluorouracil (5-FU) on SW480 cells. This combination inhibited the growth of SW480 cells in a synergistic or additive manner by disrupting their progression through the cell cycle. Exposure of SW480 cells to matrine and 5-FU was followed by an increased rate of expression for caspase-3, caspase-9 and poly-ADP ribose polymerase (PARP) and inhibited the subcutaneous transplantation of SW480 tumors into Balb/c nude mice. Histopathological analysis showed that this effect was most pronounced in the spleens of treated animals. Typical cytotoxic effects observed in 5-FU-treated mice included fibrosis and lymphopenia, whereas in mice treated with 5-FU combined with matrine, the spleen ultrastructure remained intact. These findings indicate that matrine may enhance the therapeutic effectiveness of 5-FU in SW480 tumors by enhancing apoptosis and overcome the threat to immunocompetence associated with 5-FU.
A critical role of TRPM2 channel in Aβ42 -induced microglial activation and generation of tumor necrosis factor-α

Alawieyah Syed Mortadza S, Sim JA, Neubrand VE, Jiang LH

Glia, 2018 03;66(3):562-575.
PMID: 29143372 DOI: 10.1002/glia.23265

Amyloid β (Aβ)-induced neuroinflammation plays an important part in Alzheimer's disease (AD). Emerging evidence supports a role for the transient receptor potential melastatin-related 2 (TRPM2) channel in Aβ-induced neuroinflammation, but how Aβ induces TRPM2 channel activation and this relates to neuroinflammation remained poorly understood. We investigated the mechanisms by which Aβ42 activates the TRPM2 channel in microglial cells and the relationships to microglial activation and generation of tumor necrosis factor-α (TNF-α), a key cytokine implicated in AD. Exposure to 10-300 nM Aβ42 induced concentration-dependent microglial activation and generation of TNF-α that were ablated by genetically deleting (TRPM2 knockout ;TRPM2-KO) or pharmacologically inhibiting the TRPM2 channel, revealing a critical role of this channel in Aβ42 -induced microglial activation and generation of TNF-α. Mechanistically, Aβ42 activated the TRPM2 channel via stimulating generation of reactive oxygen species (ROS) and activation of poly(ADPR) polymerase-1 (PARP-1). Aβ42 -induced generation of ROS and activation of PARP-1 and TRPM2 channel were suppressed by inhibiting protein kinase C (PKC) and NADPH oxidases (NOX). Aβ42 -induced activation of PARP-1 and TRPM2 channel was also reduced by inhibiting PYK2 and MEK/ERK. Aβ42 -induced activation of PARP-1 was attenuated by TRPM2-KO and moreover, the remaining PARP-1 activity was eliminated by inhibiting PKC and NOX, but not PYK2 and MEK/ERK. Collectively, our results suggest that PKC/NOX-mediated generation of ROS and subsequent activation of PARP-1 play a role in Aβ42 -induced TRPM2 channel activation and TRPM2-dependent activation of the PYK2/MEK/ERK signalling pathway acts as a positive feedback to further facilitate activation of PARP-1 and TRPM2 channel. These findings provide novel insights into the mechanisms underlying Aβ-induced AD-related neuroinflammation.
The impact of cycleanine in cancer research: a computational study

Nwaefulu ON, Al-Shar'i NA, Owolabi JO, Sagineedu SR, Woei LC, Wai LK, et al.

J Mol Model, 2022 Oct 04;28(11):340.
PMID: 36194315 DOI: 10.1007/s00894-022-05326-1

Cancer is imposing a global health burden because of the steady increase in new cases. Moreover, current anticancer therapeutics are associated with many drawbacks, mainly the emergence of resistance and the severe adverse effects. Therefore, there is a continuous need for developing new anticancer agents with novel mechanisms of action and lower side effects. Natural products have been a rich source of anticancer medication. Cycleanine, a natural product, was reported to exert an antiproliferative effect on ovarian cancer cells by causing apoptosis through activation of caspases 3/7 and cleavage of poly (ADP-ribose) polymerase to form poly (ADP-ribose) polymerase-1 (PARP1). It is well-established that PARP1 is associated with carcinogenesis, and different PARP1 inhibitors are approved as anticancer drugs. In this study, the cytotoxic activity of cycleanine was computationally investigated to determine whether it is a PARP1 inhibitor or a caspase activator. Molecular docking and molecular dynamics (MD) simulations were utilized for this purpose. The results showed that cycleanine has a good binding affinity to PARP1; moreover, MD simulation showed that it forms a stable complex with the enzyme. Consequently, the results showed that cycleanine is a potential inhibitor of the PARP1 enzyme.
Fulltext Panduratin A, a possible inhibitor in metastasized A549 cells through inhibition of NF-kappa B translocation and chemoinvasion

Cheah SC, Lai SL, Lee ST, Hadi AH, Mustafa MR

Molecules, 2013 Jul 24;18(8):8764-78.
PMID: 23887718 DOI: 10.3390/molecules18088764

In the present study, we investigated the effects of panduratin A (PA), isolated from Boesenbergia rotunda, on apoptosis and chemoinvasion in A549 human non-small cell lung cancer cells. Activation of the executioner procaspase-3 by PA was found to be dose-dependent. Caspase-3 activity was significantly elevated at the 5 µg/mL level of PA treatment and progressed to a maximal level. However, no significant elevated level was detected on procaspase-8. These findings suggest that PA activated caspase-3 but not caspase-8. Numerous nuclei of PA treated A549 cells stained brightly by anti-cleaved PARP antibody through High Content Screening. This result further confirmed that PA induced apoptotic cell death was mediated through activation of caspase-3 and eventually led to PARP cleavage. Treatment of A549 cells with PA resulted in a strong inhibition of NF-κB activation, which was consistent with a decrease in nuclear levels of NF-κB/p65 and NF-κB/p50 and the elevation of p53 and p21. Besides that, we also showed that PA significantly inhibited the invasion of A549 cells in a dose-dependent manner through reducing the secretion of MMP-2 of A549 cells gelatin zymography assay. Our findings not only provide the effects of PA, but may also be important in the design of therapeutic protocols that involve targeting of either p53 or NF-κB.
Fulltext Tocotrienols promote apoptosis in human breast cancer cells by inducing poly(ADP-ribose) polymerase cleavage and inhibiting nuclear factor kappa-B activity

Loganathan R, Selvaduray KR, Nesaretnam K, Radhakrishnan AK

Cell Prolif, 2013 Apr;46(2):203-13.
PMID: 23510475 DOI: 10.1111/cpr.12014

OBJECTIVES: Tocotrienols and tocopherols are members of the vitamin E family, with similar structures; however, only tocotrienols have been reported to achieve potent anti-cancer effects. The study described here has evaluated anti-cancer activity of vitamin E to elucidate mechanisms of cell death, using human breast cancer cells.
MATERIALS AND METHODS: Anti-cancer activity of a tocotrienol-rich fraction (TRF) and a tocotrienol-enriched fraction (TEF) isolated from palm oil, as well as pure vitamin E analogues (α-tocopherol, α-, δ- and γ-tocotrienols) were studied using highly aggressive triple negative MDA-MB-231 cells and oestrogen-dependent MCF-7 cells, both of human breast cancer cell lines. Cell population growth was evaluated using a Coulter particle counter. Cell death mechanism, poly(ADP-ribose) polymerase cleavage and levels of NF-κB were determined using commercial ELISA kits.
RESULTS: Tocotrienols exerted potent anti-proliferative effects on both types of cell by inducing apoptosis, the underlying mechanism of cell death being ascertained using respective IC50 concentrations of all test compounds. There was marked induction of apoptosis in both cell lines by tocotrienols compared to treatment with Paclitaxel, which was used as positive control. This activity was found to be associated with cleavage of poly(ADP-ribose) polymerase (a DNA repair protein), demonstrating involvement of the apoptotic cell death signalling pathway. Tocotrienols also inhibited expression of nuclear factor kappa-B (NF-κB), which in turn can increase sensitivity of cancer cells to apoptosis.
CONCLUSION: Tocotrienols induced anti-proliferative and apoptotic effects in association with DNA fragmentation, poly(ADP-ribose) polymerase cleavage and NF-κB inhibition in the two human breast cancer cell lines.