B. S. Jayashree

In Vitro and in Vivo Evaluation of Novel Cinnamyl Sulfonamide Hydroxamate Derivative Against Colon Adenocarcinoma

The potential of cinnamic acid as an anti-inflammatory and anti-cancer agent has been studied previously. In our investigation, novel bio-isosters of cinnamyl sulfonamide hydroxamate were synthesized, characterized and confirmed for their structure and evaluated for cytotoxicity. Three NCEs namely, NMJ-1, -2 and -3 showed cell-growth inhibition in 6 human cancer cell lines with IC50 at the range of 3.3±0.15-44.9±2.6 μM. The hydroxamate derivatives of cinnamyl sulfonamide are reported inhibitors of HDAC enzyme. Thus, the effectiveness of these molecules was determined by whole cell HDAC assay in HCT 116 cell line. NMJ-2 (0.41±0.01 μM) exhibited better enzyme inhibition (IC50) compared to SAHA (2.63±0.07). In order to evaluate induction of apoptosis by treatment, Hoechst 33342 and AO/EB nuclear staining methods were used. Further, cell cycle analysis, Annexin V binding and caspase 3/7 activation assays were performed by flow cytometry where NMJ-2 significantly arrested the cell cycle at G2/M phase, increased Annexin V binding to the cell surface and activation of caspase-3/7. Bax/Bcl-2 ratio was observed by Western blot and showed an increase with NMJ-2 treatment. This was comparable to standard SAHA. The acute toxicity study (OECD-425) showed that NMJ-2 was safe up to 2000 mg/kg in rats. 1,2-Dimethyl hydrazine (DMH) was used to produce experimental colon adenocarcinoma in Wistar rats. 5-FU and NMJ-2 (100 mg/kg p.o. and 10 mg/kg i.p. once daily for 21 days, respectively) were administered to the respective groups. Both treatments significantly reduced ACFs, adenocarcinoma count, TNF-α, IL-6, nitrite and nitrate levels in colonic tissue. Our findings indicate that NMJ-2 has potent anti-cancer activity against colon cancer, by acting through HDAC enzyme inhibition and activation of intrinsic mitochondrial apoptotic pathway, with additional anti-inflammatory activity.

Iminoflavones Combat 1,2-Dimethyl Hydrazine-Induced Aberrant Crypt Foci Development in Colon Cancer

The aim of the present study was to evaluate the antitumor potential of iminoflavones in in vitro and in vivo anticancer models. Preliminary screening in various cancer cell lines revealed four potential iminoflavones out of which IMF-8 was taken based on its activity against colon cancer cells. This was further confirmed by observing the nuclear changes in the cells by AO/EB and Hoechst 33342 staining studies. In vivo activity was assessed by dimethyl hydrazine-(DMH-) induced colon cancer model in rats. Animals were administered DMH (20u2009mg/kg, b.w. for 10 weeks and 30u2009mg/kg b.w., i.p. for 10 weeks) and were supplemented with (IMF-8) iminoflavone-8 (200u2009mg/kg, p.o. for 14 days). Results showed that DMH induced 100% aberrant crypt foci (ACF) and polyps which were significantly reduced in the IMF-8 treated group. IMF-8 significantly increased the catalase and GSH levels whereas it reduced the TNF-α and IL-6 levels markedly which suggests the antioxidative and anti-inflammatory actions of flavonoids present in IMF-8. The histopathological images of the IMF-8 treated colon showed no signs of mucosal crypt abscess. These findings suggest that the semi-synthetic iminoflavones, IMF-8, effectively inhibit DMH-induced ACFs and colonic crypts by alleviating the oxidative stress and suppressing the inflammation.

Novel flavonol analogues as potential inhibitors of JMJD3 histone demethylase—A study based on molecular modelling

Epigenetic modulation of gene expression has drawn enormous attention among researchers globally in the present scenario. Since their discovery, Jmj-C histone demethylases were identified as useful markers in understanding the role of epigenetics in inflammatory conditions and in cancer as well. This has created arousal of interest in search of suitable candidates. Potential inhibitors from various other scaffolds such as hydroxyquinolines, hydroxamic acids and triazolopyridines have already been identified and reported. In this direction, our present study attempts to target one of the important members of the family- namely JMJD3 (also known as KDM6B), that plays a pivotal role in inflammatory and immune reactions. Using molecular modeling approaches, myricetin analogues were identified as promising inhibitors of JMJD3. Extensive literature review showed myricetin as the most promising flavonol inhibitor for this enzyme. It served as a prototype for our study and modification of its scaffold led to generation of analogues. The ZINC database was used as a repository for natural compounds and their analogues. Using similarity search options, 65 analogues of myricetin were identified and screened against JMJD3 (PDB ID: 4ASK), using the high throughput virtual screening and ligand docking tools in Maestro Molecular Modeling platform (version 10.5) from Schrödinger, LLC. 8 analogues out of 65 were identified as the most appropriate candidates which gave the best pose in ligand docking. Their binding mode and energy calculations were analysed using induced fit docking (IFD) and prime-MMGBSA tool, respectively. Thus, our findings highlight the most promising analogues of myricetin with comparable binding affinity as well as binding energy than their counterparts that could be taken for further optimisation as inhibitors of JMJD3 in both in vitro and in vivo screening studies.

Investigating the potential of tetrahydropyridinyl chalcones as useful agents against breast carcinoma: An in vitro and in vivo study

N-Benzyltetrahydropyridinyl-4,6-dimethoxy phenyl-substituted 2′-hydroxychalcones SJC1–15 were synthesized using Claisen–Schmidt condensation, their structures confirmed by spectral analysis, and their anticancer activity evaluated. To support their biological activity, physicochemical parameters such as lipophilicity and oxidation potential were determined. To assess their relative cytotoxicity, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed using MCF-7, T-47D, MDA MB-231, HepG2, and Vero cell lines. The cytotoxicity of the chalcones was found to vary with the nature of the ring B substituents. The lipophilicity of the cytotoxic compounds expressed in terms of distribution coefficient was found to lie in the range of 2.4–4.2. Further evaluation of their antioxidant potential revealed antioxidant activity by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assay and irreversible electrochemical reaction with oxidation potential in the range of 0.879–1.048xa0V. Of the 15 chalcones, SJC4, 5, 9 were selected for further inxa0vitro studies using MCF-7. The compounds exhibited significant apoptotic effect and caused cell cycle arrest at G0/G1 and G2/M phase. Among them, two of the O-alkylated chalcones (SJC5, 9) showing promising activity against hormone-responsive breast cancer cells were evaluated for their inxa0vivo anticancer activity using 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumor model. Three-week treatment with the test compounds at oral dosage of 100xa0mgxa0kg−1xa0per day significantly improved elevated tumor parameters compared with tumor control. Treatment with chalcone SJC5 (a 2,4,5-trimethoxy derivative) exhibited anticancer effects similar to those of doxorubicin (2xa0mgxa0kg−1xa0per week, i.p.) and was free from toxic effects observed with doxorubicin treatment.

Epigenetic modulation of macrophage polarization- perspectives in diabetic wounds

Diabetes is a chronic metabolic disorder that poses a global burden to healthcare. Increasing incidence of diabetes-related complications in the affected population includes a delay in wound healing that often results in non-traumatic limb amputations. Owing to the intricacies of the healing process and crosstalk between the multitude of participating cells, the identification of hyperglycaemia-induced changes at both cellular and molecular levels poses a challenge. Macrophages are one of the key participants in wound healing and continue to exert functional changes at the wound site since the time of injury. In the present review, we discuss the role of these cells and their aberrant functions in diabetic wounds. We have extensively studied the process of macrophage polarization (MP) and its modulation through epigenetic modifications. Data from both pre-clinical and clinical studies on diabetes have co-related hyperglycaemia induced changes in gene expression to an increased incidence of diabetic complications. Hyperglycaemia and oxidative stress, create an environment prone to changes in the epigenetic code, that is manifested as an altered inflammatory gene expression. Here, we have attempted to understand the different epigenetic modulations that possibly contribute towards dysregulated MP, resulting in delayed wound healing.