Phlorotannins-bioactivity and extraction perspectives.

Phlorotannins, a seaweed based class of polyphenolic compounds, have proven to possess potential bioactivities such as antioxidant, antimicrobial, anti-allergic, anti-diabetic, anti-inflammatory, anti-cancerous, neuroprotection etc. These bioactivities have further increased demand globally and sustainable techniques such as supercritical fluid extraction, microwave assisted extraction, enzyme assisted extraction, extraction using deep eutectic solvents etc. are being explored currently for production of phlorotannin-rich extracts. In spite of such well documented bioactivities, very few phlorotannin-based nutraceuticals are available commercially which highlights the significance of generating consumer awareness about their physiological benefits. However, for industry level commercialization accurate quantification of phlorotannins with respect to the different classes is vital requiring sophisticated analytical techniques such as mass spectrometry, 1H-NMR spectroscopy etc. owing to the wide structural diversity. This review summarizes the extraction and bioactivities of phlorotannins based on the findings of in vivo and in vitro studies.

Synthesis and Evaluation of Anisomelic acid-like Compounds for the Treatment of HPV-Mediated Carcinomas.

The vast majority of cervical and 75% of oropharyngeal carcinomas are triggered by infection with a type of high-risk oncogenic human papillomavirus (HPV). It is well-known that E6 and E7 oncoproteins are critical for viral-induced cancer, and hence, they represent valuable targets for therapeutic intervention in HPV-mediated cancers. Our earlier research on the cembranoid, anisomelic acid (AA) showed that, AA has the potential to induce apoptosis in HPV cells by the depletion of E6 and E7 oncoproteins. The present study describes the structure-activity relationship and the evaluation of synthetic AA like compounds, i.e simplified cembranoid-like structures, as HPV inhibitors against some papilloma cell lines. Both from experimental and computational results, we observed that these compounds induced apoptosis by the same E6/E7-based mechanism as AA, but at earlier time points, thus being far more effective than AA. Further, the data indicated that only part of the structure of AA is required for the molecular action. Based on these results, we identified some novel and potential compounds for specific treatment of HPV-associated carcinomas.

Plasma Protein Binding of Anisomelic Acid: Spectroscopy and Molecular Dynamic Simulations.

Anisomelic acid (AA) is a macrocyclic cembranolide compound extracted from Anisomeles herbal species. Recently, we have shown that AA possesses both anticancer and antiviral activity. However, to date, the plasma protein binding properties of AA are unknown. Here, we describe the molecular interactions of AA with two serum proteins, human serum albumin (HSA) and bovine serum albumin (BSA), adopting multiple physicochemical methods. Besides, molecular docking and dynamics simulations were performed to predict the interaction mode and the dynamic behavior of AA with HSA and BSA. The experimental results revealed that hydrophobic forces play a significant part in the interaction of AA to HSA and BSA. The outcomes of the principal components analysis (PCA) of the poses based on root-mean-squared distances showed less variation in AA-HSA, opposed to what is seen for BSA-AA. Furthermore, binding free energies estimated for AA-HSA and AA-BSA complexes at different temperatures (298, 303, 308, and 313 K) based on molecular mechanics-generalized Born surface area (MMGBSA) approaches were well correlated with our experimental results.

Targeted delivery of a novel anticancer compound anisomelic acid using chitosan-coated porous silica nanorods for enhancing the apoptotic effect.

Targeted cancer therapies are currently a strong focus in biomedical research. The most common approach is to use nanocarrier-based targeting to specifically deliver conventional anticancer drugs to enhance their therapeutic efficacy, increase bioavailability, and decrease the side-effects on normal cells. A step further towards higher specificity and efficacy would be to employ specific novel drugs along with specific nanocarrier-based targeting. Our recent studies have demonstrated that a plant-derived diterpenoid compound, anisomelic acid (AA), induces apoptosis in cervical cancer cells. In this work, we describe the development of a folic acid (FA)-targeted AA delivery system using chitosan-coated rod-shaped mesoporous silica particles (Chitosan-NR-MSP). The cellular internalization and uptake enhancement of the FA-Chitosan-NR-MSP towards cancerous folate receptor (FR)-positive (SiHa and HeLa) and/or normal FR-negative (HEK 293) cells were assessed, which indicated that the intracellular uptake of FA-conjugated Chitosan-NR-MSP was more target-specific. Furthermore, the induction of apoptosis by AA-loaded chitosan-coated rod-shaped particles on SiHa cells was studied. By employing caspase-3 activation and PARP cleavage as measure of apoptosis, the FA-particle mediated AA treatment was clearly more effective, significantly enhancing apoptosis in comparison to non-targeted Chitosan-NR-MSP or free AA in SiHa cells, suggesting that the FA-Chitosan-NR-MSPs can be potentially utilized as a drug delivery system for cervical cancer treatment.

Novel action modality of the diterpenoid anisomelic acid causes depletion of E6 and E7 viral oncoproteins in HPV-transformed cervical carcinoma cells.

Cervical cancer, the second most common malignancy among women, is mainly caused by human papilloma virus (HPV) infection. In HPV-positive cervical cancer cells, the activity of p53 and the induction of p21 are inhibited by the HPV oncoproteins E6 and E7. Therefore, blocking the activity of E6 and E7 would serve as an important therapeutic target in these cancer cells. In this study, anisomelic acid (AA), a natural compound belonging to the same diterpenoid family of bioactive compounds as taxol, was found to deplete the E6 and E7 proteins in HPV-positive cervical cancer cells. Consequently, p53 and the p53-responsive gene, p21, were dramatically induced, leading to G2/M-phase cell cycle arrest. AA-mediated cell cycle arrest and p21 expression were canceled when p53 was down-regulated by p53-shRNA. AA also induced p53-independent intrinsic apoptosis by depletion of the cellular inhibitor of apoptosis protein 2 (cIAP2) whose proteosomal degradation is inhibited by E6. The in ovo chick embryo chorioallantoic membrane (CAM) assay showed that anisomelic acid inhibited the tumor growth of the cervical cancer SiHa cells. AA is revealed to hold a novel action modality based on specific targeting of the HPV oncoproteins, which restores p53-mediated growth arrest and induces apoptosis by terminating E6-mediated cIAP2 stabilization.

Nurse-led epilepsy follow-up clinic in India: is it feasible and acceptable to patients? A pilot study.

PURPOSE: India has an epilepsy treatment gap of up to 90%. Shortage of doctors, especially in rural communities makes getting epilepsy treatment almost impossible for the vast majority. Nurses are relatively more in number and available even in smaller cities and villages. This pilot study investigated if a nurse-led epilepsy follow-up clinic is feasible in India and is acceptable to patients. METHOD: A II year Nursing postgraduate student was given 8h of didactic teaching tailored for epilepsy patient follow-up, followed by supervised observation time in the epilepsy clinic with a neurologist before conducting epilepsy follow-up clinics independently. Epilepsy patients ≥ 10 years of age and in follow-up for ≥ 6 months were included. They were independently followed-up both in the nurse-led clinic and in the neurologist's clinic. Outcome was measured in terms of interrater agreement (kappa) between the recommendations of the neurologist and the nurse in five domains. Patient satisfaction for nurse-led clinic was also evaluated. RESULTS: The interrater agreement between the trained nurse and neurologist in following-up 175 enrolled patients was 76-94%; most unanimity (κ=94%) seen in identifying AED adverse effects while least agreement (κ=76%) was present regarding decisions to modify AED. The mean patient satisfaction score was 37.63 ± 3.26 (maximum possible score 40). CONCLUSION: It is feasible for trained nurses to run epilepsy follow-up clinics in India and patients are likely to be satisfied with this approach.

The antitumor lignan Nortrachelogenin sensitizes prostate cancer cells to TRAIL-induced cell death by inhibition of the Akt pathway and growth factor signaling.

Prostate cancer cells frequently develop resistance toward androgen-deprivation and chemotherapy. To identify new approaches to treat androgen-dependent prostate cancer, we have performed a structure-activity analysis of lignan polyphenols for cancer cell specific sensitization to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a death ligand that has ability to induce tumor-specific cell death. In this study, we report that the lignan nortrachelogenin (NTG) is the most efficient of the 27 tested lignan compounds in sensitizing prostate cancer cells to TRAIL-induced apoptosis. Importantly, pretreatment with NTG does not sensitize a non-malignant prostate cell line to TRAIL-induced cell death. The structural comparison of lignans reveals that the dibenzylbutyrolactone skeleton is required for the apoptosis-sensitizing activity, while substitutions at the aromatic rings do not seem to play a critical role in this lignan function. Our study also characterizes the cellular effects and molecular mechanisms involved in NTG anticancer activity. We previously reported that specific lignans inhibit the Akt survival-signaling pathway in concert with TRAIL sensitization. While NTG is also shown to be a effective inhibitor of Akt signaling, in this study we further demonstrate that NTG potently inhibits tyrosine kinase (RTK) activation in response to growth factors, such as insulin and insulin-like growth factor I (IGF-I). Our results identify NTG as a novel agent for prostate cancer therapy with ability to inhibit Akt membrane localization and activity as well as the activation of growth factor receptors (GFRs), thereby efficiently synergizing with TRAIL exposure.

Chloroform Extract of Rasagenthi Mezhugu, a Siddha Formulation, as an Evidence-Based Complementary and Alternative Medicine for HPV-Positive Cervical Cancers.

Rasagenthi Mezhugu (RGM) is a herbomineral formulation in the Siddha system of traditional medicine and is prescribed in the southern parts of India as a remedy for all kinds of cancers. However, scientific evidence for its therapeutic efficacy in cervical cancer is lacking, and it contains heavy metals. To overcome these limitations, RGM was extracted, and the fractions were tested on HPV-positive cervical cancer cells, ME-180 and SiHa. The extracts, free from the toxic heavy metals, affected the viability of both the cells. The chloroform fraction (cRGM) induced DNA damage and apoptosis. Mitochondria-mediated apoptosis was indicated. Though both the cells responded to the treatment, ME-180 was more responsive. Thus, this study brings up scientific evidence for the efficacy of RGM against the HPV-mediated cervical cancer cells and, if the toxic heavy metals are the limitation in its use, cRGM would be a suitable candidate as evidence-based complementary and alternative medicine for HPV-positive cervical cancers.

Human serum albumin binding and cytotoxicity studies of surfactant-cobalt(III) complex containing 1,10-phenanthroline ligand.

The characteristics of the binding reaction of surfactant-cobalt(III) complex, cis-[Co(phen)2(C14H29NH2)]Cl2·3H2O (phen=1,10-phenanthroline, C14H29NH2=tetradecylamine) with human serum albumin (HSA) were studied by fluorescence and UV-vis absorption spectroscopy. In addition, the effect of the surfactant-cobalt(III) complex on the conformation of HSA was analysed using synchronous fluorescence spectroscopy. The experimental results showed that surfactant-cobalt(III) complex caused the fluorescence quenching of HSA through a combination of static and dynamic quenching. The number of binding sites (n) and apparent binding constant (K(a)) of surfactant-cobalt(III) complex (above and below the critical micelle concentration (cmc) were determined at various temperatures. According to the thermodynamic parameters, it is likely that hydrophobic interactions are involved in the binding process. The cancer chemotherapeutic potential of surfactant-cobalt(III) complex on ME-180 cervical cancer cell was determined using MTT assay and specific staining techniques. The complex affected the viability of the cells significantly and the cells succumbed through an apoptosis process as seen in the nuclear morphology and cytoplasmic features. In addition, single-cell electrophoresis indicated DNA damage.