In Silico Identification of Novel Flavonoids Targeting Epidermal Growth Factor Receptor.

BACKGROUND: Epidermal growth factor receptor (EGFR, ErBb) belongs to family of receptor tyrosine kinase (RTKs) that plays an important role in multiple cell signaling pathways, which includes cell growth, multiplication apoptosis, etc. Overexpression of EGFR results in development of malignant cells. Therefore, EGFR is considered one of the important target for cancer therapy. OBJECTIVE: In this study, virtual screening of 329 flavonoids obtained from the Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target (NPACT) database had been performed to identify novel EGFR inhibitors. MATERIALS AND METHODS: Virtual screening of flavonoids were carried out using different in silico methods, which includes molecular docking studies, prediction of druglikeness, in silico toxicity studies and bioactivity prediction. RESULTS: Six flavonoids NPACT00061, NPACT00062, NPACT00066, NPACT00280, NPACT00700 and NPACT00856 were identified as potential EGFR inhibitors with good docking score and druglikeness properties. In the in silico toxicity studies, compound NPACT00061, NPACT00062, NPACT00066 and NPACT00856 were found to be carcinogenic. Finally, two flavonoids NPACT00280 and NPACT00700 were recognized as novel EGFR inhibitors. CONCLUSION: Our findings suggest that compound NPACT00280 and NPACT00700 could be further explored as novel EGFR inhibitors.

In Silico Discovery of Novel Flavonoids as Poly ADP Ribose Polymerase (PARP) Inhibitors.

BACKGROUND: The concept of synthetic lethality is an emerging field in the treatment of cancer and can be applied for new drug development of cancer as already been represented by Poly (ADP-ribose) polymerase (PARPs) inhibitors. OBJECTIVE: In this study, we performed virtual screening of 329 flavonoids obtained from the Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target (NPACT) database to identify novel PARP inhibitors. MATERIALS AND METHODS: Virtual screening carried out using different in silico methods which include molecular docking studies, prediction of drug-likeness and in silico toxicity studies. RESULTS: Fifteen out of 329 flavonoids achieved better docking score as compared to rucaparib which is an FDA approved PARP inhibitor. These 15 hits were again rescored using accurate docking mode and drug-likeliness properties were evaluated. The accuracy of the docking method was checked using re-docking. Finally NPACT00183 and NPACT00280 were identified as potential PARP inhibitors with docking score of -139.237 and -129.36, respectively. These two flavonoids also showed no AMES toxicity and no carcinogenicity which was predicted using admetSAR. CONCLUSION: Our finding suggests that NPACT00183 and NPACT00280 have promising potential to be further explored as PARP inhibitors.

In Silico Discovery of Novel Phytoconstituents of Amyris pinnata as a Mitotic Spindle Kinase Inhibitor.

BACKGROUND: Despite many successes in the discovery of numerous cancer chemotherapeutic agents from natural sources, some of the moieties were dropped because of its inefficiency or serious toxicity. Mitosis is an ordered series of fundamentally mechanical events in which identical copies of the genome are moved to two discrete locations within the dividing cell. The crucial role of the mitotic spindle in cell division has identified, which is an important target in cancer chemotherapy. In the present study, we are reporting molecular docking studies and in silico pharmacokinetic profiles of selected phytoconstituents obtained from Amyris pinnata. METHODS: Molecular docking studies of selected phytoconstituents were performed using iGEMDOCK. The crystal structure of the protein was exported from the protein data bank (PDB id: 4C4H). In silico pharmacokinetic profile of selected phytoconstituents was performed using the SWISSADME server. RESULTS: Compound AMNP6 showed higher binding affinity as compared to the standard ligand. All the selected phytoconstituents have passed the Lipinski rule of five and shown no violations. CONCLUSION: Good binding affinity and drug likeliness of the AMNP6 suggest that it can be further investigated and explored as mitotic spindle kinase inhibitor in cancer disease.

Topical liposomal gel of idoxuridine for the treatment of herpes simplex: pharmaceutical and clinical implications.

The optimization of the method of preparation of idoxuridine (IDU) liposomes by the reverse phase evaporation (REV) method was carried out by three variables at three levels (3(3)) factorial design. The three independent variables selected were volume of organic phase (x1), volume of aqueous phase (x2), and drug/phosphatidylcholine/cholesterol in molar ratio (x3). Twenty-seven batches of IDU liposomes were prepared by the REV method and subjected to evaluation for percentage drug entrapment (PDE), size, and size distribution. A reduced polynomial equation was derived by multiple regression of the data of PDE and the transformed values of the three independent variables. Three contour plots at fixed level of-- 1 (low), 0 (medium), and 1 (high) of major contributing variable (x3) were plotted between x1 and x2 at predetermined PDE to understand the physical meaning of independent variables. Liposomal gels were prepared by dispersing optimized IDU liposomes in 2%w/w and 5%w/w (HPMC) K4M gel bases so as to contain 1%w/w IDU (LIG-1 and LIG-2, respectively). The percentage of drug retention (PDR) studies of optimized batch 14 (Lipo-14) and LIG-1 and LIG-2 were carried out at three different storage conditions (2-8 degrees C, 25 +/- 2 degrees C, and 37 degrees C). A comparative diffusion study of LIG-1 and LIG-2 with PIG-1 and PIG-2 (1%w/w IDU with components of liposome dispersed in 2%w/w and 5%w/w HPMC K4M gel bases, respectively), respectively, through human cadaver skin was conducted. A comparative double blind clinical pilot study of optimized LIG-2 gel was carried out for eight weeks and compared with PIG-2 on 20 Herpes simplex patients (10 patients each for HSV-1 and HSV-2, divided into two groups each of 5 patients). Batch 14 (Lipo-14) was found to have maximum PDE of 74.4%. The PDR study showed maximum drug retention at 2-8 degrees C. A significant increase in PDR (p<0.05) was observed in LIG-1 and LIG-2 when compared with Lipo-14 at all the three temperatures. In the diffusion studies, a significant (p<0.05) flux reduction; 3.5 times in LIG-1 when compared with PIG-1 and 2.3 times in LIG-2 when compared with PIG-2 was observed. Approximately 2.2- and 2.5-fold increase in skin drug retention in LIG-1 and LIG-2, respectively, was determined. A double blind clinical study demonstrated an approximately 2.0- and 1.6-fold increase in average percentage improvement in healing of the lesions in patients suffering from HSV-1 and HSV-2 diseases, respectively, when treated with LIG-2 compared with PIG-2. However, complete removal of lesions was not observed. Local side effects such as itching, burning, inflammation in HSV-1 and HSV-2, and burning micturation in HSV-2 associated with the use of PIG-2 were reduced considerably with the use of LIG-2. The findings of this investigation establish the role of the derived equation and plotted contour plots in predicting the values of independent variables for preparation of IDU liposomes by the REV method. The study also demonstrated that IDU liposomal gels retain more drug when compared with plain liposomes at all temperatures for the period of three months, while maximum PDR was found at refrigeration temperature. The skin retention of IDU was enhanced due to its entrapment in the liposomal vesicles. The clinical study suggested the improvement of therapeutic efficacy of IDU entrapped in liposomes in treatment of HSV-1 and HSV-2 patients.

Role of acyclovir gel in herpes simplex: clinical implications.

BACKGROUND: Acyclovir (ACY) is effective in the treatment of herpes simplex (HSV-1) & (HSV-2) but has systemic toxic effects if given orally or intravenously. ACY has not been used to treat the disease topically due to poor drug penetration into skin. A novel 1% liposomal ACY topical gel in a 5% Hydroxypropylmethyl cellulose (HPMC) K4M gel base has been developed and clinically evaluated in HSV-1 and HSV-2 patients. MATERIAL/METHODS: 26 patients suffering from recurrent mild facial (HSV-1) and genital (HSV-2) infections (HSV-1: 4F, 6M, age 21-34 years; HSV-2: 16M, age 24-40 years) were subjected to double blind clinical evaluation. Plain ACY gel (PAG) and Liposomal ACY gel (LAG) were clinically evaluated by application five times daily on herpetic lesions for up to eight weeks. RESULTS: A significant increase in the average percent improvement of lesion healing was observed in HSV-1 and HSV-2 patients after 2-3 weeks treatment with LAG, as well as a significant decrease in side effects associate with ACY, such as itching and burning in both HSV-1 and HSV-2, and burning micturation in HSV-2. CONCLUSIONS: The results demonstrate that a five-fold reduction in the ACY content in liposomal gel is sufficient for the complete healing of herpetic lesions in HSV-1 and HSV-2 infection. The increased duration of topical therapy may be acceptable for patients suffering from mild herpetic lesions because of the advantage of avoiding systemic and local side effects

Mathematical modelling of preparation of acyclovir liposomes: reverse phase evaporation method.

PURPOSE: The aim of this study was to derive simple reduced second order polynomial equation for constructing contour plots to obtain predetermined % drug entrapment (PDE) within liposomes of acyclovir (ACY) when prepared by reverse phase evaporation (REV) method using technique of three variables at three levels (3(3)) factorial design. METHOD: Three independent variables selected were volume of organic phase (x(1)), volume of aqueous phase (x(2)), and Drug/Phosphatidylcholine (PC) /Cholesterol (CHOL) in molar ratio (x(3)). Based on factorial design, twenty-seven batches of ACY liposomes were prepared by REV method. Prepared liposomal batches were evaluated for size, lamellarity, and PDE. The PDE (dependent variable) and the transformed values of independent variables were subjected to multiple regressions to establish a second order polynomial equation (full model). To simplify the equation, F-statistic was applied to reduce polynomial equation (reduced model) by neglecting nonsignificant (p>0.05) terms. The coefficient value for independent variable, Drug/PC/CHOL in molar ratio (x(3)) was found to be maximum (b(3) = 2.52) and hence the variable x(3) was considered to be a major contributing variable for PDE within liposomes by REV method. The reduced polynomial equation was used to plot three two-dimensional contour plots at a fixed levels of -1, 0 and 1 of major contributing variable (x(3)) to obtain various combinations of values of two other independent variables (x(1) & x(2)) at predetermined PDE. The conformity of the established equation was checked by preparing three batches three times taking values of the independent variables from the contour plots for prefixed value of PDE. RESULTS: Prefixed PDE value taken for designing the experiment and results obtained experimentally were compared using student 't' test and difference between experimentally obtained and theoretically calculated values of PDE was found to be statistically nonsignificant (p>0.05). CONCLUSIONS: Findings of this study establishes the role of the derived equation and plotted contour plots in predicting the values of independent variables for preparation of ACY liposomes by REV method having predetermined PDE.