Radhakrishnan Narayanaswamy

Cosmetic potential of Southeast Asian herbs: an overview

Herbs and spices have been used in retaining and boosting human beauty since time immemorial. Herbal cosmetic has growing demand in the worldwide market and is an invaluable gift of Mother Nature. In the present review, the focus is on the cosmetic herbs of Southeast Asian countries namely Malaysia, Cambodia, Laos, Myanmar [Burma], Thailand, Vietnam, Brunei, East Timor, Indonesia, Philippines and Singapore in highlighting both traditional and scientific knowledge or background of the selected potential herbs. The available literature was searched in the following scientific database such as PubMed, Google Scholar, Science Direct and Springer for publications and patents. In view of traditional uses, herbs like Allium sativum, Aloe vera, Centella asiatica, Curcuma longa, Hibiscus rosa-sinensis, Lawsonia inermis and Tamarindus indica L. were classified as need of special mention. Many herbs have been scientifically evaluated for their cosmetic potentials such as anti-aging, anti-acne, melanogenic and anti-tyrosinase activities. The great void remains for a systematic study, thorough review of scientific report that provides a basis for the use of specific herbs due to their efficacy as cosmetics. In addition, two of the Malay herbs; Labisia pumila (Kacip Fatimah) and Ficus deltoidea (Mas cotek), are proposed to be clinically studied for their safety in cosmetic application aspects wherein the need for safety evaluation and fruitful application of herbal cosmetics were emphasized.

Synthesis and Docking Studies of 2,4,6-Trihydroxy-3-Geranylacetophenone Analogs as Potential Lipoxygenase Inhibitor

The natural product molecule 2,4,6-trihydroxy-3-geranyl-acetophenone (tHGA) isolated from the medicinal plant Melicope ptelefolia was shown to exhibit potent lipoxygenase (LOX) inhibitory activity. It is known that LOX plays an important role in inflammatory response as it catalyzes the oxidation of unsaturated fatty acids, such as linoleic acid to form hydroperoxides. The search for selective LOX inhibitors may provide new therapeutic approach for inflammatory diseases. Herein, we report the synthesis of tHGA analogs using simple Friedel-Craft acylation and alkylation reactions with the aim of obtaining a better insight into the structure-activity relationships of the compounds. All the synthesized analogs showed potent soybean 15-LOX inhibitory activity in a dose-dependent manner (IC50 = 10.31–27.61 μM) where compound 3e was two-fold more active than tHGA. Molecular docking was then applied to reveal the important binding interactions of compound 3e in soybean 15-LOX binding site. The findings suggest that the presence of longer acyl bearing aliphatic chain (5Cs) and aromatic groups could significantly affect the enzymatic activity.

Molecular Docking Analysis of Selected Clinacanthus nutans Constituents as Xanthine Oxidase, Nitric Oxide Synthase, Human Neutrophil Elastase, Matrix Metalloproteinase 2, Matrix Metalloproteinase 9 and Squalene Synthase Inhibitors.

Background: Clinacanthus nutans (Burm. f.) Lindau has gained popularity among Malaysians as a traditional plant for anti-inflammatory activity. Objective: This prompted us to carry out the present study on a selected 11 constituents of C. nutans which are clinacoside A–C, cycloclinacoside A1, shaftoside, vitexin, orientin, isovitexin, isoorientin, lupeol and β-sitosterol. Materials and Methods: Selected 11 constituents of C. nutans were evaluated on the docking behavior of xanthine oxidase (XO), nitric oxide synthase (NOS), human neutrophil elastase (HNE), matrix metalloproteinase (MMP 2 and 9), and squalene synthase (SQS) using Discovery Studio Version 3.1. Also, molecular physicochemical, bioactivity, absorption, distribution, metabolism, excretion, and toxicity (ADMET), and toxicity prediction by computer assisted technology analyzes were also carried out. Results: The molecular physicochemical analysis revealed that four ligands, namely clinacoside A–C and cycloclinacoside A1 showed nil violations and complied with Lipinskis rule of five. As for the analysis of bioactivity, all the 11 selected constituents of C. nutans exhibited active score (>0) toward enzyme inhibitors descriptor. ADMET analysis showed that the ligands except orientin and isoorientin were predicted to have Cytochrome P4502D6 inhibition effect. Docking studies and binding free energy calculations revealed that clinacoside B exhibited the least binding energy for the target enzymes except for XO and SQS. Isovitexin and isoorientin showed the potentials in the docking and binding with all of the six targeted enzymes, whereas vitexin and orientin docked and bound with only NOS and HNE. Conclusion: This present study has paved a new insight in understanding these 11 C. nutans ligands as potential inhibitors against XO, NOS, HNE, MMP 2, MMP 9, and SQS.

In Silico Analysis of Selected Honey Constituents as Human Neutrophil Elastase (HNE) and Matrix Metalloproteinases (MMP 2 and 9) Inhibitors

In the present study 12 constituents of honey were evaluated on the docking behavior of human neutrophil elastase and matrix metalloproteinases (MMP 2 and MMP 9) using Discovery Studio. In addition molecular physicochemical, bioactivity, absorption, distribution, metabolism, excretion, and toxicity, and toxicity prediction by komputer assisted technology analyses were done. The molecular physicochemical analysis revealed thatall of the ligands comply with Lipinski’s rule of five. Docking studies revealed that 3-phenyllacticacid exhibited the maximum interaction energy irrespective of its target proteins.The present study provided new insight in understanding these honey constituents as potential enzyme inhibitors.

Molecular docking analysis of phytic acid and 4-hydroxyisoleucine as cyclooxygenase-2, microsomal prostaglandin e synthase-2, tyrosinase, human neutrophil elastase, matrix metalloproteinase-2 and -9, xanthine oxidase, squalene synthase, nitric oxide synthase, human aldose reductase, and lipoxygenase inhibitors

Background: The phytoconstituents phytic acid and 4-hydroxyisoleucine have been reported to posses various biological properties. Objective: This prompted us to carry out the docking study on these two ligands (phytic acid & 4-hydroxyisoleucine) against eleven targeted enzymes. Materials and Methods: Phytic acid & 4-hydroxyisoleucine were evaluated on the docking behaviour of cyclooxygenase-2 (COX-2), microsomal prostaglandin E synthase-2 (mPGES-2), tyrosinase, human neutrophil elastase (HNE), matrix metalloproteinase (MMP 2 and 9), xanthine oxidase (XO), squalene synthase (SQS), nitric oxide synthase (NOS), human aldose reductase (HAR) and lipoxygenase (LOX) using Discovery Studio Version 3.1 (except for LOX, where Autodock 4.2 tool was used). Results: Docking and binding free energy analysis revealed that phytic acid exhibited the maximum binding energy for four target enzymes such as COX-2, mPGES-2, tyrosinase and HNE. Interestingly, we found that 4-hydroxyisoleucine has the potential to dock and bind with all of the eleven targeted enzymes. Conclusion: This present study has paved a new insight in understanding 4-hydroxyisoleucine as potential inhibitor against COX-2, mPGES-2, tyrosinase, HNE, MMP 2, MMP 9, XO, SQS, NOS, HAR and LOX. Abbreviations used: COX-2: Cyclooxygenase-2, mPGES-2: Microsomal prostaglandin E synthase-2, HNE: Human neutrophil elastase, MMP-2 and -9: Matrix metalloproteinase-2 and -9, XO: Xanthine oxidase, SQS: Squalene synthase, NOS: Nitric oxide synthase, HAR: Human aldose reductase, LOX: Lipoxygenase, ADME: Absorption, distribution, metabolism, and excretion, TOPKAT: Toxicity Prediction by Computer-assisted Technology.

Nanobiomaterial-based delivery of drugs in various cancer therapies

Cancer remains one of the most devastating diseases in the world amid epidemiologic studies suggesting that cancer will be the number one disease in prevalence by 2020. It is described as an abnormal growth of cells triggered by numerous alterations in the expression of crucial genes that leads to the dysregulated balance of cell proliferation and cell death that causes significant morbidity. Using nanotechnology for treating or delivering drugs to the site of cancer cells is acquiring considerable attention. Nanoparticles have also been used to deliver drugs to target tissues and to increase stability against degradation by enzymes. In general, biopolymers, such as protein (silk, collagen, gelatin, β-casein, and albumin), protein-mimicked polypeptides (elastin-like polypeptide), polysaccharides (chitosan, alginate, pullulan, starch, and heparin), lipid-based nanoparticles, polymeric nanoparticles (PLA, PLGA and PCL), and nanotubes (fullerene derivatives), are widely used nowadays to deliver drugs or siRNA to the tumor site. The advantages, limitations, and efficacy of nanoparticles in cancer therapy will be discussed in this chapter also focusing on changes in the biochemical and molecular pathway of cancer cells during nanoparticle-mediated cancer therapy.

Basics to different imaging techniques, different nanobiomaterials for image enhancement

Abstract The recent applications of nanobiomaterials and functionalized nano-devices are now impacting the global market and show the great promise that this technology holds for the rest of this century. The changes in nanotechnology have provided new insights for material schemes that are centered on the structural switch of atoms and molecules. This technology has transformed and completely changed the field of innovative functional materials. Especially after the Genome Project in 2000, the present knowledge, in combination with the huge amount of acquired techniques and material know-hows, has allowed us to conceptualize new medical technologies. One of the cutting-edge visual non-invasive methods is medical imaging, which allows an understanding of the interior organs of the body without any surgical intervention. Nanobiomaterials are very useful in medicine for developing diagnostic devices, contrast/visual agents, analytical tools, drug delivery systems, tissue engineering, and physical therapy vehicles. The fate of these materials is categorically visualized by multimodal molecular imaging/medical imaging. This chapter presents the major insights and current status of nanotechnology and nanobiomaterials to its various applications in medical imaging.