Curcumin nanoformulations for antimicrobial and wound healing purposes.

The development and spread of resistance to antimicrobial drugs is hampering the management of microbial infectious and wound healing processes. Curcumin is the most active and effective constituent of Curcuma longa L., also known as turmeric, and has a very long and strong history of medicinal value for human health and skincare. Curcumin has been proposed as strong antimicrobial potentialities and many attempts have been made to determine its ability to conjointly control bacterial growth and promote wound healing. However, low aqueous solubility, poor tissue absorption and short plasma half-life due its rapid metabolism needs to be solved for made curcumin formulations as suitable treatment for wound healing. New curcumin nanoformulations have been designed to solve the low bioavailability problem of curcumin. Thus, in the present review, the therapeutic applications of curcumin nanoformulations for antimicrobial and wound healing purposes is described.

Zebrafish: An emerging whole-organism screening tool in safety pharmacology.

During the last two decades, the development in drug discovery is slackening due to drug withdrawal from the market or reported to have postmarket safety events. The vital organ toxicities, especially cardiotoxicity, hepatotoxicity, pulmonary toxicity, and neurotoxicity are the major concerns for high drug attrition rates. The pharmaceutical industry is looking for high throughput, high content analysis based novel assays that would be fast, efficient, reproducible, and cost-effective; would address toxicity, the safety of lead molecules, and complement currently used cell-based assays in preclinical testing. The use of zebrafish, a vertebrate screening model, for preclinical testing is increasing owing to the number of advantages and striking similarities with the mammal. The zebrafish embryo development is fast and all vital organs such as the heart, liver, brain, pancreas, and kidneys in zebrafish are functional within 96-120hpf. The maintenance cost of zebrafish is reasonably low as compared to mammalian systems. Due to these features, zebrafish has arisen as a potential experimental screening model in lead identification and validation in the drug efficacy, toxicity, and safety evaluation. Numbers of drugs and chemicals are screened using zebrafish embryos, and results were found to show 100% concordance with mammalian screening data. The application of zebrafish, being a whole-organism screening model, would show a significant reduction in the cost and time required in the drug development process. The present challenge includes complete automation of the zebrafish screening model, i.e., from sorting, imaging of embryos to data analysis to accelerate the therapeutic target identification, and validation process.

Virus-Induced Silencing of Key Genes Leads to Differential Impact on Withanolide Biosynthesis in the Medicinal Plant, Withania somnifera.

Withanolides are a collection of naturally occurring, pharmacologically active, secondary metabolites synthesized in the medicinally important plant, Withania somnifera. These bioactive molecules are C28-steroidal lactone triterpenoids and their synthesis is proposed to take place via the mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways through the sterol pathway using 24-methylene cholesterol as substrate flux. Although the phytochemical profiles as well as pharmaceutical activities of Withania extracts have been well studied, limited genomic information and difficult genetic transformation have been a major bottleneck towards understanding the participation of specific genes in withanolide biosynthesis. In this study, we used the Tobacco rattle virus (TRV)-mediated virus-induced gene silencing (VIGS) approach to study the participation of key genes from MVA, MEP and triterpenoid biosynthesis for their involvement in withanolide biosynthesis. TRV-infected W. somnifera plants displayed unique phenotypic characteristics and differential accumulation of total Chl as well as carotenoid content for each silenced gene suggesting a reduction in overall isoprenoid synthesis. Comprehensive expression analysis of putative genes of withanolide biosynthesis revealed transcriptional modulations conferring the presence of complex regulatory mechanisms leading to withanolide biosynthesis. In addition, silencing of genes exhibited modulated total and specific withanolide accumulation at different levels as compared with control plants. Comparative analysis also suggests a major role for the MVA pathway as compared with the MEP pathway in providing substrate flux for withanolide biosynthesis. These results demonstrate that transcriptional regulation of selected Withania genes of the triterpenoid biosynthetic pathway critically affects withanolide biosynthesis, providing new horizons to explore this process further, in planta.

Ethnopharmacological based Evaluation of Anogeissus pendula Edgew Extracts for Antioxidant and Hepatoprotective Potential.

BACKGROUND: Anogeissus pendula has various reported ethnomedicinal uses and is reported to contain phenolic compounds which have antioxidant potential. AIM: The present study was undertaken to evaluate the in vitro antioxidant potential and in vivo hepatoprotective activity along with the oxidative stress parameters of stem bark and leaves of Anogeissus pendula for the first time. SETTINGS AND DESIGN: Albino rats were divided into seven groups of six animals each. Healthy control (Group I) and toxic control (Group II) received the vehicle. Group III, IV, V, VI and VII were treated with silymarin (100 mg/kg body weight, orally) and two hydro-alcoholic extracts i.e., APB (stem bark) and APL (leaves) at doses of 200 and 400 mg/kg b. w., orally, respectively. Hepatotoxicity was induced by allyl alcohol. MATERIALS AND METHODS: Albino Wistar rats of either sex between 8-12 weeks old were used. The plant parts were collected from Sawai Madhopur (Rajasthan, India) and extracted with hydro-alcoholic solvent to get two extracts i.e., APB (stem bark) and APL (leaves) which were investigated for the in vitro antioxidant potential through DPPH radical and H2O2 scavenging assay along with in vivo hepatoprotective potential through allyl alcohol induced hepatotoxicity. STATISTICAL ANALYSIS: Statistical comparisons between different groups were done by using one-way ANOVA followed by the Bonferroni test. P < 0.05 was considered significant. RESULTS AND CONCLUSIONS: APB showed more potent activity than APL in case of in vitro antioxidant potential with IC50 of 44.29 µg/ml in DPPH radical scavenging activity and 53.09 µg/ml in hydrogen peroxide scavenging assay. Both the extracts revealed antioxidant and hepatoprotective potentials in a dose dependent manner but more significant results were obtained in case of APB at 400 mg/kg. More amounts of phytoconstituents might be the reason behind the more significant activity of extract of stem bark than that of the leaves.

Comprehensive assessment of the genes involved in withanolide biosynthesis from Withania somnifera: chemotype-specific and elicitor-responsive expression.

Withania somnifera (L.) Dunal (Family, Solanaceae), is among the most valuable medicinal plants used in Ayurveda owing to its rich reservoir of pharmaceutically active secondary metabolites known as withanolides. Withanolides are C28-steroidal lactones having a triterpenoidal metabolic origin synthesised via mevalonate (MVA) pathway and methyl-D-erythritol-4-phosphate (MEP) pathway involving metabolic intermediacy of 24-methylene (C30-terpenoid) cholesterol. Phytochemical studies suggest differences in the content and/or nature of withanolides in different tissues of different chemotypes. Though development of genomic resources has provided information about putative genes encoding enzymes for biosynthesis of intermediate steps of terpenoid backbone, not much is known about their regulation and response to elicitation. In this study, we generated detailed molecular information about genes catalysing key regulatory steps of withanolide biosynthetic pathway. The full-length sequences of genes encoding enzymes for intermediate steps of terpenoid backbone biosynthesis and their paralogs have been characterized for their functional and structural properties as well as phylogeny using bioinformatics approach. The expression analysis suggests that these genes are differentially expressed in different tissues (with maximal expression in young leaf), chemotypes and in response to salicylic acid (SA) and methyl jasmonate (MJ) treatments. Sub-cellular localization studies suggest that both paralogs of sterol ∆-7 reductase (WsDWF5-1 and WsDWF5-2) are localized in the endoplasmic reticulum (ER) thus supporting their indispensible role in withanolide biosynthesis. Comprehensive information developed, in this study, will lead to elucidation of chemotype- as well as tissue-specific withanolide biosynthesis and development of new tools for functional genomics in this important medicinal plant.

The genus Anogeissus: A review on ethnopharmacology, phytochemistry and pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Anogeissus (axlewood tree, ghatti tree, button tree and chewing stick tree) belongs to Combretaceae, includes eight species that are distributed in Asia and Africa. Plants are used as an ethnomedicine in Asia and Africa to treat various ailments like diabetes, fever, diarrhoea, dysentery, tuberculosis, wound healing, skin diseases (eczema, psoriasis), snake and scorpion venom. Based on the traditional knowledge, different phytochemical and pharmacological activities have been at the focus of research. The aim of this review is to provide updated, comprehensive and categorized information on the ethnobotany, phytochemistry, pharmacological research and toxicity of Anogeissus species in order to identify their therapeutic potential and directs future research opportunities. MATERIALS AND METHODS: The relevant data was searched by using the keyword "Anogeissus" in "Scopus", "Google Scholar", "Web of Science", "PubMed", and "ScienceDirect" databases. Plant taxonomy was validated by the databases "The Plant List" and A.J. Scott, 1979. RESULTS: This review discusses the current knowledge of the ethnobotany, phytochemistry and in vitro as well as in vivo pharmacological evaluations carried out on the extracts and isolated main active constituents of Anogeissus genus. Among eight species, most of the phytochemical and pharmacological studies were performed on four species. About 55 secondary metabolites are isolated from the genus. Stem bark, leaf, seed, fruit, root of the plants are used for the treatment of several health disorders such as diabetes, fever, diarrhoea, dysentery, tuberculosis, wound healing, skin diseases (eczema, psoriasis), snake and scorpion venom. Gum ghatti obtained from Anogeissus latifolia is used after delivery as tonic and in spermatorrhoea. Many phytochemical investigations on this genus confirmed that it is rich in phenolic compounds. Modern pharmacology research has confirmed that the crude extracts or the isolated active compounds of the genus Anogeissus possess antioxidant, antimicrobial, wound healing, antiulcer, anti-inflammation, anti-diabetics, hepatoprotective, hypolipidemic, antiparasitic and neuroprotective effects. CONCLUSIONS: This review confirms that some Anogeissus species have emerged as a good source of the traditional medicine for wound healing, inflammation, skin diseases, microbial infection and diabetes. Many traditional uses of Anogeissus species have now been validated by modern pharmacology research. Intensive investigations of all the species of Anogeissus regarding phytochemical and pharmacological properties, especially their mechanism of action, safety and efficacy could be the future research interests before starting clinical trials.