In vitro protective effect of Pandanus ordoratissimus extract on ultraviolet B (UVB)-induced DNA damage

Pandanus ordoratissimus is an herb which has been widely used in Thai traditional medicines. A number of studies provided experimental evidence indicating that extracts from roots and leaves of P. ordoratissimus had powerful antioxidant and anti-inflammatory activities. However, the protective effects of extract from P. ordoratissimus flowers on ultraviolet B (UVB)-induced DNA damage have not yet been reported. This study focused on assessing the protective effect of P. odoratissimus extract (POE) against UVB by using human keratinocyte stem cells (KSCs) as an in vitro testing system. The keratinocytes were pre-treated with POE before being assayed for DNA damages caused by UVB (290 to 315 nm). Ascorbyl glucoside and DN-AGE®, reagents commonly used in cosmetic products to protect the skin against UV exposure due to their abilities to scavenge free radicals, were used as positive controls. The alkaline comet assay was used to quantify DNA damage. Photo-dependent cytogenetic lesions were assessed by the micronucleus test (MNT). It was found that POE effectively reduced the extent of DNA breakages and cytogenetic lesions upon exposure to UVB (erythemal ultraviolet (EUV); 17.09 mJ/cm2). POE significantly decreased tail DNA (TD%), tail length (TL) and micronucleus frequencies (MNFs) which is similar to the protective effects provided by ascorbyl glucoside and DN-AGE®.Key words: Pandanus odoratissimus, comet assay, micronucleus test

Ethnobotany and antimicrobial peptide from plants of Solanaceae family: An update and future prospect

The Solanaceae is an important plant family that has been playing an essential role in traditional medicine and human nutrition. Members of the Solanaceae are rich in bioactive metabolites and have been used by different tribes around the world for ages. Antimicrobial peptides (AMPs) from plants have drawn great interest in recent years and raised new hope for developing new antimicrobial agents for meeting the challenges of antibiotic resistance. This review aims to summarize the reported AMPs from plants of the Solanaceae with possible molecular mechanisms of action as well as to correlate their traditional uses with reported antimicrobial actions of the peptides. A systematic literature study was conducted using different databases until August 2019 based on the inclusion and exclusion criteria. According to literature, a variety of AMPs including defensins, protease inhibitor, lectins, thionin-like peptides, vicilin-like peptides, and snaking were isolated from plants of the Solanaceae and were involved in their defense mechanism. These peptides exhibited significant antibacterial, antifungal and antiviral activity against organisms for both plant and human host. Brugmansia, Capsicum, Datura, Nicotiana, Salpichora, Solanum, Petunia, and Withania are the most commonly studied genera for AMPs. Among these genera, Capsicum and the Solanum ranked top according to the total number of studies (35%–38% studies) for different AMPs. The mechanisms of action of the reported AMPs from Solanaceae was not any new rather similar to other reported AMPs including alteration of membrane potential and permeability, membrane pore formation, and cell aggregation. Whereas, induction of cell membrane permiabilization, inhibition of germination and alteration of hyphal growth were reported as mechanisms of antifungal activity. Plants of the Solanaceae have been used traditionally as antimicrobial, insecticidal, and antiinfectious agents, and as poisons. The reported AMPs from the Solanaceae are the products of chemical shields to protect plants from microorganisms and pests which unfold an obvious link with their traditional medicinal use. In summary, it is evident that AMPs from this family possess considerable antimicrobial activity against a wide range of bacterial and fungal pathogens and can be regarded as a potential source for lead molecules to develop new antimicrobial agents

TEM micrographs of <i>S</i>. <i>epidermidis</i> after treatment with BcDef1.

<p>(A and C) Untreated cells possessed intact cell walls and cell membranes. After 2 h of BcDef1 treatment, (B and D), BcDef1 induced cell lysis (black arrow) and ultrastructural damage in <i>S</i>. <i>epidermidis</i> cells, including some mesosome-like structure formation (blue arrow), and ruptures of cell walls (green arrow) and cell membranes (red arrow).</p

Multiple alignment of plant defensins.

<p>Shading indicates sequence identity from low (light blue) to high (dark blue). The brackets indicate the conserved α-core and γ-core motifs consensus sequence, respectively. Disulphide bonds are depicted by connecting lines.</p

Maximum Likelihood phylogenetic tree of BcDef and defensins of the Solanaceae plant family.

<p>Maximum Likelihood phylogenetic tree of BcDef and defensins of the Solanaceae plant family.</p

Higher magnification pictures show the structural observations of <i>S</i>. <i>epidermidis</i> treated with BcDef1.

<p>(A) Untreated cells possessed intact cell wall and cell membrane. After 2 h of BcDef1 treatment, several structural alterations were observed, including changes in cell wall thickness (B and C), pore formation in cell wall and cell membrane (D), cell wall and cell membrane disruption (E and F), and release of cellular content (F).</p