Brajesh N. Vaidya

Antioxidant Capacity of Fresh and Dry Leaf Extracts of Sixteen Scutellaria Species

The antioxidant capacity of 16 Scutellaria species was examined using Trolox equivalent antioxidant capacity (TEAC) assay. Total polyphenol, antioxidant capacity estimation and flavonoid content measurements were conducted on fresh and air dried leaf extracts. The highest total polyphenol content was obtained in dry leaf extracts of S. ocmulgee at 732.41 67 mg/g of gallic acid equivalent. Dry leaf extracts of S. ocmulgee registered 2480.93 μmol/g of Trolox equivalent antioxidant capacity and the highest total flavonoid content with 200.63 μg/mL from fresh leaf extracts of S. alpina. Rosemary (Rosmarinus officinalis), a common herb with known high antioxidant potential, was used as a standard for comparison with the Scutellaria species. INTRODUCTION The genus Scutellaria, commonly known as skullcap (scullcap) belongs to the family Lamiaceae (Mint family). Of the 400 known Scutellaria species, over 90 of these plants have been recorded as growing in North America. In the current study, 20 Scutellaria spp. that grow in and adjacent to the state of Georgia were used (Joshee et al., 2002). Scutellaria ocmulgee and Scutellaria montana, two species that grow in Georgia, are relatively rare and protected by the state and federal government (Chafin, 2007). Scutellaria species are known for their potential pharmaceutical/therapeutic properties and have been used in the traditional medicine of many countries for their anti-inflammatory, antioxidant, and anti-viral properties useful in treating human ailments (Huang et al., 2005b; Shang et al., 2010). S. baicalensis, native to China, and S. barbata, from Korea, have been extensively employed in traditional Chinese medicine (TCM) and in Japanese Kampo medicine (JKM) (Watanabe et al., 2002; Murch et al., 2004). Leaf extract from S. ocmulgee has demonstrated inhibitory properties against malignant gliomas (Parajuli et al., 2009, 2011). Plants, such as basil (Ocimum spp.), mint (Mentha spp.), rosemary (Rosmarinus officinalis), lavender (Lavandula spp.), and Baikal skullcap (Scutellaria baicalensis), are known to contain relatively high levels of phenolics and have demonstrated antioxidant activity (Zheng and Wang, 2001; Shao et al., 2004; Waisundara, 2010; Atanassova and Georgieva, 2010). Leaves from peppermint (M. x piperita), rosemary, sage (Salvia spp., spearmint (M. spicata), and thyme (Thymus spp. growing in a greenhouse exhibit total polyphenol (TPP) and Trolox equivalent antioxidant capacity (TEAC) as plants grown under field conditions, plus anti-tumorigenic activity against colon cancer cells (Yi and Wetzstein, 2010; 2011). Free radicals can cause disorders, such as atherosclerosis, central nervous system injury, and gastritis in the human body (Kumpulainen and Salonen, 1999; Pourmorad et al., 2006). By boosting the human immune system, plant-based antioxidants block free radicals produced through oxidation (Schuler, 1990), thus inhibiting chain reactions that could lead to degradation and death of cells (Pratt, 1992; Velioglu et al., 1998; Hu and Willett, 2002). The antioxidant activity delays and inhibits oxidation of cellular components and molecules (Nijveldt et al., 2001). Thus, the level of activity of various phytochemicals is important for the evaluation of their potential health benefit to humans. Vaidya et al.: Antioxidant Capacity of Fresh and Dry Leaf Extracts of Sixteen Sc

Paulownia as a Medicinal Tree: Traditional Uses and Current Advances

Paulownia is one of the most useful and sought after trees, in China and elsewhere, due to its multipurpose status. Though not regarded as a regular medicinal plant species, various plant parts (leaves, flowers, fruits, wood, bark, roots and seeds) of Paulownia have been used for treating a variety of ailments and diseases. Each of these parts has been shown to contain one or more bioactive components, such as ursolic acid and matteucinol in the leaves; paulownin and dsesamin in the wood/xylem; syringin and catalpinoside in the bark. The fruits contain fatty oils, alkaloids, flavonones as well as flavonoids with antioxidant properties. The flavonoid contents and TROLOX Equivalent Antioxidant Capacity (TEAC) value in fresh and dry leaf extracts of Paulownia elongata suggest that this species has potential for advanced medicinal use. In vitro grown Paulownia fortunei Hemsl. seedlings, inoculated with Agrobacterium rhizogenes have a potential to produce hairy roots and synthesize bioactive compounds such as acteosides (verbascosides). With various new studies describing isolation of therapeutic compounds and their probable application in human health, it is an opportune moment to revisit medicinal potential of this tree. In this review, the Mini-review Article He et al.; EJMP, 14(1): 1-15, 2016; Article no.EJMP.25170 2 usage of Paulownia in traditional medicine has been revisited and current advances in various fields of research in the genus Paulownia are summarized.

Cross-species PCR and field studies on Paulownia elongata: A potential bioenergy crop

Abstract Paulownia elongata is a short-rotation fast growing tree and is known for high biomass accumulation and carbon sequestration potential. Optimization of protocols for nucleic acid extraction, PCR, RT-PCR, and other molecular biology techniques are required for better understanding of cellulose synthesis and to assess the potential of Paulownia as a biofuel tree. The main objective of this work was to study a putative cellulose synthase amplicon expression under various environmental conditions and evaluate the potentials of Paulownia as a biofuel tree. Using cross-species PCR an amplicon representative of a putative cellulose synthase gene from Paulownia was identified. This 177-bp long DNA sequence was 46% similar with cellulose synthase genes from Arabidopsis as expected. Gene specific primers for this particular Paulownia cellulose synthase gene were designed and reverse transcription PCR was performed to confirm its transcription. We report an inexpensive cDNA dot-blot method to study expression of this gene under various environmental conditions. We observed that cold and, to a lesser extent, heat stress downregulated its expression. This information will help to understand cellulose deposition in plant cell wall under stressful conditions. To the best of our knowledge this is the first characterization of a cDNA sequence from Paulownia elongata.