Phenolic composition and antioxidant activity of culms and sugarcane (Saccharum officinarum L.) products

Physico-chemical properties, wax composition, aroma profiles, and antioxidant activity of granulated non-centrifugal sugars from sugarcane cultivars of Thailand

Non-centrifugal cane sugar (NCS) is globally consumed and has various health benefits. It is mostly produced in hardened block form, which is less convenient than in granulated form for food applications. In terms of the traditional processing of NCS, preparation of granulated products is difficult due to the impurities found in the cane juice extracted from the whole stalk. Therefore, the aim of this study was to characterize and determine the physico-chemical properties, wax composition (policosanols and long-chain aldehydes), volatile aroma profiles, and antioxidant activity of traditional NCS in granular form made from four different cane cultivars of Thailand. The total soluble solid, pH, color, and mineral content varied among the sugarcane cultivars, whereas there was no significant difference in the total sugar, phenolic and flavonoid content. The total policosanol, a cholesterol-lowering nutraceutical wax component, and long-chain aldehyde contents were similar in the NCS products amongst three cultivars, and ranged from 2.63 to 3.69 mg/100 g. The granulated NCS products, in which acetaldehyde and dimethyl sulfide were the main volatile compounds, gave less aroma components than traditional NCS. The use of different sugarcane cultivars thus influenced the quality attributes of granulated non-centrifugal sugar products.

Phenolic compounds and anticancer activity of commercial sugarcane cultivated in Brazil

The cultivation of sugarcane hybrids (X Saccharum officinarum L.) is an important revenue source for the Brazilian economy. Herein it is reported the evaluation of the cytotoxic activity of mid-polarity sugarcane extracts against human cancer cell lines, as well as the isolation of steroids sitosterol, stigmasterol and campesterol, phenolic acids p-hydroxybenzoic, p-hydroxycinnamic, vanillic and ferulic acid, terpenoids α-tocopherol and β-carotene and a novel substance in sugarcane, the flavonoid aglycone tricin (5,7,4-trihydroxy-3,5-dimethoxyflavone). The presence of large amounts of phenolic acids and the flavonoid tricin may explain the cytostatic activity observed for the mid-polarity crude extract and filtrates.

Immobilization of β-glucosidase onto silicon oxide nanoparticles and augment of phenolics in sugarcane juice

Purified β-glucosidase was immobilized on SiO2 nanoparticles with 52 % efficiency and 14.1 % yield. It had a temperature optima at 60 °C and pH optima of 5.0. Immobilized enzyme was fairly stable at 60-70 °C. After immobilization, the Km value of β-glucosidase for p-nitrophenyl-β-d-glucopyranoside (pNPG) increased from 0.9 to 1.074 mM and Vmax decreased from 3.5 to 1.513 U/mg. The immobilized enzyme showed improved storage stability at temperature 4 and 25 °C and was reusable for up to ten cycles with 70 % residual activity in pNPG and 60 % residual activity in sugarcane juice treatment. Sugarcane juice density, viscosity; surface tension etc. changed after treatment with immobilized β-glucosidase. β-Glucosidase treated sugarcane juice showed higher phenolics than untreated sugarcane juice. Caffeic acid which was absent in juice, was detected in β-glucosidase treated juice at a concentration of about 1 mg/L.

A novel process for obtaining phenylpropanoic acid precursor using Escherichia coli with a constitutive expression system

Phenylpropanoids are widely used in food supplements, pharmaceuticals, and cosmetics with diverse benefits to human health. Trans-cinnamic acid or p-coumaric acid is usually used as the starting precursor to produce phenylpropanoids. Synthetic bioengineering of microbial cell factories offers a sustainable and flexible alternative method for obtaining these compounds. In this study, a constitutive expression system consisting of Rhodotorula glutinis phenylalanine/tyrosine ammonia lyase was developed to produce a phenylpropanoic acid precursor in Escherichia coli. To improve trans-cinnamic acid and p-coumaric acid production, BioBrick optimization was investigated, causing a 7.2- and 14.2-fold increase in the yield of these compounds, respectively. The optimum strain was capable of de novo producing 78.81 mg/L of trans-cinnamic acid and 34.67 mg/L of p-coumaric acid in a shake flask culture. The work presented here paves the way for the development of a sustainable and economical process for microbial production of a phenylpropanoic acid precursor.

Antioxidant, Antibacterial, Cytotoxic, and Anti-Inflammatory Potential of the Leaves of Solanum lycocarpum A. St. Hil. (Solanaceae)

Ethanol extract and fractions obtained from leaves of Solanum lycocarpum were examined in order to determine their phenolic composition, antioxidant, antibacterial, anti-inflammatory, and cytotoxic potential. High performance liquid chromatography coupled with DAD analysis indicated that the flavonoids apigenin and kaempferol were the main phenolic compounds present in dichloromethane and ethyl acetate fractions, respectively. The antioxidant activity was significantly more pronounced for dichloromethane, ethyl acetate, and hydroethanol fractions than that of the commercial antioxidant 2,6-di-tert-butyl-4-methylphenol. The hexane and dichloromethane fractions were more active against the tested bacteria. The hydroethanol fraction exhibited significant anti-inflammatory activity at the dose of 75 and 150 mg/kg in the later phase of inflammation. However, the antiedematogenic effect of the higher dose of the ethyl acetate fraction (150 mg/kg) was more pronounced. The ethyl acetate fraction also presented a less cytotoxic effect than the ethanol extract and other fractions. These activities found in S. lycocarpum leaves can be attributed, at least in part, to the presence of phenolic constituents such as flavonoids. This work provided the knowledge of phenolic composition in the extract and fractions and the antioxidant, antibacterial, anti-inflammatory, and cytotoxic activities of leaves of S. lycocarpum.

Ethnopharmacological analysis of medicinal plants and animals used in the treatment and management of pain in Mauritius

ETHNOPHARMACOLOGICAL RELEVANCE

Pain is a multi-faceted and multi-factorial condition which is challenging to manage and treat. Conventional therapies such as analgesics, Non-steroidal anti-inflammatory drugs (NSAIDs), and corticosteroids amongst others have been successful to some extent in its management and treatment. Nonetheless, such therapies tend to be accompanied by undesirable effects and have a limited therapeutic range. Consequently, there is a pressing need to probe for novel analgesic and anti-nociceptive drugs from traditional medicines (TM). This study was designed to record, document and analyze herbal and animal-based therapies used for the management and treatment of pain in the tropical of Mauritius.

MATERIALS AND METHODS

Data was collected via face-to-face interviews with TM users (n=332) and practitioners (n=20). Seven quantitative ethnopharmacological indexes, namely family use value (FUV), use value (UV), informant agreement ratio (IAR), relative frequency of citation (RFC), fidelity level (FL), relative importance (RI) and ethnobotanicity index (EI) were calculated.

RESULTS

A total of 79 plant species distributed within 40 families and 20 polyherbal preparations was recorded. Interestingly, 6 indigenous/endemic plants have been reported for the first time to be in common use for pain management and treatment in Mauritius. The most significant biologically important plant family was Xanthorrhoeaceae with highest FUV. The species which ranked highest according to its UV was Morinda citrifolia L. Morinda citrifolia L. and Ricinus communis L. also scored the highest RFC. The IAR values for the disease categories were high (0.95-0.97). Based on EI, plants species which are known to be useful in TM accounted for 11.5% of the total flora in Mauritius. Coix lacryma-jobi L. (FL=100%) had highest FL for lower back ache. Morinda citrifolia L. scored highest on most of the quantitative indices calculated including RI, which is endorsed by extensive documentation on its versatility and particularly its anti-nociceptive properties. Seven animal species were recorded to be in common use.

CONCLUSION

The present ethnopharmacological study revealed a panoply of TM to be in common use for pain management and treatment in Mauritius. This study has documented for the first time medicinal plants and animal species with potential analgesic and/or anti-nociceptive properties. This study has therefore provided important baseline primary data for the discovery of new lead molecules for drug development geared towards pain management and treatment.

Sugar cane stillage: a potential source of natural antioxidants

Biorefinery of sugar cane is the first economic activity of Reunion Island. Some sugar cane manufactured products (juice, syrup, molasses) have antioxidant activities and are sources of both phenolic compounds and Maillard Reaction Products (MRP). The study aimed to highlight the global antioxidant activity of sugar cane stillage and understand its identity. Chromatographic fractionation on Sephadex LH-20 resin allowed the recovery of a MRP-rich fraction, responsible for 58 to 66% of the global antioxidant activity according to the nature of the sugar cane stillage (DPPH test), and a phenolic compounds-rich fraction for 37 to 59% of the activity. A good correlation was recorded between the antioxidant activity of the sugar cane stillage and its content in total reducing compounds amount (Folin-Ciocalteu assay), among them 2.8 to 3.9 g/L of phenolic compounds (in 5-caffeoylquinic acid equivalent). Preliminary experiments by HPLC-DAD-MS allowed to identify several free phenolic acids and gave clues to identify esters of quinic acids.

Phytochemical contents and antioxidant capacities of different parts of two sugarcane (Saccharum officinarum L.) cultivars

Antioxidant capacities and phytochemicals such as phenolics, flavonoids, triterpenoids, phytosterols of four parts of two sugarcane cultivars have been characterised. The total triterpenoid content (TTC), total phenolic content (TPC), total flavonoid content (TFC) and total sterol content (TSC) were different among parts and cultivars of sugarcane. The node of both cultivars contained the highest TTC (2096.02 and 1779.66 mg ursolic acid/100g DW for green-rind and red-rind sugarcane, respectively). However, the highest TPC, TFC and TSC were found in the rind. Green-rind sugarcane cultivars contained higher TSC than the red-rind sugarcane cultivars in most parts, while opposite trend were found in TPC and TFC. Stigmasterol and β-sitosterol were found as two main phytosterols. Furthermore, TPC and TFC revealed good correlations with DPPH and FRAP. As cultivars and parts could affect phytochemical content, present result may provide a theoretical basis for further exploitation of the health beneficial resources of sugarcane.