This study aimed to optimise potential extraction conditions using response surface methodology (RSM) for yielding maximum levels of total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging capacity of henna (Lawsonia inermis) stems. The ranges for selected independent variables, namely acetone concentration (20−90%, v/v), extraction time (10−90 min), and extraction temperature (25−45°C) were identified by screening tests. Optimum conditions obtained for extraction of TPC were 47.0% acetone, extraction time of 47.6 min and extraction temperature of 37.3oC. The result also showed that 75.8% acetone, extraction time of 26.2 min and extraction temperature of 41oC yielded the highest DPPH• scavenging capacity. The optimized extraction conditions have resulted in TPC and DPPH• scavenging capacity of 5232.4 mg GAE/100 g DW and 6085.7 mg TE/100 g DW, respectively which similar to the predicted values. Therefore, RSM has successfully optimized the extraction conditions for TPC and radical scavenging capacity of henna stems.
Henna plant (Lawsonia inermis) is an Indian medicinal plant used in traditional medicine for the treatment of various diseases, besides its popularity as a natural dye to colour hand and hair. Research in the recent past has accumulated enormous evidence revealing henna plant to be an excellent source of antioxidants such as total phenolics. In this study, the extraction of total phenolics from henna stems was evaluated using the Folin-Ciocalteu assay. A set of single factor experiments was carried out for identifying the optimum condition of each independent variable affecting total phenolic content (TPC) extraction efficiency of henna stems, namely the solvent type, solvent concentration (v/v, %), extraction time (min) and extraction temperature (oC). Generally, high extraction yield was obtained using aqueous acetone (about 40%) as solvent and the extraction yield could further be increased using a prolonged time of 270 min and a higher incubation temperature of 55°C. Under these optimized conditions, the experimental maximum yield of TPC of 5554.15 ± 73.04 mg GAE/100 g DW was obtained.
The antioxidant activity of several Malaysian plant extracts was analyzed simultaneously with their pro-oxidant capacity. This ratio represents an index (ProAntidex) of the net free radical scavenging ability of whole plant extracts. We observed that ethanolic extracts of Nephelium lappaceum peel, Fragaria x ananassa leaf, Lawsonia inermis leaf, Syzygium aqueum leaf and grape seed had a lower Pro-Antidex than the commercially available Emblica™ extract which is an antioxidant agent with very low pro-oxidant activity. Among the aqueous extracts, Lawsonia inermis leaf, Nephelium mutobile leaf and grape seed had lower pro-oxidant activity compared to the Emblica™ extract. Among these extracts, aqueous extract of Nephelium mutobile leaf had a very low index of 0.05 compared to 0.69 for Emblica™. Most of the extracts had a far lower ProAntidex compared to the Vitamin C. The index enables us to identify extracts with high net free radical scavenging activity potential. The ProAntidex is beneficial as a screening parameter to the food industries and healthcare.
During the last quarter of the twentieth century there have been intensive research activities looking for green sources of energy. The main aim of the green generators or converters of energy is to replace the conventional (fossil) energy sources, hence reducing further accumulation of the green house gasses GHGs. Conventional silicon and III-V semiconductor solar cell based on crystalline bulk, quantum well and quantum dots structure or amorphous and thin film structures provided a feasible solution. However, natural dye sensitized solar cells NDSSC are a promising class of photovoltaic cells with the capability of generating green energy at low production cost since no vacuum systems or expensive equipment are required in their fabrication. Also, natural dyes are abundant, easily extracted and safe materials. In NDSSC, once dye molecules exposed to light they become oxidized and transfer electrons to a nanostructured layer of wide bandgap semiconductors such as TiO2. The generated electrons are drawn outside the cell through ohmic contact to a load. In this paper we review the structure and operation principles of the dye sensitized solar cell DSSC. We discuss preparation procedures, optical and electrical characterization of the NDSSC using local dyes extracted from Henna (lawsonia inermis L.), pomegranate, cherries and Bahraini raspberries (rubus spp.). These natural organic dyes are potential candidates to replace some of the man-made dyes used as sensitizer in many commercialized photoelectrochemical cells. Factors limiting the operation of the DSSC are discussed. NDSSCs are expected to be a favored choice in the building-integrated
photovoltaics (BIPV) due to their robustness, therefore, requiring no special shielding from natural events such as tree strikes or hails.
In the present work, aqueous ethanolic (60% ethanol) extracts from selected Malaysian herbs
including Murraya koenigii L. Spreng, Lawsonia inermis L., Cosmos caudatus Kunth, Piper
betle L., and P. sarmentosum Roxb. were evaluated for their ergogenic, anti-diabetic and
antioxidant potentials. Results showed that the analysed herbs had ergogenic property and
were able to activate 5'AMP-activated protein kinase (AMPK) in a concentration dependant
manner. The highest AMPK activation was exhibited by M. koenigii extract which showed no
significant (p > 0.05) difference with green tea (positive control). For anti-diabetic potential,
the highest α-glucosidase inhibition was exhibited by M. koenigii extract with IC50 of 43.35
± 7.5 µg/mL, which was higher than acarbose (positive control). The determinations of free
radical scavenging activity and total phenolics content (TPC) indicated that the analysed herbs
had good antioxidant activity. However, C. caudatus extract showed superior antioxidant
activity with IC50 against free radical and TPC of 21.12 ± 3.20 µg/mL and 221.61 ± 7.49 mg
GAE/g, respectively. RP-HPLC analysis established the presence of flavonoids in the herbs
wherein L. inermis contained the highest flavonoid (catechin, epicatechin, naringin and rutin)
content (668.87 mg/kg of extract). Correlations between the analyses were conducted, and
revealed incoherent trends. Overall, M. koenigii was noted to be the most potent herb for
enhancement of AMPK activity and α-glucosidase inhibition but exhibited moderate antioxidant activity. These results revealed that the selected herbs could be potential sources of
natural ergogenic and anti-diabetic/antioxidant agents due to their rich profile of phenolics.
Further analysis in vivo should be carried out to further elucidate the mechanism of actions of
these herbs as ergogenic aids and anti-diabetic/antioxidant agents.
The incidence of diabetes mellitus (DM) is increasing worldwide. One of the main complications in DM is delayed wound healing which often requires amputation. Various drugs have been used to treat DM but they present with various complications and patients often do not comply with such treatment. This opens the door for complementary and alternative medicine. In the present review, we explore the molecular concept of wound healing occurring in different stages with special emphasis to DM. We also highlight potential herbal products such as NF3 (Chinese 2-Herb Formula), Zicao, Jing Wan Hong ointment, mixture of Adiantum capillus-veneris, Commiphora molmol, Aloe Vera, and henna, Aleo vera, Phenol-rich compound sweet gel, Jinchuang ointment, San-huang-sheng-fu (S) oil, Yi Bu A Jie extract, Astragali Radix (AR) and Rehmanniae Radix (RR), Yiqi Huayu, Tangzu yuyang ointment, Shengji Huayu recipe, Angelica sinensis, Lithospermun erythrorhison, Hippophae rhamnoides L., Curcuma longa, and Momordica charantia that could be effectively used to treat DM wounds. Future clinical trials are needed for designing potential drugs which may be effective in treating DM wounds.
Thirteen Malaysian plants; Artocarpus champeden, Azadirachta indica, Fragaria x ananassa, Garcinia mangostana, Lawsonia inermis, Mangifera indica, Nephelium lappaceum, Nephelium mutobile, Peltophorum pterocarpum, Psidium guajava and Syzygium aqueum, selected for their use in traditional medicine, were subjected to a variety of assays. Antioxidant capability, total phenolic content, elemental composition, as well as it cytotoxity to several cell lines of the aqueous and ethanolic extracts from different parts of these selected Malaysian plants were determined. In general, the ethanolic extracts were better free radical scavengers than the aqueous extracts and some of the tested extracts were even more potent than a commercial grape seed preparation. Similar results were seen in the lipid peroxidation inhibition studies. Our findings also showed a strong correlation of antioxidant activity with the total phenolic content. These extracts when tested for its heavy metals content, were found to be below permissible value for nutraceutical application. In addition, most of the extracts were found not cytotoxic to 3T3 and 4T1 cells at concentrations as high as 100 microg/mL. We conclude that although traditionally these plants are used in the aqueous form, its commercial preparation could be achieved using ethanol since a high total phenolic content and antioxidant activity is associated with this method of preparation.