Evaluation of in vitro antioxidant and antidiabetic potential of extracts from Phaseolus vulgaris L. seeds (Black turtle beans)

Introduction: Phaseolus vulgaris L also known as common beans or black turtle beans are known worldwide as the most important legume for direct human consumption. Many parts of the plant are known to have important pharmacological potential against many diseases including diabetes. Despite the importance of this legume, P. vulgaris remains an underutilized and under-researched legume in Nigeria. Its therapeutic potential is being overlooked and undermined due to insufficient data on its bioactivity. These bioactive compounds present in some plant derived foods are found as fraction, crude extract, and isolated bioactive compounds that have been screened for antioxidative and antidiabetic potential. Several plant-derived foods and isolated bioactive compounds with potential antidiabetic properties are very limited.Objective: To investigate and estimate the antioxidative and antidiabetic effect of the different solvent extracts of P. vulgaris seed in vitro. Methods: Samples were subjected to antioxidant assays using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity, ferric reducing power and 2,2-azino-bis (3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) Anti-diabetic potential in vitro was estimated by evaluating various solvent extracts on α-amylase and α-glucosidase for any inhibitory effects at doses ranging from (100-500μg/ml). Characterization of possible bioactive constituent in the different solvent extract was done using FTIR spectroscopy.Results: Aqueous extract showed a higher number of total polyphenol (11.3 ± 0.01mg/gGAE) and anthocyanin content of 76.34 ± 1.12 mg/g when compared with the other solvent extract. This was followed closely by the ethanol extract with a value of 7.3±0.01Mg and 74.53 ± 0.24 Mg/g. Ascorbic acid had a significantly higher (P<0.05) activity in the antioxidant assays used. However, among the solvent extracts tested, ethanol extract displayed highest (P<0.05) for ferric reducing power activity, (80.78±0.6mg/ml), ethyl acetate, aqueous and ethanol extracts had similar DPPH activities (12.92±2.30 mg/ml, 12.59±2.33 mg/ml and 12.54±2.30mg/ml) respectively. Dichloromethane, hexane, ethanol and ethyl acetate had similar ABTS activities. (5.69±2.86 mg/ml; 6.92±0.14 mg/ml; 10.10±1.11 mg/ml; 10.76±2.98 mg/ml) respectively. All solvent extracts displayed similar inhibitory activities against α amylase. However, ethyl acetate, aqueous and ethanol extracts showed significantly (P<0.05) higher values for α-glucosidase (3.07±0.61mg/ml; 2.82±0.14mg/ml; 2.60±0.61mg/ml). The Fourier Transform infra-red spectrophotometer (FTIR) of the extracts disclosed that the presence of polyphenol and flavonoids were due to the OH stretching and the terpenes were due to the C-H group. Conclusion: In conclusion, different solvent extracts from the seed of Phaseolus vulgaris have demonstrated low antioxidative but very promising anti –diabetic activities in vitro. The ethanol extract however displayed higher activity than other solvent extracts, FT-IR results of ethanol extracts revealed the presence of flavonoids, anthocyanins and phenolics. This study may further suggest that seeds of Phaseolus vulgaris signify a functional food as well as a nutraceutical in terms of managing of Type 2 diabetes.Keyword: Phaseolus vulgaris, α amylase, α glucosidase, antioxidative

Comparative Study of different Solvent Extract of Plectranthus amboinicus Stem for their Diuretic Activity

Diuresis can be beneficial in removing toxins from the body. Globally traditional and folklore medicines plays a vital role in health care services. Plectranthus amboinicus belongs to Lamiaceae family is an Indian medicinal plant which has been utilized traditionally to treat various diseases. However, there is no systematic methodology for the use of Plectranthus amboinicus stem as a diuretic. Hence the present study is proposed to evaluate the diuretic activity of various solvent extract of Plectranthus amboinicus stem in the rat model. The acute toxicity study was performed in albino mice by fixed-dose method (OECD guidelines number 425) of CPCSEA. The diuretic activity was carried out using the Lipschitz method. The total urine volume collected in 24hours was observed. Sodium, potassium and chloride concentration in urine were also recorded. The ionic concentrations were recorded calorimetrically. Acute toxicity study proved no toxicity and mortality in any of the animal up to the dose of 2000mg/kg bodyweight. All three extracts of Plectranthus amboinicus have exhibited dose-dependent diuretic activity by increasing urine volume and excreting sodium ions in urine. The urine pH was also elevated. From the study, it can be concluded that the plant Plectranthus amboinicus could be considered as a diuretic agent. This current study encourages the use of this plant in folk medicine. Further study is required for isolation, characterization and formulation of the active constituents responsible for its diuretic activity.

DYEING AND COLORFASTNESS PROPERTIES OF TENCEL FABRIC TREATED WITH NATURAL DYE EXTRACTED FROM ORANGE PEEL

The usage of natural dyes for coloration has attained attention in recent years due to their ecofriendly environment. Therefore, in this study, orange peel solvent extract is used as a natural dye for coloring Tencel fabric samples. Pre-mordanting and post-mordanting methods were accomplished with two different mordants, i.e. ferrous sulfate and copper sulfate. The dyeing shade effects were retrieved through colorfastness properties according to the ISO standardizations. The results revealed that the best color shade ([Formula: see text]/[Formula: see text]: 4.56) was achieved using mordant ferrous sulfate through the post-mordanting method. The effect of lightfastness on all dyed Tencel fabric samples was observed good (3–4) in both mordanting methods. However, mordant ferrous sulfate showed better lightfastness (4) than copper sulfate (3–3.5) through both mordanting methods. Comparatively, in the rubbing fastness, copper sulfate has superior results in both mordanting methods. The ferrous and copper sulfates in both mordanting methods have similar tests results (4.5) of washing fastness, acidic and alkaline perspiration. Furthermore, the FTIR test substantiated that not any structural change occurred through orange peel dyed Tencel fabric samples through both methods. TGA observed samples were relatively stable up to 300∘C temperature. Overall, the best results of colorfastness for Tencel fabric samples were obtained with ferrous sulfate mordant through the post-mordanting extraction method.