Browsing by Author "Jayawardena, B. M."

Now showing 1 - 6 of 6

Antioxident activitiy and α-amylase activity of pressurized water extract of Cinnamomum zeylanicum (L.) bark oil.
(International Research Symposium on Pure and Applied Sciences, 2017 Faculty of Science, University of Kelaniya, Sri Lanka., 2017) Wariyapperuma, W. A. N. M.; Jayawardena, B. M.; Kannangara, S. D. P.; Wijayasinghe, Y. S.; Skandaraja, S.
Cinnamon (Cinnamomum zeylanicum) is an evergreen plant widely grown across Asia as a spice and to extract its essential oil. The composition of essential oil, obtained from different parts of the plant differ in chemical composition. Further, the extraction method would also influence the chemical composition of the essential oil. The aim of the current study was to examine the use of pressurized water to extract oil from Cinnamomum zeylanicum bark and to determine whether this extraction method would give a higher quality oil with enhanced anti-diabetic properties. Bark of Ceylon Cinnamon was powdered and extracted using pressurized water (0.098 MPa). The extract was tested for the total phenolic content (TPC), percentage reducing activity, content of condensed tannin and IC50 values for α-amylase inhibition using Folin-ciocalteu method, vanillin assay and ferric reducing antioxidant power assay respectively. The extract obtained by soxhlet extraction was used as a control. The results showed that percentage yield, the content of total phenolic and content of condensed tannin were 4.24%, 0.065 g gallic acid equivalent/ g extract and 0.012 g catechin equivalent/g extract, while those for the control were 5.16%, 0.19 and 0.015 respectively. The ferric reducing power and the pancreatic α-amylase inhibition (IC50 value) were 203.71 and 50.03 μg/mL for pressurized extract and 260.20 and 38.91 μg/mL for control respectively. Present study reveals that cinnamon bark oil obtained using pressurized water has comparable values for phenolic content, reducing power and α-amylase inhibition compared to soxhlet extraction.
Hypoglycemic effect and antioxidant effect of pressured water extracts of Alpinia
(Faculty of Science, University of Kelaniya Sri Lanka, 2022) De Silva, P. H. U. W.; Jayawardena, B. M.
Diabetes mellitus is a chronic metabolic condition that accounts for 1.5 million deaths annually worldwide. Since oral hypoglycemic medicines have adverse effects, there is a growing interest in employing herbal remedies for diabetes mellitus. Alpinia calcarata, a medicinally important plant from the Zingiberaceae family that grows in tropical climates like Sri Lanka and India, has a range of therapeutic uses. The rhizome of the plant has been used as a traditional systemic medicine in Sri Lanka for respiratory tract conditions, including asthma, cough, and bronchitis, as well as for inflammatory conditions like arthritis and metabolic disorder like diabetes mellitus. Since antioxidant activity inhibits hypoglycemic related complications, if A. calcarata rhizomes contain phytochemicals with antioxidant activities, it would be beneficial for diabetic patients. Therefore, the objective of this study was to investigate the hypoglycemic activity and antioxidant activity of low pressurised water extract (LPWE) and medium pressurised water extract (MPWE) of dried A. calcarata rhizomes. Phytochemicals in the ground rhizome of A. calcarata were extracted into the water by low pressurised water extraction method (0.098 MPa, 200 mL for 10 minutes) and medium pressurised water extraction method (0.103 MPa, 121°C, 100 mL for 20 minutes). The hypoglycemic effect was determined by performing the α- amylase inhibitory assay and glucose uptake by Yeast cells assay for three glucose concentrations (5 mM, 10 mM, and 25 mM). According to the results of α-amylase inhibitory assay, the IC50 values of LPWE and MPWE were 166.8 ± 0.1 μg/mL and 152.1 ± 0.1 μg/mL, respectively. The glucose uptake by Yeast cell assay has revealed that the rate of glucose uptake by the plasma membrane of the yeast cell in all three glucose concentrations (5 mM, 10 mM, and 25 mM), was linear and the percent increase in the glucose uptake by the yeast cells was found to be inversely proportional to the glucose concentration. The antioxidant ability was assessed by performing the Ferric reducing antioxidant power (FRAP) assay, and by comparing the absorbance changes at 593 nm in both pressured water extracts with a standard series of ferrous ions (100-1000 μM). The FRAP value of MPWE exhibited a higher FRAP value than that of LPWE and both LPWE and MPWE were proportionate to their concentrations. Altogether, the results revealed that the LPWE and MPWE of dried A. calcarata rhizomes may have both hypoglycemic and antioxidant activities. Additionally, the current study suggests that preparing MPWE is a more effective way than preparing LPWE for obtaining more hypoglycemic phytochemicals from the dried rhizome of A. calcarata.
Influence of domestic cooking on the levels of bioactive compounds and antioxidant activity in green leafy vegetables
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Dewangani, H. G. N.; Jayawardena, B. M.
Green leafy vegetables (GLVs) are a rich source of natural antioxidants and polyphenols. These phytochemicals play an important role in the daily diet in Sri Lanka. Most GLVs are cooked prior to consumption to make GLVs more palatable and digestible. However, cooking alters the physical and chemical properties of GLVs and it may affect the levels of nutrients and bioactive compounds. In traditional meal preparations locals add scraped coconut and spices in the preparation of GLVs. Here, the effects of boiling and cooking of Asiatic pennywort (Centella asiatica), Manioc leaves (Manihot esculenta), Amaranthus (Alternanthera sessilis), andSesbenia (Sesbania grandiflora) were explored by measuring antioxidant activity (AO) and total phenolic content (TPC) of raw, boiled (6 min) and cooked (80 ± 10°C for 8 min) GLVs according to the Sri Lankan domestic cooking style. Total phenolic content (TPC) and antioxidant (AO) activity of GLVs were evaluated using the Folin–Ciocalteu method and diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging assay respectively. The results revealed that raw Manihot esculenta had the highest AO activity (0.076 ± 0.001 mg/mL) and TPC content (61.14 ± 0.04 mg GAE/g) among all the GLVs analyzed (p< 0.001), but shows a significant reduction (p<0.001) with boiling (AO: 0.149 ± 0.001 mg/mL, TPC: 25.04 ± 0.03 mg GAE/g) and cooking treatment (AO: 0.267 ± 0.001 mg/mL, TPC: 31.95 ± 0.04 mg GAE/g). The radical scavenging activities of both raw and boiled GLVs were in the order of Manihot esculenta > Alternanthera sessilis > Centella asiatica > Sesbania grandiflora. Boiling and cooking treatments significantly reduced the TPC and AO content (p< 0.001). This study revealed that a 6 min boiling treatment significantly decreased (p < 0.001) the TPC of all GLVs studied. The AO activity of amaranthus and Centella was significantly improved by boiling, whereas it decreased for manioc and sesbania samples (P < 0.001). However, boiling caused a greater loss of AO and TPC than did cooking with scrapped coconut. The present findings suggest that the Sri Lankan style of cooking with scrapped coconut may be a better cooking method of choice to improve the health-promoting properties of GLVs by conserving the bioavailability of antioxidants and dietary polyphenols of the four leafy vegetables investigated in this study
Pressured Water Extraction and Solvent Extraction of Cinnamomum zeylanicum (L.) Bark and Evaluation of Anti-Diabetic Properties.
(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Wariyapperuma, W. A. N. M.; Kannangara, S. D. P.; Wijayasinghe, Y. S.; Skandaraja, S.; Jayawardena, B. M.
Pressured water extraction (PWE) is an environmentally friendly technique that has been used to extract anti-diabetic substances than solvent extraction. In the present study, Ceylon Cinnamon(CC, Cinnamomum zeylanicum)was selected as a natural source for anti-diabetic agent. The purpose of this study was to determine the inhibitory potential of α-amylase and αglucosidase by CC bark extracts and to compare the efficiency of the extract with antidiabetic properties from CC by PWE and solvent extraction. The dried bark of CC was powdered and extracted using pressured water (PW, 0.098 MPa), microwave digestion (MD), steam distillation (SD) and soxhlet extraction (SE) with 75% ethanol. The resultant extract from SE was fractionated with hexane. Each extract was tested for the total phenolic content (TPC) and content of proanthocyanidin (PC) using Folin-Ciocalteu method and vanillin assay respectively. IC50 values of α-amylase and α-glucosidase inhibitions by the extracts were determined. Acarbose was used as the positive control. Table 1: TPC, PC and IC50 values of α-amylase and α-glucosidase inhibitions As per the results in table 1 CC water extract obtained by pressured water and aqueous layer from SE have high anti-diabetic properties compared to the other extractions. IC50 values of α-amylase and αglucosidase inhibitions by the acarbose were 95.06±6.84 and 172.52±12.06 respectively. The financial assistance provided by National Science Foundation (SP/CIN/2016/03) is highly appreciated.
Synthesis and characterization of BSA nanoparticles loaded with antidiabetic compounds from Alpinia calcarata extract
(Faculty of Science, University of Kelaniya Sri Lanka, 2022) Jayawardena, B. M.; Wanniarachchi, B. S.
Diabetes is the ninth leading cause of death in the world is also the no.1 cause of kidney failure, adult blindness, and lower-limb amputations. Due to this reason, the necessity for the use of antidiabetic drugs has arisen across the globe. But due to the high cost and side effects of oral antidiabetic drugs, scientists have started focusing their attention on natural products as safer and more potent alternatives for the treatment of diabetes. The rhizome of Alpinia calcarata Roscoe (Heen araththa) is known to exert its antidiabetic activity through the inhibition of intestinal glucose absorption by inhibiting the activity of pancreatic α-amylase and α-glucosidase enzymes. Therefore, once its antidiabetic compounds are extracted using the pressurised water extraction method, which has proven to be one of the promising techniques, an anti-diabetic nutraceutical can be produced for the treatment of diabetes. Bovine Serum Albumin (BSA) nanoparticles loaded with the bioactive compounds of A. calcarata are a good form of an anti-diabetic nutraceutical as they result in protection of active compounds from environmental agents, specific delivery to target sites, reduced side effects, and prolonged shelf-life. The objective of the present study was to synthesize and characterize A. calcarata loaded BSA nanoparticles to be used as a powder form nutraceutical with higher antidiabetic activity. In this study, an aqueous A. calcarata extract (4.00 mL) was added to BSA (20 mg/mL, 4.00 mL, pH 9) in the presence of citric acid as the crosslinking agent. The synthesized nanoparticles were tested for antidiabetic activity using α-amylase inhibition assay and yeast glucose uptake assay and characterized using parameters such as particle size, surface charge, morphology, and particle structure using FTIR. The IC50 value calculated using the GraphPad Prism 9.2.0 software for the nanoparticles was 147.00±0.97 μg/mL. The glucose uptake percentage at 5 mM glucose concentration for the 0.5 mg/mL nanoparticle sample was 73.09 ±0.06% and that obtained under the same conditions for an aqueous A. calcarata extract was 45.30 ±0.97%. The synthesized nanoparticles were 1030.70±75.3 nm in size, with a polydispersity index of 0.199± 0.003, zeta potential value of 2.57±0.32 mV, spherical morphology, and uniform size. The FT-IR results showed that citric acid had caused conformational changes in the protein structure of BSA and that the active compounds were successfully loaded into the synthesized nanoparticles which interacted with the protein matrix via covalent bonds. Therefore, it can be concluded that the synthesized nanoparticles have an anti-diabetic effect and the antidiabetic activity of bioactive compounds of the aqueous A. calcarata extract is enhanced when loaded onto the nanocarriers. The nanoparticles have also been synthesized effectively and therefore, can be used as a powder form anti-diabetic nutraceutical for the treatment of diabetes.
Synthesis and characterization of cinnamon enriched BSA particles with antidiabetic properties
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Sathsarani, H. M. W. K.; Dewangani, H. G. N.; Jayawardena, B. M.
Diabetes mellitus is the most common endocrine illness of the current world. Since synthetic drugs exert adverse side effects, scientists have focused more on natural hypoglycemic agents. “Sri Vijaya” cinnamon variety (CCSV) is an accession of Cinnamomum zeylanicum that contains considerable amount of hypoglycemic agents. Pressured water extract of the dried quills of CCSV can be used as a liquid form antidiabetic nutraceutical. Due to the higher stability and the easiness of storage and transportation, powder form nutraceuticals are preferred over liquids. But the most powdering techniques decrease the activity of the aqueous extracts. Plant extracts can be encapsulated in nanoparticles to convert them into more stable powder form products with higher biological activity. The objective of the percent study was to develop cinnamon encapsulated Bovine Serum Albumin (BSA) particles as a powder form nutraceutical with higher hypoglycemic activity. In this study four different products were synthesized from aqueous cinnamon extract. Two of them were synthesized using BSA (8.8 % (w/v), pH 5) in the presence of citric acid and ascorbic acid as cross-linking agents separately. The other two products were synthesized using BSA (20 mg/mL, pH 9) in the presence of same cross-linking agents. Products were tested for antidiabetic activity by carrying out alpha-amylase inhibition assay and alpha glucosidase inhibition assay and the results were compared with the results obtained for the crude cinnamon extract and the positive control acarbose. IC50 values on both enzymes were calculated using GraphPad prism 8 software. The synthesized BSA particles were characterized for parameters such as water solubility, loading percentage and cinnamon entrapment efficiency. All the obtained data were statistically analysed using Minitab software package. Since the product synthesised using BSA (20 mg/mL, pH 9) and citric acid showed the lowest IC50 value on α- amylase enzyme [117.60(±1.73) µg/mL], and the highest water solubility [53.00(±1.00) %], loading percentage [3.69(±0.01) %] and cinnamon entrapment efficiency [77.97(±0.03) %] those conditions were concluded as the optimum conditions that are required to synthesize highly active antidiabetic powder form of nutraceutical from CCSV. The product synthesized using BSA (20 mg/mL, pH 9) and ascorbic acid showed the highest yield [75.36 %] and the lowest IC50 value on α-glucosidase enzyme [112.40(±0.57) µg/mL].