Anti-protein glycation and free-radical scavenging properties of Sri Lankan antidiabetic medicinal plant Salacia reticulata l. (Kothala Himbutu)

Abstract Background Decoctions of the root and stem of the medicinal plant Salacia reticulata is an indigenous remedy for diabetics and its complications in Sri Lanka. In diabetics, the formation of advanced glycation end products (AGEs) leads to many pathologies. Nevertheless, the anti-protein-glycation property of this plant is poorly documented. This study reports the anti-protein-glycation and radical scavenging potential of various plant parts of S. reticulata. Methods Hot water extracts (2g dried powder/50 ml) of root, stem, leaf, twigs, and fruits at various concentrations (15.6 to 500.0 µg/ml) were subjected to anti-glycation and glycation reversing assays in vitro. 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was used for free radical scavenging property. Results Various plant parts of S. reticulata showed anti-protein-glycation and free-radical scavenging activities. IC50 for the anti-glycation activity of root, stem, leaf, twigs, and fruit extracts were 11.92 ± 1.14, 35.18 ± 2.79, 113.3 ± 1.91, 149.59 ± 1.06, and 1120.37 ± 229.48 µg/ml respectively. IC50 of Rutin was 21.88 ± 2.82 µg/ml. EC50 of the root, stem, twigs, and leaf extracts for glycation reversing was 102.09 ± 6.23, 116.99 ± 5.82, 154.45 ± 5.79, and 278.78 ± 14.19 µg/ml respectively. The EC50 values for the radical scavenging activity of leaf, stem, and roots were 26.4±4.7, 9.0±1.2, and 9.1±1.3 respectively. Root had significantly (p<0.05) high activity for all the parameters tested. Conclusion Salacia reticulata possess anti-glycation, glycation-reversing, and free radical scavenging activities. Other than root and stem, the leaves and twigs too may be a useful source for anti-diabetic bioactive molecules

Topical Anti-Inflammatory Activity of Essential Oils of Alpinia calcarata Rosc., Its Main Constituents, and Possible Mechanism of Action

This study aimed at investigating the anti-inflammatory potential of essential oil from rhizome and leaf of Alpinia calcarata Rosc. (ACEO) with the focus of its topical anti-inflammatory activity along with its dominant compounds 1,8-cineole and α-terpineol using mouse ear edema model. ACEOs were analyzed by GC-MS. The anti-inflammatory activity was determined by studying the inhibition of overproduction of proinflammatory mediators—nitric oxide, reactive oxygen species, prostaglandins, cyclooxygenases, and cytokines induced by lipopolysaccharides in murine macrophages. Topical anti-inflammatory and antinociceptive activity was studied by 12-O-tetradecanoylphorbol-13-acetate (TPA) induced skin inflammation and formalin-induced pain model in mice, respectively. Rhizome oil has 1,8-cineole (31.08%), α-terpineol (10.31%), and fenchyl acetate (10.73%) as major compounds whereas the ACEO from leaves has 1,8-cineole (38.45%), a-terpineol (11.62%), and camphor (10%). ACEOs reduced the production of inflammatory mediators in vitro in a concentration-dependent manner. Further, ACEO and its major compounds reduced ear thickness, weight, myeloperoxidase, and cytokines significantly (p<0.01) in mouse ear. Dose-dependent reduction in flinching and licking in both the phases of pain sensation concludes the topical analgesic effect. Our findings suggest the potency of topical use of ACEOs for inflammatory disease conditions

Anti-Acetylcholinesterase Activity of Commercially Important Ceylon Black Tea (Camellia sinensis L.) Grades Belonging to Different Elevations: Potential Natural Product for Type 3 Diabetes Management?

Aims: Sri Lankan tea which is known as the Ceylon tea is the world’s finest tea. Currently Sri Lanka remains as the second main black tea (BT) exporter and the main orthodox BT exporter in the world. Although several pharmacological activities of Ceylon tea have been reported, its anti-acetylcholinesterase (AChE) activity which has a direct relationship with the management of Alzheimer's disease or type 3 diabetes has not reported to date. Further, there are no comprehensive studies on anti-AChE activity of tea world over. Present study evaluated anti-AChE activity of commercially important Ceylon BT grades belonging to different elevations. Methodology: Freeze dried hot water extracts of Broken Orange Pekoe Fannings (BOPF), Orange Pekoe (OP) and Dust No.1 BT grades from low, mid and high grown elevations and a Ceylon green tea sample collected from the local market were studied for anti-AChE activity using 96 well micro plate-based assay (n=3 each). Results: Results showed that all tested Ceylon tea had anti-AChE activity with varying degrees of potentials in a dose dependent manner. The mean IC50 values of BOPF, OP and Dust No. 1 tea grades at different elevations varied from 499.61±10.95 - 569.19±5.78, 598.80±24.95 - 677.81±6.61 and 509.44±3.81 - 621.39±3.29 µg/mL respectively. Interestingly, observed anti-AChE activity of black tea showed significant differences (P&lt; 0.05) among elevations. The order of potency of BOPF, OP and Dust No:1 BT for anti-AChE activity at different elevations was low grown&gt;high grown=mid grown, high grown=low grown&gt;mid grown and mid grown&gt;low grown&gt;high grown respectively. Anti-AChE activity of Ceylon green (433.96 ± 5.95 µg/mL) tea was significantly high (P&lt;0.05) compared to the tested BT and activities of all Ceylon tea were moderate compared to the reference standard Galantamine (IC50:2.52±0.17 µg/mL). Conclusion: It is concluded that selected Ceylon BT grades had varying levels of anti-AChE activity and it varied with the elevations

Immunomodulatory Activity of a Traditional Sri Lankan Concoction of Coriandrum sativum L. and Coscinium fenestratum G.

Objective. To investigate the immunomodulatory activity of a traditional Sri Lankan concoction of Coriandrum sativum L. and Coscinium fenestratum (Gaertn.) Colebr., which is a Sri Lankan traditional medicine used to relieve inflammation and cold. Methods. In vivo anti-inflammatory activity was tested using carrageenan-induced rat paw-edema model. Mechanism of anti-inflammatory activity was assessed by investigating the production of nitric oxide (NO), expression of iNOS enzyme, and reactive oxygen species (ROS) by rat peritoneal cells. The membrane stabilizing activity was also tested. The antibody response was determined by assessing the specific haemagglutination antibodies raised against sheep red blood cells. Results. The three doses of freeze-dried concoction used ((human equivalent dose (HED)—183 mg/kg) 2 × HED and 1/2HED; n = 6 rats/group) showed significant inhibition of paw edema compared to water control at 3rd–5th hours (p<0.05). Both HED and 1/2HED exhibited marked anti-inflammatory activity (72–83% inhibition at 4th-5th hours; p<0.05). The HED of the concoction showed significant inhibition of NO (77.5 ± 0.73%, p<0.001) and ROS production (26.9 ± 2.55%; p<0.01) by rat peritoneal cells. Inhibition of NO production in the concoction treated rat peritoneal cells was confirmed by the lack of iNOS expression. The concoction also exhibited significant membrane stabilizing activity (IC50 = 0.0006 μg/ml; p=0.001). HED resulted in a significantly high induction of specific antibody production against SRBC antigens as detected by SRBC haemagglutination assay (mean day 14 titers 253.3 compared to control: 66.7) (p<0.01). Conclusions. The traditional Sri Lankan concoction of C. sativum and C. fenestratum demonstrated potent in vivo anti-inflammatory activity, significant reduction of ROS, and NO production by rat peritoneal cells and the lack of iNOS expression confirmed the low NO production. The increased membrane stability also supports the anti-inflammatory activity of the concoction. Further, this concoction induced a significantly high antibody response reflecting its immunostimulatory activity. Together these results scientifically validate the therapeutic use of the concoction of C. sativum and C. fenestratum in Sri Lankan traditional medicinal system for immunomodulatory effects