Homalium zeylanicum attenuates streptozotocin-induced hyperglycemia and cellular stress in experimental rats via attenuation of oxidative stress imparts inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Homalium zeylanicum (Gardner) Benth (Salicaceae) leaves are being used as folklore medicine to treat diabetes by the local folk of Andhra Pradesh, India. The medicinal claim of this plant with hypoglycaemic effects was initially studied by the authors. Results demonstrated the important antioxidant activities of the hydroalcohol fraction of leaves of H. zeylanicum leaves (HAHZL) were positively correlated with phenols and flavonoids contents. AIM OF THE STUDY: Based on the previous findings, additional research is needed to examine the efficacy of using HAHZL to treat hyperglycemia. We therefore investigated in vitro and in vivo glycemic response of HAHZL, and evaluation of possible mechanism of bioactive molecules in mitigating streptozotocin-induced cellular stress in experimental rats via attenuation of oxidative stress imparts inflammation. METHODS: GC-MS/MS analysis of HAHZL was carried out to identify bioactive constituents. In vitro antidiabetic (α-glucosidase, α-amylase) and anti-inflammatory activities were investigated. HFD/low-STZ-prompted diabetic Wistar rats were administered with HAHZL (300 and 400 mg/kg; oral) for 28 days. Blood serum, oxidative stress, inflammation, DNA damage, and antidiabetic markers of pancreas and liver were determined. Histopathological studies of liver and pancreas were performed to assess the protective role of HAHZL. RESULTS: GC-MS/MS study revealed 7 bioactive compounds e.g., Phenol, 4-ethenyl-, acetate (28.68%), hydroquinone (9.10%), n-hexadecanoic acid (0.55%), phytol (0.57%), arbutin (17.65%), Vitamin E (1.04%), ß-Sitosterol (1.54%) which possess antioxidant, anti-inflammatory and anti-diabetic activities. HAHZL showed significant in vitro glycemic response as evidenced by the inhibition of α-amylase, and α-glucosidase activities. Lineweaver-Burk plot revealed that HAHZL exhibited competitive and mixed competitive inhibition towards α-amylase and α-glucosidase, respectively. HAHZL at 400 mg/kg modulated the pathophysiology associated with HFD/STZ-induced type2 diabetes mellitus and significantly (p < 0.001) improved antihyperglycemic (SG, SI, HOMA-IR, and HbA1C), antidyslipidemic (TC, HDL-C, LDL-C, and TG), antioxidative (MDA, SOD, CAT, GSH, and 8-OHdG) and anti-inflammatory (TNF-α, and CRP) markers in serum, pancreas and liver. In vitro and in vivo test results were corroborated by the improvement of pancreatic and hepatic tissue architecture in diabetic rats. CONCLUSION: HAHZL bearing bioactive components phenol, 4-ethenyl-,acetate, hydroquinone, n-hexadecanoic acid, arbutin, phytol, vitamin E and ß-sitosterol balanced glycemic level by normalising the levels of glycaemic indices, lipid profile, pancreas and liver functional markers in STZ-induced T2DM rats.

The modulatory role of prime identified compounds in the bioactive fraction of Homalium zeylanicum in high-fat diet fed-streptozotocin-induced type 2 diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Homalium zeylanicum (Gardner) Benth. is a medicinal plant traditionally used in controlling diabetes which thus far has been assessed by the authors only to a very limited extent. PURPOSE: To fill the research gap in the literature review, we investigated the antihyperglycemic effects of hydro alcohol fraction of bark of H. zeylanicum (HAHZB) by modulating oxidative stress and inflammation in high-fat diet fed-streptozotocin (HFD/STZ)-induced type-2 diabetic rats. MATERIALS AND METHODS: To understand the antioxidant capacity of HAHZB, oxygen radical absorbance capacity (ORAC) and cell-based antioxidant protection in erythrocytes (CAP-e) were performed. GC-MS/MS analysis was performed to assess the bioactive components in HAHZB. HFD/STZ-induced diabetic rats were treated orally with HAHZB (300 and 400 mg/kg) for 28 days. After the end of the experiment, marker profiling and histopathological observation of blood and pancreas were examined. The study also highlights interaction between diabetes, oxidative stress and inflammation by examining the increased pro-inflammatory cytokines e.g. TNF-α and C-reactive protein (CRP) promotes DNA damage e.g. oxidation of 8-hydroxy-2-deoxyguanosine (8-OHdG) in chronic hyperglycaemia. RESULTS: In ex vivo cellular antioxidant capacity of -CAP-e and ORAC assays, HAHZB showed remarkable free radical scavenging ability in a dose dependent manner. GC-MS/MS analysis identified 28 no. of compounds and out of which, oleic acid (1.03%), ethyl tridecanoate (11.77%), phytol (1.29), 9,12-octadecadienoic acid, methyl ester, (E,E)-(5.97%), stigmasterol (1.30%) and ß-sitosterol (2.86%) have antioxidant, anti-inflammatory and anti-diabetic activities. HAHZB 400 mg/kg significantly (p < 0.001) improved the lipid profile (TC: 74.66 ± 0.59, HDL-C: 22.08 ± 0.46, LDL-C: 38.06 ± 0.69, and TG: 171.92 ± 1.01 mg/dL) as well as restoring antidiabetic markers (SG: 209.62 ± 1.05 mg/dL, SI: 15.07 ± 0.11 µIU/mL, HOMA-IR: 7.79 ± 0.04 %, and HbA1C: 8.93 ± 0.03 %) and renal functional markers (Tg: 291.26 ± 0.57 pg/mL, BUN: 23.79 ± 0.14 mg/dL, and Cr: 1.34 ± 0.04 mg/dL) in diabetic rats. Oxidative stress markers of pancreas (MDA: 3.65 ± 0.17 nM TBARS /mg protein, SOD: 3.14 ± 0.28 U/mg protein, CAT: 7.88 ± 0.23 U/mg protein, GSH: 12.63 ± 0.28 µM/g of tissue) were restored to normal as evidenced by histological architecture of pancreatic islet cells. The increased level of pro-inflammatory cytokines and oxidative DNA damage were significantly restored (TNF-α: 54.48 ± 3.19 pg/mL, CRP: 440.22 ± 7.86 ng/mL, and 8-OHdG: 63.65 ± 1.84 ng/mL) by HAHZB in diabetic rats. CONCLUSION: The present findings confirm that the presence of bioactive compounds in HAHZB exert therapeutic protective effect by decreasing oxidative, inflammation and pancreatic ß-cell damage in oxidative stress induced diabetic rats.

Ameliorative effect of Homalium zeylanicum against carbon tetrachloride-induced oxidative stress and liver injury in rats.

Objective is to evaluate the ameliorative effects of Homalium zeylanicum in carbon tetrachloride-induced oxidative stress and liver injury in rats. To establish the nature of antioxidant principles in the bioactive ethyl acetate fractions of bark (HZEB) and leaf (HZEL); oxygen radical absorbance capacity (ORAC) and cell-based antioxidant protection in erythrocytes (CAP-e) assays were performed. From acute toxicity study, HZEB and HZEL at 200 and 300 mg/kg b.w., were relatively safe at their effective doses. The degree of protection was measured by using biochemical parameters such as serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), total bilirubin (TB) and total protein (TP) contents. Hepatic markers e.g. thiobarbituric acid reactive species (TBARS), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) were evaluated along with histopathological observations of liver tissues. Both fractions showed significant improvement in restoring SGOT, SGPT, ALP, TB and TP level. TBARS, SOD, CAT and GSH levels were significantly altered towards normal values. Both fractions at 300 mg/kg showed remarkable improvement in liver markers as compared to silymarin. Histopathological examinations showed reduction in hepatic necrosis and appeared normal hepatocellular architecture in HZEB and HZEL treated groups. In CAP-e assay, IC50 of HZEB (54.66 mg/mL) was higher than HZEL (60.88 mg/mL) and in ORAC assay, AUC of HZEB and HZEL were 33.46, 21.29 respectively and results were comparable with trolox. GC-MS and LC-MS analysis identified a total no. of 44 compounds. Few compounds were identified as bioactive compounds e.g. catechol (7.23%), tetraacetyl-d-xylonic nitrile (3%), oleic acid (0.49%), 2,6-bis(1,1-dimethylethyl)-phenol (3.71%), 3,4,5-trimethoxy-phenol (0.31%), and conifer alcohol (7.41%). The presence of antioxidant principles in both fractions were responsible for hepatoprotective activities, however, the presence of catechol (7.23%) in the bark part imparted better activities in protecting liver than leaf of H. zeylanicum.

In vitro biological assessment of Homalium zeylanicum and isolation of lucidenic acid A triterpenoid.

Homalium zeylanicum (Gardner) Benth. (Flacourtiaceae) is a medicinal plant useful in controlling rheumatism, inflammation and diabetes. The objective of this work evaluates in vitro antioxidant, antidiabetic, and antiinflammatory properties of hydroalcohol extract of bark of H. zeylanicum (HAHZ). It also describes isolation and structure determination of lucidenic acid A, which is the first report in this plant. In order to explain the role of antioxidant principles, DPPH, nitric oxide, hydroxyl, superoxide and metal chelating assays were performed. Antidiabetic and anti-inflammatory activities were investigated by quantifying α-amylase, α-glucosidase and protein denaturation inhibitory activities of HAHZ. Biochemical estimations were performed. The chemical structure of the triterpenoid was elucidated using 1H, 13C NMR and high resolution-MS. IC50 of DPPH, nitric oxide, hydroxyl, superoxide and metal chelating activities were of 36.23 ± 0.27, 40.11 ± 0.32, 35.23 ± 0.57, 43.34 ± 0.22 and 11.54 ± 0.08 µg/mL, respectively. IC50 of α-amylase and α-glucosidase activities were 29.12 ± 0.54, and 18.55 ± 0.15 µg/mL. Total phenolic and total flavonoid contents were recorded at 233.65 mg/g GAE and 172.7 mg/g QE. Regarding kinetic behaviour, HAHZ showed competitive inhibition on α-glucosidase and mixed competitive inhibition on α-amylase. Lucidenic acid A was confirmed by spectroscopic studies. Anti-inflammatory activity of lucidenic acid A was determined by using protein denaturation assay with IC50 13 µg/mL but HAHZ showed 30.34 ± 0.13 µg/mL. Phenols and flavonoids could be attributed to inhibition of intestinal carbohydrases for anti-diabetic activities whereas triterpenoids could be responsible for anti-inflammatory activity of H. zeylanicum.