Opeyemi J. Olatunji

Anti-Ulcerogenic Properties of Lycium chinense Mill Extracts against Ethanol-Induced Acute Gastric Lesion in Animal Models and Its Active Constituents.

The objective of this study was to explore the gastroprotective properties of the aerial part of Lycium chinense Mill (LCA) against ethanol-induced gastric mucosa lesions in mice models. Administration of LCA at doses of 50, 100, 200 and 400 mg/kg body weight prior to ethanol consumption dose dependently inhibited gastric ulcers. The gastric mucosal injury was analyzed by gastric juice acidity, glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), myeloperoxidase (MPO) activities. Furthermore, the levels of the inflammatory mediators, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in serum were also analyzed using ELISA. Pathological changes were also observed with the aid of hematoxylin-eosin (HE) staining. Our results indicated that LCA significantly reduced the levels of MPO, MDA and increased SOD and GSH activities. Furthermore, LCA also significantly inhibited the levels of TNF-α, IL-6, and IL-1β in the serum of ulcerated mice in a dose dependent manner. Immunohistological analysis indicated that LCA also significantly attenuated the overexpression of nuclear factor-κB in pretreated mice models. This findings suggests Lycium chinense Mill possesses gastroprotective properties against ethanol-induced gastric injury and could be a possible therapeutic intervention in the treatment and management of gastric ulcers.

Neuroprotective effect of trans-N-caffeoyltyramine from Lycium chinense against H2O2 induced cytotoxicity in PC12 cells by attenuating oxidative stress

Natural products play a critical role in the promotion of good health as regards the prevention and management of oxidative stress related and neurodegenerative disorders. Oxidative stress has been implicated in several apoptotic pathways associated with cell damages in neuronal disorders. The aim of this study was to investigate the antioxidant effect of trans-N-caffeoyltyramine (TNC) isolated from Cortex lycii against hydrogen peroxide (H2O2) induced cell damages in PC12 cells as well as its mechanism of action. The results obtained indicated that pretreatment with TNC before the exposure of cells to H2O2 toxicity lead to a significant increase in the cell viability and the antioxidant enzyme activities catalase (CAT), superoxide dismutase (SOD), glutathione (GSH) and reduced the level of malondialdehyde (MDA). Furthermore, TNC attenuated the influx of Ca2+, ROS formation and restored the impaired mitochondria membrane potential (MMP). Thus TNC may be used as an alternative therapy for the prevention and treatment of neuronal disorders elicited by oxidative stress.

Chemical Constituents from the Aerial Parts of Cyrtopodium paniculatum

We report the first phytochemical study of the neotropical orchid Cyrtopodium paniculatum. Eight new compounds, including one phenanthrene 1, one 9,10-dihydro-phenanthrene 2, one hydroxybenzylphenanthrene 3, two biphenanthrenes 4–5, and three 9,10 dihydrophenanthrofurans 6–8, together with 28 known phenolic compounds, mostly stilbenoids, were isolated from the CH2Cl2 extract of its leaves and pseudobulbs. The structures of the new compounds were established on the basis of extensive spectroscopic methods.

Evaluation of In Vitro α-Amylase and α-Glucosidase Inhibitory Potentials of 14 Medicinal Plants Constituted in Thai Folk Antidiabetic Formularies

The sporadic increase in the occurrence and prevalence of diabetes mellitus have compelled and vigorous search for alternative anti‐diabetic therapeutic approach from medicinal plants and its bioactive. One of the major approach employed is the reduction of gastrointestinal glucose levels through the inhibition of carbohydrate digesting enzymes notably α‐amylase and α‐glucosidase. In this study, the ethanol extracts of 14 selected plants from Mor Porns recipe were screened for their α‐amylase and α‐glucosidase inhibitory activity. The ethanolic extract from the stem of Vitex glabrata displayed the highest percentage inhibitory activity of 84.98 ± 0.59 and 84.71 ± 1.51 against α‐glucosidase and α‐amylase enzymes, respectively. Chemical investigation of the active extract of V. glabrata indicated that pentacyclic triterpenes were the major compounds responsible for the activity. The result obtained from this study suggests the potential use of V. glabrata as an alternative natural source for the treatment of diabetes mellitus.

Evaluation of the Anti-Diabetic Activity of Polysaccharide from Cordyceps cicadae in Experimental Diabetic Rats

Cordyceps cicadae is a medicinal fungus used in treating night sweat, childhood convulsions, vision improvement and pain. This study was designed to evaluate the anti‐diabetic activity of the crude polysaccharide (SHF) from the mycelium and body portion of C. cicadae. Diabetes mellitus was induced in the rat with a single intravenous injection of alloxan monohydrate (150 mg/kg). In other to evaluate the anti‐diabetic effects of C. cicadae polysaccharide in alloxan‐induced diabetic rats, the crude polysaccharide (SHF at 100, 200 and 400 mg/kg body weight) and glibenclamide were administered orally to diabetic rats for 30 days. Blood glucose level, total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphate (ALP), creatinine (CREA), urea, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH) were determined. SHF showed significant reduction in blood glucose in diabetic rats. Treatment of diabetic rats also resulted an improvement in body weights, increased HDL, SOD and GSH, as well as decreased TC, TG, LDL, MDA, urea, CREA, ALT, AST and ALP. These results suggested that C. cicadae polysaccharide displayed anti‐hyperglycemic, anti‐hyperlipidemic and antioxidant activities and could be a promising therapeutic source in managing diabetes mellitus and its associated complications.

Allium tuberosum : Antidiabetic and hepatoprotective activities

Allium tuberosum (AT) is traditionally used for treating nocturnal emissions, abdominal pain, diarrhea, sexual dysfunction and asthma. This study aimed at investigating the antidiabetic and hepatoprotective activities of the butyl alcohol fraction from the methanolic extract of A. tuberosum. For the antidiabetic activity, rats were induced with diabetes by intraperitoneal injection of 150mg/kg alloxan and treated for 30days with AT extract (100, 200 and 400mg/kg). Animals were sacrificed after the study and the fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), HDL, malondialdehyde (MDA) catalase, superoxide dismutase and glutathione levels were determined. The hepatoprotective assay, mice were pretreated for seven days with AT (100, 200 and 400mg/kg) and silymarin (100mg/kg or). Thereafter 10ml/kg of 2% v/v CCl4 was administered intraperitoneally on the 7th day to induce acute liver injury. Blood and liver samples were obtained and serum enzymes ALT, AST, ALP, SOD, GSH, CAT, MDA and pro-inflammatory mediators were assessed. AT significantly decrease FBG, serum TG, TC, MDA levels and significant increased HDL, SOD, GSH and CAT activities in the diabetic rats. In addition, AT significantly inhibited MDA, IL-1b, IL-6 and TNF-α levels and prevented the depletion of the antioxidant enzymes GSH, SOD and CAT activities in CCl4 induced liver damage. Furthermore, AT markedly reduced AST, ALT and ALP levels in the CCl4 treated mice groups. In conclusion, the antidiabetic and hepatoprotective effect of AT may be associated with its antioxidant and its ability to inhibit the pro-inflammatory mediators.

Two New Stilbenoids from the Aerial Parts of Arundina graminifolia (Orchidaceae)

Two new phenanthrene derivatives, a phenanthrenequinone named arundiquinone (1) and a 9,10-dihydrophenanthrene named arundigramin (2) together with a known lignin dimer (3) and seven known stilbenoids (4–10) were isolated from the aerial parts of the Asian orchid Arundina graminifolia. The structures of the isolated compounds were elucidated by spectroscopic methods, including extensive 1D, 2D NMR (heteronuclear single quantum coherence (HSQC), heteronuclear multiple-bond correlation spectroscopy (HMBC), and HR-ESI-MS techniques, as well as comparison with respective literature reports. The cytoprotective activity of the isolated compounds were evaluated for their ability to reduce beta amyloid induced toxicity on undifferentiated PC12 cells. Compound 8 showed moderate cytoprotective activity at 0.5 µmol/L (71% of cell viability) while the other compounds showed no significant activity at the highest concentration tested.

Proteomic-Based Approach to the Proteins Involved in 1-Deoxynojirimycin Accumulation in Silkworm Bombyx mori (Lepidoptera: Bombycidae)

Abstract 1-Deoxynojirimycin (DNJ) is the most abundant poly-hydroxylated alkaloid in the latex of mulberry leaves and it protects mulberry from insect predation. However, silkworms can survive the poisoning effect of DNJ and accumulate DNJ by consumption of the mulberry leaves. In order to determine the molecular mechanism of DNJ accumulation in silkworm, comparative proteomic analysis was employed to evaluate protein expression in two groups of silkworm bodies (the third instar silkworm bodies had the maximum content of DNJ throughout life, and the newly hatched silkworm bodies had no DNJ). Our results indicated some differentially expressed proteins in the third instar silkworm involved in material metabolism, energy metabolism, oxidation-reduction, detoxification, immune, and transport regulation may correspond to the accumulation of DNJ. Furthermore, the expression levels of five selected differentially expressed protein-encoding genes namely heat shock cognate protein (Hsp 70), glutathione S-transferase sigma 1 (GST), serine protease precursor (Ser), hemolymph protein (30K), and thiol peroxiredoxin (TPx) were investigated by quantitative real-time PCR and the accumulation of DNJ was measured by HPLC. Correlation analysis showed that the expression levels of Hsp70 and Ser were negatively correlated to DNJ accumulation with weak correlation, while 30K, GST, and TPx genes had positive correlation with DNJ accumulation. The findings suggested that these three proteins were probably important in the physiological process of DNJ accumulation in silkworm.

The genus Cordyceps : An extensive review of its traditional uses, phytochemistry and pharmacology

The genus Cordyceps has about 750 identified species which are distributed in many regions of the World, but mainly found in South Asia, Europe and North America. The species of the genus are highly priced and are widely used as food and medicine for the treatment of various ailments. This present review compiles literature information on the ethno-medicinal, phytochemistry and pharmacological properties of species in the genus Cordyceps. In addition, the review also suggest recommendations for the future researches. Thirty five Cordyceps species have been reported in the literature to have medicinal properties or has a report on the isolation of bioactive compounds. In vitro and in vivo research studies reporting the validation of the medicinal properties of some species were also reviewed. The phytochemical diversity of this genus was demonstrated with over 200 metabolites including nucleosides, sterols, cyclic peptides, flavonoids, dihydrobenzofurans, bioxanthracenes, polyketide, terpenes, alkaloids and phenolics isolated from various Cordyceps species. Cordyceps sinensis was identified as the most frequently used and most explored member of the Cordyceps genus. Cyclodepsipeptides, nucleosides and polysaccharides were identified as the most studied class of compounds from the genus and they show immunomodulatory, antioxidant, antitumor, cytotoxic, anti-inflammatory, anti-allergic, antidiabetic, analgesic, anti-HIV, antibacterial, antimalarial and antifungal activities. Thus, species belonging to the genus Cordyceps showcases an important source of treating various disorders due to the presence of bioactive constituents that displays potent bioactivities and could serve as possible leads in drug discovery.

Arundinosides A-G, new glucosyloxybenzyl 2 R -benzylmalate derivatives from the aerial parts of Arundina graminifolia

Seven new glucosyloxybenzyl 2R-benzylmalate derivatives, arundinosides A-G (1-7) were isolated from the aerial parts of the bamboo orchid Arundina graminifolia. This is the first occurrence of this class of compounds in the genus Arundina. Their planar structures and absolute configuration were determined by extensive NMR spectroscopic data as well as chemical conversion. Their neuroprotective properties were also evaluated on their potential ability to reduce the beta amyloid damage on PC12 cell model.