Natural Xanthine Oxidase Inhibitor 5-O-Caffeoylshikimic Acid Ameliorates Kidney Injury Caused by Hyperuricemia in Mice.

Xanthine oxidase (XOD) inhibition has long been considered an effective anti-hyperuricemia strategy. To identify effective natural XOD inhibitors with little side effects, we performed a XOD inhibitory assay-coupled isolation of compounds from Smilacis Glabrae Rhizoma (SGR), a traditional Chinese medicine frequently prescribed as anti-hyperuricemia agent for centuries. Through the in vitro XOD inhibitory assay, we obtained a novel XOD inhibitor, 5-O-caffeoylshikimic acid (#1, 5OCSA) with IC50 of 13.96 µM, as well as two known XOD inhibitors, quercetin (#3) and astilbin (#6). Meanwhile, we performed in silico molecular docking and found 5OCSA could interact with the active sites of XOD (PDB ID: 3NVY) with a binding energy of -8.6 kcal/mol, suggesting 5OCSA inhibits XOD by binding with its active site. To evaluate the in vivo effects on XOD, we generated a hyperuricemia mice model by intraperitoneal injection of potassium oxonate (300 mg/kg) and oral gavage of hypoxanthine (500 mg/kg) for 7 days. 5OCSA could inhibit both hepatic and serum XOD in vivo, together with an improvement of histological and multiple serological parameters in kidney injury and HUA. Collectively, our results suggested that 5OCSA may be developed into a safe and effective XOD inhibitor based on in vitro, in silico and in vivo evidence.

Altered plasma and brain disposition of isopropylidene shikimic acid liposome in rats and the brain protection in cerebral ischemia-reperfusion.

CONTEXT: Cerebral ischemia-reperfusion (I/R) injury is a secondary injury caused by oxidative stresses and inflammatory responses after recovery from cerebral ischemia. Brain protective drugs were used to reduce the injury. In order to improve the distribution in brain and enhance the brain-protective efficacy, some pharmaceutical technologies were used to achieve brain targeting delivery. OBJECTIVE: To investigate the physiological disposition of ISA liposome, and provide references for the further study about high-efficacy brain-protective preparations for I/R injury. MATERIALS AND METHODS: Comparative studies were carried out. The pharmacodynamics in t-MCAO model rats were studied first, and then the pharmacokinetics and brain distribution of the two preparations were determined. RESULTS: At the same dose, the efficacy of ISA liposome was better (P < 0.05). The efficacy was dose dependent, with significant difference of 20 mg/kg (P < 0.01) and indistinctive difference of 10 mg/kg (P = 0.22), compared with vehicle-treated rats. The parameters, T(1/2ß), MRT and AUC were different significantly between the two preparations. The enhancement of brain distribution for ISA in the liposome was obvious, with the maximum concentration 7.18 µg/g, while close to zero for the solution group. DISCUSSION AND CONCLUSION: ISA liposome could increase the distribution in brain and enhance the efficacy significantly. The results revealed that the liposomal DDS was potential as a novel strategy for the treatment of cerebral I/R injury. In addition, further targeted modification, such as PEG-modified liposomes, which possess a long circulating property in the bloodstream, would further improve the targeting delivery to the brain and lead to more significant efficacy.

Protective effects of 3,4-oxo-isopropylidene-shikimic acid on experimental colitis induced by trinitrobenzenesulfonic acid in rats.

BACKGROUND: 3,4-Oxo-isopropylidene-shikimic acid (ISA) is a derivative of shikimic acid (SA). SA is extracted from Illicium verum Hook.fil., which has been used in traditional Chinese medicine and used for treating vomiting, stomach aches, insomnia, skin inflammation, and rheumatic pain. AIMS: To investigate the effects and the protective mechanism of 3,4-oxo-isopropylidene-shikimic acid on experimental colitis model induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats. METHODS: Colitis in rats was induced by colonic administration with TNBS. ISA (50, 100, and 200 mg/kg) was administered for 12 days to experimental colitis rats. The inflammatory degree was assessed by macroscopic damage score, colon weight/length ratios (mg/cm), and myeloperoxidase (MPO) activity. Malondialdehyde (MDA), glutathione (GSH), and nitric oxide (NO) levels, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), inducible nitric oxide synthase (iNOS) activities were measured with biochemical methods. RESULTS: ISA significantly ameliorated macroscopic damage, reduced colon weight/length ratios and the activity of MPO, depressed MDA and NO levels and iNOS activity, and enhanced GSH level, and GSH-Px and SOD activities in the colon tissues of experimental colitis in a dose-dependent manner. Moreover, the effect of ISA (200 mg/kg) was as effective as sulfasalazine (500 mg/kg). CONCLUSIONS: The findings of this study demonstrate the protective effect of ISA on experimental colitis, probably due to an antioxidant action.

Shikimic acid in the light of current knowledge.

Shikimic acid (SA) has been mainly used in the pharmaceutical industry for production of drugs, however, recently it has also appeared in the world of cosmetics. So far, there have not been many publications on cosmetics containing SA or research studies on the compound, especially those that would involve testing cosmetic products on subjects. The main source of SA is star anise. The recommended concentration of SA in cosmetic preparations ranges between 1 and 5%. The pH of a 5% solution of SA in water is 3. SA at a concentration of 5% has a similar exfoliative effect to that of 50% glycolic acid. It shows antiviral, exfoliating, deodorizing, anti-acne, anti-dandruff, whitening and moisturizing activity. It also regulates the amount of secreted sebum, moreover, it has antibacterial, anti-inflammatory, hair-growth stimulating, anti-aging effect and antifungal properties.

Shikimic acid promotes estrogen receptor(ER)-positive breast cancer cells proliferation via activation of NF-κB signaling.

Shikimic acid (SA), a widely-known hydroaromatic compound enriched in Bracken fern and Illicium verum (also known as Chinese star anise), increases the risk of gastric and esophageal carcinoma, nevertheless, the influence of SA on breast cancer remains indistinct. Herein we found that, with models in vitro, SA significantly promoted estrogen receptor(ER) positive cells proliferation and NF-κB activation was involved in it. Moreover, our data showed that IκBα, a critically endogenous inhibitor of NF-κB, was repressed. Subsequently, we found increase of miR-300 by SA treatment sand miR-300 could target IκBα mRNA. Additionally, inhibition of miR-300 abrogated the repression of IκBα by SA. As a result, miR-300 was also involved in NF-κB activation and breast cancer cells proliferation promotion due to SA exposure. Taken together, with ER-positive breast cancer cell models in vitro, MCF-7 and T47D, our results implied that SA promoted breast cancer cells proliferation via a miR-300-induced NF-κB dependent pathway controlling cell cycle proteins.

Natural products and their derivatives as cholinesterase inhibitors in the treatment of neurodegenerative disorders: an update.

Alzheimer's disease (AD) is the most common form of neurodegenerative disorders. If more effective therapies than the ones currently available are not developed that either prevent AD or other neurodegenerative or block progression of the diseases in its very early stages, the economic and societal cost of caring for AD patients will be devastating. Besides the neuropathologic hallmarks of the diseases, namely neurofibrillary tangles and AD neuritic plaques, the disease is characterized neurochemically by a consistent deficit in cholinergic neurotransmission, particularly affecting cholinergic neurons in basal forebrain. AD and other forms of dementia could be treated by the use of agents which restore the level of acetylcholine through inhibition of both two major forms of cholinesterase: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Moreover, the inhibition of AChE holds a key role not only to enhance cholinergic transmission in the brain but also to reduce the aggregation of beta-amyloid and the formation of the neurotoxic fibrils in AD. Following this view, in recent years, an increased interest has emerged directed to finding drugs able to inhibit both of these events. This review summarizes and highlights recent advances in current knowledge on natural products as cholinesterase inhibitors and how these compounds have also served as the starting points for semi-synthetic analogs with improved properties.

In silico Screening and Evaluation of the Anticonvulsant Activity of Docosahexaenoic Acid-Like Molecules in Experimental Models of Seizures.

BACKGROUND: Resistance to antiepileptic drugs and the intolerability in 20-30% of the patients raises demand for developing new drugs with improved efficacy and safety. Acceptable anticonvulsant activity, good tolerability, and inexpensiveness of docosahexaenoic acid (DHA) make it as a good candidate for designing and development of the new anticonvulsant medications. METHODS: Ten DHA-based molecules were screened based on in silico screening of DHA-like molecules by root-mean-square deviation of atomic positions, the biological activity score of Professional Association for SQL Server, and structural requirements suggested by pharmacophore design. Anticonvulsant activity was tested against clonic seizures induced by pentylenetetrazole (PTZ, 60 mg/kg, i.p.) and tonic seizures induced by maximal electroshock (MES, 50 mA, 50 Hz, 1 ms duration) by intracerebroventricular (i.c.v.) injection of the screened compounds to mice. RESULTS: Among screened compounds, 4-Phenylbutyric acid, 4-Biphenylacetic acid, phenylacetic acid, and 2-Phenylbutyric acid showed significant protective activity in pentylenetetrazole test with ED50 values of 4, 5, 78, and 70 mM, respectively. In MES test, shikimic acid and 4-tert-Butylcyclo-hexanecarboxylic acid showed significant activity with ED50 values 29 and 637 mM, respectively. Effective compounds had no mortality in mice up to the maximum i.c.v. injectable dose of 1 mM. CONCLUSION: Common electrochemical features and three-dimensional spatial structures of the effective compounds suggest the involvement of the anticonvulsant mechanisms similar to the parent compound DHA.

Skin whitening capability of shikimic acid pathway compound.

OBJECTIVE: To examine the skin whitening capabilities of shikimic acid pathway compounds and find the most effective molecule to be used as the active ingredient for skin whitening products. MATERIALS AND METHODS: Skin whitening is the practice of using chemical substances to lighten skin tone by the lessening the concentration of melanin. The whitening efficacy of shikimic acid pathway compounds was evaluated. Eight compounds in the shikimic acid pathway were chosen for this study: benzoic acid, p-coumaric acid, vanillic acid, syringic acid, quinic acid, shikimic acid, orcinol monohydrate, and phenyl pyruvic acid. We measured the tyrosinase inhibitory capacity of the compounds in the animal model of zebrafish and also evaluated the compounds' anti-oxidant activities using the DPPH radical scavenging, and ABTS+ free radical scavenging tests. Compounds' cytotoxicity effects were also evaluated. RESULTS: Amongst eight shikimic acid pathway compounds used in this study, shikimic acid was the most potent tyrosinase-inhibitor and the most efficient compound to be used as an active ingredient for skin whitening. Shikimic acid revealed a good radical scavenging activity (RAS) with low cell toxicity. CONCLUSIONS: Promising results obtained in this study may open a new window of opportunity to introduce another compound to be used in the skin-whiting cosmetics industry.

Shikimic acid inhibits LPS-induced cellular pro-inflammatory cytokines and attenuates mechanical hyperalgesia in mice.

BACKGROUND AND AIMS: Shikimic acid (SA) is present in a wide variety of plants and microorganisms used in traditional and folk medicine and also is an essential starting material for the synthesis of the antiviral drug Oseltamivir (Tamiflu®). Some pharmacological actions observed in SA-enriched products include antioxidant and anti-inflammatory activities. Here, we investigated the anti-inflammatory and antinociceptive actions of isolated SA. METHODS: RAW 264.7 macrophage cells were treated with bacterial LPS (1µg/mL) and the effect of SA on the modulation of cell viability, nitric oxide (NO) production, TNF-α, and IL-1ß content and MAPK (ERK1/2 and p38) activation was evaluated. Besides, the anti-hyperalgesic actions of SA on in vivo model of mechanical hyperalgesia induced by carrageenan (CG), dopamine (DA), TNF-α and prostaglandin (PGE2) were assessed. RESULTS: In RAW 264.7 cells, SA suppressed LPS-induced decrease in cell viability and nitrite accumulation to control values and inhibited up-regulation of TNF-α (65%) and IL-1ß (39%). These effects may be mediated at least in part by inhibition of LPS-induced ERK 1/2 (22%) and p38 (17%) phosphorylation. In mice, SA at 50, 100, and 200mg/kg decreased formalin-induced nociceptive behavior (around 50%) and inhibited the inflammatory nociception induced by TNF-α and PGE2 (50 to 75% each). Moreover, SA (100 and 200mg/kg) significantly attenuated the mechanical hyperalgesia induced by CG and DA (25 to 40% each). CONCLUSIONS: These results indicate that SA presents anti-inflammatory actions with potential for development of drugs to treat pro-inflammatory and painful conditions.

Anti-inflammatory effect of 3,4-oxo-isopropylidene-shikimic acid on acetic acid-induced colitis in rats.

The present work was done to investigate the possible effects of 3,4-oxo-isopropylidene-shikimic acid (ISA) on acetic acid (AA)-induced colitis in rats. Colitis was induced by intracolonic injection of 6 % AA. Several parameters, including macroscopic score and biochemical parameters, were determined to assess the degree of protection. Biochemical parameters such as myeloperoxidase (MPO) activity, malondialdehyde (MDA) and nitric oxide (NO) levels, and superoxide dismutase (SOD) and inducible NO synthase (NOS) activities were measured following standard assay procedures. The study showed that treatment of rats for 6 days with ISA (100 and 200 mg/kg) was able to give complete protection against AA-induced colitis. Moreover, biochemical changes were reversed and brought toward control. These results suggest a beneficial effect of ISA against experimental colitis and the possible mechanism of the protective effects may be partly due to an antioxidant action.

Identification of hypoglycaemic compounds from berries of Juniperus oxycedrus subsp. oxycedrus through bioactivity guided isolation technique.

ETHNOPHARMACOLOGICAL RELEVANCE: Decoction of Juniperus oxycedrus subsp. oxycedrus L. (Cupressaceae) berries is used internally as tea and pounded fruits are consumed to lower blood glucose levels in Turkey. AIM OF THE STUDY: To evaluate hypoglycaemic and antidiabetic activity of J. oxycedrus subsp. oxycedrus berries and to identify active compounds through bioactivity guided isolation technique. MATERIAL AND METHODS: Hypoglycaemic effect of J. oxycedrus subsp. oxycedrus (Joso) berry extracts on oral administration was studied using in vivo models in normal, glucose-hyperglycaemic rats. Streptozotocin induced diabetic rats were used to examine antidiabetic activity of Joso extracts, subextracts, fractions, subfractions and shikimic acid (SA). RESULTS: Through in vivo bioactivity-guided fractionation processes, shikimic acid, 4-O-ß-d-glucopyranosyl ferulic acid and oleuropeic acid-8-O-ß-d-glucopyranoside were isolated from the n-butanol subextract by silica gel and reverse phase column chromatography as the main active ingredient of the active subfraction. After 8 days administration of the major compound shikimic acid, blood glucose levels (24%), malondialdehyde levels in kidney tissues (63-64%) and liver enzymes (AST, ALT, ALP) of diabetic rats were decreased. CONCLUSION: Results indicated that Joso berry extract and its active constituents might be beneficial for diabetes and its complications.

Antinociceptive activity of aqueous extract and isolated compounds of Lithrea molleoides.

ETHNOPHARMACOLOGICAL RELEVANCE: Lithrea molleoides (Vell.) Engl. (Anacardiaceae) is a medicinal plant commonly used in traditional medicine in South America. AIM OF THE STUDY: In the present study, the in vivo antinociceptive effect of L. molleoides' aqueous extract and its isolated compounds has been investigated. MATERIALS AND METHODS: Antinociceptive activity was evaluated through writhing, formalin and hot plate tests in mice. The phytochemical analysis was performed. RESULTS: The extract produced significant inhibition on nociception induced by acetic acid (ED50: 8.7 mg/kg, i.p.) and formalin (ED50: 7.7 mg/kg, i.p.) administered intraperitoneally and also orally. Yohimbine diminished the activity of the extract in the acetic acid test meanwhile haloperidol enhanced its effect. Two majority compounds, shikimic and vanillic acid were active in chemical nociceptive models used in this work, producing the highest inhibition of the writhing response at a dose of 30 mg/kg i.p. (55.4% and 57.1%, respectively) meanwhile at 100 mg/kg p.o. produced a slight response (23.3% and 23.9%, respectively). CONCLUSIONS: These results suggest that L. molleoides' aqueous extract produced antinociception possibly related to the presence of shikimic and vanillic acid. The adrenergic and dopaminergic systems seem to be involved in the mechanism of antinociception of the extract.

Illicium verum: a review on its botany, traditional use, chemistry and pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: The fruit of Illicium verum Hook. f. (Chinese star anise) has long been used in traditional Chinese medicine and food industry with the actions of dispelling cold, regulating the flow of Qi and relieving pain. MATERIALS AND METHODS: A bibliographic investigation was carried out by analyzing recognized books including Chinese herbal classic, and worldwide accepted scientific databases (Pubmed, SciFinder, Scopus and Web of Science) were searched for the available information on I. verum. RESULTS: I. verum is an aromatic evergreen tree of the family Illiciaceae. It is sometimes contaminated with highly toxic Japanese star anise (I. anisatum L.) and poisonous star anise (I. lanceolatum A. C. Smith), which contain several neurotoxic sesquiterpenes. Traditional uses of I. verum are recorded throughout Asia and Northern America, where it has been used for more than 10 types of disorders. Numerous compounds including volatiles, seco-prezizaane-type sesquiterpenes, phenylpropanoids, lignans, flavonoids and other constituents have been identified from I. verum. Modern pharmacology studies demonstrated that its crude extracts and active compounds possess wide pharmacological actions, especially in antimicrobial, antioxidant, insecticidal, analgesic, sedative and convulsive activities. In addition, it is the major source of shikimic acid, a primary ingredient in the antiflu drug (Tamiflu). AIM OF THE REVIEW: This review summarizes the up-to-date and comprehensive information concerning the botany, traditional use, phytochemistry and pharmacology of I. verum together with the toxicology, and discusses the possible trend and scope for future research of I. verum.