In vitro antitumor activities of the lichen compounds olivetoric, physodic and psoromic acid in rat neuron and glioblastoma cells

Context Since methods utilised in the treatment of glioblastoma multiforme (GBM) are inadequate and have too many side effects, usage of herbal products in the treatment process comes into prominence. Lichens are symbiotic organisms used for medicinal purposes for many years. There are various anticancer treatments about components of two lichen species used in the present study. Objective Antitumor potential of three lichen secondary metabolites including olivetoric acid (OLA) and physodic acid (PHA) isolated from Pseudevernia furfuracea (L.) Zopf (Parmeliaceae) and psoromic acid (PSA) isolated from Rhizoplaca melanophthalma (DC.) Leuckert (Lecanoraceae) were investigated on human U87MG-GBM cell lines and primary rat cerebral cortex (PRCC) cells for the first time. Materials and methods PRCC cells used as healthy brain cells were obtained from Sprague-Dawley rats. The treatments were carried out on the cells cultured for 48 h. Cytotoxic effects of different concentrations (2.5, 5, 10, 20 and 40 mg/L) of metabolites on the cells were determined via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) analyses. Total antioxidant capacity (TAC) and total oxidant status (TOS) parameters were used for assessing oxidative alterations. Oxidative DNA damage potentials of metabolites were investigated via evaluating 8-hydroxy-2'-deoxyguanosine (8-OH-dG) levels. Results Median inhibitory concentration (IC50) values of OLA, PHA and PSA were 125.71, 698.19 and 79.40 mg/L for PRCC cells and 17.55, 410.72 and 56.22 mg/L for U87MG cells, respectively. It was revealed that cytotoxic effects of these metabolites showed positive correlation with concentration, LDH activity and oxidative DNA damage. Discussion and conclusion The present findings obtained in this study revealed that primarily OLA and then PSA had high potential for use in the treatment of GBM.

In vitro effects of preserved and unpreserved anti-allergic drugs on human corneal epithelial cells

PURPOSE

Treatment with topical eye drops for long-standing ocular diseases like allergy can induce detrimental side effects. The purpose of this study was to investigate in vitro cytotoxicity of commercially preserved and unpreserved anti-allergic eye drops on the viability and barrier function of monolayer and stratified human corneal-limbal epithelial cells.

METHODS

Cells were treated with unpreserved ketotifen solution, benzalkonium chloride (BAC)-containing anti-allergic drugs (ketotifen, olopatadine, levocabastine) as well as BAC alone. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to determine cell viability. Effects of compounds on barrier function were analyzed measuring transepithelial electrical resistance (TEER) to determine paracellular permeability and rose bengal assays to evaluate transcellular barrier formation.

RESULTS

The BAC-preserved anti-allergic formulations and BAC alone significantly reduced cell viability, monolayer cultures being more sensitive to damage by these solutions. Unpreserved ketotifen induced the least diminution in cell viability. The extent of decrease of cell viability was clearly dependent of BAC presence, but it was also affected by the different types of drugs when the concentration of BAC was low and the short time of exposure. Treatment with BAC-containing anti-allergic drugs and BAC alone resulted in increased paracellular permeability and loss of transcellular barrier function as indicated by TEER measurement and rose bengal assays.

CONCLUSIONS

The presence of the preservative BAC in anti-allergic eye drop formulations contributes importantly to the cytotoxic effects induced by these compounds. Stratified cell cultures seem to be a more relevant model for toxicity evaluation induced on the ocular surface epithelia than monolayer cultures.

[Toxicity of topical ocular anti-allergic agents on human corneal epithelial cells in vitro]

OBJECTIVE

To investigate the cytotoxic effect of three kinds of topical ocular anti-allergic agent, including olopatadine 0.1% (A group), ketotifen fumarate 0.025% (B group) and pemirolast potassium 0.1% (C group), on cultured human corneal epithelial cells in vitro.

METHODS

Primary human corneal epithelial cells were cultured with keratinocyte serum-free medium. The cells were exposed to three kinds of topical ocular anti-allergic agent for a period of 10 min, 30 min, 2 h, 6 h, 12 h and 24 h. Toxicity was examined in three ways. MTT assay was used to quantify cytotoxicity. Cell membrane permeability and intracellular esterase activity were analyzed with live-dead viability staining of fluorescent calcein-AM/ethidium homodimer. The morphologic analysis was performed by light and scanning electron microscopy. Statistical methods adopted one-way ANOVA (analysis of variance) and Student-Newman-Keuls q test between each group. The P-value of 0.05 was considered statistically significant.

RESULTS

(1) Morphologic changes: The Findings under the light microscopy were demonstrated that cells became round or edematic and detached from dishes after exposure to topical ocular anti-allergic agent. The cellular damage was more severe with longer exposure time and increasing concentration. Likewise, the electron microscopy examination showed reduced microvilli with longer exposure time and increasing concentration. The cellular changes of 20.0% olopatadine 0.1% were reduced when compared to the other agents. (2) Live/dead viability/cytotoxicity assay: Ethidium homodimeric permeates damaged cell membranes and results in red fluorescence. These results indicated that cell membrane damage caused by 20.0% olopatadine 0.1% at 6, 12, 24 h was less than those of ketotifen fumarate 0.025% and pemirolast potassium 0.1%. The data of A group were (29.7 +/- 2.6)%, (36.9 +/- 3.2)%, (51.2 +/- 4.3)%, B group were (36.5 +/- 3.1)%, (48.5 +/- 4.3)%, (75.5 +/- 3.8)% and C group were (37.1 +/- 2.2)%, (52.7 +/- 3.4)%, (71.1 +/- 5.1)%, respectively. The q values of A to B group and A to C group at 6 h were 3.27, 4.31, respectively (P < 0.05). The green fluorescent staining of calcein-AM indicated intracellular esterase activity was decreased after incubation with increasing concentration and longer exposure time. There was no significantly different result between each group (P > 0.05). The proportion of green staining cell of A, B and C group at 24 h were 100.0% with 50.0% concentration and were (23.2 +/- 4.6)%, (29.5 +/- 5.2)%, (31.1 +/- 5.5)% respectively with 20.0% concentration (F = 1.97, P = 0.377). (3) MTT assay: The results of the three groups revealed cell viability decreased significantly with increasing concentration and longer exposure time at all the concentrations except 0.8%. MTT values for A, B and C group at the concentration of 20.0%, at 6 h were 0.429 +/- 0.028, 0.367 +/- 0.038, 0.379 +/- 0.012 and 4% at 24 h were 0.457 +/- 0.025, 0.401 +/- 0.008, 0.387 +/- 0.012, respectively. The data for olopatadine 0.1% were significantly improved over those of ketotifen fumarate 0.025% and pemirolast potassium 0.1%. The q value of A to B group, A to C group were 3.01, 3.77 (P < 0.05) at the concentration of 20.0%, 6 h and were 3.63, 4.11 (P < 0.05) at the concentration, 24 h. There were no statistical significant results at other concentrations.

CONCLUSIONS

The topical ocular anti-allergic agent, olopatadine 0.1%, showed less toxic effects on human corneal epithelial cells compared to ketotifen fumarate 0.025% and pemirolast potassium 0.1%. Olopatadine 0.1% may offer a safer option to the corneal epithelium when used to treat allergic keratoconjunctivitis over an extended period of time.

Prolongation of antipyretic action and reduction of gastric ulcerogenicity in the rat by controlled-release granules of bermoprofen, a new nonsteroidal anti-inflammatory drug

While bermoprofen [(+-)-10,11-dihydro-alpha,8-dimethyl-11- oxodibenz[b,f]oxepin-2-acetic acid], a new nonsteroidal antiinflammatory drug (NSAID), has potent antipyretic and analgesic activities with a short biological half-life, it shows ulcerogenic activity as a side-effect like other nonsteroidal anti-inflammatory drugs. A bermoprofen preparation was specially designed to prolong its duration of action and to reduce its side effect. Immediate-release granules (IRGs) were prepared by coating particles of Nonpareil 103 with bermoprofen. The IRGs were also coated by spraying a film solution composed of ethylcellulose and hydroxypropylmethylcellulose (3:2), and, thereby, three kinds of retard-release granules (RRGs) were obtained with the coating amounts of 1.5, 2.5, and 4%. Peak plasma bermoprofen levels were seen 0.5, 1, 2, and 3 h after single oral administrations of IRG, RRG(1.5%), RRG (2.5%), and RRG(4%), respectively, in rats. The potency order in ulcerogenic activity was RRG(1.5%) greater than IRG greater than RRG(2.5%) greater than RRG(4%) after a single oral dosage in rats. Then, IRG and RRG(4%) were mixed (in the ratio 3:7, which was calculated from their simulated plasma bermoprofen profiles) in order to get fast onset and long duration of antipyretic action. These mixed granules [i.e., the sustained-release granules (SRGs)] exhibited a falt plasma bermoprofen profile, and longer lasting antipyretic and lower ulcerogenic activities in rats in comparison with IRG or bermoprofen. From these results, it is suggested that a bermoprofen SRG preparation has more durable therapeutic activity and lower side-effects as a NSAID.

A postulated mechanism of beta-sympathomimetic induction of rib and limb anomalies in rat fetuses

Treatment of gravid rats (days 6-15 of gestation) with the beta-sympathomimetic doxaminol resulted in wavy ribs and bent limbs in the offspring. The fetuses also exhibited defective mineralization. These anomalies were produced by pharmacologically effective doses of the drug. Prior treatment with the beta-receptor blocker carazolol prevented their formation, so that the beta-sympathomimetic action of doxaminol is evidently a causative factor. Various hypotensive agents whose activity is not mediated by beta-receptors failed to produce abnormalities. This eliminates the possibility of a non-specific etiology such as diminished placental perfusion. The cyclooxygenase inhibitor indomethacin lowered the incidence of wavy ribs. Furosemide, a loop diuretic that stimulates renal prostaglandin synthesis, increased the incidence of abnormalities when combined with doxaminol. The nature of the anomalies found suggests that 1) fetal compression by the myometrium and 2) defective mineralization are prerequisites for their development. The first condition could be produced via the complex mechanism of beta-sympathomimetic-induced stimulation of prostaglandin synthesis. Defective mineralization can result directly from cAMP-mediated activation of osteoclasts and possibly be further promoted by beta-sympathomimetic-mediated prostaglandin action on the osteoclast. The pathological findings in the fetal rat skeleton cannot be correlated with corresponding findings in human neonates whose mothers were subjected to prolonged therapeutic uterine relaxation with beta 2-sympathomimetics, for example. Since the anomalies in the rat disappear spontaneously in the post-natal period, their clinical relevance appears to be slight.

Mutagenicity of lichen constituents

Usnic acid (the most abundant lichen constituents), physodic, and physodalic acids isolated from Hypogymnia enteromorph (Ach.) Nyl. were tested for mutagenicity in the Ames Salmonella/microsome assay. Physodalic acid exhibited clear dose-related mutagenicity against Salmonella typhimurium strain TA 100 with or without S9 mix in both plate-incorporation and preincubation assays. The addition of S9 mix increased the number of revertants approximately threefold and fourfold in preincubation and plate-incorporation assays, respectively.

Nonsteroidal antiinflammatory agents. 2. Derivatives/analogues of dibenz[b,e]oxepin-3-acetic acid

6,11-Dhydro-11-oxodibenz[b,e]oxepins and some related compounds have been synthesized and evaluated for antiinflammatory effect according to the carrageenan paw edema method in rats. The structure-activity relationships have been discussed among acetic acid, carboxylic acid, alcohol, and tetrazole derivatives of dibenzoxepins and acetic acid derivatives of thienobenzoxepins and of the corresponding thiepins. The 3-isopropyl alcohol 9 and 11-deoxo-3-propionic acid (49) were more active than indomethacin but not as active as the title compound (i.e., 43). Carboxylic acids, tetrazoles, esters, amides, and ketones were less active than the corresponding acetic acids. Three compounds (31, 33, and 34) were evaluated for ulcerogenicity and lethality but none surpassed 6,11-dihydro-11-oxodibenz[b,e]oxepin-3-acetic acid (41) in therapeutic ratio.