Cytotoxicity of isolated compounds from Picrasma crenata (Vell.) Engl. in animal tumor cell (HTC).

The study aim was to evaluate the cytotoxic activity, using the MTT test [3-(4,5-Dimethilthiazol-2-yl)-2,5-diphenil tetrazolium bromide], from the crude extract of Picrasma crenata (Pau Tenente) and its isolated compounds, quassin and parain, in culture of rat liver tumor cells (HTC). The test was carried out exposing the cells for 24, 48 and 72 hours to concentrations of 5, 10, 50, 100, 200, 300, 400, 500 and 1000 µg of crude extract of Pau Tenente/mL of culture medium and 1, 5, 10, 15, 20, 40, 60, 80 and 100 µg of quassin or parain compounds/mL of culture medium. The absorbances averages results obtained showed that the crude extract did not present cytotoxicity for the HTC cells in all the concentrations and evaluated times. For quassin, the concentrations of 80 and 100 µg/mL were cytotoxic, after 72 hours of treatment. For parain, the concentrations of 1, 5, 20, 40, 60, 80 and 100 µg/mL, in 72 hours, were cytotoxic, revealing a new activity for this compound. Thus, the results demonstrate a first indication of the cytotoxic activity of compounds quassin and parain, adding an important social and economic value to them, and may have application in future research and in pharmaceutical industry.

Cytotoxicity of capsaicin and its analogs in vitro.

Capsaicin (CAP) is the main compound responsible for the spicy flavor of Capsicum plants. However, its application can be inhibited due to its pungency and toxicity. This study aimed to evaluate and compare the cytotoxic effect of CAP and its analogs N-benzylbutanamide (AN1), N-(3-methoxybenzyl) butanamide (AN2), N-(4-hydroxy-3-methoxybenzyl) butanamide (AN3), N-(4-hydroxy-3-methoxybenzyl) hexanamide (AN4) and N-(4-hydroxy-3-methoxybenzyl) tetradecanamide (AN5) on the hepatoma cells of Rattus norvegicus using the MTT test. The results showed cytotoxicity of CAP at concentrations of 100, 150, 175, and 200 µM (24 hours), AN1 at 150 and 175 µM (48 hours), AN2 at 50 µM (24 hours) and 10, 25, 50, and 75 µM (48 hours), AN4 at 175 µM (24 hours), and AN5 at 50 µM (48 hours). Removing the hydroxyl radical from the vanillyl group of capsaicin, together with reducing the acyl chain to 3 carbons, which is the case of AN2, resulted in the best biological activity. Increasing the carbon chain in the acyl group of the capsaicin molecule, which is the case of AN5, also showed evident cytotoxic effects. The present study proves that the chemical modifications of capsaicin changed its biological activity.

Cytotoxicity of extracts and compounds isolated from Croton echioides in animal tumor cell (HTC).

The search for compounds with anticancer effects is of paramount importance today due to the high incidence of the disease. The Euphorbiaceae family is known for having compounds with therapeutic properties, one of its genera being Croton. It has several species, which contain compounds already known for their biological activities, presenting anti-inflammatory, antimicrobial and anticancer properties. Thus, the cytotoxicity/antiproliferative activity of semi-purified fractions and compounds isolated from Croton echioides in liver tumor cells of Rattus norvegicus (HTC) was evaluated by the MTT test. The semi-purified fractions showed cytotoxicity at concentrations above 200 µg/mL, at 24, 48 and 72 hours, reaching cell viability of 24.78% [400 µg/mL] at 24 hours, 12.79% [500 µg/mL] at 48 hours and 10.57% [300 µg/mL] at 72 hours. For the isolated compounds, lupeol had a cytotoxic effect in all concentrations (1, 5, 10, 15, 20, 40, 60, 80 and 100 µg/mL) and tested times (24, 48 and 72 hours), reaching minimum viability of 4.37% [100 µg/mL], within 72 hours. The clerodan diterpenes CEH-1 and CEH-4 also showed antiproliferative activity, with minimum viability of 36.19% [100 µg/mL] over 72 hours and 21.33% [100 µg/mL] over 48 hours, respectively. However, the clerodan diterpenes CEH-2 and CEH-3 did not shows a cytotoxic effect for HTC cells. Thus, there is a cytotoxic/antiproliferative potential of C. echioides against tumor cells, with targeted to mitochondrial enzymes, associated with cell proliferation, indicating that this species deserves prominence in the search for new molecules for the treatment of cancer.

Cytotoxicity of iodine-131 radiopharmaceutical in tumor and non-tumor human cells and radioprotection by integral juices of Vitis labrusca L.

Iodine-131 (I-131) radioisotope it causes the formation of free radicals, which lead to the formation of cell lesions and the reduction of cell viability. Thus, the use of radioprotectors, especially those from natural sources, which reduce the effects of radiation to healthy tissues, while maintaining the sensitivity of tumor cells, stands out. The objective of the present study was to evaluate the cytoprotective/radioprotective effects of whole grape juices manufactured from the conventional or organic production systems, whether or not exposed to ultraviolet (UV-C) light irradiation. The results showed that I-131 presented a cytotoxic effect on human hepatocellular cells (HepG2/C3A) at concentrations above 1.85 MBq/mL, after 24 and 48 hours of treatment, though all concentrations (0.0037 to 7.40 MBq/mL) were cytotoxic to non-tumor human lung fibroblast (MCR-5) cells, after 48 hours. However, grape juices (10 and 20 µL/mL) did not interfere with the cytotoxic effect of the therapeutic dose of I-131 on tumor cells within 48 hours of treatment, while protecting the non-tumor cells, probably due to its high antioxidant activity. In accordance with their nutraceutical potential, antioxidant and radioprotective activity, these data stimulate in vivo studies on the use of natural products as radioprotectants, such as grape juice, in order to confirm the positive beneficial potential in living organisms.

Chemotherapeutical effects of the herbal medicine Uncaria tomentosa (Willd.) DC.

The use of medicinal plants dates back to the beginning of humanity, and today their application as complementary therapy has been widely disseminated as an alternative to conventional therapy. The medicinal plant named Uncaria tomentosa (Willd.) DC. (known as cat's claw) is a common woody vine of the Amazon forest that has traditionally been used in the treatment of arthritis because of its anti-inflammatory properties. This study aimed to evaluate the cytotoxic, mutagenic, and antimutagenic potentials of this medicinal plant. The biological activities of U. tomentosa were determined on bone marrow cells of Wistar rats that were treated in vivo. For the cytotoxic and mutagenic analyses, aqueous plant extract solutions were administered by gavage (1, 2, or 3 mg/mL) for 24 h (an acute treatment) or 7 days (a subchronic treatment). For the antimutagenic analyses, aqueous plant extract solutions (1 mg/mL) were administered by gavage before (pretreatment), simultaneous to (simultaneous treatment), or after (post-treatment), the administration of cyclophosphamide (1.5 mg/mL). U. tomentosa did not show any cytotoxic or mutagenic effects in any of the cytological or chromosomal analyses. Besides, the antimutagenic tests showed that the plant extracts displayed antimutagenic activities, which significantly reduced the percentages of the chromosomal aberrations that were induced by cyclophosphamide at 53.91, 58.60, and 57.03%, respectively, for the simultaneous treatment, pretreatment, and post-treatment. The results suggested a safe use of this herbal medicine that is available free of charge from the Brazilian Public Health System for the treatment of arthritis. This medicinal plant can also effectively contribute to improving the quality of life and the recovery of people undergoing chemotherapeutical treatments.

In vivo antimutagenic activity of the medicinal plants Pfaffia glomerata (Brazilian ginseng) and Ginkgo biloba.

Complementary and alternative therapies, including the use of medicinal plants, have become almost standard among the world's population. Pfaffia glomerata (PG), popularly known as Brazilian ginseng, is widely used as a restorer of vital functions, increasing mental balance, and is used for the treatment of diabetes and rheumatism. Ginkgo biloba (GB) is one of the oldest known gymnosperms, whose leaves are widely used for its potentiating action on the nervous system. The biological activities of these plants were determined on bone marrow cells of Wistar rats treated in vivo. For cytotoxic and mutagenic acute analysis, plant extracts were administered by gavage at concentrations of 0.15, 1.5, and 15 mg PG/mL water and 1, 2, and 3 mg GB/mL water. For antimutagenic analysis, plant extracts aqueous solution (PG, 1.5 mg/mL or GB, 2 mg/mL) were administered by gavage before (pretreatment), simultaneous to (simultaneous treatment), or after (post-treatment) the administration of cyclophosphamide (1.5 mg/mL, intraperitoneally). Both plant extracts have no cytotoxic or mutagenic potential, and they significantly reduce the percentage of chromosomal aberrations induced by the cyclophosphamide given simultaneously (PG, 87%; GB, 75%), pretreatment (PG, 98%, GB, 78%) and post-treatment (PG, 99%, GB, 75%). This beneficial antimutagenic property of the medicinal plants P. glomerata and G. biloba presented here, with no cytotoxic or mutagenic activity, can efficiently contribute to improvements in quality of life and recovery for people undergoing chemotherapeutic treatment, or those looking for health and preventive habits.

Influence of processing and storage of integral grape juice (Vitis labrusca L.) on its physical and chemical characteristics, cytotoxicity, and mutagenicity in vitro.

Integral grape juice is extracted from the grape through processes that allow the retention of their natural composition. However, due to the severity of some processes, fruit juices can undergo changes in their quality. The present study evaluated the cytotoxic and mutagenic effects of integral grape juice by a cytokinesis-blocked micronucleus assay in Rattus norvegicus hepatoma cells (HTC) in vitro. Vitis labrusca L. (variety Concord) were produced organically and by a conventional system, and their juice was extracted by a hot extraction process. The organic grapes were subjected to ultraviolet-type C radiation (UV-C). Experiments were performed after production and after 6 months in storage. Physicochemical analyses revealed that UV-C irradiation of organic grapes, the juice production process, and storage resulted in nutraceutical alterations. However, none of the juice concentrations were cytotoxic to HTC cells by the cytokinesis-blocked proliferation index results or were mutagenic, because the formation of micronucleated cells was not induced. In general, juice induced cell proliferation, possibly due to the presence of vitamins and sugar content (total soluble solid). The data increased the understanding of food technology and confirmed the quality and safety consumption of these juices.

In vivo antimutagenic effects of the Barbados cherry fruit (Malpighia glabra Linnaeus) in a chromosomal aberration assay.

Barbados cherry (BC) (Malpighia glabra Linnaeus) is a functional fruit that is consumed to prevent disease. It is used as an adjuvant in the treatment of several diseases, and acts as an antianemic, an appetite stimulant, a wound healer, an anti-inflammatory, a mineralizer, an antifungal, and an antioxidant agent. Several chemotherapeutic agents, such as cyclophosphamide, may result in undesirable side effects, and generate mutations in normal cells. Thus, the present study evaluated the antimutagenic potential of the fresh (BCN) and frozen (BCF) juices of BC pulp, with and without concomitant administration of cyclophosphamide, using a chromosomal aberration test system in the bone marrow cells of Wistar rats treated in vivo for 24 h. The results showed that neither the BC juice (0.4 mg/mL) alone, nor that with concomitant cyclophosphamide (1.5 mg/mL), were cytotoxic. BC has potential as an antimutagenic, and statistically reduced the percentages of chromosomal alterations induced by cyclophosphamide when administered simultaneously (BCN: 80.75%; BCF: 88.26%), pre-treatment (BCN: 86.85%; BCF: 87.32%), or post-treatment (BCN: 90.14%; BCF: 86.85%). This was due to the antioxidant activity of the fruit and the action of its bioactive compounds, which may have inhibited cyclophosphamide metabolism or scavenged the free radicals generated by this compound. Thus, attenuation of cyclophosphamide-induced mutagenicity suggests that the consumption of fresh or frozen BC should be encouraged for the prevention of disease, and for the maintenance and promotion of health.

Different responses of vanillic acid, a phenolic compound, in HTC cells: cytotoxicity, antiproliferative activity, and protection from DNA-induced damage.

The consumption of healthy and natural foods has increased over the last few years, primarily because these foods are rich in substances with biological properties of interest, such as exerting anticancer effects and decreasing oxidative stress in living tissues. These foods support adequate nutrition, maintain health, and improve quality of life. Vanillic acid (VA) is a phenolic compound used widely in the food industry as a flavoring, preservative, and food additive. VA can be found in various cereals, whole grains, fruits, herbs, green tea, juices, beers, and wines and possesses antioxidant, hepatoprotective, cardioprotective, and antiapoptotic activities. Studying the cytotoxicity as well as the mutagenic and antimutagenic effects of different concentrations of VA in Rattus norvegicus hepatoma cells (HTC) can identify new cellular activities of this substance. Concentrations up to 100 µM VA are not cytotoxic to HTC cells in a MTT [3-(4,5-dimethilthiazol-2-yl)-2,5-diphenil tetrazolium bromide] assay after 96-h exposure; therefore, VA does not compromise mitochondrial activity. Similarly, concentrations up to 500 µM do not compromise plasma membrane integrity. VA at 10 and 50 µM showed no mutagenic/clastogenic effects, as no significant micronuclei induction was observed. VA 10 µM presented no antiproliferative activity and reduced the cytotoxicity induced by benzo[a]pyrene. The antimutagenic activity of 10 µM VA was observed by the simultaneous, pre-, and post-treatments, as the phenolic compound significantly reduced the frequency of micronuclei induced by the mutagen. These results indicate that VA exerts different responses in HTC cells. Low concentrations present no cytotoxic, mutagenic, or antiproliferative effects and protect cells from DNA damage.

Cytotoxicity and mutagenicity of fluoxetine hydrochloride (Prozac), with or without vitamins A and C, in plant and animal model systems.

Fluoxetine, commonly known as Prozac, is the first representative of the so-called new generation of antidepressants that promise efficacy, with few side effects, against deep depression, nervous bulimia, and anxiety. As there is a growing number of people suffering from anxiety and depression; consequently, the use of fluoxetine is also increasing. Verifying absence of drug effects such as cytotoxicity or mutagenicity is of great importance. Certain vitamins, such as vitamin A (retinol, retinoids) and vitamin C (ascorbic acid) protect and are extremely active against mutagens. We evaluated the cytotoxic and mutagenic activity of fluoxetine, with and without concomitant administration of vitamin A or C, in Allium cepa meristem cells and Wistar rat bone marrow cells. The A. cepa meristem cells showed fluoxetine cytotoxicity; concomitant treatment with vitamin A or C proved non-protective. Treatment of Wistar rats with fluoxetine intraperitoneally or via gavage did not affect cell division or cause clastogenic effects. Vitamin A and C did not affect the cytotoxicity or mutagenicity of fluoxetine in the rat cells.

Cytotoxic and mutagenic effects of iodine-131 and radioprotection of acerola (Malpighia glabra L.) and beta-carotene in vitro.

The radioisotope iodine-131 [(131)I] can damage DNA. One way to prevent this is to increase the amount of antioxidants via dietary consumption. The goal of this study was to evaluate the radioprotective effect of fresh acerola pulp and synthetic beta-carotene in Rattus norvegicus hepatoma cells (HTC) in response to [(131)I] exposure in vitro. Cellular DNA damage was subsequently assessed using a cytokinesis block micronucleus assay. The mutagenic and cytotoxic activities of doses of [(131)I] (0.1, 0.5, 1, 5, and 10 µCi), acerola (0.025, 0.125, and 0.25 g acerola pulp/mL), and beta-carotene (0.2, 1, and 2 µM) were evaluated. Radioprotective tests were performed by simultaneous treatment with acerola (0.25 g/mL) plus [(131)I] (10 µCi) and beta-carotene (0.2 µM) plus [(131)I] (10 µCi). Acerola, beta-carotene, and low concentrations of [(131)I] did not induce micronucleus formation in HTC cells; in contrast, high concentrations of [(131)I] (10 µCi) were mutagenic and induced DNA damage. Moreover, neither acerola nor beta-carotene treatment was cytotoxic. However, acerola reduced the percentage of [(131)I]-induced damage, although beta-carotene did not show a similar effect. Thus, our results suggest that acerola diet supplementation may benefit patients who are exposed to [(131)I] during thyroid diagnostics and therapy.