Sweet as honey, bitter as bile: Mitochondriotoxic peptides and other therapeutic proteins isolated from animal tissues, for dealing with mitochondrial apoptosis.

Mitochondria are subcellular organelles involved in cell metabolism and cell life-cycle. Their role in apoptosis regulation makes them an interesting target of new drugs for dealing with cancer or rare diseases. Several peptides and proteins isolated from animal and plant sources are known for their therapeutic properties and have been tested on cancer cell-lines and xenograft murine models, highlighting their ability in inducing cell-death by triggering mitochondrial apoptosis. Some of those molecules have been even approved as drugs. Conversely, many other bioactive compounds are still under investigation for their proapoptotic properties. In this review we report about a group of peptides, isolated from animal venoms, with potential therapeutic properties related to their ability in triggering mitochondrial apoptosis. This class of compounds is known with different names, such as mitochondriotoxins or mitocans.

Determination toxic effects of Hystrix Brachyura Bezoar extracts using cancer cell lines and embryo zebrafish (Danio rerio) models and identification of active principles through GC-MS analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Porcupine bezoar (PB) is used as folk medicine for various medical conditions including cancer treatment in Malaysia. However, its toxicity profile has never been thoroughly ascertained to confirm its safe nature as an efficacious traditional medicine in the treatment of cancer as well as other ailments. AIM OF THE STUDY: This study was aimed to reveal three different PBs' aqueous extracts(viz. PB-A, PB-B, PB-C) chemical constituent's profile using GC-MS analysis, anticancer property on A375, HeLa and MCF7 cancer cells, toxicity profile on zebrafish embryo morphology, EC50, LC50 and teratogenicity index. MATERIALS AND METHODS: PBs' extracts characterization was performed through GC-MS analysis, in vitro anticancer effect was carried out on A375, HeLa and MCF7 cancer cell lines and finally and toxicity properties on three different PBs aqueous extracts (viz. PB-A, PB-B, PB-C) were determined using zebrafish embryo model. RESULTS: The GC-MS analysis revealed 10 similar compounds in all PBs' extracts. Dilauryl thiodipropionate was found to be a major compound in all PBs' extracts followed by tetradecanoic acid. An in vitro anticancer study revealed PB extracts exerted median inhibition concentration (IC50) <50 µg/mL, on cancer cells viz. A375, HeLa and MCF7 with no significant toxicity on normal cells viz. NHDF cells. In vivo toxicity of PBs extracts found affecting tail detachment, hatching, craniofacial, brain morphology, soft tissues, edema, spinal, somites, notochord and cardiovascular system (brachycardia, disruption of blood circulation) deformities. The LC50 and EC50 demonstrated PB extracts effect as dose and time dependent with median concentration <150.0 µg/mL. Additionally, teratogenicity index (TI) viz. >1.0 revealed teratogenic property for PB extracts. CONCLUSIONS: The findings revealed that all three PBs aqueous extracts possessed anticancer activity and exhibited significant toxicological effects on zebrafish embryos with high teratogenicity index. Hence, its use as an anticancer agent requires further investigation and medical attentions to determine its safe dose.

Is cytotoxicity a determinant of the different in vitro and in vivo effects of bioactives?

BACKGROUND: Foodstuffs of both plant and animal origin contain a wide range of bioactive compounds. Although human intervention studies are mandatory to assess the health effects of bioactives, the in vitro approach is often used to select the most promising molecules to be studied in vivo. To avoid misleading results, concentration and chemical form, exposure time, and potential cytotoxicity of the tested bioactives should be carefully set prior to any other experiments. METHODS: In this study the possible cytotoxicity of different bioactives (docosahexaenoic acid, propionate, cyanidin-3-O-glucoside, protocatechuic acid), was investigated in HepG2 cells using different methods. Bioactives were supplemented to cells at different concentrations within the physiological range in human blood, alone or in combination, considering two different exposure times. RESULTS: Reported data clearly evidence that in vitro cytotoxicity is tightly related to the exposure time, and it varies among bioactives, which could exert a cytotoxic effect even at a concentration within the in vivo physiological blood concentration range. Furthermore, co-supplementation of different bioactives can increase the cytotoxic effect. CONCLUSIONS: Our results underline the importance of in vitro cytotoxicity screening that should be considered mandatory before performing studies aimed to evaluate the effect of bioactives on other cellular parameters. Although this study is far from the demonstration of a toxic effect of the tested bioactives when administered to humans, it represents a starting point for future research aimed at verifying the existence of a potential hazard due to the wide use of high doses of multiple bioactives.

Safety evaluation of water-soluble palm fruit bioactives.

Water-soluble palm fruit bioactives, derived from the aqueous stream of palm oil processing, have shown anti-diabetogenic effects in rodent models. To assess the safety of potential incorporation of this polyphenol-containing material in food, in vitro bacterial reverse mutation and in vitro chromosome aberration assays were conducted along with a 90-day subchronic toxicity study in Sprague-Dawley rats. Water-soluble palm fruit bioactives were inactive in the Ames and in vitro chromosome aberration assays up to the limit doses of 5000 µg/plate and 5000 µg/mL, respectively. In the 90-day feeding study, water-soluble palm fruit bioactives were administered via gavage at doses 0, 500, 1000 or 2000 mg/kg body weight/day. No significant effects were noted on body weight, food consumption, hematology, clinical chemistry, organ weights, and histopathological examination. The No Observable Adverse Effect Level was considered to be 2000 mg/kg body weight/day, the highest dose tested. These data provide evidence to support the safe use of water-soluble palm fruit bioactives in food or food ingredients.

Haematological, biochemical and histopathological aspects of Hericium erinaceus ingestion in a rodent model: A sub-chronic toxicological assessment.

ETHNOPHARMACOLOGICAL RELEVANCE: Hericium erinaceus is a culinary-medicinal mushroom and has a long history of usage in traditional Chinese medicine as a tonic for stomach disorders, ulcers and gastrointestinal ailments. AIM OF THE STUDY: The present investigation was aimed to evaluate the potential toxic effects of the aqueous extract from the fruiting bodies of H. erinaceus in rats by a sub-chronic oral toxicity study. MATERIALS AND METHODS: In this sub-chronic toxicity study, rats were orally administered with the aqueous extract of H. erinaceus (HEAE) at doses of 250, 500 and 1000mg/kg body weight (b.w.) for 90 days. Body weights were recorded on a weekly basis and general behavioural changes were observed. The blood samples were subjected to haematological, biochemical, serum electrolyte, and antioxidant enzyme estimations. The rats were sacrificed and organs were processed and examined for histopathological changes. RESULTS: No mortality or morbidity was observed in all the treated and control rats. The results showed that the oral administration of HEAE daily at three different doses for 90 days had no adverse effect on the general behaviour, body weight, haematology, clinical biochemistry, and relative organ weights. Histopathological examination at the end of the study showed normal architecture except for few non-treatment related histopathological changes observed in liver, heart and spleen. CONCLUSION: The results of this sub-chronic toxicity study provides evidence that oral administration of HEAE is safe up to 1000mg/kg and H. erinaceus consumption is relatively non-toxic.

Appropriate use of recovery groups in nonclinical toxicity studies: value in a science-driven case-by-case approach.

A recovery phase--a nondosing period that follows the main dosing phase of a study--is sometimes included in nonclinical toxicity studies, and it is designed to understand whether toxicities observed at the end of the dosing phase are partially or completely reversible. For biopharmaceuticals with long half-lives, the inclusion of recovery arms can be helpful in understanding effects of prolonged exposure and assessing antidrug antibodies. This commentary discusses when to include recovery groups in nonclinical toxicity studies, the number of recovery groups to include in a given study, the number of animals to include in each recovery group, and the duration of the recovery phase. In general, the inclusion of recovery arms should follow a case-by-case approach that values rational scientific design and reflects the development needs and regulatory requirements applicable to individual nonclinical programs to ensure appropriate guidance for human studies while minimizing laboratory animal use.

Safety evaluation of natural flavour complexes.

Natural flavour complexes (NFCs) are chemical mixtures obtained by applying physical separation methods to botanical sources. Many NFCs are derived from foods. In the present paper, a 12-step procedure for the safety evaluation of NFCs, 'the naturals paradigm', is discussed. This procedure, which is not intended to be viewed as a rigid check list, begins with a description of the chemical composition of the commercial product, followed by a review of the data on the history of dietary use. Next, each constituent of an NFC is assigned to one of 33 congeneric groups of structurally related substances and to one of three classes of toxic potential, each with its own exposure threshold of toxicological concern. The group of substances of unknown structure is placed in the class of greatest toxic potential. In subsequent steps, for each congeneric group the procedure determines the per capita intake, considers metabolic pathways and explores the need and availability of toxicological data. Additional toxicological and analytical data may be required for a comprehensive safety evaluation. The procedure concludes with an evaluation of the NFC in its entirety, also considering combined exposure to congeneric groups. The first experiences with the use of this procedure are very promising. Future safety evaluations of larger numbers of NFCs will indicate the usefulness of the system, either in its present form or in a form modified on the basis of experience.

Development of a bioassay for phytochemicals using Daphnia pulex.

The freshwater cladoceran Daphnia pulex was explored as an alternative to Artemia salina for the biological screening of phytochemicals. This paper reports on the results of screening 27 compounds, and comparisons are made with screens using Artemia salina. The effect of miniaturisation of the assay system was investigated. Petri-dish based tests were performed for the 27 compounds using 10 daphnids at each of 5 concentrations (1 - 1000 mg l(-1)). Potassium dichromate was used as a control and the number immobile after 24 hours were counted. Results were expressed as EC(50) values. The active compounds (EC(50) < 25 mg l(-1)) comprised mainly adrenoceptor agonist alkaloids, while the cytotoxins vincristine and colchicine, and several antibiotics were relatively non-toxic towards Daphnia. The method was validated by comparative bioassay of A. belladonna fractions. Overall, this screen compared favourably with those based on Artemia. Daphnia were sensitive to a wide range of biologically active molecules including CNS-stimulants, anti-malarials, narcotics and anti-spasmodics, and the sensitivity was broader than previously seen with Artemia. The screen is perhaps limited by the lack of sensitivity to cytotoxins, but this might be overcome by altering the test criteria.

"Orostim"--polymicrobial preparation for oral administration. I. "In vivo" determination of toxicity and of inborn resistance stimulation characteristic.

"Orostim" is a polymicrobial immunomodulator for oral administration, obtained from bacterial suspensions, disintegrated by ultrasonics and dried by atomization. The preparation was chemically characterized before and after atomization without presenting essential modifications. Orostim was not shown to be toxic in mice and rats by esophageal intubation, as long as 20 days. The animals presented normal evolution; hemoleukograms, serum proteins and alkaline phosphatase, in rats, did not present significant modifications in comparison with controls. Histopathologic examination of the organs, obtained from mice, treated for 20 days (liver, spleen, lung) did not emphasize modifications in comparison with controls. Circulating neutrophils phagocytosis in rabbits, orally treated with Orostim, was increased as compared to 0 time; serum complement values decreased compared to the initial ones for 0 time but turned to normal and reached even superior limits, 10 days after the treatment ending.

[Comparative pathomorphologic study of the toxic properties of a corpuscular pertussis vaccine and of a cell-free pertussis preparation]. / Sravnitel'noe patomorfologicheskoe izuchenie toksicheskikh svoistv korpuskuliarnoi kokliushnoi vaktsiny i beskletochnogo kokliushnogo preparata.

The comparative study of morphological changes in the body of outbred mice under the action of corpuscular pertussis vaccine and acellular pertussis preparation has been made. The corpuscular vaccine has been shown to produce a pronounced, dynamically increasing toxic effect, thus causing the damage of lymphoid thymic and spleen cells, prolonged interstitial reaction in the lungs, destructive inflammatory process at the site of injection. The acellular pertussis preparation is less toxic, induces less pronounced changes in these organs at the early period of the experiment, stimulates the proliferation of lymphoid cells and lymphoblast transformation. As noted in this study, the damaging action of pertussis vaccine is mainly indicated by pathological phenomena appearing in the organs of the immune system, pulmonary parenchyma and muscular tissue (in the inoculation zone).