Evaluation of extracts from Coccoloba mollis using the Salmonella/microsome system and in vivo tests

Seif-Eldein N, Anwar Aly Taie H, Marzouk M. Coccoloba uvifera Leaves: Polyphenolic Profile, Cytotoxicity, and Antioxidant Evaluation

This study aimed to investigate the chemical composition of Coccoloba uvifera leaves and evaluate the antioxidant and antitumor effects of the total extract and its major metabolites. Four assays were used to determine the antioxidant activity, including radical scavenging abilities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), radical cation, and ferric-reducing power. Additionally, vincristine was used as a reference medication to examine the anticancer activity on Ehrlich aesthete carcinoma cells (EACC). Nine compounds were isolated from C. uvifera leaves aqueous methanol extract. Their structures were identified as gallic acid (1), methyl gallate (2), protocatechuic acid methyl ester (3), protocatechuic acid (4), quercetin 3-O-β-d-glucopyranoside (isoquercitrin, 5), kaempferol 3-O-β-D-neohespridoside (6), myricitrin 4″-O-gallate (7), myricetin 3-O-β-d-glucopyranoside (8), and myricetin 3-O-arabinopyranoside (9). The majority possess noticeable antioxidant and antitumor properties. However, compounds 1, 5, 4, 2, and 7 displayed a strong antioxidant potential in terms of DPPH radical scavenging activity, with values of 85.72 ± 0.30, 82.16 ± 0.20, 81.34 ± 0.20, 79.62 ± 0.29, and 79.34 ± 0.20%, respectively. Compounds 4, 1, 5, 7, and 2 revealed high reducing power activity, with respective values of 1.348 ± 0.043, 1.303 ± 0.011, 1.154 ± 0.020, 1.058 ± 0.032, and 1.056 ± 0.019. Compounds 4 and 1 showed the highest ABTS radical scavenging capabilities (91.90 ± 0.24 and 91.83 ± 0.74%) and ferric-reducing power ability (1979 ± 14.53 and 1965 ± 26.86 μmol Trolox/100 g, respectively). Compound 4 has the highest level of cytotoxicity, resulting in 78.710.21% dead cells.

Current Trends in Toxicity Assessment of Herbal Medicines: A Narrative Review

Even in modern times, the popularity level of medicinal plants and herbal medicines in therapy is still high. The World Health Organization estimates that 80% of the population in developing countries uses these types of remedies. Even though herbal medicine products are usually perceived as low risk, their potential health risks should be carefully assessed. Several factors can cause the toxicity of herbal medicine products: plant components or metabolites with a toxic potential, adulteration, environmental pollutants (heavy metals, pesticides), or contamination of microorganisms (toxigenic fungi). Their correct evaluation is essential for the patient’s safety. The toxicity assessment of herbal medicine combines in vitro and in vivo methods, but in the past decades, several new techniques emerged besides conventional methods. The use of omics has become a valuable research tool for prediction and toxicity evaluation, while DNA sequencing can be used successfully to detect contaminants and adulteration. The use of invertebrate models (Danio renio or Galleria mellonella) became popular due to the ethical issues associated with vertebrate models. The aim of the present article is to provide an overview of the current trends and methods used to investigate the toxic potential of herbal medicinal products and the challenges in this research field.