Safety evaluation of orally-administered methanol extract of Muntingia calabura Linn. leaves: A sub-chronic toxicity study in Sprague Dawley rats

Muntingia calabura (M. calabura), locally known as "kerukup siam" or "buah ceri" belongs to the family Muntingiaceae and has been scientifically demonstrated to exert various pharmacological activities. The objectives of the current study are to evaluate the antioxidant activities and to determine the subchronic toxicity of 90 days orally-administered methanol extract of M. calabura (MEMC) in male Sprague Dawley rats. The rats were randomly divided into four groups (n=6). Vehicle control received 8% tween 80 and treatment group received 50, 250 and 500 mg/kg of MEMC orally administered daily for 90 days. Blood collection was carried out to obtain the hematological and biochemical profile of the rats. The organs harvested were subjected to histopathological analysis. For the antioxidant test, the extract was subjected to antioxidant study using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH)- and superoxide anion-radical scavenging activity, total phenolic content (TPC) and phytochemical screening. Results obtained show that no adverse effects were observed during the experimental period. Hematological and biochemical analysis also showed no significant changes in this toxicity study. Besides, antioxidant analyses revealed that MEMC has higher DPPH- and SOD-radical scavenges activity as well as higher TPC value. In conclusion, M. calabura is safe for consumption and possesses beneficial antioxidant effect.

Anticarcinogenic activity of Muntingia calabura leaves methanol extract against the azoxymethane-induced colon cancer in rats involved modulation of the colonic antioxidant system partly by flavonoids

CONTEXT

Leaves of Muntingia calabura (Elaeocarpaceae) are widely used in traditional medical practice; scientific findings show various pharmacological activities. However, its anticancer effect has not been investigated thoroughly yet.

OBJECTIVE

The objective of this study is to study the chemoprevention effects of MEMC_L against azoxymethane (AOM)-induced colon cancer and to examine the involvement of endogenous antioxidants Materials and methods: Male Sprague-Dawley rats, divided into five groups (n = 7), were injected intraperitoneally once weekly for 2 weeks with 15 mg/kg AOM, except for the normal group (received saline). The animals were then administered orally for 8 weeks with 8% Tween-80 (vehicle; normal group), 8% Tween-80 (vehicle; cancer group) or, 50, 250 or 500 mg/kg MEMC. After treatments, colon samples were collected from each rat for the histopathological analysis, quantification of aberrant crypt foci formed and determination of colon antioxidant levels. MEMC was also subjected to HPLC analysis.

RESULTS

The extract exerted significant (p < 0.05): (i) anti-carcinogenesis activity, indicated by a decrease in the total aberrant crypt formation; (ii) antioxidant activity by increasing the colon tissue antioxidant markers [i.e., superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH)] and reducing the oxidant marker (i.e., malonaldehyde (MDA) levels in comparison with the cancer group. HPLC analysis demonstrated the presence of rutin.

DISCUSSION AND CONCLUSIONS

Muntingia calabura leaves exert anticancer effect against AOM-induced colon cancer possibly via the action of flavonoids on the colon tissue antioxidant activity.

Natural radioactivity and effective dose due to the bottom sea and estuaries marine animals in the coastal waters around Peninsular Malaysia

Malaysia is among the countries with the highest fish consumption in the world and relies on seafood as a main source of animal protein. Thus, the radioactivity in the mostly consumed marine animals such as fishes, crustaceans and molluscs collected from the coastal waters around Peninsular Malaysia has been determined to monitor the level of human exposure by natural radiation via seafood consumption. The mean activity concentrations of naturally occurring radionuclides (226)Ra ((238)U), (228)Ra ((232)Th) and (40)K ranged from 0.67 ± 0.19 Bq kg(-1) (Perna viridis) to 1.20 ± 0.70 Bq kg(-1) (Rastrelliger), from 0.19 ± 0.17 Bq kg(-1) (Teuthida) to 0.82 ± 0.67 Bq kg(-1) (Caridea) and from 34 ± 13 Bq kg(-1) (Caridea) to 48 ± 24 Bq kg(-1) (Teuthida), respectively. The mean annual committed effective dose due to the individual radionuclides shows an order of (228)Ra > (226)Ra > (40)K in all marine samples. The obtained doses are less than the global internal dose of 290 µSv y(-1) set by the United Nations Scientific Committee on the Effects of Atomic Radiation, discarding any significant radiological risks to the populace of Peninsular Malaysia.

Muntingia calabura: a review of its traditional uses, chemical properties, and pharmacological observations

CONTEXT

Different parts of Muntingia calabura L. (Elaeocarpaceae), or "kerukup siam" in Malay, have been reported to possess medicinal value, supported by a number of scientific studies.

OBJECTIVE

To gather all information related to the ethnomedicinal uses, phytochemical compositions, and pharmacological activities of M. calabura and present them as a comprehensive and systematic review article.

MATERIALS AND METHODS

Literature has been retrieved from a number of databases (e.g., Pubmed, Science Direct, Springer Link, etc.). General web searches were also carried out using Google and Yahoo search engines by applying some related search terms (e.g., Muntingia calabura, phytochemical, pharmacological, extract, and traditional uses). The articles related to agriculture, ecology, and synthetic work and those using languages other than English or Malay have been excluded. The bibliographies of papers relating to the review subject were also searched for further relevant references.

RESULTS AND DISCUSSION

The literature search conducted using the above-mentioned Internet search engines only lead to the identification of 36 journals published as early as 1987. From the articles reviewed, M. calabura possessed various pharmacological activities (e.g., cytotoxic, antinociceptive, antiulcer, anti-inflammatory), which supported the folklore claims and could be attributed to its phytoconstituents.

CONCLUSION

Muntingia calabura possesses remarkable medicinal value, which warrants further and in-depth studies. Therefore, this review paper is presented to help guide researchers to plan their future studies related to this plant in the hope of isolating potential leads for future drug development.