Potential medicinal benefits of Cosmos caudatus (Ulam Raja): A scoping review TICLE R Shi-Hui Cheng1, Mohd Yusof Barakatun-Nisak1,2, Joseph Anthony3, Amin Ismail1,2 1Department of Nutrition of Dietetics, 2Research Centre of Excellence for Nutrition and Non-Communicable Diseases, 3Department of A Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia Cosmos caudatus is widely used as a traditional medicine in Southeast Asia. C. caudatus has been reported as a rich source of bioactive compounds such as ascorbic acid, quercetin, and chlorogenic acid. Studies have shown that C. caudatus exhibits high anti- oxidant capacity and various medicinal properties, including anti-diabetic activity, anti-hypertensive properties, anti-inflammatory EVIEW responses, bone-protective effect, and anti-microbial activity. This review aims to present the potential medicinal benefits Cof . caudatus from the available scientific literature. We searched PubMed and ScienceDirect database for articles published from 1995 R to January 2015. Overall, 15 articles related to C. caudatus and its medicinal benefits are reviewed. All these studies demonstrated that C. caudatus is effective, having demonstrated its anti-diabetic, anti-hypertensive, anti-inflammatory, bone-protective, anti- microbial, and anti-fungal activity in both in vitro and animal studies. None of the studies showed any negative effect ofC. caudatus related to medicinal use. Currently available evidence suggests that C. caudatus has beneficial effects such as reducing blood glucose, reducing blood pressure, promoting healthy bone formation, and demonstrating anti-inflammatory and anti-microbial properties. However, human clinical trial is warranted. Key words: Anti-diabetic, anti-hypertensive, anti-inflammatory, anti-microbial, anti-oxidant, bone-protective,Cosmos caudatus, medicinal effect How to cite this article: Cheng S-H, Barakatun-Nisak MY, Anthony J, Ismail A. Potential medicinal benefits ofCosmos caudatus (Ulam Raja): A scoping review. J Res Med Sci 2015;20:1000-6. INTRODUCTION grows up to 3 m in height and bears pink or purple flowers. The leaves and shoots of C. caudatus can be Ulam refers to a group of traditional Malay vegetables, consumed raw. The unique taste makes it a flavorful, usually consumed raw. In Malaysia, the Ministry of favored side dish. It is usually eaten by dipping in Health has been promoting the consumption of ulam shrimp and chili paste to enhance the flavors.[4] As a under the Malaysian Dietary Guidelines (2010).[1] The local delicacy, C. caudatus leaf can be seen served in results from the third National Health and Nutrition hotels and restaurants across Malaysia. Examination Survey revealed that salad and raw vegetable consumers tend to have increased serum level Traditionally, C. caudatus has been used to boost of vitamins, including vitamin C, vitamin E, folic acid, blood circulation, to strengthen the bones, to reduce β-carotene, and lycopene.[2] body heat, as an anti-aging agent, and to treat infectious disease.[3,5] In addition, various studies Cosmos caudatus, known locally as Ulam Raja or have revealed that C. caudatus has potential medicinal [6-10] “King’s Salad,” belongs to the family Asteraceae. properties. With the increasing interest in the C. caudatus is a medicinal plant originating from traditional medicinal plants and herbs, there is a need Latin America and later grown in Southeast Asia.[3] It to review the traditional claims about C. caudatus with regard to its medicinal uses before it can be used for further nutraceutical application. Therefore, Access this article online Quick Response Code: Website: This is an open access article distributed under the terms of the www.jmsjournal.net Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited DOI: and the new creations are licensed under the identical terms. **** For reprints contact: [email protected] Address for correspondence: Dr. Barakatun Nisak Mohd Yusof, Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang - 43400, Selangor, Malaysia. E-mail: [email protected] Received: 07-07-2015; Revised: 04-08-2015; Accepted: 16-10-2015 | October 2015 | © 2015 Journal of Research in Medical Sciences | Published by Wolters Kluwer - Medknow 1000 Cheng, et al.: Cosmos caudatus and its medicinal benefits this review aims to contribute to the substanti-al body Medicinal uses of C. caudatus of knowledge about the potential medicinal benefits of The significant findings on the medicinal uses ofC. caudatus C. caudatus. Owing to the pivotal role of anti-oxidants are summarized in Table 2. against the development of chronic disease, we also report the bioactive compounds and the anti-oxidant Anti-oxidant potential potential of C. caudatus in this review. Reported evidence showed that C. caudatus exhibits high anti-oxidant activity.[6,14-17] Studies have shown that 100 g of METHODS fresh C. caudatus contains approximately 2500 mg ascorbic acid equivalent anti-oxidant capacity (AEAC) compared We searched Pubmed and ScienceDirect databases for to local fruits with AEAC index of less than 300 mg.[14] A articles published from 1995 to January 2015 using the comparison of the AEAC value in selected foods is depicted in key words “Cosmos caudatus and blood glucose,” “Cosmos Table 3.[6,14] Among the 11 vegetables tested, ethanol extracts caudatus and blood pressure,” “Cosmos caudatus and bone,” of Pluchea indica and C. caudatus exhibited the highest anti- “Cosmos caudatus and inflammation,” “Cosmos caudatus oxidant activity when measured by ferric cyanide reducing and anti-microbial,” “Cosmos caudatus and anti-oxidant,” power, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical- and “Cosmos caudatus and toxicity.” Overall, 5 articles were scavenging, 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic retrieved on the anti-oxidant potential of C. caudatus and 10 acid) (ABTS)-scavenging, and inhibition of linoleic acid.[13] articles were retrieved on the medicinal effects ofC. caudatus. All published studies related to C. caudatus and its medicinal In another study, Wong et al. (2006) assessed the anti-oxidant benefits are included in this review. activities of aqueous extracts of 25 tropical plants using DPPH scavenging and ferric ion reducing anti-oxidant RESULTS potential (FRAP) assays.[15] Among the 25 plants, C. caudatus exhibited the highest DPPH free radical-scavenging activity Nutritional composition and bioactive compounds and the highest ferric ion reducing activity. This result was In general, 100 g of C. caudatus contains 2.9 g protein, 0.6 g in agreement with a recent study by Reihani and Azhar carbohydrate, 0.4 g fat, and 93.1 g water, and provide 18 (2012), which evaluated the total phenolic content and kcal of energy. Besides, C. caudatus is also rich in minerals anti-oxidant activity of five Ulams using DPPH and FRAP and vitamins. The plant contains 64.6 mg of vitamin C, assays.[16] In this study, C. caudatus and Oenanthe javanica 3568 µg of β-carotene, 0.13 mg of vitamin B1, and 0.24 mg (Selom) aqueous extracts were found to have the highest of vitamin B2 per 100 g fresh samples. In terms of mineral DPPH and FRAP values. This finding has further indicated composition, it has 426 mg potassium, 270 mg calcium, 37 that C. caudatus is a good source of anti-oxidant. mg phosphorus, 50 mg magnesium, 4.6 mg iron, 0.9 g zinc, [11] 4.0 mg sodium, and 0.2 g copper. Anti-diabetic activity A previous study on obese, C. caudatus extract-treated rats C. caudatus was found to have high total phenolic content showed a significant reduction in plasma blood glucose as (1274 ± 98 GAE mg/100 g fresh weight) in the acetone/ compared to the control rats after one month ofC. caudatus [6] water system. Furthermore, among the nine aqueous extract supplementation.[17] Acarbose, an alpha-glucosidase extracts of Malaysian plants, namely C. caudatus, Curcuma inhibitor, is widely used to treat type 2 diabetes.[22] However, domestica, Kaempferia galanga, Piper betle, Piper sarmentosum, excessive alpha-amylase inhibition may lead to abnormal Polygonum minus, Centella asiatica, Hydrocotyle bonariensis, bacterial fermentation of undigested carbohydrates in and Barringtonia racemosa, the aqueous extract of C. caudatus the intestine and result in unwanted side effects such as [12] contained the highest phenolic content. Table 1 depicts abdominal distension, flatulence, and diarrhea.[23] Hence, [13] the biological active compounds of C. caudatus. mild amylase inhibition is beneficial. A local study reported that the hexane extract of C. caudatus has high alpha- Table 1: Biologically active compounds in C. caudatus glucosidase inhibitory activity with low alpha-amylase Compound Total (mg/100 g) inhibition.[7] Therefore, C. caudatus may be potentially useful Ascorbic acid 108.83±0.50 in treating postprandial hyperglycemia in vitro. Quercetin 51.28±4.06 Kaempferol 0.90±0.05 Anti-hypertensive activity Chlorogenic acid 4.54±0.18 The anti-hypertensive effects of C. caudatus in adrenaline- Caffeic acid 3.64±0.14 Ferulic acid 3.14±0.28 treated and sodium chloride-treated rat models have been [9] Anthocyanin 0.78±0.05 reported. In adrenaline-treated rats, both 500 mg/kg and β-carotene 1.35±0.03 1000 mg/kg aqueous extracts of C. caudatus were shown Reference:[13] to inhibit the increase of heartbeat frequency and stroke 1001 Journal of Research in Medical Sciences | October 2015 | Cheng, et al.: Cosmos caudatus and its medicinal benefits Table 2: Summary of potential medicinal benefits ofC. caudatus Potential Extracting solvent Effects/properties Author, year, references medicinal benefits Anti-oxidant activity Fresh sample C. caudatus contained 2500 mg AEAC per 100 g of fresh sample Shui et al. 2005;[6] Ethanol extract C. caudatus exhibited highest anti-oxidant activity when measured by Leong et al. 2002[14] FRAP, DPPH scavenging, ABTS scavenging, and linoleic acid inhibition Andarwulan et al.