1.1Background of study
Malaysia has a living heritage of various herbal species and crude extracts of plants, fruits, herbs, and vegetables are becoming popular and experiencing tremendous growth in Malaysia. Out of this diversity, many have been scientifically proven to contain medicinal and healing properties and most consumer are looking for herbal medicine and herbal product as an alternative since plants and fruits are potential natural source that contain different phytochemicals and enzymes which are present as antioxidant defense to improve body’s transformation, maintain body system and human health. Most of the herbal infusions is commonly used as home medicines because they have antioxidative and pharmacological properties related to the presence of phenolic compounds, especially phenolic acids derivatives and flavonoids. Flavonoids and terpenoids is act as colouring pigments in plants which is also function as potent antioxidants at various levels (Amzad et al., 2011).
Furthermore, this is the herbs of interest in this study which are clinacanthus nutans (belalai gajah), centella asiatica (pegaga), persicaria odorata (kesum), ficus deltoldea (mas cotek), eurycoma longifolia (tongkat ali) and . orthosiphon stamineus (misai kucing) which is also one of the supply of five main herbs in Malaysia which is initial phase of EPP1 is focuses on. This is nutritional recommendation for people to consume more natural antioxidant like herbs compared to synthetic antioxidant because it was claimed that antioxidant activities such as flavonoid may be from biochemical source and this will give side effect to human body such as cancer, heart diseases and other chronic diseases that more harmful to us (Amzad et al., 2011). Other than that, synthetic antioxidant is more carcinogenic and give toxicity effect. World Health Statistics reported that from the estimated 57 million global deaths in 2008, 36 million (63%) were due to non-communicable diseases (NCDs) (WHO, 2011).
Basically, we focus on the study of the total phenolic compound, total flavonoid and non flavonoid concentration and also antibacterial activities against pathogenic bacteria of Malaysia’s herbs. Even though herbs is claimed as a safe and natural antioxidant but we still have to take caution on quality and safety issue and do not simply consume it because there are some interaction of herbal medicine with synthetic drug may give effect toxicity unless the chemical content are known and pharmacological properties of Malaysia’s herbs are well-established by clinical method or pharmacy (Ibrahim, 2006).
Six herbs that can naturally found in Malaysia
Malaysia is one of the well-known country in Asian that has rich of biodiversity which is composed of species thousand of flora and fauna. Most of this herbs grows in tropical rainforest which are warm and damp areas (P.M. Ridzuan et al., 2013). This herbs is commonly used as traditional medicine to treat minor injuries but there are still limited scientific studies of its use and each part of herbs plant have their own special characteristic and function. Basically, the sample will be collected in several areas around Malaysia and all this herbs are extract from their leaves and stems by using most suitable solvent which is aqueous mixture and chemicals like methanol, n- hexane and acetyl acetate (Nadarajan et al., 2015).
This are selected herbs of interest :
clinacanthus nutans persicaria odorata centella asiatica
(belalai gajah) (kesum) (pegaga)
eurycoma longifolia ficus deltoldea orthosiphon stamineus
(tongkat ali) (mas cotek) (misai kucing)
Oxidation is a chemical reaction that can produce free radicals which will lead to chain reactions that may damage cells so an antioxidant is the molecule that will inhibit the oxidation of molecule. Nowadays, many scientific study was conducted on selected local herbs to make sure that we will choose natural antioxidant compared to synthetic antioxidant which is already used worldwide to avoid toxicity effect to human body. There are two methods have been used to determine antioxidant activities of the extracts and fractions by using the DPPH radical assay according to the method proposed by Von Gadow, Joubert and Hansmann (1997) as the standard DPPH free radical scavenging assay and also Ferric-reducing antioxidant power assay (FRAP) which is used to measures the change in absorbance that was carried out according to the procedure of Benzie and Strain (1996) (M.J. Rodríguez Vaquero, 2010). Different concentration were taken in different test tubes and the control sample was also prepared without any extract (M.J. Rodríguez Vaquero, 2010).
For a long period of time, plants have been a valuable source of natural products and have been traditionally used in medicine, cuisines, pharmacy and cosmetics medicine for maintaining human health (P.M. Ridzuan et al., 2013). There are reported that antibacterial effect of selected herbs is related with the concentration of phenolic compounds (M.J. Rodríguez Vaquero, 2010). Escherichia coli ATCC 35218 and Staphylococcus aureus ATCC 25923 are bacterial strain that is used as test organism and one of the herbs possessed strong antibacterial activity with significant amounts of active compounds in its leaves (P.M. Ridzuan et al., 2013).
Extraction of total phenolic compound and total flavonoids
The large group of natural phenols can be separated into two categories which are flavonoids and non-flavonoids. Flavonoids are group of antioxidant compounds found primarily in plants and it is classified according to their chemical structure while non-flavanoid antioxidant can be broken down into three categories which are vitamins, minerals and plant pigments (Amzad et al., 2011). Colorimetric determination of total phenolics and concentration of total phenolics in different organic extracts were determined using Folin- Ciocalteu reagent method as described by Singleton and Rossi (1965) and a standard calibration curve was established using gallic acid as cited in M.J. Rodríguez Vaquero (2010). The flavonoid content was obtained by the difference between total phenol and non-flavonoid content or by using the aluminium chloride colorimetric method as described by Willet with some modification (Amzad et al., 2011) .