~ 3010 ~ Journal of Pharmacognosy and Phytochemistry 2018; 7(5): 3010-3017 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2018; 7(5): 3010-3017 Received: 04-07-2018 Accepted: 06-08-2018 Carlo C Bondoc La Consolacion University Philippines Correspondence Carlo C Bondoc La Consolacion University Philippines Curcuma longa Linn rhizome extract as an alternative stain for histological studies Carlo C Bondoc Abstract Most chemically-synthesized stains used in histological practices are expensive, hazardous to human and animal health, and threatening to the environment. Extraction of natural dye out of local plants have gained global interest and give promising tissue staining when outcomes are investigated. Curcuma longa rhizomes are proven to contain curcuminoids that exhibit various medicinal properties, and curcumin the bright yellow component of the plant that is being used as colorant. This natural dye from C. longa provides significant alternative as they are safer to use without health hazards, biodegradable, and have easy disposability. Nine biological specimens were used to compare the staining capacity of 15, 20, and 25-gram concentrations of C. longa extract and the commercial stain and were observed under microscope. The results revealed that the 15, 20, and 25-gram concentrations of C. longa stains do not have significant differences in the staining effect on various plant and animal tissues. Also, the staining effects of commercial and C. longa stains on monocot and dicot root and stem, leaf midrib, frog blood smear, and cycloid scale do not have significant differences Therefore, the alternative stain out of C. longa can be used as substitute to commercially available stains. Keywords: Alternative stain, Curcuma longa Linn, histology, staining Introduction At the height of technological advancement and mass production of goods, people nowadays would prefer to use natural and organic if given a chance to choose against the commercial, chemically-synthesized products. Why choose natural or alternative products? Aside from reducing if not avoiding skin or body parts irritation awhen they are used, the natural organic products have stood over the test of time, giving people no side effects. Using natural organic products is environment-friendly aside from the fact that they are more economical. The turmeric or the Curcuma longa Linn is an example of the plant that a natural product can be derived. It is a tropical and sub-tropical perennial herb belonging to the family Zingiberaceae which is related to ginger. The genus Curcuma includes many other economically important species, including C. Angustifolia (wild arrowroot, narrow-leaved turmeric), C. Amada (mango ginger), and C. zedoaria (zedoary), and C. aromatica (Cochin turmeric, wild turmeric). The exact origin of this plant is not identified, but it is thought to originate from South or Southeast Asia, most probably from China, Vietnam, or western India. India is the world's largest producer, consumer, and exporter of turmeric but it is cultivated widely in Bangladesh, China, Thailand, Cambodia, Malaysia, Indonesia and the Philippines. (Chairman et al., 2015) [8] . It is also proven to contain medicinal properties like antidiabetic, anti-ulcer, anti-coagulant, antifertility (Yadav et al., 2017) [22] , antiviral, antibacterial, antifungal (Moghadamtousi et al, 2014) [17] , antimicrobial (Suebkhampet et al., 2014) [20] , antioxidant, anti-inflammatory, antiseptic and anti-cancer. Moreover, rhizomes of C. longa are proven to contain curcuminoids that have been demonstrated to be antiatherosclerotic, anti-inflammatory, etc. (Foldesiova et al., 2016) [11] . Additionally, it has also been shown to treat jaundice, flatulence, hemorrhage, hematuria, and skin diseases (Labban, 2014) [16] . This plant plays a vital role in preventing and treating numerous ailments from cancer to neurological, autoimmune, and cardiovascular illnesses (Kocaadam et al., 2015) [12] . Likewise, this is also publicized to have the anti-HIV activity to fight acquired immunodeficiency syndrome (AIDS) (Nasri et al., 2014) [18] to those who are infected with the virus. Aside from being recognized for its medicinal benefits, C. longa is used extensively as traditional Indian spice (Krup et al., 2013) [14] , the source of coloring agent for foods, textiles, and cosmetics (Dash et al., 2014) [10] . Its tuberous rhizomes have been used as a condiment, an aromatic stimulant, and colorant. The bright yellow colored compound found in Turmeric is called curcumin. Such main fluorescent component or the curcumin in Turmeric is so