Camellia (Camellia japonica), commonly known as the Japanese camellia, is a flowering plant in the Theaceae family. Native to eastern and southern Asia, including Japan, China, and Korea, it is widely cultivated for its ornamental value. This evergreen shrub is celebrated for its beautiful, showy flowers that can be red, pink, or white.

Botanical Classification

• Kingdom: Plantae
• Order: Theales
• Family: Theaceae
• Genus: Camellia
• Species: Camellia japonica

Plant Characteristics

Camellia japonica is an evergreen shrub that can grow up to 4 meters (13 feet) in height. It features glossy, dark green leaves and produces large, single or double flowers in various colors, typically from winter to early spring. The plant is known for its attractive blooms and leathery foliage, making it a popular choice for gardens and landscapes.

Chemical Composition and Structure

The plant contains several bioactive compounds, including:

• Flavonoids: Such as catechins and quercetin, which have antioxidant and anti-inflammatory properties.
• Saponins: Compounds with potential immune-boosting and skin-conditioning effects.
• Triterpenes: Compounds that contribute to the plant’s therapeutic and cosmetic benefits.

How to Cultivate It

Camellia japonica prefers acidic, well-drained soil and partial to full shade. It is best grown in cooler climates, though it can tolerate a range of temperatures. Regular watering and mulching are recommended to maintain soil moisture and acidity. The plant should be protected from strong winds and extreme temperatures to prevent damage.

Uses and Benefits

• Ornamental: Widely cultivated for its striking flowers and evergreen foliage, making it a popular choice for decorative purposes in gardens and landscapes.

• Cosmetic: Extracts of Camellia japonica are used in skincare products for their moisturizing, anti-aging, and soothing properties. They are included in formulations such as creams, serums, and masks.

• Medicinal: Traditional uses include treatments for various ailments, such as inflammation and skin conditions. The plant's extracts are also explored for their potential health benefits due to their antioxidant properties.

Applications

• Ornamental: Used in garden design and landscaping for its aesthetic appeal and year-round greenery.

• Cosmetic: Incorporated into skincare products to provide hydration, improve skin texture, and offer anti-aging benefits.

• Medicinal: Research into the plant's extracts for potential therapeutic uses, including anti-inflammatory and antioxidant applications.

Environmental and Safety Considerations

Camellia japonica is generally safe for ornamental and cosmetic uses. It requires specific growing conditions to thrive, including appropriate soil acidity and shade. The plant should be managed to prevent invasive spreading and ensure it remains suitable for its environment.

Studies

Camellia species are considered in the scientific literature to be natural sources of antioxidant compounds and in particular with increased activity in flowers where a relevant presence of phenolic acids and flavonol glycosides has been noted (1).

As antibiotic resistance has become a worldwide problem, research tends to turn to natural sources, and many studies have evaluated the antimicrobial activity of Camellia japonica against Gram-negative and Gram-positive bacteria (2).

References_____________________________________________________________________

(1) Lee, H. H., Cho, J. Y., Moon, J. H., & Park, K. H. (2011). Isolation and identification of antioxidative phenolic acids and flavonoid glycosides from Camellia japonica flowers. Horticulture, Environment, and Biotechnology, 52, 270-277.

Abstract. The ethyl acetate (EtOAc) layer of the hot water extracts of Camellia japonica flowers was found to have higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity than the other solvent layers. Nine phenolic compounds were isolated and purified from the EtOAc layer by Sephadex LH-20 column chromatography and octadecyl silane-high performance liquid chromatography using a guided DPPH radical-scavenging assay. The isolated compounds were identified as 3,4,5-trihydroxybenzoic acid (1), 3,4-dihydroxybenzoic acid (2), 4-hydroxybenzoic acid (3), 2,3-digalloyl-O-α-D-glucopyranoside (4), 2,3-digalloyl-O-β-D-glucopyranoside (5), quercetin 3-O-β-D-galactopyranoside (6), quercetin 3-O-β-D-glucopyranoside (7), kaempferol 3-O-β-D-galactopyranoside (8), and kaempferol 3-O-β-D-glucopyranoside (9), based on mass spectrometry and nuclear magnetic resonance. Four compounds (6–9) had been previously identified in the leaves of this plant, but other compounds (1–5) were newly isolated from this plant. Their DPPH radical-scavenging activities based on the 50% scavenging concentration decreased in the following order: 4 = 5 (4.7 μM) > 1 (9.8 μM) > 6 = 7 (8.2 μM) > α-tocopherol (24.7 M) > ascorbic acid (25.1 μM) > 2 (35.6 M) > 3 = 8 = 9 (> 250 μM). Quercetin glycosides (6, 7), gallic acid (1) and its glucosides (4, 5) showed higher DPPH radical-scavenging activities than other compounds. These results indicate that the antioxidant effect of C. japonica flowers may be attributable to quercetin glycosides and gallic acid derivatives. These isolated compounds will be useful in basic studies of plant physiology, food manufacturing, and biological function of C. japonica flowers.

(2) Kim KY, Davidson PM, Chung HJ. Antibacterial activity in extracts of Camellia japonica L. petals and its application to a model food system. J Food Prot. 2001 Aug;64(8):1255-60. doi: 10.4315/0362-028x-64.8.1255. 

Abstract. The potential presence of naturally occurring antimicrobials in petals of Camellia japonica L., a member of the tea family, was investigated against foodborne pathogens in microbiological media and food. Petals of the camellia flower (C. japonica L.) were extracted with methanol and fractionated into basic, acidic, and neutral fractions. The acidic fraction (equivalent to 1.0 g of raw sample per disk) produced an inhibitory zone of 14 to 19 mm (diameter) in a disk assay against the pathogens Salmonella Typhimurium DT104, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus on agar plates. Silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, and preparative purification by high-pressure liquid chromatography were used to purify compounds in the fraction. The mass spectrum of the antibacterial compound isolated had a molecular ion (M+) of m/z 116 and showed good conformity with the spectrum of fumaric acid (HOOC-CH=CH-COOH). An aqueous extract from the petals of C. japonica L. had an inhibitory effect on growth of all pathogens at 37 degrees C in microbiological media by increasing the lag phase. None of the microorganisms was inhibited completely. Milk was used as a model food system. Aqueous extract at a concentration of 100 mg/ml was bacteriostatic against all the foodborne pathogens in the milk stored at 25 degrees C for up to 4 days.