Guajava is a beautiful flowering shrub that grows about 1 to 2 m in height. It produces pretty yellow flowers in a column that resemble yellow candlesticks - earning its common name candlestick or candle bush. It is native to the Amazon Rainforest and can be found in Peru, Brazil, French Guiana, Guyana, Suriname, Venezuela and Colombia. Due to its beauty, it has been cultivated around the world as an ornamental plant and has naturalized in many tropical regions in the world including tropical Africa, tropical Asia, Australia, Mexico, the Caribbean, Melanesia, Polynesia, & Hawaii.

TRIBAL AND HERBAL MEDICINE USES

The Tikuna Indians of the Amazon prepare a decocotion of the flowers as a purgative and one cup is taken each morning. In Cuba, the plant is named guacamaya francesa and it is used for herpes ulcers and other skin conditions, as a diuretic and as a laxative. In Peruvian herbal medicine systems the plant is called retama and the flowers are prepared in an infusion to treat urinary infections and used to increase urination; the leaves and stems are prepared in a decoction for acaries, herpes ulcers, ringworm, and other skin conditions; and, the root, leaves, wood and flowers are decocted for a remedy against intestinal parasites and hepatitis. Interestingly, the flowers are used as a diuretic (to increase urination), while the leaves are believe to be anti-diuretic. In Brazil, the plant is called guajava or mata-pasto. An infusion of the bark and roots is used for hydropsy, skin erruptions and fever. The leaves are considered an ememmagogue and diuretic and are prepared in extracts or capsules for liver problems, anemia, dyspepsia, menstrual problems, and high fevers. The leaves are juiced and mixed with lemon juice and applied to the skin for dematitis and taken internally for syphilis.

PLANT CHEMICALS

Guajava, like most Cassia and Senna plants, contain a group of chemicals called anthraquinones. These chemicals are well known for their laxative effect. Guajava leaves also contain a chemical called adenine which has been documented as an effective platelet aggregating inhibitor (reduces sticky blood and arterial plaque).

Other chemicals in guajava include chrysoeriol-7-O-(2"-O-beta-D-mannopyranosyl)-beta-D-allopyranoside, kaempferol, kaempferol 3-O-gentiobioside, naringenin, quercetin, and rhamnetin-3-O-(2"-O-beta-D-mannopyranosyl)-beta-D-allopyranoside.

BIOLOGICAL ACTIVITIES AND CLINICAL RESEARCH

Guajava has demonstrated effective broad spectrum antibacterial, anticandidal, and antifungal activities in several laboratory studies over the years. Researchers in Malaysia reported their findings in 2002 stating: "Based on the current findings, it can be concluded that this plant has antimicrobial activity, which is as potent as standard antimicrobial drugs against certain microorganisms." Japanese researchers in 2003 reported that a leaf extract evidenced anti-inflammatory activity. In animal studies conducted in the Phillipines in 2002, guajava leaves were reported to possess pain-relieving, anti-inflammatory, antimutagenic, and hypoglycemic actions. In 1994 a 10-year human study was published in India which indicated that a guajava leaf extract can be reliably used as a herbal medicine to treat Pityriasis versicolor (a type of skin fungus) without side effects. Another human study conducted in 1990 verified and validated the plant's use as an effective laxative. In 1993 guajava was reported to have choleretic actions in a rat study. According to results obtained, the choleretic activity of the plant at 15 mg/kg was better than the control used (Hebucol ND), but in higher doses, the plant tended to inhibit bile secretion.