Camphor tree, Cinnamomum camphora (L.); Ethnobotany and pharmacological updates

This review paper highlights the recent updates of the fragrant camphor tree (Cinnamomum camphora) and camphor oil is used as a medicine for controlling many human diseases, relief of pain, inflammation and irritation in the body and skin. It can also be very effective in treating and preventing some serious, life threatening diseases. Recently medicinal plants (sweet worm wood; Artemisia annua) containing camphor essential oil has been tested against corona virus (SARS-CoV-2) disease (Covid-19). Commercially, camphor is very important with many biological properties and is used as a topical ointment since camphor is a very toxic substance and oral consumption of camphor should be avoided.

Cinnamomum agasthyamalayanum Robi, Sujanapal & Udayan has been reported from Western Ghat Forests of Kerala (4,6). The exact distribution range of Cinnamomum agasthyamalayanum population is between Attayar and Chemungi areas of Agasthyamala Hills, Kerala, India (4,6). At present, there are only two known species with camphor smell namely Cinnamomum camphora is cultivated in china, Taiwan, Japan and Korea and C. capparucoronde is very common tree found in forests of Sri Lanka (14)(15)(16)(17).
Cinnamomum camphora is used as a plasticizer in the preparation of explosives and disinfectants. The camphor tree is large with pale brown bark, dark green to yellowish leaves and small white flowers followed by small purple berries. The camphor tree is very attractive with camphoraceous odour and grows in tropical rain forests at different altitudes (18)(19)(20)(21)(22).
Camphor has been used as a herbal medicine for the treatment of heart related health disorders (1,26,34). In addition, camphor also acts as a potential skin penetration enhancer (1,27,35,36). The effect of camphor on the sexual activity of male rats was investigated by Love et al., 2003 (1, 28,37) by measuring the parameters mount latency and frequency as well as intromission latency and frequency (28,37). Therefore, the administration of camphor at 50 mg/kg increased the sexual desire and performance of male rats (1,28,37).
The growth inhibition of one plant by another plant is known as Allelopathic activity which is one of the characteristic properties of the camphor laurel tree (Cinnamomum camphora) (12,(39)(40). Among all the parts of the camphor tree, leaves had a direct inhibitory effect on germination and resulted in the reduced the competitiveness of the surrounding vegetations (12,13,(39)(40). Therefore, camphor could be used as a natural pesticide (12,(39)(40).
Camphor is very toxic in nature and toxicity has been confirmed. One of the major issues is the toxicity of camphor in humans is directly related to availability of camphor-containing products as unhazardous medicines rather than in the intrinsic toxicity of camphor. The oral consumption of higher concentrations of 3.5 g of camphor can cause death (1,14,36,37). Further consumption of 2.0 g of camphor causes toxic effects in adults leading to congestion of the gastrointestinal tract, kidney and brain (1,(36)(37)(38)(39)(40)(41). There is no antidote for Camphor poisoning (1, 25-30, 36, 37). Many medicinal plants contain camphor is a major component (1,40). Lopes-Lutz et al., (39) confirmed the antimicrobial properties.

CONCLUSION
Camphor is the most versatile molecule with a multitude of applications. Camphor is used to treat medical conditions in humans and a natural poison to kill insects. The antiviral property of camphor has been exploited for controlling coronavirus (SARS-CoV-2) disease (covid- 19). Camphor is very toxic and higher concentrations of oral consumption can cause to death and used for external topical applications.

CONFLICT OF INTEREST
Authors declare no conflicts of interest.