Basil (Ocimum basilicum): Benefits, Uses,Safety and Dosage

Basil is a common culinary herb used to garnish soups and stews. It belongs to the family Lamiaceae and is commonly called St. Joseph’s wort, tulsi, or royal herb. It is native to Central Africa, Southeast Asia, and India. Currently, it is cultivated in Italy, France, Morocco, and parts of the United States (California/New Jersey).

Basil is used as follows:

• Reducing fasting and post-meal glucose levels
• Reducing bad cholesterol while improving the profile of good cholesterol (HDL)
• Reducing anxiety and stress
• Improving attention and memory
• Boosting immunity
• Helps in asthmatics (reducing symptoms)
• In oral health to reduce plaque

Medical Uses and ethnopharmacological profile of Basil

Traditional Uses

In ancient Egypt, it was one of the ingredients in an embalming preparation. Medicinally, it was used for fainting spells, fatigue, and headaches. It was also used in preparations that dealt with coughs and clearing the respiratory airway. It was applied as a digestive stimulant in improving appetite and dealing with gas and bloating. It was brewed as tea for use in controlling fevers and parasites.

In Rome, it was used as an aphrodisiac.

Clinical Uses and Research

Hyperlipidemia: In adults with metabolic syndrome, mucilaginous basil seeds given 30 grams daily elicited a decrease in total cholesterol levels and a mild reduction in triglycerides. Soluble fibers and alpha-linoleic acid were isolated to act through bile sequestration, binding to bile acid in the gut, hence forcing the liver to utilize more low-density lipoproteins.

Anxiety and stress: In a study involving adults struggling with insomnia and stress, holy basil leaf extract at a dose of 250 mg daily for 8 weeks achieved a 37% reduction in perceived stress and significantly improved sleep. This was identified as the action of ursolic, rosmarinic, and ocimarin acids via regulation of the HPA axis, effectively reducing cortisol levels.

Cognitive performance: In healthy adults, standardized leaf extract at a dose of 300 mg daily for 4 weeks was able to increase reaction time, reduce errors during task switching, and enhance short-term memory. The compound rosmarinic acid acted by inhibiting the enzyme acetylcholinesterase, thus increasing levels of acetylcholine in the brain and improving signaling.

Major depressive disorder: The hydroalcoholic leaf extract of sweet basil administered as 5 ml (500 mg) twice daily for 8 weeks decreased BDI and HAM-A scores in depressed adults. Linalool, eugenol, and rosmarinic acid were isolated to have the action of enhancing GABA transmission and BDNF levels.

Glycemic control: Encapsulated fresh leaf powder at a dose of 2.5 grams daily for 4 weeks showed a 17.6% decrease in fasting blood sugar and a 7.3% reduction in postprandial glucose. Orientin, anthocyanins, and eugenol were isolated to have the capacity to inhibit hepatic glucose generation as well as stimulate the release of insulin from pancreatic beta cells. (Anandhi 2023)

In Vivo Uses and Research

Neuroprotection: In a rat stroke-induced model, sweet basil hydroethanolic leaf extract, at an oral dose of 200 mg/kg, reduced cerebral dead tissue and elicited improved motor coordination post stroke. Flavonoids acted as antioxidants by increasing levels of superoxide dismutase and glutathione, which decreased lipid peroxidation in brain tissue. (CABI 2011)

Gastric ulcer protection: In ulcer-induced rats, aqueous and methanolic leaf extract at 100-400 mg/kg for 10 days showed a reduced ulcer index and gastric protection levels comparable to omeprazole. Eugenol acted by increasing the synthesis of gastric mucus and decreasing production of stomach acid via inhibition of type 2 histamine receptors.

Hypertension: In rats with spontaneous hypertension, aqueous extract at a dose of 100 mg/kg both orally and intravenously decreased pressure and was able to maintain both diastolic and systolic pressure without affecting heart rate. Vicenin-2 and rosmarinic acid prevented constriction of blood vessels.

In Vitro Uses and Research

Anticancer: Sweet basil essential oil, when applied to human breast and liver cancer cells, was able to inhibit cancer cell viability. Estragole and linalool were able to fragment sick cell DNA selectively and inhibit apoptosis via the caspase 3 pathway. (Perna 2022)

Antimicrobial: In resistant strains of S. aureus, E. coli, and P. aeruginosa, ethanolic leaf extract and essential oils showed eradication of foodborne pathogens. Methyl-chavicol and eugenol disrupted bacterial cell membrane permeability, causing leakage of cell constituents and death.

Antiviral: In herpes 1, adenovirus, and SARS-CoV-2 viruses, leaf extract rich in apigenin inhibited the cleavage of viral proteases without any toxicity to the host cell.

Safety and Dosing profile of Basil

Forms and Dosing

Fresh leaves- a handful (1-5 or more), raw or pounded

Dried leaves- a handful (1-3)

Herbal teas and infusions- 1-2 gram dissolved in water.

Sabja/tukmaria seeds- 10-20 grams soaked in water

Essential oils

Standardized capsules and tablets- 500-1200mg

Tinctures(1:5)-  2-5 ml thrice daily

Powders- 2-3 grams

• Generalized anxiety disorder- 300 mg twice a day
• Glucose controll- 250-500 mg twice daily
• Cardiovascular risk- 500mg twice daily

Interactions

• Antidiabetic medication- risk of hyperglycemia
• Antihypertensives- risk of hypotension
• Blood thinner- risk of increased bleeding
• Sedatives- risk of potentiating effects

Side effects

• Carcinogen concern due to estragole
• Allergic reaction, both skin and internal
• Nausea and vomiting
• Acid reflux and diarrhea
• Dizziness and sedation
• Tachycardia
• Seizures in extreme doses

Contraindications

• Two weeks before surgery
• Pregnancy and breastfeeding
• Bleeding disorders