Plectranthus amboinicus, also known as Indian borage, has a documented history of use in traditional medicine for oral ailments, including gingivitis. More recently, scientific studies have begun to assess its efficacy. The primary rationale for its use in gingivitis is its antimicrobial and anti-inflammatory properties. Several in vitro studies have demonstrated that extracts of Plectranthus amboinicus possess significant antibacterial activity against oral pathogens, including Streptococcus mutans and Porphyromonas gingivalis, which are implicated in gingival inflammation and periodontal disease.

In addition, an in vivo study published in the Journal of Indian Society of Periodontology (2017) evaluated a mouthwash containing Plectranthus amboinicus extract in comparison to chlorhexidine. The study found that the herbal mouthwash reduced gingival scores, though it was less effective than chlorhexidine. Other studies have reported anti-inflammatory effects due to the plant’s content of carvacrol, thymol, and other phenolic compounds.

However, most of the evidence remains preliminary, with small sample sizes or in vitro designs, and there is a lack of large-scale, robust clinical trials. Thus, while there is scientific interest and some early validation, the evidence is modest and does not yet reach a high level of clinical proof.