Solanum indicum, commonly known as Indian nightshade, has a history of use in various traditional medicine systems, particularly in Ayurveda and Siddha. In these traditions, the plant is used for its purported anti-inflammatory and healing properties, and it is sometimes included in formulations aimed at treating oral ulcers, including canker sores (aphthous ulcers). The rationale is often based on the plant's general use for "ulcers" or wound healing, rather than specific clinical evidence for canker sores.

Scientific research on Solanum indicum’s efficacy for canker sores specifically is extremely limited. A few in vitro and animal studies have shown that extracts from the plant possess anti-inflammatory, antimicrobial, and antioxidant properties, which could theoretically be beneficial for oral mucosal healing. However, these studies do not directly address canker sores, nor do they provide robust clinical trial data supporting its use for this condition in humans.

In summary, Solanum indicum’s use for canker sores is primarily justified by traditional practice rather than scientific evidence. The supporting data are indirect, mostly relating to general wound healing and anti-inflammatory effects rather than targeted, high-quality studies on canker sores.