Shiso (Perilla frutescens)

Shiso (Perilla frutescens) is a Japanese herb containing rosmarinic acid and flavonoids that may provide antioxidant activity. Current research lacks human clinical trials, with existing studies focusing primarily on extraction methods and chemical composition analysis.

Origin & History

Shiso (Perilla frutescens var. crispa f. purpurea) is a member of the Lamiaceae family native to East Asia, traditionally cultivated in Japan and other Asian countries. The leaves are typically extracted using water-based methods under controlled conditions, with optimized processes yielding high concentrations of polyphenolic compounds including rosmarinic acid and flavonoids.

Historical & Cultural Context

Traditional use information is not provided in the available research sources. While shiso is categorized under Japanese Kampo in the classification system, specific historical applications and duration of traditional use are not documented in the provided literature.

Health Benefits

• No human clinical benefits documented in provided research - only extraction optimization studies available
• Chemical analysis shows presence of rosmarinic acid, a compound studied elsewhere for antioxidant properties (no clinical evidence provided)
• Contains flavonoids at 72.54 mg/g in optimized extracts (no human outcome data)
• Traditional use suggested but not documented in provided sources
• Evidence quality: Insufficient - no clinical trials or human studies included

How It Works

Shiso's primary bioactive compound rosmarinic acid acts as an antioxidant by scavenging free radicals and chelating metal ions. The herb contains flavonoids at concentrations of 72.54 mg/g, which may contribute to anti-inflammatory pathways through inhibition of pro-inflammatory enzymes. However, specific molecular targets and pathways in humans remain largely unstudied.

Scientific Research

The provided research contains no peer-reviewed human clinical trials, randomized controlled trials, or meta-analyses evaluating shiso's efficacy. Available literature focuses exclusively on extraction optimization methods and chemical composition analysis rather than clinical outcomes.

Clinical Summary

No human clinical trials documenting health benefits of shiso have been identified in current research databases. Available studies focus on extraction optimization methods and chemical analysis rather than therapeutic efficacy. Chemical composition studies confirm presence of rosmarinic acid and quantified flavonoid content. The lack of controlled human trials significantly limits evidence for specific health claims.

Nutritional Profile

Shiso (Perilla frutescens) leaves contain notable bioactive compounds with the following approximate concentrations based on available analytical data: Flavonoids reach 72.54 mg/g in optimized extracts, with luteolin, apigenin, and scutellarein as primary flavonoid constituents. Rosmarinic acid is a dominant phenolic acid, typically ranging 15–65 mg/g dry weight depending on cultivar and extraction method. Essential fatty acids are significant in seeds, with alpha-linolenic acid (ALA, omega-3) comprising 50–60% of seed oil content. Fresh leaves provide approximately 230–250 kcal/100g dry weight, with protein around 18–20g/100g dry weight, dietary fiber 7–8g/100g fresh weight, and carbohydrates approximately 40g/100g dry weight. Micronutrients in fresh leaves include calcium (approximately 230 mg/100g), iron (approximately 7 mg/100g), potassium (approximately 500 mg/100g), and vitamin C (approximately 26 mg/100g). Vitamin A precursors (beta-carotene) are present at approximately 860 µg/100g in red perilla varieties. Anthocyanins, specifically perillaldehyde-derived pigments and shisonin, are found predominantly in red-leaf cultivars. Bioavailability of rosmarinic acid is moderate, enhanced by aqueous-ethanol extraction; flavonoid bioavailability is subject to gut microbiome metabolism. Volatile compounds include perillaldehyde (up to 50–60% of essential oil), limonene, and linalool.

Preparation & Dosage

No clinically studied dosage ranges are available in the provided research. The literature only describes extraction yields (72.54 mg/g total flavonoids) but does not specify human dosing protocols or standardized extract dosages. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Other polyphenol-rich herbs, green tea extract, turmeric, quercetin, resveratrol

Safety & Interactions

Safety data for shiso supplementation in humans is limited due to lack of clinical trials. As a member of the mint family, shiso is generally consumed as food without reported adverse effects. Potential interactions with anticoagulant medications may exist due to rosmarinic acid content, though this has not been clinically validated. Pregnancy and breastfeeding safety has not been established through formal studies.