What is sanguiin H-6 and why is it important in cloudberry?

Sanguiin H-6 is a hydrolyzable ellagitannin polyphenol concentrated in cloudberry seeds that has demonstrated an MIC of 0.25 mg/L against MRSA in laboratory settings. It is considered the primary bioactive compound responsible for cloudberry's antimicrobial activity, and it also inhibits MRSA biofilm formation in vitro alongside the related compound lambertianin C.

Can cloudberry extract kill antibiotic-resistant bacteria like MRSA?

In vitro studies show sanguiin H-6 from cloudberry seeds inhibits MRSA growth at a minimum inhibitory concentration of 0.25 mg/L, which is a relatively potent threshold. Additionally, both sanguiin H-6 and lambertianin C prevented MRSA biofilm formation in laboratory conditions, though no human trials have confirmed these effects in clinical infections.

Does cloudberry help with wound healing?

A murine wound model found that sanguiin H-6 from cloudberry seeds reduced wound area by 10.5%, suggesting a potential topical antimicrobial benefit that could support wound healing. This evidence is considered preliminary, as no human wound-healing trials have been conducted, and the mechanism is primarily attributed to MRSA inhibition rather than direct tissue regeneration.

What is the difference between sanguiin H-6 and lambertianin C in cloudberry?

Both sanguiin H-6 and lambertianin C are ellagitannin polyphenols found in cloudberry seeds with demonstrated anti-biofilm activity against MRSA in vitro. Sanguiin H-6 has been more specifically characterized for its MIC value of 0.25 mg/L and wound-area reduction in murine models, while lambertianin C is a larger oligomeric ellagitannin whose individual MIC and in vivo data are less thoroughly quantified in published literature.

Is cloudberry safe to take as a supplement?

Cloudberry is safe when consumed as a whole food and has a long history of dietary use in Scandinavian and Arctic regions without reported toxicity. However, concentrated extracts standardized for sanguiin H-6 or lambertianin C lack human clinical safety data, and potential interactions with narrow-therapeutic-index drugs metabolized by CYP enzymes cannot be excluded based on the known properties of ellagitannins.

What is the bioavailability of cloudberry ellagitannins like sanguiin H-6?

Cloudberry ellagitannins undergo extensive metabolism by gut microbiota, converting to urolithin metabolites that may have superior bioavailability compared to the parent compounds. The actual systemic availability of sanguiin H-6 remains largely uncharacterized in human studies, though animal models suggest degradation begins in the small intestine. Processing methods (freeze-dried vs. air-dried) and individual microbiome composition significantly affect how much bioactive compound reaches systemic circulation.

Does cloudberry interact with antibiotics or immune-modulating medications?

While cloudberry's antimicrobial compounds show in vitro activity against resistant bacteria, there is insufficient clinical evidence to confirm interactions with prescription antibiotics or immunosuppressants. The anti-inflammatory and ellagitannin content theoretically could modulate immune response, but no human interaction studies exist. Individuals taking immunosuppressive medications or antibiotics should consult a healthcare provider before supplementing with concentrated cloudberry extracts.

How does cloudberry's anti-inflammatory effect compare to other berry extracts for metabolic health?

Cloudberry's attenuation of inflammatory gene expression in preliminary studies appears comparable to other polyphenol-rich berries like blueberries and raspberries, though direct comparative trials are lacking. Cloudberry's unique ellagitannin profile (sanguiin H-6 and lambertianin C) may offer distinct mechanisms versus anthocyanin-dominant berries, but evidence strength for metabolic outcomes remains preliminary. No clinical trials have directly ranked cloudberry against standardized berry extracts for human inflammatory or metabolic markers.

Rubus chamaemorus (Cloudberry)

Cloudberry (Rubus chamaemorus) is a wild-harvested Arctic fruit whose seeds contain sanguiin H-6 and lambertianin C, ellagitannin polyphenols with potent antimicrobial properties. These compounds inhibit methicillin-resistant Staphylococcus aureus (MRSA) by disrupting bacterial cell integrity and preventing biofilm formation in vitro.

Category: Herb Evidence: 2/10 Tier: Emerging

Rubus chamaemorus (Cloudberry) — Hermetica Encyclopedia

Origin & History

Rubus chamaemorus (cloudberry) is a circumpolar boreal herbaceous perennial plant in the Rosaceae family, native to northern regions of Europe, Asia, and North America, producing amber-colored edible fruits and seeds. The bioactive compounds, primarily ellagitannins like sanguiin H-6 and lambertianin C, are extracted from seeds and fruits using fractionation methods such as methanol extraction followed by butanol partitioning.

Historical & Cultural Context

Cloudberry has been widely used in folk medicine by northern indigenous cultures for food preservation and health purposes. Leaf extracts have shown historical antimicrobial evaluation against Gram-positive bacteria in traditional applications.

Health Benefits

• Antimicrobial activity: Sanguiin H-6 from cloudberry seeds inhibited MRSA growth (MIC 0.25 mg/L) and reduced wound area by 10.5% in murine models (preliminary evidence)
• Anti-biofilm properties: Both sanguiin H-6 and lambertianin C prevented MRSA biofilm formation in vitro (preliminary evidence)
• Metabolic inflammation reduction: Air-dried cloudberry attenuated inflammatory gene expression (Tnfa and Cxcl14, p<0.05) in high-fat diet mice (preliminary evidence)
• Glucose metabolism improvement: Cloudberry supplementation improved glucose tolerance via IPGTT in mice fed high-fat diets (preliminary evidence)
• Potential wound healing: Topical sanguiin H-6 demonstrated significant wound area reduction (p=0.0206) in infected murine wounds (preliminary evidence)

How It Works

Sanguiin H-6 and lambertianin C are hydrolyzable ellagitannins that disrupt bacterial membrane integrity and interfere with cell wall synthesis in MRSA strains, yielding a minimum inhibitory concentration of 0.25 mg/L for sanguiin H-6. Both compounds also suppress biofilm matrix formation by inhibiting the extracellular polysaccharide and protein adhesion processes that allow MRSA to establish persistent surface colonies. These actions are thought to involve direct binding to bacterial surface proteins and inhibition of sortase-mediated adhesin anchoring, though precise receptor-level mechanisms require further characterization.

Scientific Research

No human clinical trials, RCTs, or meta-analyses have been conducted on Rubus chamaemorus. Available research consists of in vitro studies showing antimicrobial effects against MRSA (n=3 replicates per strain) and a 12-week murine metabolic study with air-dried cloudberry supplementation.

Clinical Summary

Current evidence for cloudberry's antimicrobial activity is preliminary and derived largely from in vitro assays and murine wound models. In laboratory studies, sanguiin H-6 isolated from cloudberry seeds achieved an MIC of 0.25 mg/L against MRSA, a notably low threshold suggesting high potency. A murine wound model demonstrated a 10.5% reduction in wound area following treatment with sanguiin H-6, providing early proof-of-concept for topical antimicrobial application. No controlled human clinical trials have been published to date, and translation of these findings to human dosing and efficacy remains unestablished.

Nutritional Profile

Cloudberry (Rubus chamaemorus) is a low-calorie fruit (~51 kcal/100g fresh weight) with the following composition: Macronutrients: carbohydrates ~8.6g/100g (primarily fructose and glucose), dietary fiber ~4.5g/100g (notably pectin and cellulose), protein ~1.5g/100g, fat ~0.8g/100g (seed oil rich in tocopherols and unsaturated fatty acids including linoleic and α-linolenic acid). Micronutrients: Vitamin C is exceptionally high at ~158mg/100g (approximately 3x that of orange), making cloudberry one of the richest Nordic sources; Vitamin E (tocopherols) ~2.4mg/100g primarily in seeds; Vitamin A precursors (carotenoids) ~90µg/100g; Manganese ~0.7mg/100g; Potassium ~100mg/100g; Magnesium ~9mg/100g; Phosphorus ~28mg/100g; Calcium ~18mg/100g; Iron ~0.7mg/100g. Bioactive compounds: Ellagitannins are the dominant polyphenols — sanguiin H-6 and lambertianin C are the primary bioactives, concentrated especially in seeds (ellagitannin content ~200–400mg/100g fresh weight total); ellagic acid present as a hydrolysis product; anthocyanins are absent or trace-level (cloudberry lacks the red/blue pigments common to other Rubus species); quercetin glycosides detected at ~10–20mg/100g; citric and malic acids contribute to tartness (~1.3g/100g total organic acids); squalene and phytosterols present in seed oil. Bioavailability notes: Ellagitannins are hydrolyzed in the gut to ellagic acid, which is further metabolized by gut microbiota to urolithins (urolithin A, B) — systemic bioavailability of parent ellagitannins is low but urolithins are well-absorbed; Vitamin C bioavailability is high (~80–90% at moderate intake levels); seed-derived compounds (tocopherols, fatty acids) require fat co-ingestion or mechanical disruption of seeds for optimal absorption; fiber matrix may modestly slow glucose absorption.

Preparation & Dosage

No clinically studied human dosages are available. Preclinical studies used sanguiin H-6 at 0.25 mg/L (in vitro MIC) and up to 1 mg/mL for anti-biofilm activity. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Elderberry, Sea Buckthorn, Bilberry, Lingonberry, Rose Hips

Safety & Interactions

Cloudberry fruit is widely consumed as a food across Scandinavian and Arctic populations without documented serious adverse effects, suggesting a favorable general safety profile at dietary amounts. No formal pharmacokinetic studies or standardized dosing regimens for cloudberry extracts or isolated sanguiin H-6 have been established in humans, making therapeutic dosing guidance impossible at this time. Because ellagitannins can inhibit certain cytochrome P450 enzymes in vitro, caution is theoretically warranted in individuals taking drugs with narrow therapeutic windows, though direct drug interaction data for cloudberry compounds are absent. Pregnant and breastfeeding individuals should limit use to normal food amounts until safety data from concentrated extracts are available.